AGONISTIC TUMOR NECROSIS FACTOR RECEPTOR SUPERFAMILY POLYPEPTIDES

Abstract

Described are agonistic TNFR2 polypeptides, such as antibodies and antigen-binding fragments thereof, and the use of these polypeptides to stimulate the proliferation of regulatory T cells (Treg cells) and/or myeloid-derived suppressor cells (MDSCs), as well as to inhibit the function of, reduce the proliferation of, and/or directly kill, T effector cells, such as CD8+ T effector cells. The polypeptides, such as antibodies and antigen-binding fragments thereof, of the disclosure can be used, for example, to suppress autoimmunity and inflammation, as well as to promote the protection, healing, preservation, and/or regeneration of a wide variety of tissues and organs, such as tissues and organs containing TNFR2+ cells.

Claims

1. An antibody or antigen-binding fragment thereof that specifically binds human tumor necrosis factor receptor 2 (TNFR2), wherein the antibody or antigen-binding fragment thereof comprises: (a) a heavy chain variable domain having at least 85% sequence identity to the amino acid sequence of any one of SEQ ID NOs: 72-77; and/or (b) a light chain variable domain having at least 85% sequence identity to the amino acid sequence of any one of SEQ ID NOs: 78-83.

2. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 72.

3. The antibody or antigen-binding fragment thereof of claim 2, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 72.

4. The antibody or antigen-binding fragment thereof of claim 3, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 72.

5. The antibody or antigen-binding fragment thereof of claim 4, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 72.

6. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 73.

7. The antibody or antigen-binding fragment thereof of claim 6, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 73.

8. The antibody or antigen-binding fragment thereof of claim 7, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 73.

9. The antibody or antigen-binding fragment thereof of claim 8, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 73.

10. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 74.

11. The antibody or antigen-binding fragment thereof of claim 10, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 74.

12. The antibody or antigen-binding fragment thereof of claim 11, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 74.

13. The antibody or antigen-binding fragment thereof of claim 12, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 74.

14. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 75.

15. The antibody or antigen-binding fragment thereof of claim 14, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 75.

16. The antibody or antigen-binding fragment thereof of claim 15, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 75.

17. The antibody or antigen-binding fragment thereof of claim 16, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 75.

18. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 76.

19. The antibody or antigen-binding fragment thereof of claim 18, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 76.

20. The antibody or antigen-binding fragment thereof of claim 19, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 76.

21. The antibody or antigen-binding fragment thereof of claim 20, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 76.

22. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 77.

23. The antibody or antigen-binding fragment thereof of claim 22, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 77.

24. The antibody or antigen-binding fragment thereof of claim 23, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 77.

25. The antibody or antigen-binding fragment thereof of claim 24, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable domain having the amino acid sequence of SEQ ID NO: 77.

26. The antibody or antigen-binding fragment thereof of any one of claims 1-25, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 78.

27. The antibody or antigen-binding fragment thereof of claim 26, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 78.

28. The antibody or antigen-binding fragment thereof of claim 27, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 78.

29. The antibody or antigen-binding fragment thereof of claim 28, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having the amino acid sequence of SEQ ID NO: 78.

30. The antibody or antigen-binding fragment thereof of any one of claims 1-25, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 79.

31. The antibody or antigen-binding fragment thereof of claim 30, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 79.

32. The antibody or antigen-binding fragment thereof of claim 31, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 79.

33. The antibody or antigen-binding fragment thereof of claim 32, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having the amino acid sequence of SEQ ID NO: 79.

34. The antibody or antigen-binding fragment thereof of any one of claims 1-25, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 80.

35. The antibody or antigen-binding fragment thereof of claim 34, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 80.

36. The antibody or antigen-binding fragment thereof of claim 35, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 80.

37. The antibody or antigen-binding fragment thereof of claim 36, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having the amino acid sequence of SEQ ID NO: 80.

38. The antibody or antigen-binding fragment thereof of any one of claims 1-25, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 81.

39. The antibody or antigen-binding fragment thereof of claim 38, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 81.

40. The antibody or antigen-binding fragment thereof of claim 39, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 81.

41. The antibody or antigen-binding fragment thereof of claim 40, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having the amino acid sequence of SEQ ID NO: 81.

42. The antibody or antigen-binding fragment thereof of any one of claims 1-25, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 82.

43. The antibody or antigen-binding fragment thereof of claim 42, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 82.

44. The antibody or antigen-binding fragment thereof of claim 43, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 82.

45. The antibody or antigen-binding fragment thereof of claim 44, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having the amino acid sequence of SEQ ID NO: 82.

46. The antibody or antigen-binding fragment thereof of any one of claims 1-25, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 85% sequence identity to the amino acid sequence of SEQ ID NO: 83.

47. The antibody or antigen-binding fragment thereof of claim 46, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 90% sequence identity to the amino acid sequence of SEQ ID NO: 83.

48. The antibody or antigen-binding fragment thereof of claim 47, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having at least 95% sequence identity to the amino acid sequence of SEQ ID NO: 83.

49. The antibody or antigen-binding fragment thereof of claim 48, wherein the antibody or antigen-binding fragment thereof comprises a light chain variable domain having the amino acid sequence of SEQ ID NO: 83.

50. The antibody or antigen-binding fragment thereof of any one of claims 1-49, wherein the antibody or antigen-binding fragment thereof comprises a human IgG1 or IgG2 CH1 domain comprising a deletion or substitution at cysteine residue 127.

51. The antibody or antigen-binding fragment thereof of claim 50, wherein said CH1 domain comprises a C127S mutation.

52. The antibody or antigen-binding fragment thereof of claim 50 or 51, wherein said IgG1 CH1 domain has an amino acid sequence that is at least 85% identical to the amino acid sequence of SEQ ID NO: 6.

53. The antibody or antigen-binding fragment thereof of claim 52, wherein said IgG1 CH1 domain has an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 6.

54. The antibody or antigen-binding fragment thereof of claim 53, wherein said IgG1 CH1 domain has an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 6.

55. The antibody or antigen-binding fragment thereof of any one of claims 50-54, wherein said IgG1 CH1 domain has the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO: 7.

56. The antibody or antigen-binding fragment thereof of claim 50 or 51, wherein said IgG2 CH1 domain has an amino acid sequence that is at least 85% identical to the amino acid sequence of SEQ ID NO: 8.

57. The antibody or antigen-binding fragment thereof of claim 56, wherein said IgG2 CH1 domain has an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 8.

58. The antibody or antigen-binding fragment thereof of claim 57, wherein said IgG2 CH1 domain has an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 8.

59. The antibody or antigen-binding fragment thereof of any one of claims 50, 51, and 56-58, wherein said IgG2 CH1 domain has the amino acid sequence of SEQ ID NO: 8 or SEQ ID NO: 9.

60. The antibody or antigen-binding fragment thereof of any one of claims 1-59, wherein the antibody or antigen-binding fragment thereof has an IgG3 or IgG4 isotype.

61. The antibody or antigen-binding fragment thereof of any one of claims 1-60, wherein said antibody or antigen-binding fragment thereof comprises at least two antigen-binding sites that are separated by a distance of fewer than about 133 Å.

62. The antibody or antigen-binding fragment thereof of claim 61, wherein said antigen-binding sites are separated by a distance of from about 90 Å to about 132 Å.

63. The antibody or antigen-binding fragment thereof of claim 62, wherein said antigen-binding sites are separated by a distance of from about 95 Å to about 130 Å.

64. The antibody or antigen-binding fragment thereof of claim 63, wherein said antigen-binding sites are separated by a distance of from about 98 Å to about 128 Å.

65. The antibody or antigen-binding fragment thereof of any one of claims 1-64, wherein the antibody or antigen-binding fragment thereof specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD1.

66. The antibody or antigen-binding fragment thereof of claim 65, wherein the epitope is defined by one or more of amino acid residues 56-60 (KCSPG) of SEQ ID NO: 1.

67. The antibody or antigen-binding fragment thereof of any one of claims 1-66, wherein the antibody or antigen-binding fragment thereof specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD2.

68. The antibody or antigen-binding fragment thereof of any one of claims 1-67, wherein the antibody or antigen-binding fragment thereof specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD3.

69. The antibody or antigen-binding fragment thereof of any one of claims 1-68, wherein said antibody or antigen-binding fragment thereof activates TNFR2 signaling.

70. The antibody or antigen-binding fragment thereof of any one of claims 1-69, wherein said antibody or antigen-binding fragment thereof binds TNFR2 with a K.sub.D of no greater than about 10 nM.

71. The antibody or antigen-binding fragment thereof of claim 70, wherein said antibody or antigen-binding fragment thereof binds TNFR2 with a K.sub.D of no greater than about 1 nM.

72. The antibody or antigen-binding fragment thereof of any one of claims 1-71, wherein said antibody or antigen-binding fragment thereof binds TNFR2 to form an antibody-antigen complex with a k.sub.on of at least about 10.sup.4 M.sup.-1s.sup.-1.

73. The antibody or antigen-binding fragment thereof of claim 72, wherein said antibody or antigen-binding fragment thereof binds TNFR2 to form an antibody-antigen complex with a k.sub.on of at least about 10.sup.5 M.sup.-1s.sup.-1.

74. The antibody or antigen-binding fragment thereof of any one of claims 1-73, wherein said antibody or antigen-binding fragment thereof binds TNFR2 to form an antibody-antigen complex, and wherein said complex dissociates with a k.sub.off of no greater than about 10.sup.-3 .sub.S.sup.-1.

75. The antibody or antigen-binding fragment thereof of claim 74, wherein said antibody or antigen-binding fragment thereof dissociates from TNFR2 with a k.sub.off of no greater than about 10.sup.-4 .sub.S.sup.-1.

76. The antibody or antigen-binding fragment thereof of any one of claims 1-75, wherein said antibody or antigen-binding fragment thereof promotes proliferation of T regulatory (Treg) cells.

77. The antibody or antigen-binding fragment thereof of claim 76, wherein said Treg cells express CD25.sup.Hi and CD45RA.sup.Low.

78. The antibody or antigen-binding fragment thereof of any one of claims 1-77, wherein said antibody or antigen-binding fragment thereof directly kills, or promotes the death of, CD8+ T cells.

79. The antibody or antigen-binding fragment thereof of any one of claims 1-78, wherein said antibody or antigen-binding fragment thereof promotes an increase in the level of one or more mRNA molecules encoding a protein selected from the group consisting of clAP2, TRAF2, Etk, VEGFR2, PI3K, Akt, a protein involved in the angiogenic pathway, an IKK complex, RIP, NIK, MAP3K, a protein involved in the NFkB pathway, NIK, JNK, AP-1, a MEK (e.g., MEK1, MEK7), MKK3, NEMO, IL2R, Foxp3, IL2, TNF, lymphotoxin, lymphotoxin α, and lymphotoxin β.

80. The antibody or antigen-binding fragment thereof of any one of claims 1-79, wherein said antibody or antigen-binding fragment thereof promotes an increase in the level of one or more proteins selected from the group consisting of clAP2, TRAF2, Etk, VEGFR2, PI3K, Akt, a protein involved in the angiogenic pathway, an IKK complex, RIP, NIK, MAP3K, a protein involved in the NFkB pathway, NIK, JNK, AP-1, a MEK (e.g., MEK1, MEK7), MKK3, NEMO, IL2R, Foxp3, IL2, TNF, lymphotoxin, lymphotoxin α, and lymphotoxin β.

81. The antibody or antigen-binding fragment thereof of any one of claims 1-80, wherein said antibody or antigen-binding fragment thereof promotes an increase in the level of itaconate upon administration to a subject, optionally wherein the subject is a human subject.

82. The antibody or antigen-binding fragment thereof of any one of claims 1-81, wherein the antibody or antigen-binding fragment thereof is selected from the group consisting of a monoclonal antibody or antigen-binding fragment thereof, a polyclonal antibody or antigen-binding fragment thereof, a human antibody or antigen-binding fragment thereof, a humanized antibody or antigen-binding fragment thereof, a primatized antibody or antigen-binding fragment thereof, a bispecific antibody or antigen-binding fragment thereof, a multi-specific antibody or antigen-binding fragment thereof, a dual-variable immunoglobulin domain, a monovalent antibody or antigen-binding fragment thereof, a chimeric antibody or antigen-binding fragment thereof, a single-chain Fv molecule (scFv), a diabody, a triabody, a nanobody, an antibody-like protein scaffold, a domain antibody, a Fv fragment, a Fab fragment, a F(ab′).sub.2 molecule, and a tandem scFv (taFv), optionally wherein said antibody or antigen-binding fragment thereof is a human antibody or antigen-binding fragment thereof, a humanized antibody or antigen-binding fragment thereof, or a chimeric antibody or antigen-binding fragment thereof.

83. The antibody or antigen-binding fragment thereof of any one of claims 1-82, wherein the antibody or antigen-binding fragment thereof is a single-chain polypeptide.

84. A single-chain polypeptide that competitively inhibits the binding of human TNFR2 to the single-chain polypeptide of claim 83.

85. A construct comprising a first polypeptide domain and a second polypeptide domain, wherein the first polypeptide domain and the second polypeptide domain each independently comprise a single-chain polypeptide of claim 83 or 84.

86. The construct of claim 85, wherein the first polypeptide domain and the second polypeptide domain are bound by a covalent linker.

87. The construct of claim 86, wherein the covalent linker comprises an amide bond or a disulfide bond.

88. A polynucleotide encoding the antibody or antigen-binding fragment thereof of any one of claims 1-83.

89. A polynucleotide encoding the single-chain polypeptide of claim 84.

90. A polynucleotide encoding the construct of any one of claims 85-87.

91. A vector comprising the polynucleotide of any one of claims 88-90.

92. The vector of claim 91, wherein the vector is an expression vector.

93. The vector of claim 92, wherein the expression vector is a eukaryotic expression vector.

94. The vector of claim 91, wherein the vector is a viral vector.

95. The vector of claim 94, wherein the viral vector is selected from the group consisting of adenovirus (Ad), retrovirus, poxvirus, adeno-associated virus, baculovirus, herpes simplex virus, and a vaccinia virus.

96. The vector of claim 95, wherein the adenovirus is a serotype 2, 5, 11, 12, 24, 26, 34, 35, 40, 48, 49, 50, 52, or Pan9 adenovirus, or a human, chimpanzee, or rhesus adenovirus.

97. The vector of claim 95, wherein the retrovirus is a y-retrovirus or a lentivirus.

98. The vector of claim 95, wherein the vaccinia virus is a modified vaccinia Ankara (MVA).

99. An isolated host cell comprising the vector of any one of claims 91-98.

100. The host cell of claim 99, wherein the host cell is a prokaryotic cell.

101. The host cell of claim 99, wherein the host cell is a eukaryotic cell.

102. The host cell of claim 101, wherein the eukaryotic cell is a mammalian cell.

103. The host cell of claim 102, wherein the mammalian cell is a CHO cell or HEK cell.

104. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1-83, the single-chain polypeptide of claim 84, the construct of any one of claims 85-87, the polynucleotide of any one of claims 88-90, the vector of any one of claims 91-98, or the host cell of any one of claims 99 and 101-103, and a pharmaceutically acceptable carrier or excipient.

105. The pharmaceutical composition of claim 104, wherein said antibody or antigen-binding fragment thereof is present in said pharmaceutical composition in an amount of from about 0.001 mg/ml to about 100 mg/ml.

106. The pharmaceutical composition of claim 104 or 105, wherein said pharmaceutical composition further comprises an additional therapeutic agent.

107. The pharmaceutical composition of claim 106, wherein said additional therapeutic agent is an immunotherapy agent.

108. The pharmaceutical composition of claim 107, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 agent, an agonistic anti-PD-1 agent, an agonistic anti-PD-L1 agent, an agonistic anti-PD-L2 agent, an agonistic anti-CD27 agent, an agonistic anti-CD30 agent, an agonistic anti-CD40 agent, an agonistic anti-4-1 BB agent, an agonistic anti-GITR agent, an agonistic anti-OX40 agent, an agonistic anti-TRAILR1 agent, an agonistic anti-TRAILR2 agent, an agonistic anti-TWEAK agent, an agonistic anti-TWEAKR agent, an agonistic anti-cell surface lymphocyte protein agent, an agonistic anti-BRAF agent, an agonistic anti-MEK agent, an agonistic anti-CD33 agent, an agonistic anti-CD20 agent, an agonistic anti-HLA-DR agent, an agonistic anti-HLA class I agent, an agonistic anti-CD52 agent, an agonistic anti-A33 agent, an agonistic anti-GD3 agent, an agonistic anti-PSMA agent, an agonistic anti-Ceacan 1 agent, an agonistic anti-Galedin 9 agent, an agonistic anti-HVEM agent, an agonistic anti-VISTA agent, an agonistic anti-B7 H4 agent, an agonistic anti-HHLA2 agent, an agonistic anti-CD155 agent, an agonistic anti-CD80 agent, an agonistic anti-BTLA agent, an agonistic anti-CD160 agent, an agonistic anti-CD28 agent, an agonistic anti-CD226 agent, an agonistic anti-CEACAM1 agent, an agonistic anti-TIM3 agent, an agonistic anti-TIGIT agent, an agonistic anti-CD96 agent, an agonistic anti-CD70 agent, an agonistic anti-CD27 agent, an agonistic anti-LIGHT agent, an agonistic anti-CD137 agent, an agonistic anti-DR4 agent, an agonistic anti-CR5 agent, an agonistic anti-TNFRS agent, an agonistic anti-TNFR1 agent, an agonistic anti-FAS agent, an agonistic anti-CD95 agent, an agonistic anti-TRAIL agent, an agonistic anti-DR6 agent, an agonistic anti-EDAR agent, an agonistic anti-NGFR agent, an agonistic anti-OPG agent, an agonistic anti-RANKL agent, an agonistic anti-LTβ receptor agent, an agonistic anti-BCMA agent, an agonistic anti-TACI agent, an agonistic anti-BAFFR agent, an agonistic anti-EDAR2 agent, an agonistic anti-TROY agent, and an agonistic anti-RELT agent, optionally wherein the immunotherapy agent is an agonistic anti-PD-1 antibody or an agonistic anti-PD-L1 antibody.

109. The pharmaceutical composition of claim 108, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof, an agonistic anti-PD-1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L2 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-CD30 antibody or antigen-binding fragment thereof, an agonistic anti-CD40 antibody or antigen-binding fragment thereof, an agonistic anti-4-1 BB antibody or antigen-binding fragment thereof, an agonistic anti-GITR antibody or antigen-binding fragment thereof, an agonistic anti-OX40 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR1 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR2 antibody or antigen-binding fragment thereof, an agonistic anti-TWEAK antibody or antigen-binding fragment thereof, an agonistic anti-TWEAKR antibody or antigen-binding fragment thereof, an agonistic anti-cell surface lymphocyte protein antibody or antigen-binding fragment thereof, an agonistic anti-BRAF antibody or antigen-binding fragment thereof, an agonistic anti-MEK antibody or antigen-binding fragment thereof, an agonistic anti-CD33 antibody or antigen-binding fragment thereof, an agonistic anti-CD20 antibody or antigen-binding fragment thereof, an agonistic anti-HLA-DR antibody or antigen-binding fragment thereof, an agonistic anti-HLA class I antibody or antigen-binding fragment thereof, an agonistic anti-CD52 antibody or antigen-binding fragment thereof, an agonistic anti-A33 antibody or antigen-binding fragment thereof, an agonistic anti-GD3 antibody or antigen-binding fragment thereof, an agonistic anti-PSMA antibody or antigen-binding fragment thereof, an agonistic anti-Ceacan 1 antibody or antigen-binding fragment thereof, an agonistic anti-Galedin 9 antibody or antigen-binding fragment thereof, an agonistic anti-HVEM antibody or antigen-binding fragment thereof, an agonistic anti-VISTA antibody or antigen-binding fragment thereof, an agonistic anti-B7 H4 antibody or antigen-binding fragment thereof, an agonistic anti-HHLA2 antibody or antigen-binding fragment thereof, an agonistic anti-CD155 antibody or antigen-binding fragment thereof, an agonistic anti-CD80 antibody or antigen-binding fragment thereof, an agonistic anti-BTLA antibody or antigen-binding fragment thereof, an agonistic anti-CD160 antibody or antigen-binding fragment thereof, an agonistic anti-CD28 antibody or antigen-binding fragment thereof, an agonistic anti-CD226 antibody or antigen-binding fragment thereof, an agonistic anti-CEACAM1 antibody or antigen-binding fragment thereof, an agonistic anti-TIM3 antibody or antigen-binding fragment thereof, an agonistic anti-TIGIT antibody or antigen-binding fragment thereof, an agonistic anti-CD96 antibody or antigen-binding fragment thereof, an agonistic anti-CD70 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-LIGHT antibody or antigen-binding fragment thereof, an agonistic anti-CD137 antibody or antigen-binding fragment thereof, an agonistic anti-DR4 antibody or antigen-binding fragment thereof, an agonistic anti-CR5 antibody or antigen-binding fragment thereof, an agonistic anti-TNFRS antibody or antigen-binding fragment thereof, an agonistic anti-TNFR1 antibody or antigen-binding fragment thereof, an agonistic anti-FAS antibody or antigen-binding fragment thereof, an agonistic anti-CD95 antibody or antigen-binding fragment thereof, an agonistic anti-TRAIL antibody or antigen-binding fragment thereof, an agonistic anti-DR6 antibody or antigen-binding fragment thereof, an agonistic anti-EDAR antibody or antigen-binding fragment thereof, an agonistic anti-NGFR antibody or antigen-binding fragment thereof, an agonistic anti-OPG antibody or antigen-binding fragment thereof, an agonistic anti-RANKL antibody or antigen-binding fragment thereof, an agonistic anti-LTβ receptor antibody or antigen-binding fragment thereof, an agonistic anti-BCMA antibody or antigen-binding fragment thereof, an agonistic anti-TACI antibody or antigen-binding fragment thereof, an agonistic anti-BAFFR antibody or antigen-binding fragment thereof, an agonistic anti-EDAR2 antibody or antigen-binding fragment thereof, an agonistic anti-TROY antibody or antigen-binding fragment thereof, and an agonistic anti-RELT antibody or antigen-binding fragment thereof.

110. The pharmaceutical composition of claim 108, wherein the immunotherapy agent is an agonistic anti-CTLA-4 agent or an agonistic anti-PD-1 agent.

111. The pharmaceutical composition of claim 110, wherein the immunotherapy agent is an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof or an agonistic anti-PD-1 antibody or antigen-binding fragment thereof.

112. A method of producing the antibody or antigen-binding fragment thereof of any one of claims 1-83, said method comprising expressing a polynucleotide encoding said antibody or antigen-binding fragment thereof in a host cell and recovering the antibody or antigen-binding fragment thereof from host cell medium.

113. A method of producing the construct of any one of claims 85-87, said method comprising expressing a polynucleotide encoding said construct in a host cell and recovering the construct from host cell medium.

114. A method of inhibiting an immune response mediated by a B cell or CD8+ T cell in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of any one of claims 1-83, the single-chain polypeptide of claim 84, the construct of any one of claims 85-87, the polynucleotide of any one of claims 88-90, the vector of any one of claims 91-98, the host cell of any one of claims 99 and 101-103, or the pharmaceutical composition of any one of claims 104-111.

115. A method of treating an immunological disease in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of any one of claims 1-83, the single-chain polypeptide of claim 84, the construct of any one of claims 85-87, the polynucleotide of any one of claims 88-90, the vector of any one of claims 91-98, the host cell of any one of claims 99 and 101-103, or the pharmaceutical composition of any one of claims 104-111.

116. The method of claim 115, wherein said subject is in need of a tissue or organ regeneration.

117. The method of claim 116, wherein said tissue or organ is selected from the group consisting of a pancreas, salivary gland, pituitary gland, kidney, heart, lung, hematopoietic system, cranial nerves, heart, aorta, olfactory gland, ear, nerves, structures of the head, eye, thymus, tongue, bone, liver, small intestine, large intestine, gut, lung, brain, skin, peripheral nervous system, central nervous system, spinal cord, breast, embryonic structures, embryos, and testes.

118. The method of any one of claims 115-117, wherein said immunological disease is asthma, macular degeneration, muscular atrophy, a disease related to miscarriage, atherosclerosis, bone loss, a musculoskeletal disease, obesity, a graft-versus-host disease, and an allograft rejection.

119. The method of claim 118, wherein said autoimmune disease is selected from the group consisting of type I diabetes, Alopecia Areata, Ankylosing Spondylitis, Antiphospholipid Syndrome, Autoimmune Addison’s Disease, Autoimmune Hemolytic Anemia, Autoimmune Hepatitis, Behcet’s Disease, Bullous Pemphigoid, Cardiomyopathy, Celiac Sprue-Dermatitis, Chronic Fatigue Immune Dysfunction Syndrome (CFIDS), Chronic Inflammatory Demyelinating Polyneuropathy, Churg-Strauss Syndrome, Cicatricial Pemphigoid, CREST Syndrome, Cold Agglutinin Disease, Crohn’s Disease, Essential Mixed Cryoglobulinemia, Fibromyalgia-Fibromyositis, Graves’ Disease, Guillain-Barré, Hashimoto’s Thyroiditis, Hypothyroidism, Idiopathic Pulmonary Fibrosis, Idiopathic Thrombocytopenia Purpura (ITP), IgA Nephropathy, Juvenile Arthritis, Lichen Planus, Lupus, Ménière’s Disease, Mixed Connective Tissue Disease, Multiple Sclerosis, Myasthenia Gravis, Pemphigus Vulgaris, Pernicious Anemia, Polyarteritis Nodosa, Polychondritis, Polyglandular Syndromes, Polymyalgia Rheumatica, Polymyositis and Dermatomyositis, Primary Agammaglobulinemia, Primary Biliary Cirrhosis, Psoriasis, Raynaud’s Phenomenon, Reiter’s Syndrome, Rheumatic Fever, Rheumatoid Arthritis, Sarcoidosis, Scleroderma, Sjögren’s Syndrome, Stiff-Man Syndrome, Takayasu Arteritis, Temporal Arteritis/Giant Cell Arteritis, Ulcerative Colitis, Uveitis, Vasculitis, Vitiligo, and Wegener’s Granulomatosis.

120. The method of claim 118, wherein said neurological condition is selected from the group consisting of a brain tumor, a brain metastasis, a spinal cord injury, schizophrenia, epilepsy, Amyotrophic lateral sclerosis (ALS), Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, and stroke.

121. The method of claim 118, wherein said allergy is selected from the group consisting of food allergy, seasonal allergy, pet allergy, hives, hay fever, allergic conjunctivitis, poison ivy allergy oak allergy, mold allergy, drug allergy, dust allergy, cosmetic allergy, and chemical allergy.

122. The method of claim 118, wherein said allograft rejection is selected from the group consisting of skin graft rejection, bone graft rejection, vascular tissue graft rejection, ligament graft rejection, and organ graft rejection.

123. The method of claim 122, wherein said ligament graft rejection is selected from the group consisting of cricothyroid ligament graft rejection, periodontal ligament graft rejection, suspensory ligament of the lens graft rejection, palmar radiocarpal ligament graft rejection, dorsal radiocarpal ligament graft rejection, ulnar collateral ligament graft rejection, radial collateral ligament graft rejection, suspensory ligament of the breast graft rejection, anterior sacroiliac ligament graft rejection, posterior sacroiliac ligament graft rejection, sacrotuberous ligament graft rejection, sacrospinous ligament graft rejection, inferior pubic ligament graft rejection, superior pubic ligament graft rejection, anterior cruciate ligament graft rejection, lateral collateral ligament graft rejection, posterior cruciate ligament graft rejection, medial collateral ligament graft rejection, cranial cruciate ligament graft rejection, caudal cruciate ligament graft rejection, and patellar ligament graft rejection.

124. The method of claim 122, wherein said organ graft rejection is selected from the group consisting of heart graft rejection, lung graft rejection, kidney graft rejection, liver graft rejection, pancreas graft rejection, intestine graft rejection, and thymus graft rejection.

125. The method of claim 118, wherein said graft-versus-host disease arises from a bone marrow transplant or one or more blood cells selected from the group consisting of hematopoietic stem cells, common myeloid progenitor cells, common lymphoid progenitor cells, megakaryocytes, monocytes, basophils, eosinophils, neutrophils, macrophages, T cells, B cells, natural killer cells, and dendritic cells.

126. A method of treating an inflammatory disease in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of any one of claims 1-83, the single-chain polypeptide of claim 84, the construct of any one of claims 85-87, the polynucleotide of any one of claims 88-90, the vector of any one of claims 91-98, the host cell of any one of claims 99 and 101-103, or the pharmaceutical composition of any one of claims 104-111.

127. The method of claim 126, wherein the inflammatory disease is acute or chronic inflammation.

128. The method of claim 126, wherein the inflammatory disease is cardiac fibrosis or lung fibrosis.

129. The method of claim 126, wherein the inflammatory disease is selected from the group consisting of osteoarthritis, fibrotic lung disease, and cardiac inflammation.

130. A method of regenerating TNFR2+ tissue in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of any one of claims 1-83, the single-chain polypeptide of claim 84, the construct of any one of claims 85-87, the polynucleotide of any one of claims 88-90, the vector of any one of claims 91-98, the host cell of any one of claims 99 and 101-103, or the pharmaceutical composition of any one of claims 104-111.

131. The method of claim 130, wherein said TNFR2+ tissue is selected from the group consisting of pancreas, salivary gland, pituitary gland, kidney, heart, lung, hematopoietic system, cranial nerves, heart, aorta, olfactory gland, ear, nerve, eye, thymus, tongue, bone, liver, small intestine, large intestine, gastrointestinal, lung, brain, skin, peripheral nervous system, central nervous system, spinal cord, breast, embryonic structures, embryo, and testes tissue.

132. The method of any one of claims 114-131, wherein said method comprises administering to the human an immunotherapy agent.

133. The method of claim 132, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 agent, an agonistic anti-PD-1 agent, an agonistic anti-PD-L1 agent, an agonistic anti-PD-L2 agent, an agonistic anti-CD27 agent, an agonistic anti-CD30 agent, an anonistic anti-CD40 anent an agonistic anti-4-1BB agent an agonistic anti-GITR agent an annnistic anti-OX40 agent, an agonistic anti-TRAILR1 agent, an agonistic anti-TRAILR2 agent, an agonistic anti-TWEAK agent, an agonistic anti-TWEAKR agent, an agonistic anti-cell surface lymphocyte protein agent, an agonistic anti-BRAF agent, an agonistic anti-MEK agent, an agonistic anti-CD33 agent, an agonistic anti-CD20 agent, an agonistic anti-HLA-DR agent, an agonistic anti-HLA class I agent, an agonistic anti-CD52 agent, an agonistic anti-A33 agent, an agonistic anti-GD3 agent, an agonistic anti-PSMA agent, an agonistic anti-Ceacan 1 agent, an agonistic anti-Galedin 9 agent, an agonistic anti-HVEM agent, an agonistic anti-VISTA agent, an agonistic anti-B7 H4 agent, an agonistic anti-HHLA2 agent, an agonistic anti-CD155 agent, an agonistic anti-CD80 agent, an agonistic anti-BTLA agent, an agonistic anti-CD160 agent, an agonistic anti-CD28 agent, an agonistic anti-CD226 agent, an agonistic anti-CEACAM1 agent, an agonistic anti-TIM3 agent, an agonistic anti-TIGIT agent, an agonistic anti-CD96 agent, an agonistic anti-CD70 agent, an agonistic anti-CD27 agent, an agonistic anti-LIGHT agent, an agonistic anti-CD137 agent, an agonistic anti-DR4 agent, an agonistic anti-CR5 agent, an agonistic anti-TNFRS agent, an agonistic anti-TNFR1 agent, an agonistic anti-FAS agent, an agonistic anti-CD95 agent, an agonistic anti-TRAIL agent, an agonistic anti-DR6 agent, an agonistic anti-EDAR agent, an agonistic anti-NGFR agent, an agonistic anti-OPG agent, an agonistic anti-RANKL agent, an agonistic anti-LTβ receptor agent, an agonistic anti-BCMA agent, an agonistic anti-TACI agent, an agonistic anti-BAFFR agent, an agonistic anti-EDAR2 agent, an agonistic anti-TROY agent, and an agonistic anti-RELT agent, optionally wherein the immunotherapy agent is an agonistic anti-PD-1 antibody or an agonistic anti-PD-L1 antibody.

134. The method of claim 133, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof, an agonistic anti-PD-1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L2 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-CD30 antibody or antigen-binding fragment thereof, an agonistic anti-CD40 antibody or antigen-binding fragment thereof, an agonistic anti-4-1 BB antibody or antigen-binding fragment thereof, an agonistic anti-GITR antibody or antigen-binding fragment thereof, an agonistic anti-OX40 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR1 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR2 antibody or antigen-binding fragment thereof, an agonistic anti-TWEAK antibody or antigen-binding fragment thereof, an agonistic anti-TWEAKR antibody or antigen-binding fragment thereof, an agonistic anti-cell surface lymphocyte protein antibody or antigen-binding fragment thereof, an agonistic anti-BRAF antibody or antigen-binding fragment thereof, an agonistic anti-MEK antibody or antigen-binding fragment thereof, an agonistic anti-CD33 antibody or antigen-binding fragment thereof, an agonistic anti-CD20 antibody or antigen-binding fragment thereof, an agonistic anti-HLA-DR antibody or antigen-binding fragment thereof, an agonistic anti-HLA class I antibody or antigen-binding fragment thereof, an agonistic anti-CD52 antibody or antigen-binding fragment thereof, an agonistic anti-A33 antibody or antigen-binding fragment thereof, an agonistic anti-GD3 antibody or antigen-binding fragment thereof, an agonistic anti-PSMA antibody or antigen-binding fragment thereof, an agonistic anti-Ceacan 1 antibody or antigen-binding fragment thereof, an agonistic anti-Galedin 9 antibody or antigen-binding fragment thereof, an agonistic anti-HVEM antibody or antigen-binding fragment thereof, an agonistic anti-VISTA antibody or antigen-binding fragment thereof, an agonistic anti-B7 H4 antibody or antigen-binding fragment thereof, an agonistic anti-HHLA2 antibody or antigen-binding fragment thereof, an agonistic anti-CD155 antibody or antigen-binding fragment thereof, an agonistic anti-CD80 antibody or antigen-binding fragment thereof, an agonistic anti-BTLA antibody or antigen-binding fragment thereof, an agonistic anti-CD160 antibody or antigen-binding fragment thereof, an agonistic anti-CD28 antibody or antigen-binding fragment thereof, an agonistic anti-CD226 antibody or antigen-binding fragment thereof, an agonistic anti-CEACAM1 antibody or antigen-binding fragment thereof, an agonistic anti-TIM3 antibody or antigen-binding fragment thereof, an agonistic anti-TIGIT antibody or antigen-binding fragment thereof, an agonistic anti-CD96 antibody or antigen-binding fragment thereof, an agonistic anti-CD70 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-LIGHT antibody or antigen-binding fragment thereof, an agonistic anti-CD137 antibody or antigen-binding fragment thereof, an agonistic anti-DR4 antibody or antigen-binding fragment thereof, an agonistic anti-CR5 antibody or antigen-binding fragment thereof, an agonistic anti-TNFRS antibody or antigen-binding fragment thereof, an agonistic anti-TNFR1 antibody or antigen-binding fragment thereof, an agonistic anti-FAS antibody or antigen-binding fragment thereof, an agonistic anti-CD95 antibody or antigen-binding fragment thereof, an agonistic anti-TRAIL antibody or antigen-binding fragment thereof, an agonistic anti-DR6 antibody or antigen-binding fragment thereof, an agonistic anti-EDAR antibody or antigen-binding fragment thereof, an agonistic anti-NGFR antibody or antigen-binding fragment thereof, an agonistic anti-OPG antibody or antigen-binding fragment thereof, an agonistic anti-RANKL antibody or antigen-binding fragment thereof, an agonistic anti-LTβ receptor antibody or antigen-binding fragment thereof, an agonistic anti-BCMA antibody or antigen-binding fragment thereof, an agonistic anti-TACI antibody or antigen-binding fragment thereof, an agonistic anti-BAFFR antibody or antigen-binding fragment thereof, an agonistic anti-EDAR2 antibody or antigen-binding fragment thereof, an agonistic anti-TROY antibody or antigen-binding fragment thereof, and an agonistic anti-RELT antibody or antigen-binding fragment thereof.

135. The method of claim 132, wherein the immunotherapy agent is an agonistic anti-CTLA-4 agent or an agonistic anti-PD-1 agent.

136. The method of claim 135, wherein the immunotherapy agent is an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof or an agonistic anti-PD-1 antibody or antigen-binding fragment thereof.

137. The method of any one of claims 114-136, wherein said method comprises administering to the human an additional agent selected from the group consisting of TNFα, an agonistic TNFα mutein, and Bacillus Calmette-Guerin (BCG).

138. The method of any one of claims 114-137, wherein the antibody or antigen-binding fragment thereof that specifically binds TNFR2 is administered to the human in an amount of from about 0.001 mg/kg to about 100 mg/kg.

139. A kit comprising an agent selected from the group consisting of the antibody or antigen-binding fragment thereof of any one of claims 1-83, the single-chain polypeptide of claim 84, the construct of any one of claims 85-87, the polynucleotide of any one of claims 88-90, the vector of any one of claims 91-98, the host cell of any one of claims 99-103, and the pharmaceutical composition of any one of claims 104-111.

140. The kit of claim 139, wherein said kit comprises the antibody or antigen-binding fragment thereof any one of claims 1-83.

141. The kit of claim 139, wherein said kit comprises the single-chain polypeptide of claim 84.

142. The kit of claim 139, wherein said kit comprises the construct of any of claims 85-87.

143. The kit of claim 139, wherein said kit comprises the polynucleotide of any one of claims 88-90.

144. The kit of claim 139, wherein said kit comprises the vector of any one of claims 91-98.

145. The kit of claim 144, wherein said kit further comprises instructions for transfecting said vector into a host cell.

146. The kit of claim 145, wherein said kit further comprises instructions for expressing said antibody, antigen-binding fragment thereof, or construct in said host cell.

147. The kit of claim 139, wherein said kit comprises the host cell of any one of claims 99-103.

148. The kit of claim 147, wherein said kit further comprises a reagent that can be used to express the antibody, antigen-binding fragment thereof, or construct in said host cell.

149. The kit of claim 139, wherein said kit comprises the pharmaceutical composition of any one of claims 104-111.

150. The kit of claim 139, further comprising instructions for administering said agent to a human patient.

151. The kit of claim 139, further comprising instructions for making or using said agent.

152. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof comprises a human IgG1 or IgG2 CH1 domain comprising a deletion or substitution at cysteine residue 127.

153. The antibody or antigen-binding fragment thereof of claim 152, wherein said CH1 domain comprises a C127S mutation.

154. The antibody or antigen-binding fragment thereof of claim 152, wherein said IgG1 CH1 domain has an amino acid sequence that is at least 85% identical to the amino acid sequence of SEQ ID NO: 6.

155. The antibody or antigen-binding fragment thereof of claim 154, wherein said IgG1 CH1 domain has an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 6.

156. The antibody or antigen-binding fragment thereof of claim 155, wherein said IgG1 CH1 domain has an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 6.

157. The antibody or antigen-binding fragment thereof of claim 152, wherein said IgG1 CH1 domain has the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO: 7.

158. The antibody or antigen-binding fragment thereof of claim 152, wherein said IgG2 CH1 domain has an amino acid sequence that is at least 85% identical to the amino acid sequence of SEQ ID NO: 8.

159. The antibody or antigen-binding fragment thereof of claim 158, wherein said IgG2 CH1 domain has an amino acid sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO: 8.

160. The antibody or antigen-binding fragment thereof of claim 159, wherein said IgG2 CH1 domain has an amino acid sequence that is at least 95% identical to the amino acid sequence of SEQ ID NO: 8.

161. The antibody or antigen-binding fragment thereof of claim 152, wherein said IgG2 CH1 domain has the amino acid sequence of SEQ ID NO: 8 or SEQ ID NO: 9.

162. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof has an IgG3 or IgG4 isotype.

163. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof comprises at least two antigen-binding sites that are separated by a distance of fewer than about 133 Å.

164. The antibody or antigen-binding fragment thereof of claim 163, wherein said antigen-binding sites are separated by a distance of from about 90 Å to about 132 Å.

165. The antibody or antigen-binding fragment thereof of claim 164, wherein said antigen-binding sites are separated by a distance of from about 95 Å to about 130 Å.

166. The antibody or antigen-binding fragment thereof of claim 165, wherein said antigen-binding sites are separated by a distance of from about 98 Å to about 128 Å.

167. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD1.

168. The antibody or antigen-binding fragment thereof of claim 167, wherein the epitope is defined by one or more of amino acid residues 56-60 (KCSPG) of SEQ ID NO: 1.

169. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD2.

170. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD3.

171. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof activates TNFR2 signaling.

172. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof binds TNFR2 with a K.sub.D of no greater than about 10 nM.

173. The antibody or antigen-binding fragment thereof of claim 172, wherein said antibody or antigen-binding fragment thereof binds TNFR2 with a K.sub.D of no greater than about 1 nM.

174. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof binds TNFR2 to form an antibody-antigen complex with a k.sub.on of at least about 10.sup.4 M.sup.-1.sub.S.sup.-1.

175. The antibody or antigen-binding fragment thereof of claim 174, wherein said antibody or antigen-binding fragment thereof binds TNFR2 to form an antibody-antigen complex with a k.sub.on of at least about 10.sup.5 M.sup.-1s.sup.-1.

176. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof binds TNFR2 to form an antibody-antigen complex, and wherein said complex dissociates with a k.sub.off of no greater than about 10.sup.-3 .sub.S.sup.-1.

177. The antibody or antigen-binding fragment thereof of claim 176, wherein said antibody or antigen-binding fragment thereof dissociates from TNFR2 with a k.sub.off of no greater than about 10-.sup.4 .sub.S.sup.-1.

178. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof promotes proliferation of T regulatory (Treg) cells.

179. The antibody or antigen-binding fragment thereof of claim 178, wherein said Treg cells express CD25.sup.Hi and CD45RA.sup.Low.

180. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof directly kills, or promotes the death of, CD8+ T cells.

181. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof promotes an increase in the level of one or more mRNA molecules encoding a protein selected from the group consisting of clAP2, TRAF2, Etk, VEGFR2, PI3K, Akt, a protein involved in the angiogenic pathway, an IKK complex, RIP, NIK, MAP3K, a protein involved in the NFkB pathway, NIK, JNK, AP-1, a MEK (e.g., MEK1, MEK7), MKK3, NEMO, IL2R, Foxp3, IL2, TNF, lymphotoxin, lymphotoxin α, and lymphotoxin β.

182. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof promotes an increase in the level of one or more proteins selected from the group consisting of clAP2, TRAF2, Etk, VEGFR2, PI3K, Akt, a protein involved in the angiogenic pathway, an IKK complex, RIP, NIK, MAP3K, a protein involved in the NFkB pathway, NIK, JNK, AP-1, a MEK (e.g., MEK1, MEK7), MKK3, NEMO, IL2R, Foxp3, IL2, TNF, lymphotoxin, lymphotoxin α, and lymphotoxin β.

183. The antibody or antigen-binding fragment thereof of claim 1, wherein said antibody or antigen-binding fragment thereof promotes an increase in the level of itaconate upon administration to a subject, optionally wherein the subject is a human subject.

184. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof is selected from the group consisting of a monoclonal antibody or antigen-binding fragment thereof, a polyclonal antibody or antigen-binding fragment thereof, a human antibody or antigen-binding fragment thereof, a humanized antibody or antigen-binding fragment thereof, a primatized antibody or antigen-binding fragment thereof, a bispecific antibody or antigen-binding fragment thereof, a multi-specific antibody or antigen-binding fragment thereof, a dual-variable immunoglobulin domain, a monovalent antibody or antigen-binding fragment thereof, a chimeric antibody or antigen-binding fragment thereof, a single-chain Fv molecule (scFv), a diabody, a triabody, a nanobody, an antibody-like protein scaffold, a domain antibody, a Fv fragment, a Fab fragment, a F(ab′).sub.2 molecule, and a tandem scFv (taFv), optionally wherein said antibody or antigen-binding fragment thereof is a human antibody or antigen-binding fragment thereof, a humanized antibody or antigen-binding fragment thereof, or a chimeric antibody or antigen-binding fragment thereof.

185. The antibody or antigen-binding fragment thereof of claim 1, wherein the antibody or antigen-binding fragment thereof is a single-chain polypeptide.

186. A single-chain polypeptide that competitively inhibits the binding of human TNFR2 to the single-chain polypeptide of claim 185.

187. A construct comprising a first polypeptide domain and a second polypeptide domain, wherein the first polypeptide domain and the second polypeptide domain each independently comprise a single-chain polypeptide of claim 185.

188. The construct of claim 187, wherein the first polypeptide domain and the second polypeptide domain are bound by a covalent linker.

189. The construct of claim 188, wherein the covalent linker comprises an amide bond or a disulfide bond.

190. A polynucleotide encoding the antibody or antigen-binding fragment thereof of claim 1.

191. A polynucleotide encoding the single-chain polypeptide of claim 190.

192. A polynucleotide encoding the construct of claim 187.

193. A vector comprising the polynucleotide of claim 190.

194. The vector of claim 193, wherein the vector is an expression vector.

195. The vector of claim 194, wherein the expression vector is a eukaryotic expression vector.

196. The vector of claim 193, wherein the vector is a viral vector.

197. The vector of claim 196, wherein the viral vector is selected from the group consisting of adenovirus (Ad), retrovirus, poxvirus, adeno-associated virus, baculovirus, herpes simplex virus, and a vaccinia virus.

198. The vector of claim 197, wherein the adenovirus is a serotype 2, 5, 11, 12, 24, 26, 34, 35, 40, 48, 49, 50, 52, or Pan9 adenovirus, or a human, chimpanzee, or rhesus adenovirus.

199. The vector of claim 197, wherein the retrovirus is a y-retrovirus or a lentivirus.

200. The vector of claim 197, wherein the vaccinia virus is a modified vaccinia Ankara (MVA).

201. An isolated host cell comprising the vector of claim 193.

202. The host cell of claim 201, wherein the host cell is a prokaryotic cell.

203. The host cell of claim 201, wherein the host cell is a eukaryotic cell.

204. The host cell of claim 203, wherein the eukaryotic cell is a mammalian cell.

205. The host cell of claim 204, wherein the mammalian cell is a CHO cell or HEK cell.

206. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof of claim 1 and a pharmaceutically acceptable carrier or excipient.

207. The pharmaceutical composition of claim 206, wherein said antibody or antigen-binding fragment thereof is present in said pharmaceutical composition in an amount of from about 0.001 mg/ml to about 100 mg/ml.

208. The pharmaceutical composition of claim 206, wherein said pharmaceutical composition further comprises an additional therapeutic agent.

209. The pharmaceutical composition of claim 208, wherein said additional therapeutic agent is an immunotherapy agent.

210. The pharmaceutical composition of claim 209, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 agent, an agonistic anti-PD-1 agent, an agonistic anti-PD-L1 agent, an agonistic anti-PD-L2 agent, an agonistic anti-CD27 agent, an agonistic anti-CD30 agent, an agonistic anti-CD40 agent, an agonistic anti-4-1 BB agent, an agonistic anti-GITR agent, an agonistic anti-OX40 agent, an agonistic anti-TRAILR1 agent, an agonistic anti-TRAILR2 agent, an agonistic anti-TWEAK agent, an agonistic anti-TWEAKR agent, an agonistic anti-cell surface lymphocyte protein agent, an agonistic anti-BRAF agent, an agonistic anti-MEK agent, an agonistic anti-CD33 agent, an agonistic anti-CD20 agent, an agonistic anti-HLA-DR agent, an agonistic anti-HLA class I agent, an agonistic anti-CD52 agent, an agonistic anti-A33 agent, an agonistic anti-GD3 agent, an agonistic anti-PSMA agent, an agonistic anti-Ceacan 1 agent, an agonistic anti-Galedin 9 agent, an agonistic anti-HVEM agent, an agonistic anti-VISTA agent, an agonistic anti-B7 H4 agent, an agonistic anti-HHLA2 agent, an agonistic anti-CD155 agent, an agonistic anti-CD80 agent, an agonistic anti-BTLA agent, an agonistic anti-CD160 agent, an agonistic anti-CD28 agent, an agonistic anti-CD226 agent, an agonistic anti-CEACAM1 agent, an agonistic anti-TIM3 agent, an agonistic anti-TIGIT agent, an agonistic anti-CD96 agent, an agonistic anti-CD70 agent, an agonistic anti-CD27 agent, an agonistic anti-LIGHT agent, an agonistic anti-CD137 agent, an agonistic anti-DR4 agent, an agonistic anti-CR5 agent, an agonistic anti-TNFRS agent, an agonistic anti-TNFR1 agent, an agonistic anti-FAS agent, an agonistic anti-CD95 agent, an agonistic anti-TRAIL agent, an agonistic anti-DR6 agent, an agonistic anti-EDAR agent, an agonistic anti-NGFR agent, an agonistic anti-OPG agent, an agonistic anti-RANKL agent, an agonistic anti-LTβ receptor agent, an agonistic anti-BCMA agent, an agonistic anti-TACI agent, an agonistic anti-BAFFR agent, an agonistic anti-EDAR2 agent, an agonistic anti-TROY agent, and an agonistic anti-RELT agent, optionally wherein the immunotherapy agent is an agonistic anti-PD-1 antibody or an agonistic anti-PD-L1 antibody.

211. The pharmaceutical composition of claim 210, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof, an agonistic anti-PD-1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L2 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-CD30 antibody or antigen-binding fragment thereof, an agonistic anti-CD40 antibody or antigen-binding fragment thereof, an agonistic anti-4-1 BB antibody or antigen-binding fragment thereof, an agonistic anti-GITR antibody or antigen-binding fragment thereof, an agonistic anti-OX40 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR1 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR2 antibody or antigen-binding fragment thereof, an agonistic anti-TWEAK antibody or antigen-binding fragment thereof, an agonistic anti-TWEAKR antibody or antigen-binding fragment thereof, an agonistic anti-cell surface lymphocyte protein antibody or antigen-binding fragment thereof, an agonistic anti-BRAF antibody or antigen-binding fragment thereof, an agonistic anti-MEK antibody or antigen-binding fragment thereof, an agonistic anti-CD33 antibody or antigen-binding fragment thereof, an agonistic anti-CD20 antibody or antigen-binding fragment thereof, an agonistic anti-HLA-DR antibody or antigen-binding fragment thereof, an agonistic anti-HLA class I antibody or antigen-binding fragment thereof, an agonistic anti-CD52 antibody or antigen-binding fragment thereof, an agonistic anti-A33 antibody or antigen-binding fragment thereof, an agonistic anti-GD3 antibody or antigen-binding fragment thereof, an agonistic anti-PSMA antibody or antigen-binding fragment thereof, an agonistic anti-Ceacan 1 antibody or antigen-binding fragment thereof, an agonistic anti-Galedin 9 antibody or antigen-binding fragment thereof, an agonistic anti-HVEM antibody or antigen-binding fragment thereof, an agonistic anti-VISTA antibody or antigen-binding fragment thereof, an agonistic anti-B7 H4 antibody or antigen-binding fragment thereof, an agonistic anti-HHLA2 antibody or antigen-binding fragment thereof, an agonistic anti-CD155 antibody or antigen-binding fragment thereof, an agonistic anti-CD80 antibody or antigen-binding fragment thereof, an agonistic anti-BTLA antibody or antigen-binding fragment thereof, an agonistic anti-CD160 antibody or antigen-binding fragment thereof, an agonistic anti-CD28 antibody or antigen-binding fragment thereof, an agonistic anti-CD226 antibody or antigen-binding fragment thereof, an agonistic anti-CEACAM1 antibody or antigen-binding fragment thereof, an agonistic anti-TIM3 antibody or antigen-binding fragment thereof, an agonistic anti-TIGIT antibody or antigen-binding fragment thereof, an agonistic anti-CD96 antibody or antigen-binding fragment thereof, an agonistic anti-CD70 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-LIGHT antibody or antigen-binding fragment thereof, an agonistic anti-CD137 antibody or antigen-binding fragment thereof, an agonistic anti-DR4 antibody or antigen-binding fragment thereof, an agonistic anti-CR5 antibody or antigen-binding fragment thereof, an agonistic anti-TNFRS antibody or antigen-binding fragment thereof, an agonistic anti-TNFR1 antibody or antigen-binding fragment thereof, an agonistic anti-FAS antibody or antigen-binding fragment thereof, an agonistic anti-CD95 antibody or antigen-binding fragment thereof, an agonistic anti-TRAIL antibody or antigen-binding fragment thereof, an agonistic anti-DR6 antibody or antigen-binding fragment thereof, an agonistic anti-EDAR antibody or antigen-binding fragment thereof, an agonistic anti-NGFR antibody or antigen-binding fragment thereof, an agonistic anti-OPG antibody or antigen-binding fragment thereof, an agonistic anti-RANKL antibody or antigen-binding fragment thereof, an agonistic anti-LTβ receptor antibody or antigen-binding fragment thereof, an agonistic anti-BCMA antibody or antigen-binding fragment thereof, an agonistic anti-TACI antibody or antigen-binding fragment thereof, an agonistic anti-BAFFR antibody or antigen-binding fragment thereof, an agonistic anti-EDAR2 antibody or antigen-binding fragment thereof, an agonistic anti-TROY antibody or antigen-binding fragment thereof, and an agonistic anti-RELT antibody or antigen-binding fragment thereof.

212. The pharmaceutical composition of claim 210, wherein the immunotherapy agent is an agonistic anti-CTLA-4 agent or an agonistic anti-PD-1 agent.

213. The pharmaceutical composition of claim 212, wherein the immunotherapy agent is an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof or an agonistic anti-PD-1 antibody or antigen-binding fragment thereof.

214. A method of producing the antibody or antigen-binding fragment thereof of claim 1, said method comprising expressing a polynucleotide encoding said antibody or antigen-binding fragment thereof in a host cell and recovering the antibody or antigen-binding fragment thereof from host cell medium.

215. A method of inhibiting an immune response mediated by a B cell or CD8+ T cell in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of claim 1.

216. A method of treating an immunological disease in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of claim 1.

217. The method of claim 216, wherein said subject is in need of a tissue or organ regeneration.

218. The method of claim 217, wherein said tissue or organ is selected from the group consisting of a pancreas, salivary gland, pituitary gland, kidney, heart, lung, hematopoietic system, cranial nerves, heart, aorta, olfactory gland, ear, nerves, structures of the head, eye, thymus, tongue, bone, liver, small intestine, large intestine, gut, lung, brain, skin, peripheral nervous system, central nervous system, spinal cord, breast, embryonic structures, embryos, and testes.

219. The method of claim 216, wherein said immunological disease is selected from the group consisting of an autoimmune disease, a neurological condition, an allergy, asthma, macular degeneration, muscular atrophy, a disease related to miscarriage, atherosclerosis, bone loss, a musculoskeletal disease, obesity, a graft-versus-host disease, and an allograft rejection.

220. The method of claim 219, wherein said autoimmune disease is selected from the group consisting of type I diabetes, Alopecia Areata, Ankylosing Spondylitis, Antiphospholipid Syndrome, Autoimmune Addison’s Disease, Autoimmune Hemolytic Anemia, Autoimmune Hepatitis, Behcet’s Disease, Bullous Pemphigoid, Cardiomyopathy, Celiac Sprue-Dermatitis, Chronic Fatigue Immune Dysfunction Syndrome (CFIDS), Chronic Inflammatory Demyelinating Polyneuropathy, Churg-Strauss Syndrome, Cicatricial Pemphigoid, CREST Syndrome, ColdAgglutinin Disease, Crohn’s Gilillain Disease, Hashimoto’s Thyroiditis, Hypothyroidism, Idiopathic Pulmonary Fibrosis, Idiopathic Thrombocytopenia Purpura (ITP), IgA Nephropathy, Juvenile Arthritis, Lichen Planus, Lupus, Meniere’s Disease, Mixed Connective Tissue Disease, Multiple Sclerosis, Myasthenia Gravis, Pemphigus Vulgaris, Pernicious Anemia, Polyarteritis Nodosa, Polychondritis, Polyglandular Syndromes, Polymyalgia Rheumatica, Polymyositis and Dermatomyositis, Primary Agammaglobulinemia, Primary Biliary Cirrhosis, Psoriasis, Raynaud’s Phenomenon, Reiter’s Syndrome, Rheumatic Fever, Rheumatoid Arthritis, Sarcoidosis, Scleroderma, Sjogren’s Syndrome, Stiff-Man Syndrome, Takayasu Arteritis, Temporal Arteritis/Giant Cell Arteritis, Ulcerative Colitis, Uveitis, Vasculitis, Vitiligo, and Wegener’s Granulomatosis.

221. The method of claim 219, wherein said neurological condition is selected from the group consisting of a brain tumor, a brain metastasis, a spinal cord injury, schizophrenia, epilepsy, Amyotrophic lateral sclerosis (ALS), Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, and stroke.

222. The method of claim 219, wherein said allergy is selected from the group consisting of food allergy, seasonal allergy, pet allergy, hives, hay fever, allergic conjunctivitis, poison ivy allergy oak allergy, mold allergy, drug allergy, dust allergy, cosmetic allergy, and chemical allergy.

223. The method of claim 219, wherein said allograft rejection is selected from the group consisting of skin graft rejection, bone graft rejection, vascular tissue graft rejection, ligament graft rejection, and organ graft rejection.

224. The method of claim 223, wherein said ligament graft rejection is selected from the group consisting of cricothyroid ligament graft rejection, periodontal ligament graft rejection, suspensory ligament of the lens graft rejection, palmar radiocarpal ligament graft rejection, dorsal radiocarpal ligament graft rejection, ulnar collateral ligament graft rejection, radial collateral ligament graft rejection, suspensory ligament of the breast graft rejection, anterior sacroiliac ligament graft rejection, posterior sacroiliac ligament graft rejection, sacrotuberous ligament graft rejection, sacrospinous ligament graft rejection, inferior pubic ligament graft rejection, superior pubic ligament graft rejection, anterior cruciate ligament graft rejection, lateral collateral ligament graft rejection, posterior cruciate ligament graft rejection, medial collateral ligament graft rejection, cranial cruciate ligament graft rejection, caudal cruciate ligament graft rejection, and patellar ligament graft rejection.

225. The method of claim 223, wherein said organ graft rejection is selected from the group consisting of heart graft rejection, lung graft rejection, kidney graft rejection, liver graft rejection, pancreas graft rejection, intestine graft rejection, and thymus graft rejection.

226. The method of claim 219, wherein said graft-versus-host disease arises from a bone marrow transplant or one or more blood cells selected from the group consisting of hematopoietic stem cells, common myeloid progenitor cells, common lymphoid progenitor cells, megakaryocytes, monocytes, basophils, eosinophils, neutrophils, macrophages, T cells, B cells, natural killer cells, and dendritic cells.

227. A method of treating an inflammatory disease in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of claim 1.

228. The method of claim 227, wherein the inflammatory disease is acute or chronic inflammation.

229. The method of claim 227, wherein the inflammatory disease is cardiac fibrosis or lung fibrosis.

230. The method of claim 227, wherein the inflammatory disease is selected from the group consisting of osteoarthritis, fibrotic lung disease, and cardiac inflammation.

231. A method of regenerating TNFR2+ tissue in a human subject, said method comprising administering to the subject the antibody or antigen-binding fragment thereof of claim 1.

232. The method of claim 231, wherein said TNFR2+ tissue is selected from the group consisting of pancreas, salivary gland, pituitary gland, kidney, heart, lung, hematopoietic system, cranial nerves, heart, aorta, olfactory gland, ear, nerve, eye, thymus, tongue, bone, liver, small intestine, large intestine, gastrointestinal, lung, brain, skin, peripheral nervous system, central nervous system, spinal cord, breast, embryonic structures, embryo, and testes tissue.

233. The method of claim 216, wherein said method comprises administering to the human an immunotherapy agent.

234. The method of claim 233, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 agent, an agonistic anti-PD-1 agent, an agonistic anti-PD-L1 agent, an agonistic anti-PD-L2 agent, an agonistic anti-CD27 agent, an agonistic anti-CD30 agent, an agonistic anti-CD40 agent, an agonistic anti-4-1 BB agent, an agonistic anti-GITR agent, an agonistic anti-OX40 agent, an agonistic anti-TRAILR1 agent, an agonistic anti-TRAILR2 agent, an agonistic anti-TWEAK agent, an agonistic anti-TWEAKR agent, an agonistic anti-cell surface lymphocyte protein agent, an agonistic anti-BRAF agent, an agonistic anti-MEK agent, an agonistic anti-CD33 agent, an agonistic anti-CD20 agent, an agonistic anti-HLA-DR agent, an agonistic anti-HLA class I agent, an agonistic anti-CD52 agent, an agonistic anti-A33 agent, an agonistic anti-GD3 agent, an agonistic anti-PSMA agent, an agonistic anti-Ceacan 1 agent, an agonistic anti-Galedin 9 agent, an agonistic anti-HVEM agent, an agonistic anti-VISTA agent, an agonistic anti-B7 H4 agent, an agonistic anti-HHLA2 agent, an agonistic anti-CD155 agent, an agonistic anti-CD80 agent, an agonistic anti-BTLA agent, an agonistic anti-CD160 agent, an agonistic anti-CD28 agent, an agonistic anti-CD226 agent, an agonistic anti-CEACAM1 agent, an agonistic anti-TIM3 agent, an agonistic anti-TIGIT agent, an agonistic anti-CD96 agent, an agonistic anti-CD70 agent, an agonistic anti-CD27 agent, an agonistic anti-LIGHT agent, an agonistic anti-CD137 agent, an agonistic anti-DR4 agent, an agonistic anti-CR5 agent, an agonistic anti-TNFRS agent, an agonistic anti-TNFR1 agent, an agonistic anti-FAS agent, an agonistic anti-CD95 agent, an agonistic anti-TRAIL agent, an agonistic anti-DR6 agent, an agonistic anti-EDAR agent, an agonistic anti-NGFR agent, an agonistic anti-OPG agent, an agonistic anti-RANKL agent, an agonistic anti-LTβ receptor agent, an agonistic anti-BCMA agent, an agonistic anti-TACI agent, an agonistic anti-BAFFR agent, an agonistic anti-EDAR2 agent, an agonistic anti-TROY agent, and an agonistic anti-RELT agent, optionally wherein the immunotherapy agent is an agonistic anti-PD-1 antibody or an agonistic anti-PD-L1 antibody.

235. The method of claim 234, wherein said immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof, an agonistic anti-PD-1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L2 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-CD30 antibody or antigen-binding fragment thereof, an agonistic anti-CD40 antibody or antigen-binding fragment thereof, an agonistic anti-4-1 BB antibody or antigen-binding fragment thereof, an agonistic anti-GITR antibody or antigen-binding fragment thereof, an agonistic anti-OX40 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR1 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR2 antibody or antigen-binding fragment thereof, an agonistic anti-TWEAK antibody or antigen-binding fragment thereof, an agonistic anti-TWEAKR antibody or antigen-binding fragment thereof, an agonistic anti-cell surface lymphocyte protein antibody or antigen-binding fragment thereof, an agonistic anti-BRAF antibody or antigen-binding fragment thereof, an agonistic anti-MEK antibody or antigen-binding fragment thereof, an agonistic anti-CD33 antibody or antigen-binding fragment thereof, an agonistic anti-CD20 antibody or antigen-binding fragment thereof, an agonistic anti-HLA-DR antibody or antigen-binding fragment thereof, an agonistic anti-HLA class I antibody or antigen-binding fragment thereof, an agonistic anti-CD52 antibody or antigen-binding fragment thereof, an agonistic anti-A33 antibody or antigen-binding fragment thereof, an agonistic anti-GD3 antibody or antigen-binding fragment thereof, an agonistic anti-PSMA antibody or antigen-binding fragment thereof, an agonistic anti-Ceacan 1 antibody or antigen-binding fragment thereof, an agonistic anti-Galedin 9 antibody or antigen-binding fragment thereof, an agonistic anti-HVEM antibody or antigen-binding fragment thereof, an agonistic anti-VISTA antibody or antigen-binding fragment thereof, an agonistic anti-B7 H4 antibody or antigen-binding fragment thereof, an agonistic anti-HHLA2 antibody or antigen-binding fragment thereof, an agonistic anti-CD155 antibody or antigen-binding fragment thereof, an agonistic anti-CD80 antibody or antigen-binding fragment thereof, an agonistic anti-BTLA antibody or antigen-binding fragment thereof, an agonistic anti-CD160 antibody or antigen-binding fragment thereof, an agonistic anti-CD28 antibody or antigen-binding fragment thereof, an agonistic anti-CD226 antibody or antigen-binding fragment thereof, an agonistic anti-CEACAM1 antibody or antigen-binding fragment thereof, an agonistic anti-TIM3 antibody or antigen-binding fragment thereof, an agonistic anti-TIGIT antibody or antigen-binding fragment thereof, an agonistic anti-CD96 antibody or antigen-binding fragment thereof, an agonistic anti-CD70 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-LIGHT antibody or antigen-binding fragment thereof, an agonistic anti-CD137 antibody or antigen-binding fragment thereof, an agonistic anti-DR4 antibody or antigen-binding fragment thereof, an agonistic anti-CR5 antibody or antigen-binding fragment thereof, an agonistic anti-TNFRS antibody or antigen-binding fragment thereof, an agonistic anti-TNFR1 antibody or antigen-binding fragment thereof, an agonistic anti-FAS antibody or antigen-binding fragment thereof, an agonistic anti-CD95 antibody or antigen-binding fragment thereof, an agonistic anti-TRAIL antibody or antigen-binding fragment thereof, an agonistic anti-DR6 antibody or antigen-binding fragment thereof, an agonistic anti-EDAR antibody or antigen-binding fragment thereof, an agonistic anti-NGFR antibody or antigen-binding fragment thereof, an agonistic anti-OPG antibody or antigen-binding fragment thereof, an agonistic anti-RANKL antibody or antigen-binding fragment thereof, an agonistic anti-LTβ receptor antibody or antigen-binding fragment thereof, an agonistic anti-BCMA antibody or antigen-binding fragment thereof, an agonistic anti-TACI antibody or antigen-binding fragment thereof, an agonistic anti-BAFFR antibody or antigen-binding fragment thereof, an agonistic anti-EDAR2 antibody or antigen-binding fragment thereof, an agonistic anti-TROY antibody or antigen-binding fragment thereof, and an agonistic anti-RELT antibody or antigen-binding fragment thereof.

236. The method of claim 233, wherein the immunotherapy agent is an agonistic anti-CTLA-4 agent or an agonistic anti-PD-1 agent.

237. The method of claim 236, wherein the immunotherapy agent is an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof or an agonistic anti-PD-1 antibody or antigen-binding fragment thereof.

238. The method of claim 216, wherein said method comprises administering to the human an additional agent selected from the group consisting of TNFα, an agonistic TNFα mutein, and Bacillus Calmette-Guerin (BCG).

239. The method of claim 216, wherein the antibody or antigen-binding fragment thereof that specifically binds TNFR2 is administered to the human in an amount of from about 0.001 mg/kg to about 100 mg/kg.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0335] FIG. 1 shows the amino acid sequence of human TNFR2, with highlighted regions showing exemplary epitopes that may be bound by a TNFR2 agonistic antibody of the disclosure. Human TNFR2 is numbered herein starting with an N-terminal methionine at position 1 and concluding with a C-terminal serine at position 461 (SEQ ID NO: 1). All references to amino acid positions within TNFR2 are made in the context of the TNFR2 numbering scheme shown in FIG. 1.

[0336] FIG. 2 is a graph showing the proliferative effect of an exemplary TNFR2 agonistic antibody of the disclosure on Treg cells. The results shown in this figure were obtained by incubation of the agonistic TNFR2 antibody TNFRAG1, described herein, at various concentrations (shown along the x-axis) with Treg cells for 48-72 hours. Values along the y-axis represent the percentage of Treg cells in the cell population studied. Data represent the average of 35 individual experiments.

[0337] FIG. 3 is a graph showing the effect of a natural TNFR2 agonist, TNFα, on the expansion of Treg cells induced by a TNFR2 agonist antibody of the disclosure, TNFRAG1. Values along the x-axis denote the presence, in an in vitro population of Treg cells, of either IL-2, TNFα, or antibody TNFRAG1 alone, or of increasing concentrations of antibody TNFRAG1 in combination with 20 ng/ml of TNFα. Values along the y-axis represent the percentage of Treg cells in the cell population studied. These data demonstrate that the presence of TNFα further increases the ability of TNFR2 agonist antibodies of the disclosure, such as TNFRAG1, to stimulate Treg cell proliferation. These data are consistent with the ability of TNFR2 agonist antibodies of the disclosure to promote TNFR2 activation by binding TNFR2 monomers so as to form a trimeric structure. This binding event brings individual TNFR2 molecules into close proximity with one another, and sterically exposes sites on the TNFR2 surface that may be bound by an endogenous ligand, such as TNFα. Without being limited by mechanism, this sequence of events represents a pathway by which TNFR2 agonist polypeptides of the disclosure (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs) may effectuate TNFR2 activation in vivo.

[0338] FIG. 4 is a graph demonstrating the inhibitory effect of an anti-TNFα antibody on the ability of an agonistic TNFR2 antibody of the disclosure, TNFRAG1, to stimulate Treg cell proliferation. Values along the x-axis represent the concentration of anti-TNFα antibody, in .Math.g/ml, present in an in vitro population of Treg cells. All conditions shown along the x-axis include 2.5 .Math.g/ml of TNFRAG1. Values along the y-axis represent the percentage of Treg cells in the cell population studied.

[0339] FIGS. 5A - 5D are a series of schematics comparing the disulfide bonding arrangement present in each of the IgG2-A (FIG. 5A), IgG2-A/B.sub.1 (FIG. 5B), IgG2-B (FIG. 5C), and IgG2-A/B.sub.2 (FIG. 5D) isoforms of a human IgG2 isotype antibody. Thin lines represent disulfide bonds connecting various portions of each antibody heavy chain or light chain, which are represented by shaded rectangles. Heavy chains are represented by the longer, outermost rectangles of each antibody. Within each heavy chain, black shading denotes the constant region, and light shading denotes the variable region. Light chains are represented by the shorter, innermost rectangles of each antibody. Within each light chain, darker shading denotes the constant region, and lighter shading denotes the variable region.

[0340] FIG. 6A is a graph showing the expression density, as assessed by immunofluorescence, of TNFR2 in Treg cells from human subjects with cancer, Treg cells from healthy human subjects, and Treg cells from human type 1 diabetes patients. The mean fluorescent intensity (MFI) of TNFR2 in Treg cells obtained from subjects with cancer was 147.435 (SEM 29.053, n=10); the MFI of TNFR2 in Treg cells obtained from healthy subjects was 59.055 (SEM 9.545, n=10); and the MFI of TNFR2 in Treg cells obtained from type 1 diabetes patients was 29.313 (SEM 2.894, n=24). Grubb’s test outliers were removed.

[0341] FIG. 6B is a graph showing the expression density, as assessed by immunofluorescence, of TNFR2 in T effector (Teff) cells from human subjects with cancer, Teff cells from healthy human subjects, and Teff cells from human type 1 diabetes patients. The mean fluorescent intensity (MFI) of TNFR2 in Teff cells obtained from subjects with cancer was 32.070 (SEM 6.290, n=10); the MFI of TNFR2 in Teff cells obtained from healthy subjects was 40.811 (SEM 6.466, n=10); and the MFI of TNFR2 in Teff cells obtained from type 1 diabetes patients was 66.600 (SEM 1.815, n=10). Grubb’s test outliers were removed.

[0342] FIG. 6C is a graph showing the effect of agonist TNFR2 antibody TNFRAG1 on the proliferation of Treg cells upon incubating TNFRAG1 with a population of freshly isolated peripheral human CD4+ cells for 48 hours (n=13). Values along the x-axis represent the concentration of antibody; values along the y-axis represent the percentage of Treg cells within the population of lymphocytes. Data are mean ± SEM.

[0343] FIG. 6D is a graph showing the effect of agonist TNFR2 antibody TNFRAG1 on the proliferation of Treg cells upon incubating TNFRAG1 with a population of freshly isolated peripheral human CD4+ cells in the presence of endogenous TNFR2 ligand, TNFα (20 ng/ml) for 48 hours (n=2). Values along the x-axis represent the concentration of antibody; values along the y-axis represent the percentage of Treg cells within the population of lymphocytes. Data are mean ± SEM.

[0344] FIG. 7A is a graph showing the effect of an F(ab′).sub.2 antibody fragment, with the complementarity determining regions (CDRs) of TNFRAG1, on the proliferation of Treg cells. Values along the x-axis represent the concentration of antibody fragment; values along the y-axis represent the relative increase in Treg cell quantity, normalized with respect to Treg cells treated with interleukin-2 (IL-2). Data are mean ± SEM. These data demonstrate that a functional Fc region, which is absent in an F(ab′).sub.2 antibody fragment, is not necessary for TNFRAG1 to induce Treg proliferation.

[0345] FIG. 7B is a graph showing the effect of TNFRAG1 in the presence of a cross-linking antibody (2.5 .Math.g/ml) on the proliferation of Treg cells. The cross-linking antibody, ab9165 (Abcam), binds the Fc regions of neighboring TNFRAG1 antibodies and, thus, increases the local density of TNFRAG1 on the Treg cell surface. Data are mean ± SEM.

[0346] FIG. 7C shows two graphs comparing the effect of agonist TNFR2 antibody, MR2-1 (Abcam), on the proliferation of Treg cells in the presence of TNFα (20 mg/ml, left) with the effect of TNFα alone on the proliferation of Treg cells (right). Values along the x-axes represent the concentration of TNFR2 agonist; values along the y-axes represent the relative increase in Treg cell quantity.

[0347] FIG. 7D is a graph showing the effects of IL-2, TNFα, and TNFRAG1 on the secretion of soluble TNFR2 in a population of peripheral human CD4+ cells. Values along the y-axis are fluorescence intensity measurements obtained from an enzyme-linked immunosorbant assay (ELISA) quantifying soluble TNFR2.

[0348] FIGS. 8A - 8E are graphs showing the effect of TNFRAG1 on Treg proliferation in peripheral human lymphocytes. FIG. 8A shows the overall trend of reduced CD8+ Teff cells observed when peripheral lymphocytes were incubated with TNFRAG1. FIG. 8B shows the effect of TNFRAG1 on Teff cells alone. FIG. 8C shows the effect of TNFRAG1 on Teff cell quantity when incubated with a mixture containing Teff cells and Treg cells in a ratio of 4:1 either in the absence of rapamycin and TNFα (left), in the absence of rapamycin and in the presence of TNFα (middle), or in the presence of rapamycin and the absence of TNFα (right). FIG. 8D shows the effect of TNFRAG1 on Teff cell quantity when incubated with a mixture containing Teff cells and Treg cells in a ratio of 2:1 either in the absence of rapamycin and TNFα (left), in the absence of rapamycin and in the presence of TNFα (middle), or in the presence of rapamycin and the absence of TNFα (right). FIG. 8E shows the effect of TNFRAG1 on Teff cell quantity when incubated with a mixture containing Teff cells and Treg cells in a ratio of 1:1 either in the absence of rapamycin and TNFα (left), in the absence of rapamycin and in the presence of TNFα (middle), or in the presence of rapamycin and the absence of TNFα (right). In all experiments, cells were incubated with soluble anti-CD3 antibody (Hit3a) and IL-2 (50 U/ml) in 10% FBS RPMI for 4 days.

[0349] FIG. 9A is a graph showing the effect of TNFRAG1 on gene expression in peripheral human CD4+ cells. Expression of genes that are characteristic of Treg cells (indicated with an asterisk) is selectively upregulated.

[0350] FIG. 9B is a diagram showing particular genes that are upregulated upon incubating peripheral CD4+ cells with TNFRAG1.

[0351] FIG. 9C shows graphs that demonstrate the effect of TNFRAG1 on the expression of genes ETS (left), EP300 (middle), and CREB (right), which are characteristic of Treg cells. For comparison purposes, cells were treated with either IL-2 alone (“none”), TNFRAG1 (“TNFR2 agonist”), or a TNFR2 antagonist antibody (“TNFR2 antagonist”).

[0352] FIG. 10A is a diagram showing the glycolysis pathway, as well as the various genes that are expressed during glycolysis, and the glutaminolysis pathway, as well as the various genes that are expressed during glutaminolysis.

[0353] FIG. 10B is a graph showing the effect of TNFRAG1 on the expression of genes involved in glycolysis upon incubation of TNFRAG1 with peripheral human CD4+ cells. Treg cells are characterized by reduced glycolysis. These data demonstrate that TNFRAG1 induces an increase in the relative amount of Treg cells upon incubation with peripheral human CD4+ cells.

[0354] FIG. 10C is a graph showing the effect of TNFRAG1 on the expression of genes involved in glutaminolysis upon incubation of TNFRAG1 with peripheral human CD4+ cells. Treg cells are characterized by increased glutaminolysis. These data demonstrate that TNFRAG1 induces an increase in the relative amount of Treg cells upon incubation with peripheral human CD4+ cells.

[0355] FIG. 11A is a diagram showing the Krebs cycle and the effect that the early steps in this pathway have on upregulating itaconate, a suppressor of autoimmunity.

[0356] FIG. 11B is a graph showing the effects of TNFRAG1 on the expression of genes involved in the Krebs cycle upon incubation of TNFRAG1 with peripheral human CD4+ cells. These data demonstrate that TNFRAG1 upregulates the expression of early genes in the Krebs cycle, which results in an increase in itaconate.

[0357] FIG. 11C is a graph showing the effects of TNFRAG1 on the expression of KEAP1, a known known inducer of inflammation and autoimmunity, upon incubation of TNFRAG1 with peripheral human CD4+ cells.

[0358] FIG. 12A is a diagram showing the metabolic preferences of Treg cells. Treg cells exhibit reduced glycolysis, elevated glutaminolysis, and an increase in fatty acid consumption.

[0359] FIGS. 12B - 12D are a series of graphs showing the effects of TNFRAG1 on the expression of CPT1 A (FIG. 12B), CPT1 B (FIG. 12C), and AMPK (FIG. 12D), genes involved in fatty acid metabolism, upon incubation of TNFRAG1 with peripheral human CD4+ cells. These data further demonstrate the ability of TNFRAG1 to selectively induce Treg cell proliferation.

[0360] FIGS. 13A and 13B are tables showing the results of an ELISA experiment confirming the epitopes on TNFR2 that are bound by TNFRAG1. Epitopes within cysteine-rich domain 2 (CRD2) are indicated with a bracket. The amino acid sequences shown in FIGS. 13A and 13B correspond, from the first sequence to the last sequence, to SEQ ID NOs: 49-70, respectively.

[0361] FIG. 14 is a structural model of a TNFR2 agonist antibody bound to CRD2 of TNFR2.

[0362] FIG. 15 is a table showing the results of an ELISA experiment further confirming the epitopes on TNFR2 that are bound by TNFRAG1. The amino acid sequences shown in FIG. 15 correspond, from the first sequence to the last sequence, to SEQ ID NOs: 49-71, respectively.

DETAILED DESCRIPTION

[0363] Agonistic TNFR2 polypeptides described herein, such as single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof, may promote the proliferation, protection, healing, and/or regeneration of TNFR2-expressing cells. This may be effectuated, for instance, by binding TNFR2 (e.g., on the exterior surface of a regulatory T cell (Treg cell), myeloid-derived suppressor cell (MDSC), or TNFR2+ somatic cells (e.g., a parenchymal cell, such as a cell of the central nervous system (e.g., a neuron), among others) and inducing receptor trimerization. The activity of the TNFR2 agonist polypeptide may be augmented by the natural ligand, TNFa, such as membrane-bound trimeric TNFa. Without being limited by mechanism, this trimerization event may contribute to TNFR2 activation by bringing individual TNFR2 proteins into close proximity with one another, thereby promoting cell proliferation by way of the MAPK/NF.sub.KB/TRAF⅔ pathway. TNFR2 signal transduction is also characterized by secretion of soluble TNFR2 (sTNFR2) in a trimeric state, as well as by the dual activation of p300 and CBP, two intracellular proteins that bind the Foxp3 transcription site, thereby enhancing cell stability and maintenance. Importantly, activation of TNFR2 signaling has an inhibitory effect on T effector cells, such as CD8+ T cells. For these cells, TNFR2 agonism causes cell death.

[0364] Agonistic TNFR2 polypeptides described herein can be used to promote this trimerization event in a wide variety of TNFR2+ tissues. Thus, the compositions and methods described herein provide important physiological benefits, as the agonistic TNFR2 polypeptides of the disclosure may be used to elevate Treg cell and/or MDSC activity, and to diminish the activity of T effector cells, thereby suppressing autoimmunity, graft-versus-host disease (GVHD), inflammation, and graft rejection, among other pathologies described herein. The compositions and methods of the disclosure may also be used to directly kill effector T cells, such as CD8+ T cells, including those that react with endogenous (“self”) antigens. Agonistic TNFR2 polypeptides described herein additionally provide the beneficial feature of stimulating regeneration of TNFR2+ tissues and organs, and can be used to treat a wide variety of diseases characterized by tissue degeneration and organ failure.

[0365] The TNFR2 polypeptides (e.g., antibodies, antigen-binding fragments thereof, single-chain polypeptides, and constructs) described herein specifically bind to epitopes within TNFR2 that promote receptor activation and the various advantageous biological activities described above. Human TNFR2 contains four cysteine-rich domains (CRDs): CRD1 (amino acid residues 48-76 of SEQ ID NO: 1), CRD2 (amino acid residues 78-120 of SEQ ID NO: 1), CRD3 (amino acid residues 121-162 of SEQ ID NO: 1), and CRD4 (amino acid residues 162-202 of SEQ ID NO: 1). Agonistic TNFR2 polypeptides described herein specifically bind TNFR2 at one or more epitopes within CRD1, CRD2, and/or CRD3. In some embodiments, the agonistic TNFR2 polypeptides do not bind epitopes within CRD4. For example, the polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, or constructs thereof) of the disclosure may bind human TNFR2 at an epitope corresponding to one or more of the following residues: [0366] (a) amino acids 56-60 of SEQ ID NO: 1 (KCSPG); [0367] (b) amino acids 101-107 of SEQ ID NO: 1 (CSSDQVET); [0368] (c) amino acids 115-142 of SEQ ID NO: 1 (NRICTCRPGWYCALSKQEGCRLCAPLRK); [0369] (d) amino acids 26-45 of SEQ ID NO: 1 (QTAQMCCSKCSPGQHAKVFC); [0370] (e) amino acids 90-109 of SEQ ID NO: 1 (REQNRICTCRPGWYCALSKQ); [0371] (f) amino acids 98-117 of SEQ ID NO: 1 (CRPGWYCALSKQEGCRLCAP); [0372] (g) amino acids 106-125 of SEQ ID NO: 1 (LSKQEGCRLCAPLRKCRPGF); and/or [0373] (h) amino acids 108-127 of SEQ ID NO: 1 (KQEGCRLCAPLRKCRPGFGV), or an equivalent epitope within TNFR2 of a non-human mammal, such as a non-human mammal described herein.

[0374] The present disclosure is based, in part, on the discovery that agonistic TNFR2 polypeptides (e.g., antibodies, antigen-binding fragments thereof, single-chain polypeptides, and constructs) demonstrate substantially improved TNFR2 activation effects when these molecules are in the form of an IgG2-B isotype. As described in the examples below, it has presently been discovered that this class of TNFR2 polypeptides exhibits a surprisingly superior ability to activate TNFR2 signaling, promote Treg cell and MDSC proliferation, and heal, protect, and regenerate TNFR2-expressing tissues and organs relative to TNFR2 polypeptides of other isotypes.

[0375] Another discovery underlying the present disclosure is the finding that agonistic TNFR2 polypeptides that contain antigen-binding sites spatially separated from one another by fewer than about 133 Å exhibit unexpectedly superior TNFR2 activation effects relative to polypeptides that specifically bind TNFR2 at one or more of the epitopes described above but that contain antigen-binding sites separated from one another by about 133 Å or more. Examples of such polypeptides include IgG1, IgG2, IgG3, and IgG4 antibodies and antigen-binding fragments thereof that contain antigen-binding sites separated from one another by from about 90 Å to about 133 Å, and particularly include IgG1 antibodies and antigen-binding fragments thereof that contain antigen-binding sites separated from one another by about 117 Å, as well as IgG3 antibodies and antigen-binding fragments thereof that contain antigen-binding sites separated from one another by about 125 Å.

[0376] Agonistic TNFR2 polypeptides of the disclosure can be formulated into pharmaceutical compositions. Preferably, the polypeptides present in the pharmaceutical composition adopt a single disulfide-bonded isoform. For example, pharmaceutical compositions of the disclosure include those containing an agonistic TNFR2 polypeptide in which, e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, 99.99%, or more, of the polypeptide in the pharmaceutical composition is present in a single disulfide-bonded isoform. Agonistic TNFR2 polypeptides of the disclosure may advantageously adopt an IgG2-B disulfide-bonded isoform, which has surprisingly been found to promote a substantially more robust level of TNFR2 activation relative to other IgG2 disulfide-bonded isoforms, such as the IgG2-A, IgG2-NB.sub.1, and IgG2-A/B.sub.2 isoforms. These isoforms are shown graphically in FIGS. 5A - 5D. Polypeptides of the disclosure may be engineered to predominantly adopt an IgG2-B isoform, for example, by introducing mutations into the IgG2 heavy chain constant 1 (CH1) domain that prohibit the formation of other disulfide-bonded isoforms. Exemplary mutations in the amino acid sequence of a human IgG2 CH1 domain that promote the formation of the IgG2-B isoform at the exclusion of the remaining isoforms described above include the deletion and/or substitution of the cysteine residue at position 127 of a human IgG2 CH1 domain amino acid sequence (according to the Kabat numbering scheme, described herein), which is set forth in SEQ ID NO: 8. For example, to engineer an IgG2 antibody or antigen-binding fragment thereof so as to predominantly adopt the IgG2-B isoform, one may introduce conservative amino acid substitutions at cysteine residue 127 of SEQ ID NO: 8. An exemplary IgG2 CH1 domain that exists predominantly in the IgG2-B isoform has the amino acid sequence of SEQ ID NO: 9, which contains a C127S substitution relative to SEQ ID NO: 8.

[0377] The following biological activities are examples of agonistic TNFR2 phenotypes that are effectuated by polypeptides of the disclosure to a greater extent relative to TNFR2-binding polypeptides that (i) contain antigen-binding sites separated from one another by greater than 133 Å, and/or (ii) do not exist predominantly in a single disulfide-bonded isoform (e.g., the IgG2-B isoform): [0378] (a) Augmentation of the proliferation of, and/or the direct expansion of, Treg cells, for instance, by binding and activation TNFR2 on the Treg cell surface; [0379] (b) Augmentation of the proliferation of, and/or the direct expansion of, MDSCs, for instance, by binding and activating TNFR2 on the MDSC surface; [0380] (c) Depletion of T effector cells, such as CD8+ T cells (e.g., self-reactive CD8+ T cells); and/or [0381] (d) Augmentation of the proliferation of, and/or the direct expansion of, TNFR2-expressing parenchymal cells.

[0382] The sections that follow provide a description of exemplary characteristics of the agonistic TNFR2 polypeptides described herein, such as single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof, as well as their use in therapeutic methods.

Agonistic TNFR2 Polypeptides

IgG Isotype Antibodies Promote Superior TNFR2 Agonism

[0383] As described above and herein, robust TNFR2 activation is achieved by the TNFR2 agonist polypeptides (e.g., antibodies, antigen-binding fragments thereof, single-chain polypeptides, and constructs) described herein. Such polypeptides may have one or more, or all, of the CDRs of agonistic TNFR2 antibody TNFRAG1, described herein, or one or more CDRs having at least 85% sequence identity (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 99.9%, or 100% sequence identity) to the corresponding CDR(s) of TNFRAG1) has a human IgG1, IgG2, IgG3, or IgG4 isotype. Particularly advantageous are those polypeptides with modified IgG1 and IgG2 isotypes, such as those that contain a CH1 domain that favors an IgG2-B disulfide-bonded isoform. The disulfide bonding pattern of the various isoforms of human IgG2 antibodies are shown in FIGS. 5A - 5D. As shown in FIG. 5B, the IgG2-B isoform exhibits a disulfide bonding pattern that produces a narrower and more conformationally constrained structure relative to the other IgG2 isoforms. This structure is ideal for binding TNFR2 at the surface of a cell (e.g., a Treg cell, MDSC, or TNFR2-expressing parenchymal cell) and bringing the receptor monomers into proximity with one another so as to promote receptor trimerization, and thus, receptor activation.

[0384] To stabilize the IgG2-B disulfide-bonded isoform, mutations can be introduced into the IgG2 CH1 domain so as to prevent, or reduce the occurrence of, disulfide bonding between cysteine residues that are present as nonbonded thiols in the IgG2-B isoform. Mutations can also be introduced into the IgG2 CH1 domain to prevent the formation of all four isoform variants after administration of the antibody to a patient (e.g., a mammalian patient, such as a human), which may be caused by cysteine oxidation and reduction processes in vivo. Examples of such mutations are amino acid substitutions or deletions at residue C127 of the human IgG2 CH1 domain. By deleting this residue and/or modifying this site by way of an amino acid substitution (e.g., a conservative amino acid substitution), one can bias the disulfide bonding pattern in a population of IgG2 isoforms towards the IgG2-B isoform. A particularly advantageous mutation in the CH1 domain that can be used to favor the IgG2-B isoform is the C127S mutation.

Spacing Between Antigen-Binding Sites

[0385] Agonist TNFR2 polypeptides (e.g., single-chain polypeptides, antibody, antigen-binding fragment thereof, or construct thereof) described herein may contain antigen-binding sites (i.e., antigen-binding arms) that are separated from one another by a distance of fewer than 133 Å, which is the spacing observed between antigen-binding arms in human IgG2 isotype antibodies. As described in the examples below, it has been discovered that this spacing gives rise to antibodies having optimal TNFR2 agonistic properties. TNFR2 agonist polypeptides of the disclosure include those containing antigen-binding arms separated by, e.g., a distance of from about less than 133 Å such as a distance of 90 Å, 91 Å, 92 Å, 93 Å, 94 Å, 95 Å, 96 Å, 97 Å, 98 Å, 99 Å, 100 Å, 101 Å, 102 Å, 103 Å, 104 Å, 105 Å, 106 Å, 107 Å, 108 Å, 109 Å, 110 Å, 111 Å, 112 Å, 113 Å, 114 Å, 115 Å, 116 Å, 117 Å, 118 Å, 119 Å, 120 Å, 121 Å, 122 Å, 123 Å, 124 Å, 125 Å, 126 Å, 127 Å, 128 Å, 129 Å, 130 Å, 131 Å, or 132 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of from about 95 Å to about 130 Å, such as a distance of about 95 Å, 96 Å, 97 Å, 98 Å, 99 Å, 100 Å, 101 Å, 102 Å, 103 Å, 104 Å, 105 Å, 106 Å, 107 Å, 108 Å, 109 Å, 110 Å, 111 Å, 112 Å, 113 Å, 114 Å, 115 Å, 116 Å, 117 Å, 118 Å, 119 Å, 120 Å, 121 Å, 122 Å, 123 Å, 124 Å, 125 Å, 126 Å, 127 Å, 128 Å, 129 Å, or 130 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of from about 98 Å to about 128 Å, such as a distance of about 98 Å, 99 Å, 100 Å, 101 Å, 102 Å, 103 Å, 104 Å, 105 Å, 106 Å, 107 Å, 108 Å, 109 Å, 110 Å, 111 Å, 112 Å, 113 Å, 114 Å, 115 Å, 116 Å, 117 Å, 118 Å, 119 Å, 120 Å, 121 Å, 122 Å, 123 Å, 124 Å, 125 Å, 126 Å, 127 Å, or 128 Å.

[0386] For example, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) may contain antigen-binding sites that are separated from one another by a distance of from about 105 Å to about 127 Å, such as by a distance of about 105 Å, 106 Å, 107 Å, 108 Å, 109 Å, 110 Å, 111 Å, 112 Å, 113 Å, 114 Å, 115 Å, 116 Å, 117 Å, 118 Å, 119 Å, 120 Å, 121 Å, 122 Å, 123 Å, 124 Å, 125 Å, 126 Å, or 127 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of from about 110 Å to about 122 Å, such as by a distance of about 110 Å, 111 Å, 112 Å, 113 Å, 114 Å, 115 Å, 116 Å, 117 Å, 118 Å, 119 Å, 120 Å, 121 Å, or 122 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of from about 115 Å to about 119 Å, such as by a distance of about 115 Å, 116 Å, 117 Å, 118 Å, or 119 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of about 117 Å.In some embodiments, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) has an antigen-binding arm separation as described above, and has an IgG1 isotype.

[0387] In some embodiments, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) contains antigen-binding sites that are separated from one another by a distance of from about 115 Å to about 132 Å, such as by a distance of about 115 Å, 116 Å, 117 Å, 118 Å, 119 Å, 120 Å, 121 Å, 122 Å, 123 Å, 124 Å, 125 Å, 126 Å, 127 Å, 128 Å, 129 Å, 130 Å, 131 Å, or 132 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of from about 120 Å to about 129 Å, such as by a distance of about 120 Å, 121 Å, 122 Å, 123 Å, 124 Å, 125 Å, 126 Å, 127 Å, 128 Å, or 129 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of from about 123 Å to about 127 Å, such as by a distance of about 123 Å, 124 Å, 125 Å, 126 Å, or 127 Å.In some embodiments, the antigen-binding sites are separated from one another by a distance of about 125 Å.In some embodiments, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) has an antigen-binding arm separation as described above, and has an IgG3 isotype.

[0388] The TNFR2 agonistic polypeptides described herein may have, e.g., two, three, four, five, or more, antigen-binding arms separated by a distance specified above. Examples of antibody fragments that have two or more antigen-binding arms include, without limitation, diabodies, triabodies, F(ab′).sub.2 molecules, and tandem scFv (taFv) molecules, among others. Methods of generating these antibody fragments include peptide synthesis and recombinant protein expression techniques described herein and known in the art.

[0389] There exist a variety of methods for measuring the distance between antigen-binding arms of an antibody or antibody fragment. For example, distances between antigen-binding arms of an antibody can be made by analyzing the three-dimensional structure of an antibody or antibody fragment using computer software, such as through the use of PYMOL® and other molecular imaging software. Three-dimensional structures of polypeptides, such as antibodies and antibody fragments, can be calculated using the data obtained from X-ray crystallography experiments and nuclear magnetic resonance (NMR) techniques known in the art. Examples of X-ray crystallography and NMR methods that can be used to obtain three-dimensional polypeptide structures are described, e.g., in Eigenbrot et al., Journal of Molecular Biology, 229:969-995, 1993; and Huang et al., Science, 317:1930-1934, 2007, the disclosures of each of which are incorporated herein by reference in their entirety.

Structural Features of Heavy and Light Chain Variable Domains of Agonistic TNFR2 Polypeptides

[0390] Among the molecular features of agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs), the complementarity determining region-heavy chain 1 (CDR-H1) can dictate the TNFR2 binding properties of the molecule. In particular, TNFR2 polypeptides having a CDR-H1 as described below bind TNFR2 at one or more of the epitopes described herein as conferring agonistic activity. For example, agonistic TNFR2 polypeptides of the disclosure include those that have a CDR-H1 having the amino acid sequence of: [0391] (a) GZ.sup.1TFZ.sup.3Z.sup.2YZ.sup.3Z.sup.4 (SEQ ID NO: 2); [0392] (b) GYTFTDYNI (SEQ ID NO: 3) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; or [0393] (c) GYTFTDYNL (SEQ ID NO: 4) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0394] wherein each Z.sup.1 is independently a naturally occurring amino acid including a side-chain including an aromatic substituent; [0395] each Z.sup.2 is independently a naturally occurring amino acid including an anionic side-chain at physiological pH; [0396] each Z.sup.3 is independently a naturally occurring amino acid including a polar, uncharged side-chain at physiological pH; and [0397] each Z.sup.4 is independently leucine or isoleucine.

[0398] The presence of the CDR-H1 motifs described above may confer the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) with the ability to specifically bind human TNFR2 at an epitope defined by one or more amino acids within CRD1, such as at an epitope defined by one or more of amino acid residues 56-60 (KCSPG) within SEQ ID NO: 1. In some embodiments, in the presence of the CDR-H1, the polypeptide specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD2. In some embodiments, in the presence of the CDR-H1, the polypeptide thereof specifically binds human TNFR2 at an epitope defined by one or more amino acids within CRD3.

[0399] Agonistic TNFR2 polypeptides of the disclosure may further contain one or more, or all, of the following CDRs: [0400] (a) a CDR-H2 having the amino acid sequence INPNYDST (SEQ ID NO: 10) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0401] (b) a CDR-H3 having the amino acid sequence CARGNSWYFDV (SEQ ID NO: 11) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0402] (c) a CDR-L1 having the amino acid sequence SSVRY (SEQ ID NO: 12) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0403] (d) a CDR-L2 having the amino acid sequence LTS or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; and [0404] (e) a CDR-L3 having the amino acid sequence CQQWSSNPLT (SEQ ID NO: 13) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence.

[0405] In some embodiments, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) contains a CDR-H1 as described above in combination with one or more, or all, of the following CDRs: [0406] (a) a CDR-H2 having the amino acid sequence INPNYDST (SEQ ID NO: 10); [0407] (b) a CDR-H3 having the amino acid sequence CARGNSWYFDV (SEQ ID NO: 11); [0408] (c) a CDR-L1 having the amino acid sequence SSVRY (SEQ ID NO: 12); [0409] (d) a CDR-L2 having the amino acid sequence LTS; and [0410] (e) a CDR-L3 having the amino acid sequence CQQWSSNPLT (SEQ ID NO: 13).

[0411] In some embodiments, the CDR-H1 has the amino acid sequence GYTFTDYNI (SEQ ID NO: 3) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence. For example, agonistic TNFR2 polypeptides described herein may have the following CDRs: [0412] (a) a CDR-H1 having the amino acid sequence GYTFTDYNI (SEQ ID NO: 3); [0413] (b) a CDR-H2 having the amino acid sequence INPNYDST (SEQ ID NO: 10); [0414] (c) a CDR-H3 having the amino acid sequence CARGNSWYFDV (SEQ ID NO: 11); [0415] (d) a CDR-L1 having the amino acid sequence SSVRY (SEQ ID NO: 12); [0416] (e) a CDR-L2 having the amino acid sequence LTS; and [0417] (f) a CDR-L3 having the amino acid sequence CQQWSSNPLT (SEQ ID NO: 13).

[0418] In some embodiments, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) contains a heavy chain variable domain (V.sub.H) having an amino acid sequence that is at least 85% identical (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of any one of SEQ ID NOs: 72-77. In some embodiments, the polypeptide contains a heavy chain variable domain (V.sub.H) having an amino acid sequence that is at least 90% identical (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of any one of SEQ ID NOs: 72-77. In some embodiments, the polypeptide contains a heavy chain variable domain (V.sub.H) having an amino acid sequence that is at least 95% identical (e.g., at least 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of any one of SEQ ID NOs: 72-77. In some embodiments, the polypeptide contains a heavy chain variable domain (V.sub.H) having the amino acid sequence of any one of SEQ ID NOs: 72-77.

[0419] In some embodiments, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) contains a light chain variable domain (V.sub.L) having an amino acid sequence that is at least 85% identical (e.g., at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of any one of SEQ ID NOs: 78-83. In some embodiments, the polypeptide contains a light chain variable domain (V.sub.L) having an amino acid sequence that is at least 90% identical (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of any one of SEQ ID NOs: 78-83. In some embodiments, the polypeptide contains a light chain variable domain (V.sub.L) having an amino acid sequence that is at least 95% identical (e.g., at least 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of any one of SEQ ID NOs: 78-83. In some embodiments, the polypeptide contains a light chain variable domain (V.sub.L) having the amino acid sequence of any one of SEQ ID NOs: 78-83.

[0420] In some embodiments, the polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) contains a non-native constant region, such as a human constant region. In some embodiments, the polypeptide lacks all or a portion of an Fc domain, lacks all or a portion of a native Fc domain, or lacks an Fc domain altogether.

Framework Regions of Agonistic TNFR2 Polypeptides

[0421] Agonistic TNFR2 polypeptides of the disclosure (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) may contain a framework region having the amino acid sequence of TJDJSJJJX.sup.1YX.sup.2X.sup.3LJX.sup.4LJS (SEQ ID NO: 5) or an amino acid sequence having 10 or more of the residues of SEQ ID NO: 5, wherein each J is independently a naturally occurring amino acid; each X.sup.1 is independently A, V, or F; each X.sup.2 is independently M or I; each X.sup.3 is independently E or Q; and each X.sup.4 is independently S or R. For example, the polypeptide may contain a framework region having an amino acid sequence selected from: [0422] (a) TVDKSSSTAYMELRSLTS (SEQ ID NO: 16) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0423] (b) TADTSSNTAYIQLSSLTS (SEQ ID NO: 17) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0424] (c) TADTSTDTAYMELSSLRS (SEQ ID NO: 18) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0425] (d) TRDTSISTAYMELSRLTS (SEQ ID NO: 19) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0426] (e) TFYMELSSLRS (SEQ ID NO: 20) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0427] (f) TRDTSISTAYMELNRLTS (SEQ ID NO: 21) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; [0428] (g) TRDTSTNTVYMELTSLRS (SEQ ID NO: 22) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence; and [0429] (h) TADTSTDRAYMELSSLRS (SEQ ID NO: 23) or an amino acid sequence having up to two conservative amino acid substitutions relative to the sequence.

[0430] The foregoing amino acid sequences recognize, and are bound by, MHC class II proteins, including human leukocyte antigens (HLA) DR and DQ, among others. Typically, antibodies that are found to contain amino acid sequences that bind MHC proteins are engineered to remove such motifs, since antibodies that bind MHC proteins are susceptible to being degraded upon administration to a patient (e.g., a mammalian patient, such as a human patient) and positioned on the exterior of an antigen-presenting cell of the immune system, thereby triggering an inappropriate immune response against the administered antibody. Methods of determining whether a particular amino acid sequence is prone to bind MHC molecules are known in the art, and are described, e.g., in Wang et al., BMC Bioinformatics 11 :568, 2010; Nielsen et al., BMC Bioinformatics 8:238, 2007; Gonzalez-Galarza et al., Nucleic Acid Research 39:D913-D919, 2011; and Greenbaum etal., Immunogenetics 63:325, 2011, the disclosures of each of which are incorporated herein by reference in their entirety.

[0431] The framework regions described above are not immunogenic peptides, despite their propensity to bind MHC class II molecules. Rather, these amino acid sequences impart high affinity TNFR2 binding. Agonistic TNFR2 polypeptides of the disclosure that contain any of the foregoing framework region sequences exhibit the unexpected and beneficial property of high TNFR2 affinity without inducing an immunogenic response against the polypeptide upon administration of the polypeptide to a patient (e.g., a mammalian patient, such as a human).

Uniformity of Populations of TNFR2 Agonistic Polypeptides

[0432] Pharmaceutical compositions can be generated in which the TNFR2 agonistic polypeptide (e.g., antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct thereof) described herein is present as a single disulfide-bonded isoform. For example, at least 10%, or more, of the polypeptide in the pharmaceutical composition may be present as a single disulfide-bonded isoform (e.g., the IgG2-B isoform). This may be achieved, for example, by way of amino acid substitutions or deletions at cysteine residue 127 of the wild-type human IgG1 or IgG2 CH1 domain, thereby preventing or reducing the occurrence of disulfide bonding that could give rise to an isoform other than, for example, IgG2-B (see, e.g., FIGS. 5A - 5D). The pharmaceutical compositions of the disclosure include those in which, for example, about 10% to about 99.999% of the agonistic TNFR2 polypeptide in the pharmaceutical composition is present in a single disulfide-bonded isoform, such as the IgG2-B isoform. For example, pharmaceutical compositions of the disclosure include those containing an agonist TNFR2 polypeptide in which, e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, 99.99%, or more, of the polypeptide in the pharmaceutical composition is present in a single disulfide-bonded isoform.

[0433] Techniques for measuring the relative quantities of various disulfide-bonded isoforms present in a sample of an agonist TNFR2 polypeptide include liquid chromatography techniques known in the art and described herein, such as those exemplified in Wypych et al., The Journal of Biological Chemistry, 283:16194-16205, 2008, the disclosure of which is incorporated herein by reference in its entirety.

Effects on TNFR2 on Signal Transduction Cascades

[0434] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments thereof) described herein are capable of interacting with, and augmenting the activity of, TNFR2. The TNFR2 polypeptides of the disclosure may bind TNFR2 at one or more specific epitopes that favor the formation of a TNFR2 trimer by bringing neighboring TNFR2 monomers into close proximity with one another. Trimerization of TNFR2 is particularly beneficial to receptor activation because it positions the TNFR2 monomers in conformation in which TNFa-binding sites are sterically available. This trimerization event may activate intracellular signaling by TNFR2, which, in turn, may promote proliferation of TNFR2-expressing cells, such as Treg cells, MDSCs, and/or TNFR2+ parenchymal cells. TNFR2 activation may also lead to elevated expression levels of CD274 (PDL1), PDCD1 LG2 (PDL2), CD137 (4-1BB), and IKZF2.

[0435] Although TNFR2 activation gives rise to the expression of a variety of genes that may exert important therapeutic effects, the TNFR2 agonist polypeptides described herein may promote the expression of several proteins of particular therapeutic importance. Without being limited by mechanism, the TNFR2 polypeptides described herein may induce TNFR2-mediated cell healing, protection, proliferation, and/or regeneration by stimulating the expression of EP300 and CREB, two histone acetyl transferases that promote Foxp3 transcription. This biological activity is particularly significant, as it can promote flux through the cell cycle in TNFR2+ cells while causing the death of T effector cells, such as CD8+ T cells. The selective expansion of TNFR2+ cells and inhibition of T effector cells are some of the phenotypes that underlie the ability of agonistic TNFR2 polypeptides to treat autoimmunity, GVHD, inflammation, and other indications described herein.

[0436] One can monitor TNFR2 activation, for example, by measuring the expression of genes associated with the MAPK and TRAF⅔ signal cascade, such as the expression of genes whose transcription is mediated by NF.sub.KB (Faustman, et al., Nat. Rev. Drug Disc., 9:482-493, 2010, the disclosure of which is incorporated herein by reference).

Dual Proliferative and Cell Killing Effects of TNFR2 Agonist Polypeptides

[0437] Agonistic TNFR2 polypeptides disclosed herein, such as single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof, may not only promote the proliferation of Treg cells, MDSCs, and/or TNFR2+ parenchymal cells, but may also induce the death of T effector cells, such as CD8+ T effector cells (e.g., within a patient, such as a human patient). Agonistic TNFR2 polypeptides described herein may be capable, for instance, of increasing the total quantity of Treg cells, MDSCs, and/or TNFR2+ parenchymal cells in a sample treated with an agonist TNFR2 antibody or antigen-binding fragment thereof (such as a sample isolated from a human patient undergoing treatment for autoimmunity, GVHD, transplant rejection, allergies, chronic inflammatory disease, asthma, or another disorder described herein) by, e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or more, relative to a sample not treated with an agonist TNFR2 antibody or antigen-binding fragment thereof. The ability of agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments) described herein to augment Treg, MDSC, and/or parenchymal cell growth may be due, in part, to the ability of these polypeptides to increase the quantity of soluble TNFR2 within a sample (e.g., a sample isolated from a human patient undergoing treatment for or autoimmunity, GVHD, transplant rejection, allergies, chronic inflammatory disease, asthma, or another disorder described herein).

[0438] The stimulation of Treg and MDSC proliferation engenders important therapeutic benefits, as these cells suppress the activity of T effector cells, such as autoreactive CD8+ T cells that mount an inappropriate immune response against self tissue. Similarly, the direct killing of T effector cells imparts therapeutic activity, as TNFR2 agonist polypeptides can be used to reduce the quantity of self-reactive T cells in a patient suffering from autoimmunity, GVHD, transplant rejection, allergies, chronic inflammatory disease, asthma, or another disorder described herein.

[0439] Through one or both of these mechanisms, TNFR2 agonist polypeptides of the disclosure can be used to suppress immunological conditions in a patient, such as a mammalian patient (e.g., a human patient).

[0440] Additionally, the ability of TNFR2 agonist polypeptides of the disclosure to stimulate proliferation of TNFR2+ parenchymal cells provides the beneficial effect of inducing tissue and organ regeneration. Exemplary TNFR2+ cells that can be induced to proliferate using the TNFR2 agonist polypeptides of the disclosure include, without limitation, cells of the pancreas, salivary gland, pituitary gland, kidney, heart, lung, hematopoietic system, cranial nerves, heart, aorta, olfactory gland, ear, nerves, structures of the head, eye, thymus, tongue, bone, liver, small intestine, large intestine, gut, lung, brain, skin, peripheral nervous system, central nervous system, spinal cord, breast, embryonic structures, embryos, and testes. Thus, TNFR2 agonist polypeptides described herein can be used to treat disorders in which the regeneration, protection, and/or healing of one or more of these cell types is desired. Exemplary diseases that can be treated using the TNFR2 agonist polypeptides of the disclosure are described herein.

Selective Modulation of Active (CD25.SUP.Hi and CD45RA^{Low.) Treg Cells}

[0441] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments, and constructs thereof) described herein may be capable of augmenting the proliferation or increase the total quantity of Treg cells in a sample (e.g., a sample isolated from a human patient undergoing treatment for autoimmunity, GVHD, transplant rejection, allergies, chronic inflammatory disease, asthma, or another disorder described herein) and may act selectively on Treg cells in an actively-dividing state. For instance, agonistic TNFR2 antibodies or antigen-binding fragments thereof described herein may be capable of increasing the proliferation of Treg cells expressing CD25.sup.Hi and CD45RA.sup.Low by, e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or more, relative to Treg cells that do not express the CD25.sup.Hi and CD45RA.sup.Low proteins, such as Treg cells that express CD25.sup.Med and CD45RA.sup.Hi proteins or even T cells that are not Treg cells.

TNFR2 Agonist Polypeptides Are Not Reliant on Additional TNFR2-binding Agents for Activity

[0442] Significantly, agonistic TNFR2 polypeptides, such as single-chain polypeptides, antibodies, or antigen-binding fragments thereof described herein, are capable of binding TNFR2 and augmenting TNFR2-mediated signaling without the need for the natural TNFR2 ligand, TNFa. Such agonists are referred to herein as dominant TNFR2 agonists. Agonistic TNFR2 polypeptides, such as antibodies, antigen-binding fragments thereof, single-chain polypeptides, and constructs described herein do not require TNFa to proliferate Treg cells, MDSCs, and/or TNFR2+ parenchymal cells. Without being limited by mechanism, agonistic TNFR2 polypeptides of the disclosure may exhibit this property due to the ability of these molecules to bind TNFR2 at particular epitopes that, when bound, stabilize the trimeric conformation of the receptor and its adjacent monomers. This structural configuration potentiates NF.sub.KB signaling and augments some of the fundamental signal transduction cascades associated with Treg, MDSC, and TNFR2+ parenchymal cell activation.

[0443] For instance, agonistic TNFR2 polypeptides, such as single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof described herein, may bind TNFR2 on the surface of a TNFR2+ cell, such as a Treg cell, MDSC, and/or TNFR2+ parenchymal cell and augment the proliferation of such cells in the presence or absence of TNFa. For example, agonistic TNFR2 polypeptides described herein may increase the proliferation of such cells by, e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 200%, 300%, 400% 500%, or more, relative to such cells that are not treated with the TNFR2 agonist polypeptide. The agonistic TNFR2 polypeptide (e.g., single-chain polypeptide, antibody, or antigen-biding fragment thereof) may exhibit an EC.sub.50 value in a cell proliferation assay that is largely unchanged by the presence or absence of TNFa (e.g., an EC.sub.50 value in the presence of TNFa that is changed by less than 50%, 45%, 40%, 35%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or less than 1% relative to the EC.sub.50 value of the agonistic TNFR2 polypeptide (e.g., single-chain polypeptide, antibody, or antigen-binding fragment thereof) in the same cell proliferation assay in the absence of TNFa). Examples of Treg assays that can be used to measure the agonistic effects of TNFR2 antibodies are described herein, e.g., in Example 2 below. Similarly, agonistic TNFR2 polypeptides, such as single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof described herein, may augment TNFR2 signaling as assessed by measuring the expression of one or more genes selected from the group consisting of Foxp3, TNFSFSF18, IL2RA, IKZF2/4, CTLA4, TGF-beta, CHUK, NFKBIE, NFKBIA, MAP3K11, TRAF2, TRAF3, relB, TNF, CXCR3, PDL1 (CD274), IL2RA, IL7R, MAP3K1, MAP, MAP3K4, NFKBIB, TANK, TBK1, TNF, TNFAIP3, NFKBIA, MAP3K11, TNFRSF1B,TRAF2, relB, LTA, EP300, CREBBP, NFkB signaling proteins by, e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or more, relative to such cells that are not treated with the TNFR2 agonist polypeptide. The agonistic TNFR2 polypeptide (e.g., single-chain polypeptide, antibody, or antigen-biding fragment thereof) may exhibit an EC.sub.50 value in such a gene expression assay that is largely unchanged or augmented by the presence or absence of TNFa (e.g., an EC.sub.50 value in the presence of TNFa that is changed by less than 50%, 45%, 40%, 35%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or less than 1% relative to the EC.sub.50 value of the agonistic TNFR2 polypeptide (e.g., single-chain polypeptide, antibody, or antigen-binding fragment thereof) in the same gene expression assay in the absence of TNFa).

Activity of Antigen-Binding Fragments of Full-length TNFR2 Agonist Antibodies

[0444] Agonistic TNFR2 antibodies described herein may augment proliferation of a Treg cell, MDSC, and/or parenchymal cell, and/or promote T effector cell death, with a similar potency as that exhibited by antigen-binding fragments of such antibodies. For instance, removal of the Fc region of an agonistic TNFR2 antibody described herein may not alter the ability of the molecule to promote the proliferation of Treg cells, MDSCs, and/or parenchymal cells, and/or to directly kill T effector cells (e.g., CD8+ autoreactive T cells) in a sample (e.g., a sample isolated from a human patient undergoing treatment for autoimmunity, GVHD, allergies, transplant rejection, or another condition as described herein). Agonistic TNFR2 antibodies and antigen-binding fragments thereof described herein may function, for instance, by a pathway distinct from antibody-dependent cellular cytotoxicity (ADCC), in which an Fc region is required to recruit effector proteins in order to induce cell death. Additionally, agonistic TNFR2 antibodies or antigen-binding fragments thereof may exhibit therapeutic activity in a variety of forms, such as a single-chain polypeptide (e.g., a single-chain polypeptide containing one or more CDRs covalently bound to one another, for instance, by an amide bond, a thioether bond, a carbon-carbon bond, or a disulfide bridge), a monoclonal antibody or antigen-binding fragment thereof, a polyclonal antibody or antigen-binding fragment thereof, a humanized antibody or antigen-binding fragment thereof, a primatized antibody or antigen-binding fragment thereof, a bispecific antibody or antigen-binding fragment thereof, a multi-specific antibody or antigen-binding fragment thereof, a dual-variable immunoglobulin domain, a monovalent antibody or antigen-binding fragment thereof, a chimeric antibody or antigen-binding fragment thereof, a single-chain Fv molecule (scFv), a diabody, a triabody, a nanobody, an antibody-like protein scaffold, a domain antibody, a Fv fragment, a Fab fragment, a F(ab′).sub.2 molecule, and a tandem scFv (taFv), among others.

Specific Binding Properties of Agonistic TNFR2 Polypeptides

[0445] The specific binding of a polypeptide, such as a single-chain polypeptide, antibody, or antibody fragment described herein, to human TNFR2 can be determined by any of a variety of established methods. The affinity can be represented quantitatively by various measurements, including the concentration of antibody needed to achieve half-maximal activation of the TNFR2 receptor in vitro or in vivo (EC.sub.50) and the equilibrium constant (K.sub.D) of the antibody-TNFR2 complex dissociation. The equilibrium constant, K.sub.D, that describes the interaction of TNFR2 with an antibody described herein is the chemical equilibrium constant for the dissociation reaction of a TNFR2-antibody complex into solvent-separated TNFR2 and antibody molecules that do not interact with one another.

[0446] Polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments) described herein include those that specifically bind to TNFR2 with a K.sub.D value of less than 100 nM (e.g., 95 nM, 90 nM, 85 nM, 80 nM, 75 nM, 70 nM, 65 nM, 60 nM, 55 nM, 50 nM, 45 nM, 40 nM, 35 nM, 30 nM, 25 nM, 20 nM, 15 nM, 10 nM, 5 nM, 4 nM, 3 nM, 2 nM, or 1 nM). In some embodiments, the polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments, and constructs thereof) described herein specifically bind to TNFR2 with a K.sub.D value of less than 1 nM (e.g., (e.g., 990 pM, 980 pM, 970 pM, 960 pM, 950 pM, 940 pM, 930 pM, 920 pM, 910 pM, 900 pM, 890 pM, 880 pM, 870 pM, 860 pM, 850 pM, 840 pM, 830 pM, 820 pM, 810 pM, 800 pM, 790 pM, 780 pM, 770 pM, 760 pM, 750 pM, 740 pM, 730 pM, 720 pM, 710 pM, 700 pM, 690 pM, 680 pM, 670 pM, 660 pM, 650 pM, 640 pM, 630 pM, 620 pM, 610 pM, 600 pM, 590 pM, 580 pM, 570 pM, 560 pM, 550 pM, 540 pM, 530 pM, 520 pM, 510 pM, 500 pM, 490 pM, 480 pM, 470 pM, 460 pM, 450 pM, 440 pM, 430 pM, 420 pM, 410 pM, 400 pM, 390 pM, 380 pM, 370 pM, 360 pM, 350 pM, 340 pM, 330 pM, 320 pM, 310 pM, 300 pM, 290 pM, 280 pM, 270 pM, 260 pM, 250 pM, 240 pM, 230 pM, 220 pM, 210 pM, 200 pM, 190 pM, 180 pM, 170 pM, 160 pM, 150 pM, 140 pM, 130 pM, 120 pM, 110 pM, 100 pM, 90 pM, 80 pM, 70 pM, 60 pM, 50 pM, 40 pM, 30 pM, 20 pM, 10 pM, 5 pM, or 1 pM).

[0447] Polypeptides described herein can also be characterized by a variety of in vitro binding assays. Examples of experiments that can be used to determine the K.sub.D or EC.sub.50 of an agonistic TNFR2 polypeptide include, e.g., surface plasmon resonance, isothermal titration calorimetry, fluorescence anisotropy, ELISA-based assays, gene expression assays, and protein expression assays, among others. ELISA represents a particularly useful method for analyzing antibody activity, as such assays typically require minimal concentrations of antibodies. A common signal that is analyzed in a typical ELISA assay is luminescence, which is typically the result of the activity of a peroxidase conjugated to a secondary antibody that specifically binds a primary antibody (e.g., a TNFR2 antibody described herein). Polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments) described herein are capable of binding TNFR2 and epitopes therein, such as epitopes containing one or more continuous or discontinuous residues within CRD1, CRD2, and/or CRD3 of human TNFR2. Agonistic polypeptides described herein may additionally bind isolated peptides derived from TNFR2 that structurally pre-organize various residues in a manner that simulates the conformation of the above epitopes in the native protein. In a direct ELISA experiment, this binding can be quantified, e.g., by analyzing the luminescence that occurs upon incubation of an HRP substrate (e.g., 2,2′-azino-di-3-ethylbenzthiazoline sulfonate) with an antigen-antibody complex bound to a HRP-conjugated secondary antibody.

Kinetic Properties of Agonistic TNFR2 Polypeptides

[0448] In addition to the thermodynamic parameters of a TNFR2-polypeptide interaction, it is also possible to quantitatively characterize the kinetic association and dissociation of a polypeptide described herein with TNFR2. This can be done, e.g., by monitoring the rate of polypeptide-antigen (e.g., antibody-antigen) complex formation according to established procedures. For example, one can use surface plasmon resonance (SPR) to determine the rate constants for the formation (k.sub.on) and dissociation (k.sub.off) of an antibody-TNFR2 complex. These data also enable calculation of the equilibrium constant of (K.sub.D) of antibody-TNFR2 complex dissociation, since the equilibrium constant of this unimolecular dissociation can be expressed as the ratio of the k.sub.off to k.sub.on values. SPR is a technique that is particularly advantageous for determining kinetic and thermodynamic parameters of receptor-antibody interactions since the experiment does not require that one component be modified by attachment of a chemical label. Rather, the receptor is typically immobilized on a solid metallic surface which is treated in pulses with solutions of increasing concentrations of antibody. Antibody-receptor binding induces distortion in the angle of reflection of incident light at the metallic surface, and this change in refractive index over time as antibody is introduced to the system can be fit to established regression models in order to calculate the association and dissociation rate constants of an antibody-receptor interaction.

[0449] Polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments, and constructs thereof) described herein may exhibit high k.sub.on and low k.sub.off values upon interaction with TNFR2, consistent with high-affinity receptor binding. For example, polypeptides described herein may exhibit k.sub.on values in the presence of TNFR2 of greater than 10.sup.4 M.sup.-1s.sup.-1 (e.g., 1.0 x 10.sup.4 M-1s-1, 1.5 x 10.sup.4 M-1s-1, 2.0 x 10.sup.4 M.sup.-1s.sup.-1, 2.5 x 10.sup.4 M.sup.-1s.sup.-1, 3.0 x 10.sup.4 M-1s-1, 3.5 x 10.sup.4 M.sup.-1s.sup.-1, 4.0 x 10.sup.4 M-1s-1, 4.5 x 10.sup.4 M.sup.-1s.sup.-1, 5.0 x 10.sup.4 M-.sup.1s.sup.-1, 5.5 x 10.sup.4 M.sup.-1s.sup.-1, 6.0 x 10.sup.4 M.sup.-1S.sup.-1, 6.5 x 10.sup.4 M′.sup.1S.sup.-1, 7.0 x 10.sup.4 M.sup.-1s.sup.-1 , 7.5 x 10.sup.4 M.sup.-1s.sup.-1 , 8.0 x 10.sup.4 M.sup.-1s.sup.-1 , 8.5 x 10.sup.4 M.sup.-1s.sup.-1, 9.0 x 10.sup.4 M.sup.-1s.sup.-1, 9.5 x 10.sup.4 M′.sup.1S.sup.-1, 1.0 x 10.sup.5 M′.sup.1S.sup.-1, 1.5 x 10.sup.5 M′.sup.1S.sup.-1, 2.0 x 10.sup.5 M′.sup.1S.sup.-1, 2.5 x 10.sup.5 M-.sup.1 s.sup.-1, 3.0 x 10.sup.-5 M-.sup.1 s.sup.-1.sub., 3.5 x 10.sup.-5 M.sup.-1 s.sup.-1, 4.0 x 10.sup.-5 M.sup.-1s.sup.-1, 4.5 x 10.sup.-5 M.sup.-1s.sup.-1, 5.0 x 10.sup.-5 M.sup.-1s.sup.-1, 5.5 x 10.sup.-5 M.sup.-1 s.sup.-1, 6.0 x 10.sup.5 M.sup.-1s.sup.-1, 6.5 x 10.sup.5 M-1s-1, 7.0 x 10.sup.5 M-.sup.1s-.sup.1, 7.5 x 10.sup.5 M.sup.-1s.sup.-1, 8.0 x 10.sup.5 M-.sup.1s-.sup.1, 8.5 x 10.sup.5 M.sup.-1s.sup.-1, 9.0 x 10.sup.5 M.sup.-1s.sup.-1, 9.5 x 10.sup.5 M.sup.-1s.sup.-1, or 1.0 x 10.sup.6 M.sup.-1s.sup.-1). Polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments, and constructs thereof) described herein may exhibit low k.sub.off values when bound to TNFR2, as these polypeptides are capable of interacting with distinct TNFR2 epitopes with a high affinity. Residues within these epitopes may form strong intermolecular contacts with TFNR2, which can slow the dissociation of the antibody-TNFR2 complex. This high receptor affinity can manifest in low k.sub.off values. For instance, polypeptides described herein may exhibit k.sub.off values of less than 10.sup.-3 S.sup.-1 when complexed to TNFR2 (e.g., 1.0 x 10.sup.-3S.sup.-1, 9.5 x 10.sup.-4S.sup.-1, 9.0 x 10.sup.-4s.sup.-1, 8.5 x 10.sup.-4s.sup.-1, 8.0 x 10 .sup.-4 s.sup.-1, 7.5 x 10-.sup.4 S.sup.-1, 7.0 x 10.sup.-4 S.sup.-1, 6.5 x 10.sup.-4 S.sup.-1, 6.0 x 10.sup.-4 S.sup.-1, 5.5 x 10.sup.-4 S.sup.-1, 5.0 x 10.sup.-4 S.sup.-1, 4.5 x 10.sup.-4 S.sup.-1, 4.0 x 10.sup.-4 S.sup.-1, 3.5 x 10.sup.-4 S.sup.-1, 3.0 x 10.sup.-4 S.sup.-1, 2.5 x 10.sup.-4 s.sup.-1, 2.0 x 10.sup.-4 s.sup.-1, 1. x 10.sup.-4 S.sup.-1, 1.0 x 10.sup.-4 S.sup.-1, 9.5 x 10.sup.-5 S.sup.-1, 9.0 x 10.sup.-5 S.sup.-1, 8.5 x 10.sup.-5 s.sup.-1, 8.0 x 10.sup.-5 s.sup.-1, 7.5 x 10.sup.-5 s.sup.-1, 7.0 x 10.sup.-5 s.sup.-1, 6.5 x 10.sup.-5 s.sup.-1, 6.0 x 10.sup.-5 s.sup.-1, 5.5 x 10.sup.-5 s.sup.-1, 5.0 x 10.sup.-5 s.sup.-1, 4.5 x 10.sup.-5s.sup.-1, 4.0 x 10.sup.-5 s.sup.-1, 3.5 x 10.sup.-5s.sup.-1, 3.0 x 10.sup.-5 s.sup.-1, 2.5 x 10.sup.-5s.sup.-1, 2.0 x 10.sup.-5 s.sup.-1, 1.5 x 10.sup.-5s.sup.-1, or 1.0 x 10.sup.-5 s.sup.-1).

Epitopes Within TNFR2 Bound by Agonistic TNFR2 Polypeptides

[0450] Agonistic TNFR2 polypeptides, such as dominant agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments, and constructs thereof) described herein, may specifically bind one or more of the following residues of TNFR2: [0451] (a) amino acids 56-60 of SEQ ID NO: 1 within human TNFR2 (KCSPG); [0452] (b) amino acids 101-107 of SEQ ID NO: 1 within human TNFR2 (CSSDQVET); [0453] (c) amino acids 115-142 of SEQ ID NO: 1 within human TNFR2 (NRICTCRPGWYCALSKQEGCRLCAPLRK); [0454] (d) amino acids 26-45 of SEQ ID NO: 1 within human TNFR2 (QTAQMCCSKCSPGQHAKVFC); [0455] (e) amino acids 90-109 of SEQ ID NO: 1 within human TNFR2 (REQNRICTCRPGWYCALSKQ); [0456] (f) amino acids 98-117 of SEQ ID NO: 1 within human TNFR2 (CRPGWYCALSKQEGCRLCAP); [0457] (g) amino acids 106-125 of SEQ ID NO: 1 within human TNFR2 (LSKQEGCRLCAPLRKCRPGF); [0458] (h) amino acids 108-127 of SEQ ID NO: 1 within human TNFR2 (KQEGCRLCAPLRKCRPGFGV); and/or [0459] (i) an equivalent epitope within TNFR2 of a non-human mammal, such as a non-human mammal described herein, an epitope that exhibits at least 85% sequence identity (e.g., 85%, 90%, 95%, 97%, 99%, or 100% sequence identity) to any of the foregoing epitopes, and/or an epitope that contains one or more conservative amino acid substitutions relative to any of the above epitopes.

[0460] In some embodiments, agonistic TNFR2 polypeptides, such as dominant agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments, and constructs thereof) described herein do not bind to epitopes containing or more, or all, of residues of 142-146 of SEQ ID NO: 1 within human TNFR2 (KCRPG, SEQ ID NO: 41).

[0461] One exemplary procedure that can be used to predict the proliferative, regenerative, healing, or protective activity of a TNFR2 polypeptide described herein is to determine the affinity of the antibody or antibody fragment for a peptide containing the KCSPG motif (SEQ ID NO: 40), such as a linear or cyclic peptide that contains this motif. The peptide may be, for example, structurally pre-organized by virtue of one or more conformational constraints (e.g., backbone or side-chain-to-side-chain cyclization) in a manner that simulates the three-dimensional orientation of the KCSPG motif (SEQ ID NO: 40). For example, agonistic TNFR2 polypeptides described herein may bind a peptide containing the KCSPG motif (SEQ ID NO: 40) with an affinity that is, e.g., 10-fold, 15-fold, 20-fold, 30-fold, 40-fold, 50-fold, 60-fold, 70-fold, 80-fold, 90-fold, 100-fold, 200-fold, 300-fold, 400-fold, 500-fold, 600-fold, 700-fold, 800-fold, 900-fold, 1000-fold, or more than 1000-fold greater than the affinity of the agonistic polypeptide for a peptide containing the amino acid sequence of KCRPG (SEQ ID NO: 41).

The Agonistic TNFR2 Antibody TNFRAG1

[0462] Exemplary agonistic TNFR2 polypeptides described herein, such as single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof, may include one or more, or all, of the CDRs of TNFRAG1, a monoclonal antibody that specifically binds TNFR2 at epitopes that promote TNFR2 signal transduction, and thus, the proliferation of Treg cells and MDSCs, the regeneration, healing, and protection of TNFR2+ parenchymal cells, and the death of T effector cells (e.g., CD8+ T effector cells). For instance, the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and/or CDR-L3 of TNFRAG1, and variants of these CDRs (e.g., variants that exhibit conservative amino acid substitutions relative to these CDR sequences) can be used to generate additional agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs) of the disclosure, for example, by way of antibody humanization methods described herein or known in the art.

[0463] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments) of the disclosure may exhibit binding properties that are the same as or similar to those of TNFRAG1. Particularly, TNFRAG1 specifically binds human TNFR2 at one or more of the following residues: [0464] (a) amino acids 56-60 of SEQ ID NO: 1 (KCSPG); [0465] (b) amino acids 101-107 of SEQ ID NO: 1 (CSSDQVET); [0466] (c) amino acids 115-142 of SEQ ID NO: 1 (NRICTCRPGWYCALSKQEGCRLCAPLRK); [0467] (d) amino acids 26-45 of SEQ ID NO: 1 (QTAQMCCSKCSPGQHAKVFC); [0468] (e) amino acids 90-109 of SEQ ID NO: 1 (REQNRICTCRPGWYCALSKQ); [0469] (f) amino acids 98-117 of SEQ ID NO: 1 (CRPGWYCALSKQEGCRLCAP); [0470] (g) amino acids 106-125 of SEQ ID NO: 1 (LSKQEGCRLCAPLRKCRPGF); and/or [0471] (h) amino acids 108-127 of SEQ ID NO: 1 (KQEGCRLCAPLRKCRPGFGV).

[0472] TNFRAG1 may contain one or both of the heavy chain variable regions set forth set forth in SEQ ID NOs: 14 and 15, below. The CDRs of each of these regions are indicated in bold:

TABLE-US-00007 EVQLQQFGAELVKPGASVKISCKASGYTFTDYNIDWVKQSHGKSLEWIGD ZNPNYDSTSYSQKFRGKATLTVDKSSSTAYMELRSLTSEDTAVYYCARGN SWYFDVWGAGTTVTVSS (SEQ ID NO: 14)

TABLE-US-00008 EVQLQQFGAELVKPGASVKISCKASGYTFTDYNLDWVKQSHGKSLEWIGD INPNYDSTSYSQKFRGKATLTVDKSSSTAYMELRSLTSEDTAVYYCARGN SWYFDVWGAGTTVTVSS (SEQ ID NO: 15)

[0473] Additionally, TNFRAG1 contains a light chain variable region set forth in SEQ ID NO: 42, below. The CDRs of this region are indicated in bold.

TABLE-US-00009 QIVLTQSPALMSASPGEKVTMTCSASSSVRYMYWYQQKPRSSPKPWIYLT SNLASGVPARFSGSGSGTSYSLTISSMEAEDAATYYCQQWSSNPLTFGAG TKLELK (SEQ ID NO: 42)

[0474] The section that follows provides a detailed description of methods that can be used to prepare human, humanized, primatized, chimeric, and other polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs) based on, for example, the molecular features of TNFRAG1.

Fully Human, Humanized, Primatized, and Chimeric Antibodies

[0475] Antibodies described herein include fully human, humanized, primatized, and chimeric antibodies that contain one or more, or all, of the CDR sequences of TNFRAG1. Additionally, antibodies described herein include fully human, humanized, primatized, and chimeric antibodies that contain one or more, or all, of the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 sequences in which one or more, or all, of the CDR sequences exhibits at least 85% sequence identity (e.g., 90%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to the corresponding CDR sequence of TNFRAG1). Agonistic TNFR2 antibodies described herein further include fully human, humanized, primatized, and chimeric antibodies that contain one or more, or all, of the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 sequences in which one or more, or all, of the CDR sequences contains one or more (for instance, up to 3) amino acid substitutions (e.g., one or more conservative amino acid substitutions) relative to the corresponding CDR sequence and important to the shared heavy chain framework sequence where versions are also found in human heavy chain sequences.

[0476] As an example, one strategy that can be used to design humanized antibodies described herein is to align the sequences of the heavy chain variable region and light chain variable region of TNFRAG1 with the heavy chain variable region and light chain variable region of a consensus human antibody. Consensus human antibody heavy chain and light chain sequences are known in the art (see e.g., the “VBASE” human germline sequence database; see also Kabat, et al., Sequences of Proteins of Immunological Interest, Fifth Edition, U.S. Department of Health and Human Services, NIH Publication No. 91 -3242, 1991; Tomlinson et al., J. Mol. Biol. 227:776-98, 1992; and Cox et al, Eur. J. Immunol. 24:827-836, 1994; the disclosure of which is incorporated herein by reference). In this way, the variable domain framework residues and CDRs can be identified by sequence alignment (see Kabat, supra). One can substitute, for example, one or more of the CDRs of the consensus human antibody with the corresponding CDR(s) of TNFRAG1 in order to produce a humanized TNFR2 agonist antibody. Exemplary variable domains of a consensus human antibody include the heavy chain variable domain:

TABLE-US-00010 EVQLVESGGGLVQPGGSLRLSCAASGFTFSDYAMSWVRQAPGKGLEWVAV ISENGSDTYYADSVKGRFTISRDDSKNTLYLQMNSLRAEDTAVYYCARDR GGAVSYFDVWGQGTLVTVSS (SEQ ID NO: 43)

and the light chain variable domain:

TABLE-US-00011 DIQMTQSPSSLSASVGDRVTITCRASQDVSSYLAWYQQKPGKAPKLLIYA ASSLESGVPSRFSGSGSGTDFTLTISSLQPEDFATYYCQQYNSLPYTFGQ GTKVEIKRT (SEQ ID NO: 44)

identified in U.S. Pat. No. 6,054,297; the disclosure of which is incorporated herein by reference (CDRs are shown in bold were determined according to the method of Chothia, et al., J. Mol. Biol, 196:901-917, 1987). These amino acid substitutions can be made, for example, by recombinant expression of polynucleotides encoding the heavy and light chains of a humanized antibody in a host cell using methods known in the art or described herein.

[0477] Similarly, this strategy can also be used to produce primatized agonistic TNFR2 antibodies, as one can substitute, for example, one or more, or all, of the CDRs of a primate antibody consensus sequence with, for example, one or more, or all, of the CDRs of TNFRAG1. Consensus primate antibody sequences known in the art (see e.g., U.S. Pat. Nos. 5,658,570; 5,681,722; and 5,693,780; the disclosures of each of which are incorporated herein by reference).

[0478] In some embodiments, it may be desirable to import particular framework residues in addition to CDR sequences from an agonistic TNFR2 antibody, such as TNFRAG1, into the heavy and/or light chain variable domains of a human antibody. For instance, U.S. Pat. No. 6,054,297 identifies several instances when it may be advantageous to retain certain framework residues from a particular antibody heavy chain or light chain variable region in the resulting humanized antibody. In some embodiments, framework residues may engage in non-covalent interactions with the antigen and thus contribute to the affinity of the antibody for the target antigen. In some embodiments, individual framework residues may modulate the conformation of a CDR, and thus indirectly influence the interaction of the antibody with the antigen. Certain framework residues may form the interface between VH and VL domains, and may therefore contribute to the global antibody structure. In some cases, framework residues may constitute functional glycosylation sites (e.g., Asn-X-Ser/Thr) which may dictate antibody structure and antigen affinity upon attachment to carbohydrate moieties. In cases such as those described above, it may be beneficial to retain certain framework residues of a TNFR2 agonist antibody (e.g., TNFRAG1) in, e.g., a humanized or primatized agonistic antibody or antigen-binding fragment thereof, as various framework residues may promote high epitope affinity and improved biochemical activity of the antibody or antigen-binding fragment thereof.

[0479] Antibodies described herein also include antibody fragments, Fab domains, F(ab′) molecules, F(ab′).sub.2 molecules, single-chain variable fragments (scFvs), tandem scFv fragments, diabodies, triabodies, dual variable domain immunoglobulins, multi-specific antibodies, bispecific antibodies, and heterospecific antibodies that (i) contain one or more, or all, of the CDRs of TNFRAG1, and/or (ii) have one or more, or all, of the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 sequences in which one or more, or all, of the CDR sequences exhibits at least 85% sequence identity (e.g., 90%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to the corresponding CDR sequence of TNFRAG1. These molecules can be expressed recombinantly, e.g., by incorporating polynucleotides encoding these proteins into expression vectors for transfection in a eukaryotic or prokaryotic cell using techniques described herein or known in the art, or synthesized chemically, e.g., by solid phase peptide synthesis methods described herein or known in the art.

[0480] Polypeptides described herein additionally include antibody-like scaffolds that contain, for example, one or more, or all, of the CDRs of TNFRAG1, or in which one or more, or all, of the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 sequences exhibits at least 85% sequence identity (e.g., 90%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to the corresponding CDR sequence of TNFRAG1 and/or contains one or more (for instance, up to 3) amino acid substitutions (e.g., one or more conservative amino acid substitutions) relative to the corresponding CDR sequence of TNFRAG1. Examples of antibody-like scaffolds include proteins that contain a tenth fibronectin type III domain (.sup.10Fn3), which contains BC, DE, and FG structural loops analogous to canonical antibodies. The tertiary structure of the .sup.10Fn3 domain resembles that of the variable region of the IgG heavy chain, and one of skill in the art can graft, e.g., one or more, or all, of the CDR sequences of TNFRAG1 or sequences having at least 85% sequence identity (e.g., 90%, 95%, 97%, 99%, or 100% sequence identity) to any one or more of these CDR sequences or sequences containing amino acid substitutions, such as conservative or nonconservative amino acid substitutions (e.g., up to 3 amino acid substitutions) relative to one or more of these CDR sequences onto the fibronectin scaffold by replacing residues of the BC, DE, and FG loops of .sup.10Fn3 with residues of the corresponding CDR sequence of TNFRAG1. This can be achieved by recombinant expression of a modified .sup.10Fn3 domain in a prokaryotic or eukaryotic cell (e.g., using the vectors and techniques described herein). Examples of using the .sup.10Fn3 domain as an antibody-like scaffold for the grafting of CDRs from antibodies onto the BC, DE, and FG structural loops are reported in WO 2000/034784, WO 2009/142773, WO 2012/088006, and U.S. Pat. No. 8,278,419; the disclosures of each of which are incorporated herein by reference.

Molecular Determinants of TNFR2 Affinity and Agonism

[0481] The polypeptides of the disclosure may exhibit a series of shared structural features that give rise to a TNFR2 agonist phenotype (e.g., a dominant TNFR2 agonist phenotype). For example, alignment of the amino acid sequences of the CDR-H1 of each of TNRAG1 and two additional agonistic TNFR2 monoclonal antibodies, TNFRAG2 and TNFRAG3, demonstrate that these antibodies feature a conserved consensus CDR-H1 sequence, as shown below: [0482] G Y T F T D Y N (I/L) (TNFRAG1 CDR-H1, SEQ ID NO: 45) [0483] G F T F T D Y D (TNFRAG2 CDR-H1, SEQ ID NO: 46) [0484] G Y T F T D Y - T (TNFRAG3 CDR-H1, SEQ ID NO: 47) [0485] G (Y/F) T F T D Y (N/D) - (Consensus sequence, SEQ ID NO: 48)

[0486] Alignment of the sequences reveals a shared CDR-H1 motif, such as the motif set forth as GZ.sup.1TFZ.sup.3Z.sup.2YZ.sup.3Z.sup.4 (SEQ ID NO: 2), in which each Z.sup.1 is independently a naturally occurring amino acid including a side-chain including an aromatic substituent, each Z.sup.2 is independently a naturally occurring amino acid including an anionic side-chain at physiological pH, each Z.sup.3 is independently a naturally occurring amino acid including a polar, uncharged side-chain at physiological pH, and each Z.sup.4 is independently leucine or isoleucine. The agonistic TNFR2 polypeptides set forth in Table 1, above, each feature a CDR-H1 sequence represented by the conserved motif of SEQ ID NO: 2.

Nucleic Acids and Expression Systems

[0487] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein can be prepared by any of a variety of established techniques. For instance, an agonistic TNFR2 antibody or antigen-binding fragment thereof described herein can be prepared by recombinant expression of immunoglobulin light and heavy chain genes in a host cell. To express an antibody recombinantly, a host cell can be transfected with one or more recombinant expression vectors carrying DNA fragments encoding the immunoglobulin light and heavy chains of the antibody such that the light and heavy chains are expressed in the host cell and, optionally, secreted into the medium in which the host cells are cultured, from which medium the antibodies can be recovered. Standard recombinant DNA methodologies are used to obtain antibody heavy and light chain genes, incorporate these genes into recombinant expression vectors and introduce the vectors into host cells, such as those described in Molecular Cloning; A Laboratory Manual, Second Edition (Sambrook, Fritsch and Maniatis (eds), Cold Spring Harbor, N. Y., 1989), Current Protocols in Molecular Biology (Ausubel et al., eds., Greene Publishing Associates, 1989), and in U.S. Pat. No. 4,816,397; the disclosures of each of which are incorporated herein by reference.

Vectors for Expression of Agonistic TNFR2 Polypeptides

[0488] Viral genomes provide a rich source of vectors that can be used for the efficient delivery of exogenous genes into the genome of a cell (e.g., a eukaryotic or prokaryotic cell). Viral genomes are particularly useful vectors for gene delivery because the polynucleotides contained within such genomes are typically incorporated into the genome of a target cell by generalized or specialized transduction. These processes occur as part of the natural viral replication cycle, and do not require added proteins or reagents in order to induce gene integration. Examples of viral vectors include a retrovirus, adenovirus (e.g., Ad5, Ad26, Ad34, Ad35, and Ad48), parvovirus (e.g., adeno-associated viruses), coronavirus, negative strand RNA viruses such as orthomyxovirus (e.g., influenza virus), rhabdovirus (e.g., rabies and vesicular stomatitis virus), paramyxovirus (e.g. measles and Sendai), positive strand RNA viruses, such as picornavirus and alphavirus, and double stranded DNA viruses including adenovirus, herpesvirus (e.g., Herpes Simplex virus types 1 and 2, Epstein-Barr virus, cytomegalovirus), and poxvirus (e.g., vaccinia, modified vaccinia Ankara (MVA), fowlpox and canarypox). Other viruses useful for delivering polynucleotides encoding antibody light and heavy chains or antibody fragments described herein include Norwalk virus, togavirus, flavivirus, reoviruses, papovavirus, hepadnavirus, and hepatitis virus, for example. Examples of retroviruses include: avian leukosis-sarcoma, mammalian C-type, B-type viruses, D-type viruses, HTLV-BLV group, lentivirus, spumavirus (Coffin, J. M., Retroviridae: The viruses and their replication, In Fundamental Virology, Third Edition, B. N. Fields, et al., Eds., Lippincott-Raven Publishers, Philadelphia, 1996). Other examples include murine leukemia viruses, murine sarcoma viruses, mouse mammary tumor virus, bovine leukemia virus, feline leukemia virus, feline sarcoma virus, avian leukemia virus, human T cell leukemia virus, baboon endogenous virus, Gibbon ape leukemia virus, Mason Pfizer monkey virus, simian immunodeficiency virus, simian sarcoma virus, Rous sarcoma virus and lentiviruses. Other examples of vectors are described, for example, in McVey et al., (U.S. Patent. No. 5,801,030); the disclosures of each of which are incorporated herein by reference.

[0489] Non-viral vectors, such as plasmids, are also well known in the art and include, but are not limited to prokaryotic and eukaryotic vectors (e.g., yeast- and bacteria-based plasmids), as well as plasmids for expression in mammalian cells. Methods of introducing the vectors into a host cell and isolating and purifying the expressed protein are also well known in the art (e.g., Molecular Cloning; A Laboratory Manual, Second Edition (Sambrook, Fritsch and Maniatis (eds), Cold Spring Harbor, N. Y., 1989)).

Genome Editing Techniques

[0490] In addition to viral vectors, a variety of additional methods have been developed for the incorporation of genes, e.g., those encoding antibody light and heavy chains, single-chain polypeptides, single-chain variable fragments (scFvs), tandem scFvs, Fab domains, F(ab′).sub.2 domains, diabodies, and triabodies, among others, into the genomes of target cells for polypeptide expression. One such method that can be used for incorporating polynucleotides encoding agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, or constructs thereof) into prokaryotic or eukaryotic cells includes the use of transposons. Transposons are polynucleotides that encode transposase enzymes and contain a polynucleotide sequence or gene of interest flanked by excision sites at the 5′ and 3′ positions. Once a transposon has been delivered into a cell, expression of the transposase gene commences and results in active enzymes that cleave the gene of interest from the transposon. This activity is mediated by the site-specific recognition of transposon excision sites by the transposase. In some embodiments, these excision sites may be terminal repeats or inverted terminal repeats. Once excised from the transposon, the gene of interest can be integrated into the genome of a prokaryotic or eukaryotic cell by transposase-catalyzed cleavage of similar excision sites that exist within nuclear genome of the cell. This allows the gene encoding an agonistic TNFR2 polypeptide described herein to be inserted into the cleaved nuclear DNA at the excision sites, and subsequent ligation of the phosphodiester bonds that join the gene of interest to the DNA of the prokaryotic or eukaryotic cell genome completes the incorporation process. In some embodiments, the transposon is a retrotransposon, such that the gene encoding the polypeptide is first transcribed to an RNA product and then reverse-transcribed to DNA before incorporation in the prokaryotic or eukaryotic cell genome. Exemplary transposon systems include the piggybac transposon (described in detail in WO 2010/085699) and the sleeping beauty transposon (described in detail in US20050112764); the disclosures of each of which are incorporated herein by reference.

[0491] Another useful method for the integration of nucleic acid molecules encoding agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, or antigen-binding fragments thereof) into the genome of a prokaryotic or eukaryotic cell is the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas system, which is a system that originally evolved as an adaptive defense mechanism in bacteria and archaea against infection by viruses. The CRISPR/Cas system consists of palindromic repeat sequences within plasmid DNA and an associated Cas9 nuclease. This ensemble of DNA and protein directs site specific DNA cleavage of a target sequence by first incorporating foreign DNA into CRISPR loci. Polynucleotides containing these foreign sequences and the repeat-spacer elements of the CRISPR locus are in turn transcribed in a host cell to create a guide RNA, which can subsequently anneal to a target sequence and localize the Cas9 nuclease to this site. In this manner, highly site-specific cas9-mediated DNA cleavage can be engendered in a foreign polynucleotide because the interaction that brings cas9 within close proximity of the target DNA molecule is governed by RNA:DNA hybridization. As a result, one can theoretically design a CRISPR/Cas system to cleave any target DNA molecule of interest. This technique has been exploited in order to edit eukaryotic genomes (Hwang et al., Nat. Biotech., 31:227-229, 2013) and can be used as an efficient means of site-specifically editing eukaryotic or prokaryotic genomes in order to cleave DNA prior to the incorporation of a polynucleotide encoding an agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, or antigen-binding fragments thereof) described herein. The use of CRISPR/Cas to modulate gene expression has been described in U.S. Pat. No. 8,697,359, the disclosure of which is incorporated herein by reference.

[0492] Alternative methods for site-specifically cleaving genomic DNA prior to the incorporation of a polynucleotide encoding a TNFR2 antibody or antibody fragment described herein include the use of zinc finger nucleases and transcription activator-like effector nucleases (TALENs). Unlike the CRISPR/Cas system, these enzymes do not contain a guiding polynucleotide to localize to a specific target sequence. Target specificity is instead controlled by DNA binding domains within these enzymes. Zinc finger nucleases and TALENs for use in genome editing applications are described in Urnov et al. (Nat. Rev. Genet., 11:636-646, 2010); and in Joung et al., (Nat. Rev. Mol. Cell. Bio. 14:49-55, 2013); incorporated herein by reference. Additional genome editing techniques that can be used to incorporate polynucleotides encoding antibodies described herein into the genome of a prokaryotic or eukaryotic cell include the use of ARCUS™ meganucleases that can be rationally designed so as to site-specifically cleave genomic DNA. The use of these enzymes for the incorporation of polynucleotides encoding agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, or constructs thereof) described herein into the genome of a prokaryotic or eukaryotic cell is particularly advantageous in view of the structure-activity relationships that have been established for such enzymes. Single-chain meganucleases can thus be modified at certain amino acid positions in order to create nucleases that selectively cleave DNA at desired locations. These single-chain nucleases have been described extensively, e.g., in U.S. Pat. Nos. 8,021,867 and 8,445,251; the disclosures of each of which are incorporated herein by reference.

Polynucleotide Sequence Elements

[0493] To express agonistic TNFR2 polypeptides described herein (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, or constructs thereof), polynucleotides encoding partial or full-length light and heavy chains, e.g., polynucleotides that encode a one or more, or all, of the CDR sequences of an antibody or antigen-binding fragment thereof described herein, can be inserted into expression vectors such that the genes are operatively linked to transcriptional and translational control sequences. The expression vector and expression control sequences are chosen to be compatible with the expression host cell used. Polynucleotides encoding the light chain gene and the heavy chain of a TNFR2 polypeptide can be inserted into separate vectors, or, optionally, both polynucleotides can be incorporated into the same expression vector using established techniques described herein or known in the art.

[0494] In addition to polynucleotides encoding the heavy and light chains of an antibody (or a polynucleotide encoding a single-chain polypeptide, an antibody fragment, such as a scFv molecule, or a construct described herein), the recombinant expression vectors described herein may carry regulatory sequences that control the expression of the antibody chain genes in a host cell. The design of the expression vector, including the selection of regulatory sequences, may depend on such factors as the choice of the host cell to be transformed or the level of expression of protein desired. For instance, suitable regulatory sequences for mammalian host cell expression include viral elements that direct high levels of protein expression in mammalian cells, such as promoters and/or enhancers derived from cytomegalovirus (CMV) (such as the CMV promoter/enhancer), Simian Virus 40 (SV40) (such as the SV40 promoter/enhancer), adenovirus, (e.g., the adenovirus major late promoter (AdMLP)) and polyoma. Viral regulatory elements, and sequences thereof, are described in detail, for instance, in U.S. Pat. No. 5,168,062, U.S. Pat. No. 4,510,245, and U.S. Pat. No. 4,968,615, the disclosures of each of which are incorporated herein by reference.

[0495] In addition to the antibody chain genes and regulatory sequences, the recombinant expression vectors described herein can carry additional sequences, such as sequences that regulate replication of the vector in host cells (e.g., origins of replication) and selectable marker genes. A selectable marker gene facilitates selection of host cells into which the vector has been introduced (see e.g., U.S. Pat. Nos. 4,399,216, 4,634,665 and 5,179,017). For example, typically the selectable marker gene confers resistance to cytotoxic drugs, such as G418, puromycin, blasticidin, hygromycin or methotrexate, to a host cell into which the vector has been introduced. Suitable selectable marker genes include the dihydrofolate reductase (DHFR) gene (for use in DHFR″ host cells with methotrexate selection/amplification) and the neo gene (for G418 selection). In order to express the light and heavy chains of a TNFR2 antibody or a TNFR2 antibody fragment, the expression vector(s) containing polynucleotides encoding the heavy and light chains can be transfected into a host cell by standard techniques.

Host Cells for Expression of Agonistic TNFR2 Polypeptides

[0496] It is possible to express the polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein in either prokaryotic or eukaryotic host cells. In some embodiments, expression of polypeptides (e.g., single-chain polypeptides, antibodies, or antigen-binding fragments thereof) is performed in eukaryotic cells, e.g., mammalian host cells, for optimal secretion of a properly folded and immunologically active antibody. Exemplary mammalian host cells for expressing the recombinant antibodies or antigen-binding fragments thereof described herein include Chinese Hamster Ovary (CHO cells) (including DHFR CHO cells, described in Urlaub and Chasin (1980, Proc. Natl. Acad. Sci. USA 77:4216-4220), used with a DHFR selectable marker, e.g., as described in Kaufman and Sharp (1982, Mol. Biol. 159:601-621), NSO myeloma cells, COS cells, 293 cells, and SP2/0 cells. Additional cell types that may be useful for the expression of antibodies and fragments thereof include bacterial cells, such as BL-21 (DE3) E. coli cells, which can be transformed with vectors containing foreign DNA according to established protocols. Additional eukaryotic cells that may be useful for expression of antibodies include yeast cells, such as auxotrophic strains of S. cerevisiae, which can be transformed and selectively grown in incomplete media according to established procedures known in the art. When recombinant expression vectors encoding antibody genes are introduced into mammalian host cells, the antibodies are produced by culturing the host cells for a period of time sufficient to allow for expression of the antibody in the host cells or secretion of the antibody into the culture medium in which the host cells are grown.

[0497] Polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) can be recovered from the culture medium using standard protein purification methods. Host cells can also be used to produce portions of intact antibodies, such as Fab fragments or scFv molecules. Also included herein are methods in which the above procedure is varied according to established protocols known in the art. For example, it can be desirable to transfect a host cell with DNA encoding either the light chain or the heavy chain (but not both) of an agonistic TNFR2 antibody described herein in order to produce an antigen-binding fragment of the antibody.

[0498] Once an agonistic TNFR2 polypeptide (e.g., single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) described herein has been produced by recombinant expression, it can be purified by any method known in the art, such as a method useful for purification of an immunoglobulin molecule, for example, by chromatography (e.g., ion exchange, affinity, particularly by affinity for TNFR2 after Protein A or Protein G selection, and sizing column chromatography), centrifugation, differential solubility, or by any other standard technique for the purification of proteins. Further, the agonistic TNFR2 polypeptides described herein or fragments thereof can be fused to heterologous polypeptide sequences described herein or otherwise known in the art to facilitate purification or to produce therapeutic conjugates.

[0499] Once isolated, an agonistic TNFR2 single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct can, if desired, be further purified, e.g., by high performance liquid chromatography (see, e.g., Fisher, Laboratory Techniques in Biochemistry and Molecular Biology (Work and Burdon, eds., Elsevier, 1980); incorporated herein by reference), or by gel filtration chromatography, such as on a Superdex™ 75 column (Pharmacia Biotech AB, Uppsala, Sweden).

Agonistic TNFR2 Polypeptide Conjugates

[0500] Prior to administration of agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments thereof) described herein to a mammalian subject (e.g., a human), it may be desirable to conjugate the antibody or fragment thereof to a second molecule, e g., to modulate the activity of the antibody in vivo. Agonistic TNFR2 antibodies and fragments thereof can be conjugated to other molecules at either the N-terminus or C-terminus of a light or heavy chain of the antibody using any one of a variety of established conjugation strategies that are well-known in the art. Examples of pairs of reactive functional groups that can be used to covalently tether an agonistic TNFR2 antibody or fragment thereof to another molecule include, without limitation, thiol pairs, carboxylic acids and amino groups, ketones and amino groups, aldehydes and amino groups, thiols and alpha,beta-unsaturated moieties (such as maleimides or dehydroalanine), thiols and alpha-halo amides, carboxylic acids and hydrazides, aldehydes and hydrazides, and ketones and hydrazides.

[0501] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) can be covalently appended directly to another molecule by chemical conjugation as described. Alternatively, fusion proteins containing agonistic TNFR2 antibodies and fragments thereof can be expressed recombinantly from a cell (e.g., a eukaryotic cell or prokaryotic cell). This can be accomplished, for example, by incorporating a polynucleotide encoding the fusion protein into the nuclear genome of a cell (e.g., using techniques described herein or known in the art). Optionally, antibodies and fragments thereof described herein can be joined to a second molecule by forming a covalent bond between the antibody and a linker. This linker can then be subsequently conjugated to another molecule, or the linker can be conjugated to another molecule prior to ligation to the agonistic TNFR2 antibody or fragment thereof. Examples of linkers that can be used for the formation of a conjugate include polypeptide linkers, such as those that contain naturally occurring or non-naturally occurring amino acids. In some embodiments, it may be desirable to include D-amino acids in the linker, as these residues are not present in naturally-occurring proteins and are thus more resistant to degradation by endogenous proteases. Fusion proteins containing polypeptide linkers can be made using chemical synthesis techniques, such as those described herein, or through recombinant expression of a polynucleotide encoding the fusion protein in a cell (e.g., a prokaryotic or eukaryotic cell). Linkers can be prepared using a variety of strategies that are well known in the art, and depending on the reactive components of the linker, can be cleaved by enzymatic hydrolysis, photolysis, hydrolysis under acidic conditions, hydrolysis under basic conditions, oxidation, disulfide reduction, nucleophilic cleavage, or organometallic cleavage (Leriche et al., Bioorg. Med. Chem., 20:571-582, 2012).

Drug-Polypeptide Conjugates

[0502] An agonistic TNFR2 polypeptide (e.g., single-chain polypeptide, antibody, and antigen-binding fragment thereof) described herein can additionally be conjugated to, admixed with, or administered separately from a therapeutic agent, such as an agent used to treat autoimmunity and/or inflammation. Exemplary agents that may be conjugated to, admixed with, or administered separately from an agonistic TNFR2 polypeptide described herein include Bacillus Calmette-Guerin (BCG). Additional agents that may be conjugated to, admixed with, or administered separately from an agonistic TNFR2 polypeptide described herein include non-steroidal anti-inflammatory drugs (NSAIDs), such as (i) salicylic acid derivatives, including acetylsalicylic acid (aspirin), diflunisal, and sulfasalazine, (ii) para-aminophenol derivatives, including acetaminophen, (iii) fenamates, including mefenamic acid, meclofenamate, and flufenamic acid, (iv) propionic acid derivatives, including ibuprofen, naproxen, fenoprofen, ketoprofen, flurbiprofen, and oxaprozin, and (v) enolic acid (oxicam) derivatives, including piroxicam and tenoxicam. Additional agents that may be conjugated to, admixed with, or administered separately from an agonistic TNFR2 polypeptide described herein include glucocorticoids. The agonistic TNFR2 polypeptides described herein may, additionally or alternatively, be conjugated to, admixed with, or administered separately from a disease-modifying anti-Rheumatic drug (DMARD), such as methotrexate, leflunomide, gold compounds, sulfasalazine, azathioprine, cyclophosphamide, antimalarials, D-penicillamine, and cyclosporine. Additional agents that may be conjugated to, admixed with, or administered separately from an agonistic TNFR2 polypeptide described herein include infliximab, etanercept, adalimumab, golimumab, and certolizumab pegol, among others. Additional agents that may be conjugated to, admixed with, or administered separately from an agonistic TNFR2 polypeptide of the disclosure are described, for example, in Li et al., Front. Pharmacol. 8:460, 2017 the disclosure of which is incorporated herein by reference in its entirety.

[0503] In some embodiments, the agonistic TNFR2 polypeptides described herein are conjugated to, admixed with, or administered separately from an immunotherapy agent, such as an agonistic anti-CTLA-4 agent, an agonistic anti-PD-1 agent, an agonistic anti-PD-L1 agent, an agonistic anti-PD-L2 agent, an agonistic anti-CD27 agent, an agonistic anti-CD30 agent, an agonistic anti-CD40 agent, an agonistic anti-4-1BB agent, an agonistic anti-GITR agent, an agonistic anti-OX40 agent, an agonistic anti-TRAILR1 agent, an agonistic anti-TRAILR2 agent, an agonistic anti-TWEAK agent, an agonistic anti-TWEAKR agent, an agonistic anti-cell surface lymphocyte protein agent, an agonistic anti-BRAF agent, an agonistic anti-MEK agent, an agonistic anti-CD33 agent, an agonistic anti-CD20 agent, an agonistic anti-HLA-DR agent, an agonistic anti HLA class I agent, an agonistic anti-CD52 agent, an agonistic anti-A33 agent, an agonistic anti-GD3 agent, agonistic anti-PSMA agent, an agonistic anti-Ceacan 1 agent, an agonistic anti-Galedin 9 agent, an agonistic anti-HVEM agent, an agonistic anti-VISTA agent, an agonistic anti-B7 H4 agent, an agonistic anti-HHLA2 agent, an agonistic anti-CD155 agent, an agonistic anti-CD80 agent, an agonistic anti-BTLA agent, an agonistic anti-CD160 agent, an agonistic anti-CD28 agent, an agonistic anti-CD226 agent, an agonistic anti CEACAM1 agent, an agonistic anti-TIM3 agent, an agonistic anti-TIGIT agent, an agonistic anti-CD96 agent, an agonistic anti-CD70 agent, an agonistic anti-CD27 agent, an agonistic anti-LIGHT agent, an agonistic anti-CD137 agent, an agonistic anti-DR4 agent, an agonistic anti-CR5 agent, an agonistic anti-TNFRS agent, an agonistic anti-TNFR1 agent, an agonistic anti-FAS agent, an agonistic anti-CD95 agent, an agonistic anti-TRAIL agent, an agonistic anti-DR6 agent, an agonistic anti-EDAR agent, an agonistic anti-NGFR agent, an agonistic anti-OPG agent, an agonistic anti-RANKL agent, an agonistic anti-LTβ receptor agent, an agonistic anti-BCMA agent, an agonistic anti-TACI agent, an agonistic anti-BAFFR agent, an agonistic anti-EDAR2 agent, an agonistic anti-TROY agent, and an agonistic anti-RELT agent. For example, the immunotherapy agent may be an agonistic anti-CTLA-4 agent, an agonistic anti-PD-1 agent, or an agonistic anti-PD-L1 agent.

[0504] In some embodiments, the immunotherapy agent is selected from the group consisting of an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof, an agonistic anti-PD-1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L1 antibody or antigen-binding fragment thereof, an agonistic anti-PD-L2 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-CD30 antibody or antigen-binding fragment thereof, an agonistic anti-CD40 antibody or antigen-binding fragment thereof, an agonistic anti-4-1 BB antibody or antigen-binding fragment thereof, an agonistic anti-GITR antibody or antigen-binding fragment thereof, an agonistic anti-OX40 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR1 antibody or antigen-binding fragment thereof, an agonistic anti-TRAILR2 antibody or antigen-binding fragment thereof, an agonistic anti-TWEAK antibody or antigen-binding fragment thereof, an agonistic anti-TWEAKR antibody or antigen-binding fragment thereof, an agonistic anti-cell surface lymphocyte protein antibody or antigen-binding fragment thereof, an agonistic anti-BRAF antibody or antigen-binding fragment thereof, an agonistic anti-MEK antibody or antigen-binding fragment thereof, an agonistic anti-CD33 antibody or antigen-binding fragment thereof, an agonistic anti-CD20 antibody or antigen-binding fragment thereof, an agonistic anti-HLA-DR antibody or antigen-binding fragment thereof, an agonistic anti-HLA class I antibody or antigen-binding fragment thereof, an agonistic anti-CD52 antibody or antigen-binding fragment thereof, an agonistic anti-A33 antibody or antigen-binding fragment thereof, an agonistic anti-GD3 antibody or antigen-binding fragment thereof, an agonistic anti-PSMA antibody or antigen-binding fragment thereof, an agonistic anti-Ceacan 1 antibody or antigen-binding fragment thereof, an agonistic anti-Galedin 9 antibody or antigen-binding fragment thereof, an agonistic anti-HVEM antibody or antigen-binding fragment thereof, an agonistic anti-VISTA antibody or antigen-binding fragment thereof, an agonistic anti-B7 H4 antibody or antigen-binding fragment thereof, an agonistic anti-HHLA2 antibody or antigen-binding fragment thereof, an agonistic anti-CD155 antibody or antigen-binding fragment thereof, an agonistic anti-CD80 antibody or antigen-binding fragment thereof, an agonistic anti-BTLA antibody or antigen-binding fragment thereof, an agonistic anti-CD160 antibody or antigen-binding fragment thereof, an agonistic anti-CD28 antibody or antigen-binding fragment thereof, an agonistic anti-CD226 antibody or antigen-binding fragment thereof, an agonistic anti-CEACAM1 antibody or antigen-binding fragment thereof, an agonistic anti-TIM3 antibody or antigen-binding fragment thereof, an agonistic anti-TIGIT antibody or antigen-binding fragment thereof, an agonistic anti-CD96 antibody or antigen-binding fragment thereof, an agonistic anti-CD70 antibody or antigen-binding fragment thereof, an agonistic anti-CD27 antibody or antigen-binding fragment thereof, an agonistic anti-LIGHT antibody or antigen-binding fragment thereof, an agonistic anti-CD137 antibody or antigen-binding fragment thereof, an agonistic anti-DR4 antibody or antigen-binding fragment thereof, an agonistic anti-CR5 antibody or antigen-binding fragment thereof, an agonistic anti-TNFRS antibody or antigen-binding fragment thereof, an agonistic anti-TNFR1 antibody or antigen-binding fragment thereof, an agonistic anti-FAS antibody or antigen-binding fragment thereof, an agonistic anti-CD95 antibody or antigen-binding fragment thereof, an agonistic anti-TRAIL antibody or antigen-binding fragment thereof, an agonistic anti-DR6 antibody or antigen-binding fragment thereof, an agonistic anti-EDAR antibody or antigen-binding fragment thereof, an agonistic anti-NGFR antibody or antigen-binding fragment thereof, an agonistic anti-OPG antibody or antigen-binding fragment thereof, an agonistic anti-RANKL antibody or antigen-binding fragment thereof, an agonistic anti-LTβ receptor antibody or antigen-binding fragment thereof, an agonistic anti-BCMA antibody or antigen-binding fragment thereof, an agonistic anti-TACI antibody or antigen-binding fragment thereof, an agonistic anti-BAFFR antibody or antigen-binding fragment thereof, an agonistic anti-EDAR2 antibody or antigen-binding fragment thereof, an agonistic anti-TROY antibody or antigen-binding fragment thereof, and an agonistic anti-RELT antibody or antigen-binding fragment thereof. For example, the immunotherapy agent may be an agonistic anti-CTLA-4 antibody or antigen-binding fragment thereof, an agonistic anti-PD-1 antibody or antigen-binding fragment thereof, or an agonistic anti-PD-L1 antibody or antigen-binding fragment thereof.

[0505] In some embodiments, the immunotherapy agent is an agonistic anti-cell surface lymphocyte protein antibody or antigen-binding fragment thereof, such as an antibody or antigen-binding fragment thereof that binds and promotes the activity of one or more of CD1, CD2, CD3, CD4, CD5, CD6, CD7, CD8, CD9, CD10, CD11, CD12, CD13, CD14, CD15, CD16, CD17, CD18, CD19, CD20, CD21, CD22, CD23, CD24, CD25, CD26, CD27, CD28, CD29, CD30, CD31, CD32, CD33, CD34, CD35, CD36, CD37, CD38, CD39, CD40, CD41, CD42, CD43, CD44, CD45, CD46, CD47, CD48, CD49, CD50, CD51, CD52, CD53, CD54, CD55, CD56, CD57, CD58, CD59, CD60, CD61, CD62, CD63, CD64, CD65, CD66, CD67, CD68, CD69, CD70, CD71, CD72, CD73, CD74, CD75, CD76, CD77, CD78, CD79, CD80, CD81, CD82, CD83, CD84, CD85, CD86, CD87, CD88, CD89, CD90, CD91, CD92, CD93, CD94, CD95, CD96, CD97, CD98, CD99, CD100, CD101, CD102, CD103, CD104, CD105, CD106, CD107, CD108, CD109, CD110, CD111, CD112, CD113, CD114, CD115, CD116, CD117, CD118, CD119, CD120, CD121, CD122, CD123, CD124, CD125, CD126, CD127, CD128, CD129, CD130, CD131, CD132, CD133, CD134, CD135, CD136, CD137, CD138, CD139, CD140, CD141, CD142, CD143, CD144, CD145, CD146, CD147, CD148, CD149, CD150, CD151, CD152, CD153, CD154, CD155, CD156, CD157, CD158, CD159, CD160, CD161, CD162, CD163, CD164, CD165, CD166, CD167, CD168, CD169, CD170, CD171, CD172, CD173, CD174, CD175, CD176, CD177, CD178, CD179, CD180, CD181, CD182, CD183, CD184, CD185, CD186, CD187, CD188, CD189, CD190, CD191, CD192, CD193, CD194, CD195, CD196, CD197, CD198, CD199, CD200, CD201, CD202, CD203, CD204, CD205, CD206, CD207, CD208, CD209, CD210, CD211, CD212, CD213, CD214, CD215, CD216, CD217, CD218, CD219, CD220, CD221, CD222, CD223, CD224, CD225, CD226, CD227, CD228, CD229, CD230, CD231, CD232, CD233, CD234, CD235, CD236, CD237, CD238, CD239, CD240, CD241, CD242, CD243, CD244, CD245, CD246, CD247, CD248, CD249, CD250, CD251, CD252, CD253, CD254, CD255, CD256, CD257, CD258, CD259, CD260, CD261, CD262, CD263, CD264, CD265, CD266, CD267, CD268, CD269, CD270, CD271, CD272, CD273, CD274, CD275, CD276, CD277, CD278, CD279, CD280, CD281, CD282, CD283, CD284, CD285, CD286, CD287, CD288, CD289, CD290, CD291, CD292, CD293, CD294, CD295, CD296, CD297, CD298, CD299, CD300, CD301, CD302, CD303, CD304, CD305, CD306, CD307, CD308, CD309, CD310, CD311, CD312, CD313, CD314, CD315, CD316, CD317, CD318, CD319, and/or CD320.

[0506] In some embodiments, the immunotherapy agent is an agent (e.g., a polypeptide, antibody, antigen-binding fragment thereof, a single-chain polypeptide, or construct thereof) that binds a chemokine or lymphokine. For instance, the immunotherapy agent may be an agent (e.g., polypeptide, antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct thereof) that bind and activates one or more, or all, of CXCL1, CXCL2, CXCL3, CXCL8, CCL2 and CCL5. In some embodiments, the immunotherapy agent is an agent (e.g., a polypeptide, antibody, antigen-binding fragment thereof, a single-chain polypeptide, or construct thereof) that binds and activates one or more, or all, of CCL3, CCL4, CCL8, and CCL22.

Labeled TNFR2 Polypeptides

[0507] In some embodiments, agonistic TNFR2 single-chain polypeptides, antibodies, antigen-binding fragments thereof, or constructs described herein are conjugated to another molecule (e.g., an epitope tag) for the purpose of purification or detection. Examples of such molecules that are useful in protein purification include those that present structural epitopes capable of being recognized by a second molecule. This is a common strategy that is employed in protein purification by affinity chromatography, in which a molecule is immobilized on a solid support and exposed to a heterogeneous mixture containing a target protein conjugated to a molecule capable of binding the immobilized compound. Examples of epitope tag molecules that can be conjugated to agonistic TNFR2 polypeptides for the purposes of molecular recognition include, without limitation, maltose-binding protein, glutathione-S-transferase, a poly-histidine tag, a FLAG-tag, a myc-tag, human influenza hemagglutinin (HA) tag, biotin, streptavidin. Conjugates containing the epitopes presented by these molecules are capable of being recognized by such complementary molecules as maltose, glutathione, a nickel-containing complex, an anti-FLAG antibody, an anti-myc antibody, an anti-HA antibody, streptavidin, or biotin, respectively. For example, one can purify an agonistic TNFR2 antibody or fragment thereof described herein that has been conjugated to an epitope tag from a complex mixture of other proteins and biomolecules (e.g., DNA, RNA, carbohydrates, phospholipids, etc) by treating the mixture with a solid phase resin containing an complementary molecule that can selectively recognize and bind the epitope tag of the agonistic TNFR2 antibody or fragment thereof. Examples of solid phase resins include agarose beads, which are compatible with purifications in aqueous solution.

[0508] An agonistic TNFR2 polypeptide described herein can also be covalently appended to a fluorescent molecule, e.g., to detect the antibody or antigen-binding fragment thereof by fluorimetry and/or by direct visualization using fluorescence microscopy. Exemplary fluorescent molecules that can be conjugated to antibodies described herein include green fluorescent protein, cyan fluorescent protein, yellow fluorescent protein, red fluorescent protein, phycoerythrin, allophycocyanin, hoescht, 4′,6-diamidino-2-phenylindole (DAPI), propidium iodide, fluorescein, coumarin, rhodamine, tetramethylrhoadmine, and cyanine. Additional examples of fluorescent molecules suitable for conjugation to antibodies described herein are well-known in the art and have been described in detail in, e.g., U.S. Pat. Nos. 7,417,131 and 7,413,874, each of which is incorporated by reference herein.

[0509] Agonistic TNFR2 polypeptides containing a fluorescent molecule are particularly useful for monitoring the cell-surface localization properties of antibodies and fragments thereof described herein. For instance, one can expose cultured mammalian cells (e.g., Treg cells) to agonistic TNFR2 polypeptides described herein that have been covalently conjugated to a fluorescent molecule and subsequently analyze these cells using conventional fluorescent microscopy techniques known in the art. Confocal fluorescent microscopy is a particularly powerful method for determining cell-surface localization of agonistic TNFR2 polypeptides, as individual planes of a cell can be analyzed in order to distinguish antibodies or fragments thereof that have been internalized into a cell’s interior, e.g., by receptor-mediated endocytosis, from those that are bound to the external face of the cell membrane. Additionally, cells can be treated with agonistic TNFR2 antibodies conjugated to a fluorescent molecule that emits visible light of a particular wavelength (e.g., fluorescein, which fluoresces at about 535 nm) and an additional fluorescent molecule that is known to localize to a particular site on the Treg cell surface and that fluoresces at a different wavelength (e.g., a molecule that localizes to CD25 and that fluoresces at about 599 nm). The resulting emission patterns can be visualized by confocal fluorescence microscopy and the images from these two wavelengths can be merged in order to reveal information regarding the location of the agonistic TNFR2 antibody or antigen-binding fragment thereof on the Treg cell surface with respect to other receptors.

[0510] Bioluminescent proteins can also be incorporated into a fusion protein for the purposes of detection and visualization of an agonistic TNFR2 polypeptide, such as a single-chain polypeptide, antibody, or fragment thereof. Bioluminescent proteins, such as Luciferase and aequorin, emit light as part of a chemical reaction with a substrate (e.g., luciferin and coelenterazine). Exemplary bioluminescent proteins suitable for use as a diagnostic sequence and methods for their use are described in, e.g., U.S. Pat. Nos. 5,292,658, 5,670,356, 6,171,809, and 7,183,092, each of which is herein incorporated by reference. Agonistic TNFR2 antibodies or fragments thereof labeled with bioluminescent proteins are a useful tool for the detection of antibodies described herein following an in vitro assay. For instance, the presence of an agonistic TNFR2 antibody that has been conjugated to a bioluminescent protein can be detected among a complex mixture of additional proteins by separating the components of the mixture using gel electrophoresis methods known in the art (e.g., native gel analysis) and subsequently transferring the separated proteins to a membrane in order to perform a Western blot. Detection of the agonistic TNFR2 polypeptide among the mixture of other proteins can be achieved by treating the membrane with an appropriate Luciferase substrate and subsequently visualizing the mixture of proteins on film using established protocols.

[0511] The polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein can also be conjugated to a molecule comprising a radioactive nucleus, such that an antibody or fragment thereof described herein can be detected by analyzing the radioactive emission pattern of the nucleus. Alternatively, an agonistic TNFR2 antibody or fragment thereof can be modified directly by incorporating a radioactive nucleus within the antibody during the preparation of the protein. Radioactive isotopes of methionine (.sup.35S), nitrogen (.sup.15N), or carbon (.sup.13C) can be incorporated into antibodies or fragments thereof described herein by, e.g., culturing bacteria in media that has been supplemented with nutrients containing these isotopes. Optionally, tyrosine derivatives containing a radioactive halogen can be incorporated into an agonistic TNFR2 polypeptide by, e.g., culturing bacterial cells in media supplemented with radiolabeled tyrosine. It has been shown that tyrosine functionalized with a radioactive halogen at the C2 position of the phenol system are rapidly incorporated into elongating polypeptide chains using the endogenous translation enzymes in vivo (U.S. Pat. No. 4,925,651 ; incorporated herein by reference). The halogens include fluorine, chlorine, bromine, iodine, and astatine. Additionally, agonistic TNFR2 polypeptides can be modified following isolation and purification from cell culture by functionalizing polypeptides described herein with a radioactive isotope. The halogens represent a class of isotopes that can be readily incorporated into a purified protein by aromatic substitution at tyrosine or tryptophan, e.g., via reaction of one or more of these residues with an electrophilic halogen species. Examples of radioactive halogen isotopes include .sup.18F, .sup.75Br, .sup.77Br, .sup.122I, .sup.123I, .sup.124I, .sup.125I, .sup.129I, .sup.131I, or .sup.211At.

[0512] Another alternative strategy for the incorporation of a radioactive isotope is the covalent attachment of a chelating group to the agonistic TNFR2 polypeptide, such as a single-chain polypeptide, antibody, fragment thereof, or construct. Chelating groups can be covalently appended to an agonistic TNFR2 antibody or fragment thereof by attachment to a reactive functional group, such as a thiol, amino group, alcohol, or carboxylic acid. The chelating groups can then be modified to contain any of a variety of metallic radioisotopes, including, without limitation, such radioactive nuclides as .sup.125I, .sup.67Ga, .sup.111In, .sup.99Tc, .sup.169Yb, .sup.186Re, .sup.123I, .sup.124I, .sup.125I, .sup.131I, .sup.99mTc, .sup.111In .sup.64Cu, .sup.67Cu, .sup.186Re, .sup.188Re, .sup.177Lu, .sup.90Y, .sup.77As, .sup.72As, .sup.86Y, .sup.89Zr, .sup.211At, .sup.212Bi, .sup.213Bi, or .sup.225Ac.

[0513] In some embodiments, it may be desirable to covalently conjugate the polypeptides (e.g., single-chain polypeptides, antibodies, fragments thereof, or construct thereof) described herein with a chelating group capable of binding a metal ion from heavy elements or rare earth ions, such as Gd.sup.3+, Fe.sup.3+, Mn.sup.3+, or Cr.sup.2+. Conjugates containing chelating groups that are coordinated to such paramagnetic metals are useful as in MRI imaging applications. Paramagnetic metals include, but are not limited to, chromium (III), manganese (II), iron (II), iron (III), cobalt (II), nickel (II), copper (II), praseodymium (III), neodymium (III), samarium (III), gadolinium (III), terbium (III), dysprosium (III), holmium (III), erbium (III), and ytterbium (III). In this way, agonistic TNFR2 polypeptides can be detected by MRI spectroscopy. For instance, one can administer agonistic TNFR2 antibodies or fragments thereof conjugated to chelating groups bound to paramagnetic ions to a mammalian subject (e.g., a human patient) in order to monitor the distribution of the antibody following administration. This can be achieved by administration of the antibody to a patient by any of the administration routes described herein, such as intravenously, and subsequently analyzing the location of the administered antibody by recording an MRI of the patient according to established protocols.

[0514] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) can additionally be conjugated to other molecules for the purpose of improving the solubility and stability of the protein in aqueous solution. Examples of such molecules include PEG, PSA, bovine serum albumin (BSA), and human serum albumin (HSA), among others. For instance, one can conjugate an agonistic TNFR2 polypeptide to carbohydrate moieties in order to evade detection of the antibody or fragment thereof by the immune system of the patient receiving treatment. This process of hyperglycosylation reduces the immunogenicity of therapeutic proteins by sterically inhibiting the interaction of the protein with B cell receptors in circulation. Alternatively, agonistic TNFR2 antibodies or fragments thereof can be conjugated to molecules that prevent clearance from human serum and improve the pharmacokinetic profile of antibodies described herein. Exemplary molecules that can be conjugated to or inserted within TNFR2 antibodies or fragments thereof described herein so as to attenuate clearance and improve the pharmacokinetic profile of these antibodies and fragments include salvage receptor binding epitopes. These epitopes are found within the Fc region of an IgG immunoglobulin and have been shown to bind Fc receptors and prolong antibody half-life in human serum. The insertion of salvage receptor binding epitopes into TNFR2 antibodies or fragments thereof can be achieved, e.g., as described in U.S. Pat. No. 5,739,277; incorporated herein by reference.

Modified Agonistic TNFR2 Polypeptides

[0515] In addition to conjugation to other therapeutic agents and labels for identification or visualization, agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein can also be modified so as to improve their pharmacokinetic profile, biophysical stability, or agonistic capacity. For instance, any cysteine residue not involved in maintaining the proper conformation of the agonistic TNFR2 polypeptide may be substituted with an isosteric or isolectronic amino acid (e.g., serine) in order to improve the oxidative stability of the molecule and prevent aberrant crosslinking. Conversely, cystine bond(s) may be added to the antibody or fragment thereof to improve its stability (particularly where the antibody is an antibody fragment, such as an Fv fragment). This can be accomplished, e.g., by altering a polynucleotide encoding the antibody heavy and light chains or a polynucleotide encoding an antibody fragment so as to encode one or more additional pairs of cysteine residues that can form disulfide bonds under oxidative conditions in order to reinforce antibody tertiary structure (see, e.g., U.S. Pat. No. 7,422,899; incorporated herein by reference).

[0516] Another useful modification that may be made to agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein includes altering the glycosylation profile of these antibodies and fragments thereof. This can be achieved, e.g., by substituting, inserting, or deleting amino acids in an agonistic TNFR2 antibody so as to insert or remove a glycosylation site. Glycosylation of antibodies typically occurs in N-linked or O-linked fashion. N-linked glycosylation is a process whereby the attachment of a carbohydrate moiety to an antibody occurs at the side-chain of an asparagine residue. Consensus amino acid sequences for N-linked glycosylation include the tripeptide sequences asparagine-X-serine (NXS) and asparagine-X-threonine (NXT), where X is any amino acid except proline. The insertion of either of these tripeptide sequences in a polypeptide (e.g., an agonistic TNFR2 antibody) creates a potential glycosylation site. O-linked glycosylation refers to the attachment of one of the sugars N-acetylgalactosamine, galactose, or xylose to a hydroxyamino acid, most commonly serine or threonine, although 5-hydroxyproline or 5-hydroxylysine are also competent substrates for glycoside formation. Addition of glycosylation sites to a TNFR2 antibody can thus be accomplished by altering the amino acid sequence of the antibody (e.g., using recombinant expression techniques as described herein) such that it contains one or more of the above-described tripeptide sequences to promote N-linked glycosylation, or one or more serine or threonine residues to the sequence of the original antibody engender O-linked glycosylation (see, e.g., U.S. Pat. No. 7,422,899; incorporated herein by reference).

[0517] In alternative cases, it may be desirable to modify the antibody or fragment thereof described herein with respect to effector function, e.g., so as to enhance antigen-dependent cell-mediated cytotoxicity (ADCC) and/or complement dependent cytotoxicity (CDC) of the antibody. This may be achieved by introducing one or more amino acid substitutions in an Fc region of the antibody. For instance, cysteine residues may be introduced in the Fc region of a TNFR2 antibody or fragment thereof (e.g., by recombinant expression techniques as described herein), so as to facilitate additional inter-chain disulfide bond formation in this region. The homodimeric antibody thus generated may have increased conformational constraint, which may foster improved internalization capability and/or increased complement-mediated cell killing and antibody-dependent cellular cytotoxicity (ADCC). Homodimeric antibodies with enhanced anti-tumor activity may also be prepared using heterobifunctional cross-linkers as described, for example, in Wolff et al. (Canc. Res., 53:2560-2565, 1993); incorporated herein by reference. Alternatively, an antibody can be engineered which has dual Fc regions and may thereby have enhanced complement lysis and ADCC capabilities (see Stevenson et al. (Anti-Canc. Drug Des., 3:219-230, 1989); incorporated herein by reference).

[0518] The serum half-life of agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments thereof) described herein can be improved in some embodiments by incorporating one more amino acid modifications, such as by altering the CH1 or CL region of the Fab domain to introduce a salvage receptor motif, e.g., that found in the two loops of a CH2 domain of an Fc region of an IgG. Such alterations are described, for instance, in U.S. Pat. No. 5,869,046 and U.S.

[0519] Pat. No. 6,121,022; incorporated herein by reference. Additional framework modifications can also be made to reduce immunogenicity of the antibody or fragment thereof or to reduce or remove T cell epitopes that reside therein, as described for instance in US2003/0153043; incorporated herein by reference.

Methods of Treatment

[0520] Agonistic TNFR2 polypeptides of the disclosure (e.g., an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above) are useful therapeutics for the treatment of a wide array of immunological disorders. Agonistic TNFR2 polypeptides described herein can be administered to a subject, e.g., a mammalian subject, such as a human, in order to treat such conditions as autoimmune diseases, neurological diseases, metabolic diseases (e.g., diabetes), macular diseases (e.g., macular degeneration), muscular atrophy, diseases related to miscarriage, vascular diseases (e.g., atherosclerosis), diseases related to bone loss (e.g., bone loss as a result of menopause or osteoporosis), allergies, asthma, a blood disorder (e.g., hemophilia), a musculoskeletal disorder, a disease related to growth receptor expression or activity, obesity, graft-versus-host disease (GVHD), or an allograft rejection, among other indications. Agonistic TNFR2 polypeptides of the disclosure can also be used, for example, to treat a patient in need of organ repair or regeneration, e.g., by inducing the proliferation of cells within a damaged tissue or organ. Agonistic TNFR2 polypeptides described herein can be administered to a mammalian subject, such as a human, to stimulate the proliferation of Treg cells (e.g., CD4+, CD25+, FOXP3+ Treg cells) and/or MDSCs. This response can have the effect of reducing populations of cytotoxic T-lymphocytes (e.g., CD8+ T-cells) that are often associated with mounting an inappropriate immune response that can cause an immunological disorder. Agonistic TNFR2 polypeptides may, additionally or alternatively, directly kill T effector cells, such as CD8+ T effector cells, and may promote the proliferation, regeneration, healing, and/or protection of TNFR2-expressing parenchymal cells, as described above.

[0521] Agonistic TNFR2 polypeptides described herein (e.g., an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above) can be administered to a subject, e.g., a mammalian subject, such as a human, suffering from a graft rejection. Agonistic TNFR2 polypeptides described herein may treat graft rejections, e.g., by binding TNFR2 receptors on the surface of autoreactive CD8+ T-cells that bind antigens presented on the surface of the graft and inducing apoptosis in these CD8+ T-cells, or by inducing the expansion of Treg cells and/or MDSCs that may subsequently eliminate autoreactive CD8+ T-cells. Examples of graft rejections that can be treated by administration of the polypeptides described herein include, without limitation, skin graft rejection, bone graft rejection, vascular tissue graft rejection, ligament graft rejection (e.g., cricothyroid ligament graft rejection, periodontal ligament graft rejection, suspensory ligament of the lens graft rejection, palmar radiocarpal ligament graft rejection, dorsal radiocarpal ligament graft rejection, ulnar collateral ligament graft rejection, radial collateral ligament graft rejection, suspensory ligament of the breast graft rejection, anterior sacroiliac ligament graft rejection, posterior sacroiliac ligament graft rejection, sacrotuberous ligament graft rejection, sacrospinous ligament graft rejection, inferior pubic ligament graft rejection, superior pubic ligament graft rejection, anterior cruciate ligament graft rejection, lateral collateral ligament graft rejection, posterior cruciate ligament graft rejection, medial collateral ligament graft rejection, cranial cruciate ligament graft rejection, caudal cruciate ligament graft rejection, patellar ligament graft rejection) and organ graft rejection (e.g., heart, lung, kidney, liver, pancreas, intestine, and thymus graft rejection, among others).

[0522] Agonistic TNFR2 polypeptides described herein (e.g., an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above) may, additionally or alternatively, be administered to a subject, e.g., a mammalian subject, such as a human) suffering from a graft-versus-host disease (GVHD). Exemplary graft-versus-host diseases that can be treated using the compositions and methods of the invention include those that arises from a bone marrow transplant, as well as from the transplantation of blood cells, such as hematopoietic stem cells, common myeloid progenitor cells, common lymphoid progenitor cells, megakaryocytes, monocytes, basophils, eosinophils, neutrophils, macrophages, T-cells, B-cells, natural killer cells, and/or dendritic cells.

[0523] Agonistic TNFR2 polypeptides described herein (e.g., an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above) can also be administered to a subject, e.g., a mammalian subject, such as a human, suffering from an immunological disease, e.g., in order to bind a TNFR2 receptor on the surface of an autoreactive T-cell and induce apoptosis, and/or to promote Treg cell growth and thus suppress the activity of inappropriately reactive cytotoxic T-lymphocytes and B-lymphocytes in the patient. Antibodies of the invention can be administered to a subject, e.g., via any of the routes of administration described herein.

[0524] Immunological diseases that can be treated by administration of polypeptides described herein include allergies, such as food allergy, seasonal allergy, pet allergy, hives, hay fever, allergic conjunctivitis, poison ivy allergy oak allergy, mold allergy, drug allergy, dust allergy, cosmetic allergy, and chemical allergy.

[0525] Diseases that can be treated by administration of an agonistic TNFR2 polypeptide described herein include autoimmune diseases, such as type I diabetes, alopecia areata, ankylosing spondylitis, antiphospholipid syndrome, autoimmune Addison’s Disease, autoimmune hemolytic anemia, autoimmune hepatitis, Behcet’s Disease, bullous pemphigoid, cardiomyopathy, celiac sprue-dermatitis, chronic fatigue immune dysfunction syndrome (CFIDS), chronic inflammatory demyelinating polyneuropathy, Churg-Strauss Syndrome, cicatricial pemphigoid, limited scleroderma (CREST Syndrome), cold agglutinin disease, Crohn’s Disease, discoid lupus, essential mixed cryoglobulinemia, fibromyalgia-fibromyositis, Graves’ Disease, Guillain-Barré Syndrome, Hashimoto’s Thyroiditis, hypothyroidism, Inflammatory Bowel Disease, autoimmune lymphoproliferative syndrome (ALPS), idiopathic pulmonary fibrosis, idiopathic thrombocytopenia purpura (ITP), IgA nephropathy, juvenile arthritis, lichen planus, lupus, Ménière’s Disease, mixed connective tissue disease, multiple sclerosis, myasthenia gravis, pemphigus vulgaris, pernicious anemia, polyarteritis nodosa, polychondritis, polyglandular syndromes, polymyalgia rheumatica, polymyositis, dermatomyositis, primary agammaglobulinemia, primary biliary cirrhosis, psoriasis, Raynaud’s Phenomenon, Reiter’s Syndrome, rheumatic fever, rheumatoid arthritis, sarcoidosis, scleroderma, Sjögren’s Syndrome, Stiff-Man syndrome, Takayasu Arteritis, temporal arteritis/giant cell arteritis, ulcerative colitis, uveitis, vasculitis, vitiligo, and Wegener’s Granulomatosis.

[0526] Agonistic TNFR2 polypeptides described herein can additionally be used to treat patients in need of organ repair or regeneration. For instance, agonistic TNFR2 antibodies or antigen-binding fragments thereof of the invention may be used to stimulate organ repair or regeneration, e.g., by binding TNFR2 on the surface of cells within damaged tissue so as to induce TRAF2/3- and/or NFκB-mediated cell proliferation. Examples of tissues and organs that may be induced to regenerate by administration of an agonistic TNFR2 antibody or antigen-binding fragment thereof of the invention to a subject (e.g., a mammalian subject, such as a human) include the pancreas, salivary gland, pituitary gland, kidney, heart, lung, hematopoietic system, cranial nerves, heart, blood vessels including the aorta, olfactory gland, ear, nerves, structures of the head, eye, thymus, tongue, bone, liver, small intestine, large intestine, gut, lung, brain, skin, peripheral nervous system, central nervous system, spinal cord, breast, embryonic structures, embryos, and testes.

[0527] Agonistic TNFR2 polypeptides described herein can also be administered to a subject (e.g., a mammalian subject, such as a human) in order to treat a neurological disease or condition, such as a brain tumor, a brain metastasis, a spinal cord injury, schizophrenia, epilepsy, Amyotrophic lateral sclerosis (ALS), Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, or stroke.

[0528] A physician of ordinary skill in the art can readily determine an effective amount of an agonistic TNFR2 polypeptide described herein for administration to a mammalian subject (e.g., a human) in need thereof. For example, a physician could start prescribing doses of an agonistic TNFR2 polypeptide at levels lower than that required to achieve the desired therapeutic effect and gradually increase the dosage until the desired effect is achieved. Alternatively, a physician may begin a treatment regimen by administering an agonistic TNFR2 polypeptide at a high dose and subsequently administer progressively lower doses until a therapeutic effect is achieved (e.g., a reduction in the proliferation of a population of CD8+ T-cells or a decrease in the peripheral secretion of IFNγ). In general, a suitable daily dose of an antibody or antigen-binding fragment thereof of the invention will be an amount of the antibody which is the lowest dose effective to produce a therapeutic effect. An antibody or antigen-binding fragment thereof of the invention may be administered by injection, e.g., by intravenous, intramuscular, intraperitoneal, or subcutaneous injection, optionally proximal to the site of a target tissue. A daily dose of a therapeutic composition of an antibody or antigen-binding fragment thereof of the invention may be administered as a single dose or as two, three, four, five, six or more doses administered separately at appropriate intervals throughout the day, week, month, or year, optionally, in unit dosage forms. While it is possible for an antibody or fragment thereof of the invention to be administered alone, it may also be administered as a pharmaceutical formulation in combination with excipients, carriers, and optionally, additional therapeutic agents.

[0529] Polypeptides of the disclosure can be monitored for their ability to attenuate the progression of an immunological disease, such as an autoimmune disease, by any of a variety of methods known in the art. For instance, a physician may monitor the response of a mammalian subject (e.g., a human) to treatment with an agonistic TNFR2 polypeptide by analyzing the quantity of IFNy secreted by CD8+ T-cells within a particular patient. For example, antibodies of the invention may be capable of reducing IFNy secretion by between 1% and 100% (e.g., 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or 100%). Alternatively, a physician may monitor the responsiveness of a subject (e.g., a human) to treatment with agonisticTNFR2 antibodies or antigen-binding fragments thereof of the invention by analyzing the Treg cell population in the lymph of a particular subject. For instance, a physician may withdraw a sample of blood from a mammalian subject (e.g., a human) and determine the quantity or density of a population of Treg cells (e.g., CD4+ CD25+ FOXP3+ Treg cells or CD17+ Treg cells) using established procedures, such as fluorescence activated cell sorting. In these cases, high counts of Treg cells is indicative of efficacious therapy, while lower Treg cell counts may indicate that the patient is to be prescribed or administered higher dosages of the TNFR2 antibody of the invention until, e.g., an ideal Treg cell count is achieved. In addition, a physician of skill in the art may monitor the effect of treatment by administration of agonistic TNFR2 antibodies of antigen-binding fragments thereof to a patient suffering from an immunological disorder, such as an autoimmune disease described herein, by analyzing the quantity of autoreactive CD8+ T-cells within a lymph sample isolated from the patient. Agonistic TNFR2 antibodies and antigen-binding fragments thereof of the invention may attenuate the proliferation of autoreactive T-cells, e.g., by binding TNFR2 at the surface of an autoreactive T-cell and inducing apoptosis, and/or by stimulating the expansion of Treg cells that subsequently eliminate autoreactive T lymphocytes. Treatment with agonistic TNFR2 antibodies or antigen-binding fragments thereof can lead to reduced quantities of autoreactive T-cells within the lymph isolated from a patient receiving treatment, and a rapid decline in the population of autoreactive T-cells in a lymph sample isolated from such a patient indicates effective treatment. In cases where a lymph sample isolated from a patient exhibits an autoreactive T-cell count that has not declined in response to agonistic TNFR2 antibody therapy, a physician may prescribe the patient higher doses of the antibody or an antigen-binding fragment thereof or may administer the agonistic TNFR2 antibody or antigen-binding fragment thereof with higher frequency, e.g., multiple times per day, week, or month.

Pharmaceutical Compositions

[0530] Pharmaceutical compositions containing an agonistic TNFR2 polypeptide, such as a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct described herein, can be prepared using methods known in the art. Pharmaceutical compositions described herein may contain an agonistic TNFR2 polypeptide described herein in combination with one or more pharmaceutically acceptable excipients. For instance, pharmaceutical compositions described herein can be prepared using, e.g., physiologically acceptable carriers, excipients or stabilizers (Remington’s Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980); incorporated herein by reference), and in a desired form, e.g., in the form of lyophilized formulations or aqueous solutions. The compositions can also be prepared so as to contain the active agent (e.g., an agonistic TNFR2 antibody or fragment thereof) at a desired concentration. For example, a pharmaceutical composition described herein may contain at least 10% (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 97%, 98%, 99%, 99.5%, 99.9%, or 100%) active agent by weight (w/w).

[0531] Additionally, an active agent (e.g., an agonistic TNFR2 polypeptide described herein, such as a dominant agonistic TNFR2 polypeptide described herein) that can be incorporated into a pharmaceutical formulation can itself have a desired level of purity. For example, a polypeptide, such as a single-chain polypeptide, antibody, or antigen-binding fragment thereof described herein may be characterized by a certain degree of purity after isolating the antibody from cell culture media or after chemical synthesis, e.g., of a single-chain antibody fragment (e.g., scFv) by established solid phase peptide synthesis methods or native chemical ligation as described herein. An agonistic TNFR2 polypeptide described herein may be at least 10% pure prior to incorporating the antibody into a pharmaceutical composition (e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or 100% pure).

[0532] Additionally, agonistic TNFR2 polypeptides of the disclosure may be incorporated into a pharmaceutical composition such that many of the polypeptides present in the pharmaceutical composition adopt a single disulfide-bonded isoform. For example, pharmaceutical compositions of the disclosure include those containing an agonist TNFR2 polypeptide in which, e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, 99.99%, or more, of the polypeptide in the pharmaceutical composition is present in a single disulfide-bonded isoform, such as the IgG2-B isoform described herein.

[0533] Pharmaceutical compositions of agonistic TNFR2 polypeptides described herein can be prepared for storage as lyophilized formulations or aqueous solutions by mixing the antibody having the desired degree of purity with optional pharmaceutically acceptable carriers, excipients or stabilizers typically employed in the art, e.g., buffering agents, stabilizing agents, preservatives, isotonifiers, non-ionic detergents, antioxidants, and other miscellaneous additives. See, e.g., Remington’s Pharmaceutical Sciences, 16th edition (Osol, ed. 1980; incorporated herein by reference). Such additives must be nontoxic to the recipients at the dosages and concentrations employed.

Buffering Agents

[0534] Buffering agents help to maintain the pH in the range which approximates physiological conditions. They can be present at concentration ranging from about 2 mM to about 50 mM. Suitable buffering agents for use with agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, and antigen-binding fragments thereof) described herein include both organic and inorganic acids and salts thereof such as citrate buffers {e.g., monosodium citrate-disodium citrate mixture, citric acid-trisodium citrate mixture, citric acid-monosodium citrate mixture, etc.), succinate buffers {e.g., succinic acid- monosodium succinate mixture, succinic acid-sodium hydroxide mixture, succinic acid- disodium succinate mixture, etc.), tartrate buffers (e.g., tartaric acid-sodium tartrate mixture, tartaric acid-potassium tartrate mixture, tartaric acid-sodium hydroxide mixture, etc.), fumarate buffers {e.g., fumaric acid-monosodium fumarate mixture, fumaric acid- disodium fumarate mixture, monosodium fumarate-disodium fumarate mixture, etc.), gluconate buffers (e.g., gluconic acid-sodium gluconate mixture, gluconic acid-sodium hydroxide mixture, gluconic acid-potassium gluconate mixture, etc.), oxalate buffer (e.g., oxalic acid-sodium oxalate mixture, oxalic acid-sodium hydroxide mixture, oxalic acid-potassium oxalate mixture, etc.), lactate buffers (e.g., lactic acid-sodium lactate mixture, lactic acid-sodium hydroxide mixture, lactic acid-potassium lactate mixture, etc.) and acetate buffers {e.g., acetic acid-sodium acetate mixture, acetic acid-sodium hydroxide mixture, etc.). Additionally, phosphate buffers, histidine buffers and trimethylamine salts such as Tris can be used.

Preservatives

[0535] Preservatives can be added to a composition described herein to retard microbial growth, and can be added in amounts ranging from 0.2%-1% (w/v). Suitable preservatives for use with agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein include phenol, benzyl alcohol, meta-cresol, methyl paraben, propyl paraben, octadecyldimethylbenzyl ammonium chloride, benzalconium halides {e.g., chloride, bromide, and iodide), hexamethonium chloride, and alkyl parabens such as methyl or propyl paraben, catechol, resorcinol, cyclohexanol, and 3-pentanol. Isotonifiers sometimes known as “stabilizers” can be added to ensure isotonicity of liquid compositions described herein and include polhydric sugar alcohols, for example trihydric or higher sugar alcohols, such as glycerin, arabitol, xylitol, sorbitol and mannitol. Stabilizers refer to a broad category of excipients which can range in function from a bulking agent to an additive which solubilizes the therapeutic agent or helps to prevent denaturation or adherence to the container wall. Typical stabilizers can be polyhydric sugar alcohols (enumerated above); amino acids such as arginine, lysine, glycine, glutamine, asparagine, histidine, alanine, ornithine, L-leucine, 2-phenylalanine, glutamic acid, threonine, etc., organic sugars or sugar alcohols, such as lactose, trehalose, stachyose, mannitol, sorbitol, xylitol, ribitol, myoinisitol, galactitol, glycerol and the like, including cyclitols such as inositol; polyethylene glycol; amino acid polymers; sulfur containing reducing agents, such as urea, glutathione, thioctic acid, sodium thioglycolate, thioglycerol, a-monothioglycerol and sodium thio sulfate; low molecular weight polypeptides (e.g., peptides of 10 residues or fewer); proteins such as human serum albumin, bovine serum albumin, gelatin or immunoglobulins; hydrophilic polymers, such as polyvinylpyrrolidone monosaccharides, such as xylose, mannose, fructose, glucose; disaccharides such as lactose, maltose, sucrose and trisaccharides such as raffinose; and polysaccharides such as dextran. Stabilizers can be present in the range from 0.1 to 10,000 weights per part of weight active protein.

Detergents

[0536] Non-ionic surfactants or detergents (also known as “wetting agents”) can be added to help solubilize the therapeutic agent as well as to protect the therapeutic protein against agitation-induced aggregation, which also permits the formulation to be exposed to shear surface stressed without causing denaturation of the protein. Suitable non-ionic surfactants include polysorbates (20, 80, etc.), polyoxamers (184, 188 etc.), Pluronic polyols, polyoxyethylene sorbitan monoethers (TWEEN®-20, TWEEN®-80, etc.). Non- ionic surfactants can be present in a range of about 0.05 mg/mL to about 1.0 mg/mL, for example about 0.07 mg/mL to about 0.2 mg/mL.

[0537] Additional miscellaneous excipients include bulking agents (e.g., starch), chelating agents (e.g., EDTA), antioxidants (e.g., ascorbic acid, methionine, vitamin E), and cosolvents.

Other Pharmaceutical Carriers

[0538] Alternative pharmaceutically acceptable carriers that can be incorporated into a pharmaceutical composition described herein may include dextrose, sucrose, sorbitol, mannitol, starch, rubber arable, potassium phosphate, arginate, gelatin, potassium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrups, methyl cellulose, methylhydroxy benzoate, propylhydroxy benzoate, talc, magnesium stearate, and mineral oils, but not limited to. A composition containing an agonistic TNFR2 antibody described herein may further include a lubricant, a humectant, a sweetener, a flavoring agent, an emulsifier, a suspending agent, and a preservative. Details of suitable pharmaceutically acceptable carriers and formulations can be found in Remington’s Pharmaceutical Sciences (19th ed., 1995), which is incorporated herein by reference.

Immunotherapy Agents

[0539] Using the methods described herein, an agonistic TNFR2 polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct thereof) described herein may be co-administered with (e.g., admixed with) or administered separately from an immunotherapy agent. For example, an agonistic TNFR2 polypeptide described herein (such as a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct described herein) may be administered to a patient, such as a human patient suffering from inflammation. In some embodiments, the agonistic TNFR2 polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct described herein) is administered to the patient prior to administration of an immunotherapy agent or other agent to decrease inflammation or pain to the patient. Alternatively, the agonistic TNFR2 polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct described herein) may be administered to the patient after an immunotherapy agent. For example, the agonistic TNFR2 polypeptide (e.g., a single-chain polypeptide, antibody, antigen-binding fragment thereof, or construct described herein) may be administered to the patient after a failed immunotherapy treatment.

Blood-brain Barrier Penetration

[0540] In certain embodiments, agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein can be formulated to ensure proper distribution in vivo. For example, the blood-brain barrier (BBB) excludes many highly hydrophilic compounds. To ensure that the therapeutic compositions described herein cross the BBB (if desired), they can be formulated, for example, in liposomes. Methods of manufacturing liposomes have been described, e.g., U.S. Pat. Nos. 4,522,811; 5,374,548; and 5,399,331. The liposomes may comprise one or more moieties that are selectively transported into specific cells or organs, thereby enhancing targeted drug delivery (see, e.g., V. V. Ranade (J. Clin. Pharmacol. 29:685, 1989)). Exemplary targeting moieties include, e.g., folate or biotin (see, e.g., U.S. Pat. No. 5,416,016); mannosides (Umezawa et al. (Biochem. Biophys. Res. Commun. 153:1038, 1988)); antibodies (P. G. Bloeman et al. (FEBS Lett. 357:140, 1995); M. Owais et al. (Antimicrob. Agents Chemother. 39:180, 1995)); surfactant protein A receptor (Briscoe et al. (Am. J. Physiol. 1233:134, 1995)); the disclosures of each of which are incorporated herein by reference.

Routes of Administration and Dosing

[0541] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein can be administered to a mammalian subject (e.g., a human) by a variety of routes such as orally, transdermally, subcutaneously, intranasally, intravenously, intramuscularly, intraocularly, intratumorally, parenterally, topically, intrathecally and intracerebroventricularly. The most suitable route for administration in any given case will depend on the particular polypeptide administered, the patient, pharmaceutical formulation methods, administration methods (e.g., administration time and administration route), the patient’s age, body weight, sex, severity of the diseases being treated, the patient’s diet, and the patient’s excretion rate.

[0542] The effective dose of an agonistic TNFR2 polypeptide described herein can range, for instance, from about 0.0001 to about 100 mg/kg of body weight per single (e.g., bolus) administration, multiple administrations or continuous administration (e.g., a continuous infusion), or to achieve a serum concentration of 0.0001 -5000 .Math.g/mL serum concentration per single (e.g., bolus) administration, multiple administrations or continuous administration (e.g., continuous infusion), or any effective range or value therein depending on the condition being treated, the route of administration and the age, weight, and condition of the subject. In certain embodiments, each dose can range from about 0.0001 mg to about 500 mg/kg of body weight. For instance, a pharmaceutical composition described herein may be administered in a daily dose in the range of 0.001 -100 mg/kg (body weight). The dose may be administered one or more times (e.g., 2-10 times) per day, week, month, or year to a mammalian subject (e.g., a human) in need thereof.

[0543] Agonistic TNFR2 polypeptides described herein (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) can be administered to a patient by way of a continuous intravenous infusion or as a single bolus administration. The agonistic TNFR2 polypeptides described herein (e.g., e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) may be administered to a patient in an amount of, for example, from 0.01 .Math.g to about 5 g in a volume of, for example, from 10 .Math.L to 10 mL. The agonistic TNFR2 polypeptides may be administered to a patient over the course of several minutes to several hours. For example, the agonistic TNFR2 polypeptides described herein may be administered to a patient over the course of from 5 minutes to 5 hours, such as over the course of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes, 80 minutes, 90 minutes, 95 minutes, 100 minutes, 105 minutes, 110 minutes, 115 minutes, 120 minutes, 125 minutes, 130 minutes, 135 minutes, 140 minutes, 145 minutes, 150 minutes, 155 minutes, 160 minutes, 165 minutes, 170 minutes, 175 minutes, 180 minutes, 185 minutes, 190 minutes, 195 minutes, 200 minutes, 205 minutes, 210 minutes, 215 minutes, 220 minutes, 225 minutes, 230 minutes, 235 minutes, 240 minutes, 245 minutes, 250 minutes, 255 minutes, 260 minutes, 265 minutes, 270 minutes, 275 minutes, 280 minutes, 285 minutes, 290 minutes, 295 minutes, or 300 minutes, or more.

[0544] Agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein may be administered in combination with an immunotherapy agent, such as an agonist of PD-1 such as an antibody or antigen-binding fragment thereof, a PD-L1 agonist antibody or antigen-binding fragment thereof, and/or agonistic CTLA-4 antibody or antigen-binding fragment thereof.

Kits Containing Agonistic TNFR2 Polypeptides

[0545] Also included herein are kits that contain agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof). The kits provided herein may contain any of the agonistic TNFR2 polypeptides described above, as well as any of the polynucleotides encoding these polypeptides, vectors containing these polynucleotides, or cells engineered to express and secrete antibodies described herein (e.g., prokaryotic or eukaryotic cells).

[0546] Exemplary compositions of the disclosure that can be incorporated into a kit described herein include agonistic TNFR2 polypeptides, such as those with at least two TNFR2 binding sites in which the binding sites are spatially separated from one another by about 133 Å or less, as well as those having a human IgG2 isotype, for example, a human IgG2-B isotype. Compositions of the disclosure that can be incorporated into kits described herein also include pharmaceutical compositions containing agonistic TNFR2 polypeptides that adopt a single disulfide-bonded isoform, such as those in which, e.g., 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.9%, 99.99%, or more, of the polypeptide in the pharmaceutical composition is present in a single disulfide-bonded isoform.

[0547] A kit described herein may include reagents that can be used to produce the compositions described herein (e.g., agonistic TNFR2 polypeptides, such as single-chain polypeptides, antibodies, constructs, conjugates containing agonistic TNFR2 polypeptides, polynucleotides encoding agonistic TNFR2 polypeptides, vectors containing these polynucleotides). Optionally, kits described herein may include reagents that can induce the expression of agonistic TNFR2 polypeptides within cells (e.g., mammalian cells), such as doxycycline or tetracycline. In other cases, a kit described herein may contain a compound capable of binding and detecting a fusion protein that contains an agonistic TNFR2 antibody and an epitope tag. For instance, in such cases a kit described herein may contain maltose, glutathione, a nickel-containing complex, an anti-FLAG antibody, an anti-myc antibody, an anti-HA antibody, biotin, or streptavidin.

[0548] Kits described herein may also include reagents that are capable of detecting an agonistic TNFR2 polypeptide (e.g., single-chain polypeptide, antibody, fragment thereof, or construct thereof) directly. Examples of such reagents include secondary antibodies that selectively recognize and bind particular structural features within the Fc region of a TNFR2 antibody described herein. Kits described herein may contain secondary antibodies that recognize the Fc region of an agonistic TNFR2 antibody and that are conjugated to a fluorescent molecule. These antibody-fluorophore conjugates provide a tool for analyzing the localization of agonistic TNFR2 antibodies, e.g., in a particular tissue or cultured mammalian cell using established immunofluorescence techniques. In some embodiments, kits described herein may include additional fluorescent compounds that exhibit known sub-cellular localization patterns. These reagents can be used in combination with another antibody-fluorophore conjugate, e.g., one that specifically recognizes a different receptor on the cell surface in order to analyze the localization of a TNFR2 antibody relative to other cell-surface proteins.

[0549] Kits described herein may also contain a reagent that can be used for the analysis of a patient’s response to treatment by administration of agonistic TNFR2 polypeptides (e.g., single-chain polypeptides, antibodies, antigen-binding fragments thereof, and constructs thereof) described herein. For instance, kits described herein may include an agonistic TNFR2 antibody and one or more reagents that can be used to determine the quantity of Treg cells in a blood sample withdrawn from a subject (e.g., a human) that is undergoing treatment with an antibody described herein. Such a kit may contain, e.g., antibodies that selectively bind cell-surface antigens presented by Treg cells, such as CD4 and CD25. Optionally, these antibodies may be labeled with a fluorescent dye, such as fluorescein or tetramethylrhodamine, in order to facilitate analysis of Treg cells by fluorescence-activated cell sorting (FACS) methods known in the art. Kits described herein may optionally contain one or more reagents that can be used to quantify tumor-reactive T lymphocytes in order to determine the effectiveness of an agonistic TNFR2 polypeptide described herein in restoring tumor-infiltrating lymphocyte proliferation. For instance, kits described herein may contain an antibody that selectively binds cell-surface markers on the surface of a cytotoxic T cell, such as CD8 or CD3. Optionally, these antibodies may be labeled with fluorescent molecules so as to enable quantitation by FACS analysis.

[0550] A kit described herein may also contain one or more reagents useful for determining the affinity and selectivity of an agonistic TNFR2 polypeptide described herein for one or more peptides derived from TNFR2. For instance, a kit may contain an agonistic TNFR2 polypeptide and one or more reagents that can be used in an ELISA assay to determine the K.sub.D of an antibody described herein for one or more peptides that present a TNFR2 epitope in a conformation similar to that of the epitope in the native protein. A kit may contain, e.g., a microtiter plate containing wells that have been previously conjugated to avidin, and may contain a library of TNFR2-derived peptides, each of which conjugated to a biotin moiety. Such a kit may optionally contain a secondary antibody that specifically binds to the Fc region of an agonistic TNFR2 antibody described herein, and the secondary antibody may be conjugated to an enzyme (e.g., horseradish peroxidase) that catalyzes a chemical reaction that results in the emission of luminescent light.

[0551] Kits described herein may also contain agonistic TNFR2 polypeptides described herein and reagents that can be conjugated to such an antibody, including those previously described (e.g., a cytotoxic agent, a fluorescent molecule, a bioluminescent molecule, a molecule containing a radioactive isotope, a molecule containing a chelating group bound to a paramagnetic ion, etc). These kits may additionally contain instructions for how the conjugation of an agonistic TNFR2 antibody described herein to a second molecule, such as those described above, can be achieved.

[0552] A kit described herein may also contain a vector containing a polynucleotide that encodes an agonistic TNFR2 polypeptide, such as any of the vectors described herein. Alternatively, a kit may include mammalian cells (e.g., CHO cells) that have been genetically altered to express and secrete agonistic TNFR2 antibodies or fragments thereof from the nuclear genome of the cell. Such a kit may also contain instructions describing how expression of the agonistic TNFR2 antibody or fragment thereof from a polynucleotide can be induced, and may additionally include reagents (such as, e.g., doxycycline or tetracycline) that can be used to promote the transcription of these polynucleotides. Such kits may be useful for the manufacture of agonistic TNFR2 antibodies or antigen-binding fragments thereof described herein.

[0553] Other kits described herein may include tools for engineering a prokaryotic or eukaryotic cell (e.g., a CHO cell or a BL21 (DE3) E. coli cell) so as to express and secrete an agonistic TNFR2 polypeptide described herein from the nuclear genome of the cell. For example, a kit may contain CHO cells stored in an appropriate media and optionally frozen according to methods known in the art. The kit may also provide a vector containing a polynucleotide that encodes a nuclease (e.g., such as the CRISPER/Cas, zinc finger nuclease, TALEN, ARCUS™ nucleases described herein) as well as reagents for expressing the nuclease in the cell. The kit can additionally provide tools for modifying the polynucleotide that encodes the nuclease so as to enable one to alter the DNA sequence of the nuclease in order to direct the cleavage of a specific target DNA sequence of interest. Examples of such tools include primers for the amplification and site-directed mutagenesis of the polynucleotide encoding the nuclease of interest. The kit may also include restriction enzymes that can be used to selectively excise the nuclease-encoding polynucleotide from the vector and subsequently re-introduce the modified polynucleotide back into the vector once the user has modified the gene. Such a kit may also include a DNA ligase that can be used to catalyze the formation of covalent phosphodiester linkages between the modified nuclease-encoding polynucleotide and the target vector. A kit described herein may also provide a polynucleotide encoding an agonistic TNFR2 polypeptide, as well as a package insert describing the methods one can use to selectively cleave a particular DNA sequence in the genome of the cell in order to incorporate the polynucleotide encoding an agonistic TNFR2 antibody into the genome at this site. Optionally, the kit may provide a polynucleotide encoding a fusion protein that contains an agonistic TNFR2 antibody or fragment thereof and an additional polypeptide, such as, e.g., those described herein.

EXAMPLES

[0554] The following examples are put forth so as to provide those of ordinary skill in the art with a description of how the compositions and methods claimed herein are performed, made, and evaluated, and are intended to be purely exemplary described herein and are not intended to limit the scope of what the inventor regards as her invention.

Example 1. Mapping the Discrete Epitopes Within TNFR2 That Are Bound by Agonistic TNFR2 Polypeptides

[0555] Libraries of linear, cyclic, and bicyclic peptides derived from human TNFR2 were screened for distinct sequences within the protein that exhibit high affinity for monoclonal TNFR2 antibody TNFRAG1. In order to screen conformational epitopes within TFNR2, peptides from distinct regions of the primary protein sequence were conjugated to one another to form chimeric peptides. These peptides contained cysteine residues at strategic positions within their primary sequences. This facilitated an intramolecular cross-linking strategy that was used to constrain individual peptides to a one of a wide array of three-dimensional conformations. Unprotected thiols of cysteine residues were cross-linked via nucleophilic substitution reactions with divalent and trivalent electrophiles, such as 2,6-bis(bromomethyl)pyridine and 1,3,5-tris(bromomethyl)benzene, so as to form conformationally restricted cyclic and bicyclic peptides, respectively. In this way, peptides containing unique combinations of amino acids from disparate regions of the TNFR2 primary sequence were constrained so as to structurally pre-organize epitopes that may resemble those presented in the native TNFR2 tertiary structure. Libraries containing these peptides were screened by immobilizing peptides to distinct regions of a solid surface and treating the surface in turn with the agonistic TNFR2 antibody TNFRAG1, followed by a secondary antibody conjugated to horseradish peroxidase (HRP), and HRP substrate (2,2′-azino-di-3- ethylbenzthiazoline sulfonate) in the presence of hydrogen peroxide. The solid surface was washed in between treatment with successive reagents so as to remove excess or non-specifically bound materials. The luminescence of each region of each surface was subsequently analyzed using a charge coupled device (CCD) - camera and an image processing system.

[0556] The “Constrained Libraries of Peptides on Surfaces” (CLIPS) platform starts with the conversion of the target protein, e.g., TNFR2, into a library of up to 10,000 overlapping peptide constructs, using a combinatorial matrix design (Timmerman et al., J. Mol. Recognit., 20: 283-29, 2007). On a solid carrier, a matrix of linear peptides is synthesized, which are subsequently shaped into spatially defined CLIPS constructs. Constructs representing multiple parts of the discontinuous epitope in the correct conformation bind the antibody with high affinity, which is detected and quantified. Constructs presenting the incomplete epitope bind the antibody with lower affinity, whereas constructs not containing the epitope do not bind at all. Affinity information is used in iterative screens to define the sequence and conformation of epitopes in detail. The raw luminescence data obtained from these ELISA experiments informed the analysis of epitopes present on the surface of TNFR2 that bind agonistic TNFR2 antibodies.

Peptide Synthesis

[0557] To reconstruct epitopes of the target molecule a library of peptides was synthesized. An amino functionalized polypropylene support was obtained by grafting a proprietary hydrophilic polymer formulation via reaction with t-butyloxycarbonyl-hexamethylenediamine (BocHMDA) using dicyclohexylcarbodiimide (DCC) with N-hydroxybenzotriazole (HOBt) and subsequent cleavage of the Boc-groups using trifluoroacetic acid (TFA). Standard Fmoc-peptide synthesis was used to synthesize peptides on the amino-functionalized solid support by custom modified JANUS® liquid handling stations (Perkin Elmer). CLIPS technology allows one to structure peptides into single loops, double- loops, triple loops, sheet-like folds, helix-like folds and combinations thereof. CLIPS templates are coupled to cysteine residues. The side-chains of multiple cysteines in the peptides are coupled to one or two CLIPS templates. For example, a 0.5 mM solution of the CLIPS template (2,6- bis(bromomethyl)pyridine) is dissolved in ammonium bicarbonate (20 mM, pH 7.8)/acetonitrile (1:3(v/v)). This solution is added to a surface-bound peptide array. The CLIPS template will react with side-chains of two cysteines as present in the solid-phase bound peptides of the peptide-arrays (455 wells plate with 3 .Math.l wells). The peptide arrays are gently shaken in the solution for 30 to 60 minutes while completely covered in solution. Finally, the peptide arrays are washed extensively with excess of H.sub.2O and sonicated in disrupt-buffer containing 1 % SDS/0.1 % beta-mercaptoethanol in PBS (pH 7.2) at 70° C. for 30 minutes, followed by sonication in H.sub.2O for another 45 minutes.

Analysis of Binding Affinities of Agonistic TNFR2 Antibodies by Surface Plasmon Resonance

[0558] The affinities of agonistic TNFR2 antibodies for recombinant human TNFR2 were measured using BIACORE™ Analysis Services (Precision Antibody). Briefly, the antibody was biotinylated at a 5:1 stoichiometric ratio using biotinyl-LC-LC-NOSE (Thermo-Fisher) in PBS. Excess biotinylation reagent was removed by centrifugation chromatography and the biotinylated antibody was captured on 3000 RU of streptavidin surface to a level of 100 RU. Theoretical maximum of signal with TNFR2 with that level of antibody capture was 26 RU and that signal was reached with a preliminary experiment using 500 nM TNFR2 in the running buffer. Analysis of the kinetics of antigen binding was performed at a flow of 60 .Math.L/min with 2 min injections. Antibodies were injected at a concentration of 1 mg/ml to the final capture of 100 RU. The instrument used was BIACORE™ 3000 with the BioCap chip (GE Healthcare). Double reference method was used for analysis. Reference channel contained the identical level of streptavidin.

ELISA Screening

[0559] The binding of antibody to each of the synthesized peptides was tested in an ELISA format. Surface-immobilized peptide arrays were incubated with primary antibody solution (overnight at 4° C.). After washing, the peptide arrays were incubated with a 1/1000 dilution of an appropriate antibody peroxidase conjugate (SBA) for one hour at 25° C. After washing, the peroxidase substrate 2,2′-azino-di-3- ethylbenzthiazoline sulfonate (ABTS) and 2 .Math.l/ml of 3 percent H.sub.2O.sub.2 were added. After one hour, the color development was measured. The color development was quantified with a charge coupled device (CCD) - camera and an image processing system. The values obtained from the CCD camera range from 0 to 3000 mAU, similar to a standard 96-well plate ELISA-reader.

[0560] The affinities of a series of peptide fragments of human TNFR2 for TNFRAG1, as assessed by ELISA, are summarized in Table 3, below. Affinity is reported qualitatively using a categorical four-point scale, such that an affinity score of “0” denotes lowest affinity and an affinity score of “4” denotes highest affinity.

TABLE-US-00012 Affinities of human TNFR2 peptide fragments for agonistic TNFR2 antibody TNFRAG1 SEQ ID NO. Portion of Human TNFR2 Amino Acid Sequence Affinity Score 1 Full-length human TNFR2 MAPVAVWAALAVGLELWAAAHALPAQVAFTPYAPEPGSTCRLREYYDQTAQMCCSKCSPGQHAKVFCTKTSDTVCDSCEDSTYTQLWNWVPECLSCGSRCSSDQVETQACTREQNRICTCRPGWYCALSKQEGCRLCAPLRKCRPGFGVARPGTETSDVVCKPCAPGTFSNTTSSTDICRPHQICNVVAIPGNASMDAVCTSTSPTRSMAPGAVHLPQPVSTRSQHTQPTPEPSTAPSTSFLLPMGPSPPAEGSTGDFALPVGLIVGVTALGLLIIGVVNCVIMTQVKKKPLCLQREAKVPHLPADKARGTQGPEQQHLLITAPSSSSSSLESSASALDRRAPTRNQPQAPGVEASGAGEARASTGSSDSSPGGHGTQVNVTCIVNVCSSSDHSSQCSSQASSTMGDTDSSPSESPKDEQVPFSKEECAFRSQLETPETLLGSTEEKPLPLGVPDAGMKPS 4 49 Amino acid residues 1-20 of human TNFR2 LPAQVAFTPYAPEPGSTCRL 0 50 Amino acid residues 9-28 of human TNFR2 PYAPEPGSTCRLREYYDQTA 0 51 Amino acid residues 17-36 of human TNFR2 TCRLREYYDQTAQMCCSKCS 0 52 Amino acid residues 26-45 of human TNFR2 QTAQMCCSKCSPGQHAKVFC 1 53 Amino acid residues 34-53 of human TNFR2 KCSPGQHAKVFCTKTSDTVC 0 54 Amino acid residues 42-61 of human TNFR2 KVFCTKTSDTVCDSCEDSTY 0 55 Amino acid residues 50-69 of human TNFR2 DTVCDSCEDSTYTQLWNWVP 0 56 Amino acid residues 58-77 of human TNFR2 DSTYTQLWNWVPECLSCGSR 0 57 Amino acid residues 66-85 of human TNFR2 NWVPECLSCGSRCSSDQVET 0 58 Amino acid residues 74-93 of human TNFR2 CGSRCSSDQVETQACTREQN 0 59 Amino acid residues 82-101 of human TNFR2 QVETQACTREQNRICTCRPG 0 60 Amino acid residues 90-109 of human TNFR2 REQNRICTCRPGWYCALSKQ 2 61 Amino acid residues 98-117 of human TNFR2 CRPGWYCALSKQEGCRLCAP 1 62 Amino acid residues 106-125 of human TNFR2 LSKQEGCRLCAPLRKCRPGF 2 63 Amino acid residues 108-127 of human TNFR2 KQEGCRLCAPLRKCRPGFGV 2 64 Amino acid residues 114-133 of human TNFR2 LCAPLRKCRPGFGVARPGTE 0 65 Amino acid residues 122-141 of human TNFR2 RPGFGVARPGTETSDVVCKP 0 66 Amino acid residues 130-149 of human TNFR2 PGTETSDVVCKPCAPGTFSN 0 67 Amino acid residues 138-157 of human TNFR2 VCKPCAPGTFSNTTSSTDIC 0 68 Amino acid residues 146-165 of human TNFR2 TFSNTTSSTDICRPHQICNV 0 69 Amino acid residues 154-174 of human TNFR2 TDICRPHQICNVVAIPGNAS 0 70 Amino acid residues 162-181 of human TNFR2 ICNVVAIPGNASMDAVCTST 0 71 Amino acid residues 170-189 of human TNFR2 GNASMDAVCTSTSPTRSMAP 0

[0561] To verify the quality of the synthesized peptides, a separate set of positive and negative control peptides was synthesized in parallel. These were screened with a negative control, antibody 57.9, which does not specifically bind TNFR2 (Posthumus et al. (J. Virology. 64:3304-3309, 1990)).

Epitope Mapping

[0562] ELISA was also used to determine linear epitopes present on the extracellular surface of TNFR2. Linear peptides corresponding to various regions within the TNFR2 primary sequence were purchased from GenScript (Piscataway, NJ), diluted in coating buffer and placed on Immulon 4HBX Flat Bottom Microtiter Plates (Thermo Scientific) at a concentration of 1 .Math.g/well. Primary TNFR2 agonistic antibodies (0.1 .Math.g/well) were incubated with substrates. Secondary antibodies against rodent IgG were used to detect the primary antibodies. Absorbance was measured using the SPECTRAMAX.sup.® 190 Absorbance Plate Reader and analyzed with SoftMax Pro 6.3 (Molecular Devices).

[0563] Results of the epitope mapping analysis are shown in FIG. 1, which displays the primary structure of human TNFR2 highlighting the regions that are bound by exemplary agonistic TNFR2 antibodies of the disclosure, such as TNFRAG1. Additional results of the epitope mapping study are shown in FIGS. 13A and 13B. Together, these data demonstrate that TNFRAG1 specifically binds TNFR2 at an epitope within complementarity-determining region 2 (CRD2) of human TNFR2, which corresponds to amino acid residues 78-120 of SEQ ID NO: 1. A structural model of an agonistic TNFR2 antibody bound to CRD2 of TNFR2 is shown in FIG. 14.

Example 2. Agonistic TNFR2 Polypeptides Expand Treg Cells in a Manner That Can Be Facilitated By Endogenous TNFR2 Ligands and Inhibited by Anti-TNFα Antibodies

[0564] To investigate the ability of agonistic TNFR2 antibody TNFRAG1 to promote the proliferation of Treg cells, a series of experiments was conducted in which populations of Treg cells were incubated with varying concentrations of TNFRAG1 in vitro for 48-72 hours. At the end of the incubation period, the proportion of Treg cells in each population was assessed using flow cytometry methods. As shown in FIG. 2, agonistic TNFR2 antibody TNFRAG1 was found to exert a dose-dependent proliferative effect on Treg cells. The data shown in FIG. 2 represent the average of 35 individual experiments. These results demonstrate that agonistic TNFR2 polypeptides having molecular properties similar to TNFRAG1 (e.g., those that (i) contain a human IgG1 or IgG2 CH1 domain having a deletion or substitution at residue Cys 127, such as a C127S mutation; (ii) contain antigen-binding sites separated from one another by a distance of fewer than about 133 Å; (iii) contain a CDR-H1 having the amino acid sequence of any one of SEQ ID NOs: 2-4 or an amino acid sequence that differs from any one of SEQ ID NOs: 2-4 by way of conservative amino acid substitutions; (iv) contain a framework region having the amino acid sequence of any one of SEQ ID NOs: 5 and 16-23 or an amino acid sequence that differs from any one of SEQ ID NOs: 5 and 16-23 by way of conservative amino acid substitutions; and/or binds an epitope on human TNFR2 within residues 56-60, 101-107, and/or 115-142 of SEQ ID NO: 1) are capable of effectuating the expansion of Treg cells.

[0565] Having determined the proliferative effect of TNFRAG1 on Treg cells, a series of experiments was conducted in order to study the effect of an agonistic TNFR2 ligand, such as TNFα, on the Treg expansion capacity of TNFRAG1. Populations of Treg cells were incubated with 20 ng/ml of TNFα in vitro, either alone or in combination with varying concentrations of TNFRAG1. As shown in FIG. 3, the presence of TNFα was found to further increase the ability of TNFRAG1 to stimulate Treg cell proliferation. Without being limited by mechanism, these data support a TNFRAG1-TNFR2 binding model in which TNFRAG1 binds TNFR2 monomers and brings these individual molecules into a proximity sufficient to form a trimeric structure. This binding event sterically exposes sites on the TNFR2 surface that may be bound by another TNFR2 ligand, such as TNFα, thereby further promoting TNFR2 activation. These results demonstrate that TNFR2 agonist polypeptides of the disclosure, such as those having molecular properties similar to TNFRAG1 , can be combined with TNFα or another agonistic TNFR2 ligand described herein, in order to further augment the expansion of TNFR2-expressing cells, such as Treg cells, MDSCs, or TNFR2+ somatic cells.

[0566] To further test the model of TNFRAG1-TNFR2 binding described above, Treg cells were incubated in vitro with 2.5 .Math.g/ml of TNFRAG1 and varying concentrations of an anti-TNFα antibody. The effects of this combination on Treg proliferation are shown in FIG. 4, which demonstrates that anti-TNFα antibodies have the ability to suppress Treg expansion induced by agonistic TNFR2 polypeptides of the disclosure, such as TNFRAG1.

[0567] Taken together, these data demonstrate that agonistic TNFR2 polypeptides described herein, such as TNFRAG1 and those having TNFR2-binding properties similar to those of TNFRAG1, have the ability to promote the proliferation of TNFR2-expressing cells, such as Treg cells, MDSCs, and TNFR+ somatic cells (e.g., cells of the pancreas, salivary gland, pituitary gland, kidney, heart, lung, hematopoietic system, cranial nerves, heart, aorta, olfactory gland, ear, nerves, structures of the head, eye, thymus, tongue, bone, liver, small intestine, large intestine, gut, lung, brain, skin, peripheral nervous system, central nervous system, spinal cord, breast, embryonic structures, embryos, and testes). These results further illustrate that expansion of TNFR2-expressing cells by an agonistic TNFR2 polypeptide of the disclosure may be further enhanced by a TNFR2-activating ligand, such as TNFα or an agonistic TNFα mutein.

Example 3. Treatment of Type I Diabetes in a Human Patient by Administration of Agonistic TNFR2 Polypeptides

[0568] The agonistic TNFR2 polypeptides of the disclosure (e.g., one or more of the antibodies 1-36 of Table 1 and variants thereof) can be administered to a human patient in order to treat type I diabetes. For instance, a human patient suffering from type I diabetes can be treated by administering an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above, by an appropriate route (e.g., intravenously) at a particular dosage (e.g., between 0.001 and 100 mg/kg/day) over a course of days, weeks, months, or years. If desired, the agonistic TNFR2 antibody can be co-administered with, admixed with, or administered separately from, another therapeutic effective for treating type I diabetes, such as BCG.

[0569] The progression of type I diabetes that is treated with an agonistic TNFR2 antibody of the invention can be monitored by any one or more of several established methods. A physician can monitor the patient by direct observation in order to evaluate how the symptoms exhibited by the patient have changed in response to treatment. A urine sample isolated from the patient may be analyzed in order to determine the content of glucose in the sample, which can indicate the effectiveness of the TNFR2 antibody therapy. For instance, if the content of glucose in the urine sample is high, may indicate that the patient is to be administered higher dosages of an agonistic TNFR2 antibody of the invention until a minimal urine glucose concentration has been maintained.

Example 4. Treatment of Allograft Rejection in a Human Patient by Administration of Agonistic TNFR2 Polypeptides

[0570] The agonistic TNFR2 polypeptides of the disclosure can be administered to a human patient in order to treat allograft rejection. Administration of these antibodies induces the proliferation of a population of Treg cells, which attenuates immune responses mounted by self-reactive cytotoxic T-cells that are associated with the rejection of a tissue graft following transplantation. For instance, a human patient presenting with allograft rejection can be treated by administering an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above, by an appropriate route (e.g., intravenously) at a particular dosage (e.g., between 0.001 and 100 mg/kg/day) over a course of days, weeks, months, or years. If desired, the agonistic TNFR2 antibody can be modified, e.g., by hyperglycosylation or by conjugation with PEG, so as to evade immune recognition and/or to improve the pharmacokinetic profile of the antibody.

[0571] The progression of the allograft rejection that is treated with an agonistic TNFR2 antibody of the invention can be monitored by any one or more of several established methods. A physician can monitor the patient by direct observation in order to evaluate how the symptoms exhibited by the patient have changed in response to treatment. A blood sample can also be withdrawn from the patient in order to analyze the cell count of one or more CD8+ T-cells in order to determine if the quantity of cells has changed (e.g., decreased) in response to treatment with an agonistic TNFR2 antibody of the invention. A physician may also monitor the fluctuation in the volume of the allograft within the patient during the course of TNFR2 antibody therapy. Based on the results of these analyses, a physician may prescribe higher/lower dosages or more/less frequent dosing of the agonistic TNFR2 antibody in subsequent rounds of treatment in order to preserve the allograft.

Example 5. Treatment of Rheumatoid Arthritis in a Human Patient by Administration of Agonistic TNFR2 Polypeptides

[0572] The agonistic TNFR2 polypeptides of the disclosure can be administered to a human patient in order to treat rheumatoid arthritis. For instance, a human patient suffering from rheumatoid arthritis can be treated by administering an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above, by way of conservative amino acid substitutions) by an appropriate route (e.g., intravenously) at a particular dosage (e.g., between 0.001 and 100 mg/kg/day) over a course of days, weeks, months, or years. If desired, the agonistic TNFR2 antibody can be co-administered with, admixed with, or administered separately from, another therapeutic effective for treating rheumatoid arthritis, such as BCG.

[0573] The progression of rheumatoid arthritis that is treated with an agonistic TNFR2 antibody of the invention can be monitored by any one or more of several established methods. A physician can monitor the patient by direct observation in order to evaluate how the symptoms exhibited by the patient have changed in response to treatment. For instance, a physician of skill in the art may monitor the level of joint pain, joint stiffness, or muscle range exhibited by the patient in response to TNFR2 antibody therapy. Additionally, a lymph sample isolated from the patient may be analyzed in order to determine the quantity of autoreactive CD8+ T-cells in the sample, e.g., by FACS analysis, which can indicate the effectiveness of the TNFR2 antibody therapy. For instance, if the count of autoreactive CD8+ T-cells in the lymph sample is high, may indicate that the patient is to be administered higher dosages of an agonistic TNFR2 antibody of the invention, e.g., until the autoreactive T-cell population within the patient has been eliminated.

Example 6. Treatment of Multiple Sclerosis in a Human Patient by Administration of Agonistic TNFR2 Polypeptides

[0574] The agonistic TNFR2 polypeptides of the disclosure can be administered to a human patient in order to treat multiple sclerosis. For instance, a human patient suffering from multiple sclerosis can be treated by administering an antibody, antigen-binding fragment thereof, single-chain polypeptide, or construct containing a heavy chain variable domain and/or light chain variable domain that has at least 85% sequence identity (e.g., 85%, 97%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity) to a heavy chain variable domain and/or light chain variable domain set forth in Table 1, above, by an appropriate route (e.g., intravenously) at a particular dosage (e.g., between 0.001 and 100 mg/kg/day) over a course of days, weeks, months, or years. If desired, the agonistic TNFR2 antibody can be co-administered with, admixed with, or administered separately from, another therapeutic effective for treating multiple sclerosis, such as BCG.

[0575] The progression of multiple sclerosis that is treated with an agonistic TNFR2 antibody of the invention can be monitored by any one or more of several established methods. A physician can monitor the patient by direct observation in order to evaluate how the symptoms exhibited by the patient have changed in response to treatment. For instance, a physician of skill in the art may monitor the patient to determine if he or she is exhibiting improved vision and/or coordination, faster reflexes, increased motor activity, and/or improved cognitive performance in response to TNFR2 antibody therapy. If improvements in these traits are not observed, a physician may prescribe the patient higher doses or more frequent administration of the agonistic TNFR antibody or antigen-binding fragment thereof. Additionally, a lymph sample isolated from the patient may be analyzed in order to determine the quantity of autoreactive CD8+ T-cells in the sample, e.g., by FACS analysis, which can indicate the effectiveness of the TNFR2 antibody therapy. For instance, if the count of autoreactive CD8+ T-cells in the lymph sample that recognize myelin sheath-producing cells is high, this may indicate that the patient is to be administered higher dosages of an agonistic TNFR2 antibody of the invention, e.g., until the autoreactive T-cell population within the patient has been eliminated.

Example 7. TNFR2 Agonist Antibodies Selectively Upregulate Treg Proliferation Upon Incubation with Peripheral Human CD4+ Cells

[0576] TNFR2 agonist antibodies, such as the antibodies described herein (e.g., one or more of antibodies 1-36 of Table 1 and variants thereof) can be used to upregulate Treg cell activity, a beneficial attribute for the treatment of diseases characterized by an autoimmune response. The agonistic TNFR2 antibody, TNFRAG1, which shares the same heavy and light chain CDRs as the antibodies described herein, selectively induces Treg cells upon incubation with peripheral human CD4+ cells. This was ascertained by evaluating the gene expression and metabolic properties of isolated peripheral human CD4+ cells following incubation with the TNFR2 agonist antibody. The ability of a TNFR2 agonist antibody to selectively induce Treg cells further evidences the utility of such antibodies to treat pathologies associated with an aberrant or excessive immune response.

Materials and Methods

Research Study Participants

[0577] Human studies that involved blood drawing were approved by Massachusetts General Hospital and Partners Health Care (Study# 2007P001347, 2012P002243 and 2013P002633). Informed consent was obtained from all subjects and the experiments conformed to the principles set out in the World Medical Association Declaration of Helsinki and the Department of Health and Human Services Belmont Report. Whole blood was collected from research study participants in BD Vacutainer EDTA tubes (BD Diagnostics) and processed within two hrs of phlebotomy.

Isolation of Human CD4.SUP.+ T Cells

[0578] Fresh human whole blood was washed twice with 1x HBSS (Invitrogen) plus 2% FBS (Sigma-Aldrich). CD4.sup.+ T cells were isolated using magnetic EASYSEP™ Direct Human Monocyte Isolation kit or EASYSEP™ Direct Human CD4.sup.+ T Cell isolation kit (STEMCELL Technologies), following the instructions of the manufacturer. Briefly, 1,200 .Math.L of Isolation Cocktail and 1,200 .Math.L of RAPIDSPHERES™ was mixed with 24 mL of whole blood in a 50 mL centrifuge tube and incubated for 5 min at room temperature. Then, 24 mL of Ca.sup.2+ and Mg.sup.2+-free PBS was added and the tube placed into an Easy 50 EASYSEP™ magnet (STEMCELL Technologies). This immobilized the unwanted cells at the side of the tube. After 10 min, the CD4.sup.+ T cell enriched suspension was transferred into a new tube and the magnetic separation process repeated for 5 min with fresh RAPIDSPHERES™. The resulting highly enriched CD4.sup.+ T cell suspension was transferred into a new tube and purified for a third time using the EasySep™ magnet. The resulting purity of the final CD4.sup.+ T cell preparation was >95%. Isolated CD4.sup.+ cells were cultured in RPMI GLUTAMAX™ (Life Technologies) plus 10% FBS (Sigma-Aldrich) with 1% penicillin-streptomycin (Life Technologies). Cells were seeded in 96-well round-bottom plates at a concentration of 0.2 to 1 x 10.sup.6 cells/well, treated with various reagents, and incubated for up to 72 hrs at 37° C. with 5% CO.sub.2. All in vitro cell culture experiments included low level IL-2 (200 U/ml) in the media.

Reagents and Flow Cytometry

[0579] Reagents and flow cytometry mAbs against human TNFR2 and secreted TNFR2 (sTNFR2) were produced internally or obtained from external commercial vendors. Recombinant human TNFα and IL-2 were purchased from Sigma-Aldrich. F(ab′)2 fragments of mAbs were prepared using Pierce F(ab′)2 Preparation Kit (Life Technologies). Antibody MAB2261 (R&D Systems) was used for measuring TNFR2 cell surface expression. Cross-linking antibody against rodent IgG (ab9165) was purchased from Abcam. Cells were prepared for flow cytometry using Human Treg Flow Kit (BioLegend) according to the manufacturer’s instructions. Fluorescently stained cells were resuspended in 1x HBSS (Invitrogen) and analyzed using a BD FACS Calibur flow cytometer machine (Becton Dickinson). Antibodies used for FACS analysis of Tregs included Alexa Fluor 488 anti-human FoxP3 (Clone 259D; BioLegend) for intracellular staining of FoxP3 and phycoerythrin anti-human CD25 (Clone BC96; BioLegend) for cell surface staining of CD25. Treg populations were assessed by FACS with FL2 (red) versus FL1 (green) and defined as CD25.sup.hi and FoxP3.sup.+, whereas Teff populations were defined as CD25.sup.hi and FoxP3.sup.+. For cell suppression assays, responders were stained with carboxyfluorescein diacetate succinimidyl ester (CFSE) (BioLegend) and CDS-allophycocyanin (APC) (Clone SK1; BD Biosciences) and analyzed by FACS with FL4 (far red) versus FL1 (green) (FIG. 3). Monoclonal antibodies against TNFR2 were produced in house or purchased from commercial vendors as previously described for this paper. FACS data was processed using FlowJo software (Version 10.0.8) and analyzed on Prism (GraphPad Software, La Jolla, CA).

Measurement of Secreted TNFR2

[0580] Secreted TNFR2 (sTNFR2) was measured from cell culture supernatants using Quantikine ELISA (R&D Systems) with some modifications. Briefly, supernatants were collected after 24 - 42 hrs of incubation of CD4.sup.+ cells with IL-2 (200 U/ml) alone or with TNFα (20 ng/ml) or TNFR2 mAbs (12.5 mg/ml) and incubated on either the commercial plates or custom plates coated with 2 mg per well of TNFR2-directed antibodies. ELISA was performed according to the manufacturer’s instructions. Absorbance was measured using the SPECTRAMAX™ 190 Absorbance Plate Reader and analyzed with SOFTMAX PRO™ 6.3 (Molecular Devices). For RNA isolation and gene expression analysis, isolated CD4.sup.+ T cells were incubated for 3 hrs in the presence of IL-2 (50 U/ml) and TNFα (20 ng/ml) or TNFR2 antagonist mAb (2.5 .Math.g/ml).

Cell Proliferation and Suppression Assays

[0581] For peripheral blood leukocytes (PBL) proliferation experiments, PBL-s were stained with 1 .Math.M of CFSE. Cells were plated at the density of 2 × 10.sup.5 cells per well in 96-well plate precoated with anti-CD3 mAb (5 .Math.g ml- 1) (OKT3, eBiosciences). Four days later, cells were collected and analyzed by flow cytometry. The proliferation rate was calculated by the percentage of cells undergoing division. For Treg suppression assay, autologous PBMCs were used as responder cells. PBMCs were collected at the day of venipuncture by density gradient separation using Ficoll-Hypaque Plus (GE Healthcare, Piscataway, NJ, USA) cryopreserved at -80° C., and thawed at the day before mixed with Tregs and rested overnight in RPMI 1640 medium supplemented with 1% FBS, and 10 U/mL IL-2. On the following day, responder cells were stained with CFSE (1 .Math.M). Responder cells (5 x 10.sup.4 cells) and expanded Tregs were mixed at the ratio of 0:1, 1:1, 2:1 and 4:1 in culture media, and stimulated with anti-CD3 mAb (HIT3a, BD Biosciences) and IL-2 (50 U ml.sup.-1). After 4 days, cells were collected and analyzed by flow cytometry. Suppression index was calculated by the percentage of CD8+ T cells in responder cells that underwent division. Suppression index was calculated using following equation: (Treg proliferation without Treg -Tresp proliferation with Treg)/Tresp proliferation without Treg.

Cell Suppression Assays

[0582] For suppression assays, peripheral blood mononuclear cells (PBMCs) were used as responders. PBMCs were isolated on the day of venipuncture using a Ficoll-Plaque Plus (GE Healthcare) density gradient and cryopreserved at -80° C. Cells were thawed the day before mixing with Tregs and rested overnight in RPMI 1640 and IL-2 (10 U/ml). The next day, responder cells were stained with 1 mM CFSE. Responder cells (5 x 10.sup.4 cells) were then mixed at various ratios (0:1, 4:1, 2:1, 1:1) with Tregs that had been expanded for 14-17 days. The mixtures stimulated with either anti-CD3 mAb, an antibody directed to human CD3 protein (HIT3a, BD Biosciences), or Dynabeads Human T-Activator CD3/CD28 (Gibco) at a ratio of 2:1 (cells/beads) and IL-2 (50 to 200 U/ml). Cells were collected after 4 to 6 days and stained with CD8-APC (Clone SK1; BD Biosciences), and suppression of cell division was assessed by FACS analysis of CD8.sup.+ T cell counts versus CFSE.

Transcription Profiling Analysis (RNAseq)

[0583] Total RNA was isolated from peripheral blood CD4+ T cells from normal donors using the RNeasy Plus Mini Kit of QIAGEN (QIAGEN Sciences) and processed by the CCCB (Center for Cancer Computational Biology) at Dana Farber Cancer Institute (Boston, Mass). mRNA was prepared from isolated fresh CD4.sup.+ T cells cultured with or without TNFR2 antibodies at a concentration of 2.5 ug/ml for 6 hrs. RNA quality was determined using an Agilent 2100 bioanalyzer. RNA with a RIN value greater than 6 and less than 10% DNA contamination was used for library preparation. Using an input of 100 ng of total RNA, poly-A selection was performed using a NEBNEXT.sup.TN Poly(A) mRNA Magnetic Isolation Module. The resulting mRNA was used for library preparation using the NEBNEXT™ UltraTM Directional RNA Library Prep Kit for Illumina.sup.®. The RNAseq libraries were run on a high sensitivity DNA chip on the Agilent 2100 Bioanalyzer, and the functional concentration of the library was determined through qPCR using the KAPA Biosystems Illumina Library Quantification kit. Libraries to be sequenced were pooled at a concentration of 2 nM then denatured and diluted to a final concentration of 2 pM and loaded onto the Illumina NextSeq 500. Alignment of reads against reference genome HG19 was performed using TopHat and analyzed using Cufflinks. The resulting data was then normalized using DESeq, part of the R-Bioconductor package (Anders, Huber REF). Normalized data was analyzed using the Ingenuity Pathway Analysis software (QIAGEN Sciences), the R Statistical Programming language (Ref) and Microsoft Excel.

Statistical Methods

[0584] Statistical significance was determined using ANOVA and Tukey’s or Dunnett’s multiple comparison test, Student’s t-test, as well as Grubb’s test to remove outliers using Excel (Microsoft) or GraphPad Prism-5 software (GraphPad Software, La Jolla, CA). Computations were performed using SAS version 9.4 (SAS institute, inc, Cary, NC), the R Statistical Computing Language, or in Microsoft Excel. Confidence levels were set to 0.05.

Results

TNFR2 Expression and TNFR2 Agonism

[0585] Evaluation of TNFR2 expression in human T cell populations demonstrates significant difference among cohorts of human subjects. In terms of mean fluorescent intensity (MFI), cancer subjects express significantly higher levels of TNFR2 on Treg of normal healthy subjects or type 1 diabetics (T1D) (FIG. 6A). Conversely, T1D subjects express significantly higher levels of TNFR2 on Teff than either normal subjects of cancer patients (FIG. 6B). When CD4+ T cells are treated with TNFR2 agonist antibody, there is dose dependent proliferation of Treg cells (FIG. 6C). Even in the presence of the natural ligand TNFα (20 ng/ml), there is no significant difference (Paired T test, p>0.5) with escalating concentrations of TNFR2 agonist antibody (FIG. 6D). This demonstrates that TNFα does not augment the efficacy of the TNFR2 agonist antibody, even though TNFα itself is effective in Treg proliferation. Therefore, agonist antibody TNFRAG1 operates in a TNFα-independent manner.

Expansion of Treg and Assessment of Soluble TNFR2

[0586] Evaluation of the F(ab′)2 fragment of TNFR2 agonist antibody demonstrates that the activity of the TNFR2 agonist antibody on Treg proliferation is independent of the Fc region (FIG. 7A). Functional activity of the TNFR2 agonist antibody is also independent of receptor cross-linking, as is evidenced by the observation that co-culturing of rodent anti-IgG antibody with TNFR2 agonist does not inhibit dose dependent Treg proliferation (FIG. 7B). These data suggest that the mechanism of action of the TNFR2 agonist antibody is through an activation pathway that overrides the effect of crosslinking or Fc binding. Consistently, similar dose dependent increases are observed for the proportion of Tregs with escalating concentration of the natural ligand, TNFα, when compared to activation mediated by a TNFR2 agonist antibody (FIG. 7C). Additionally, treatment of CD4+ cells with TNFα leads to a trend of increased soluble TNFR2 in the culture media in the presence of the TNFR2 agonist (FIG. 7D).

Functional Evaluation of Expanded Treg Cells

[0587] To determine the functional capacity of Treg cells expanded in vitro with the TNFR2 agonist, their ability to suppress autologous CD8+ T cells from a type 1 diabetes patient was tested. In co-culture, it was found that the proliferative capacity of the responder, CD8+ T cells (stained with carboxyfluorescein succinimidyl ester (CFSE)) was inhibited by the presence of a greater proportion of Tregs relative to responders (FIGS. 8C - 8E, left). Additionally, the proliferative capacity of the responder, CD8+ T cells (stained with CFSE) was inhibited by Treg cells that were expanded (i) in the presence of TNFα (FIGS. 8C - 8E, middle) or TNFR2 agonist antibody and rapamycin (FIGS. 8C - 8E, right). Of the conditions tested, the greatest suppression of CD8+ T cell proliferation was observed when responder cells were incubated with Treg cells at the lowest ratio of Treg:Responders (1:1), as well as when responder cells were incubated with Treg cells that had been expanded with TNFR2 agonist antibody.

[0588] Taken together, these experiments demonstrate the ability of TNFR2 agonist antibody TNFRAG1, as well as antibodies having similar structural properties (e.g., antibodies having one or more, or all, of the CDRs of TNFRAG1) and/or TNFR2-binding properties as TNFRAG1, to suppress CD8+ T cell proliferation. This phenotype provides an important therapeutic benefit, particularly for treating autoimmune diseases and other conditions, such as those described herein, that are caused by an abnormal immune response against self tissue, as TNFRAG1 and similar antibodies can suppress the CD8+ T cells that mount an inappropriate immune response against self tissue and give rise to the autoimmune disease or other condition.

EVALUATION OF TREG EXPANSION BY ASSESSMENT OF METABOLIC ACTIVITY

[0589] Additional evidence for the expansion of Treg cells by TNFRAG1 is provided by the observation that the agonist antibody induces a metabolic shift in isolated, peripheral CD4+ cells. Particularly, upon incubating TNFRAG1 with such cells, it was observed that the cells exhibited reduced glycolysis (FIG. 10B), elevated glutaminolysis (FIG. 10C), and elevated fatty acid metabolism (FIGS. 12A - 12D). This metabolic shift demonstrates that a TNFR2 agonist antibody, such as TNFRAG1, selectively upregulated Treg cell proliferation among isolated lymphocytes. Additionally, TNFRAG1 was found to increase the expression of early genes involved in the Krebs cycle, and decrease expression of genes involved later in the Krebs cycle (FIGS. 11A - 11C). This observation is significant not only because it is further evidence of Treg expansion, but also because one of the metabolites that results from the early phase of the Krebs cycle, itaconate, is a potent suppressor of autoimmunity. Taken together, these data demonstrate that TNFRAG1, and antibodies that have similar structural properties (e.g., antibodies that have one or more, or all, of the CDRs of TNFRAG1, or a CDR having at least 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or more, sequence identity with respect to the corresponding CDR in TNFRAG1) and/or epitope-binding properties can suppress autoimmunity by selectively inducing Treg cell proliferation and by upregulating an anti-inflammatory metabolite.

Conclusion

[0590] The results of these experiments demonstrate that agonistic TNFR2 antibody TNFRAG1, as well as antibodies having similar structural and/or epitope-binding properties, can be used to selectively upregulate (i) Treg cells and (ii) an important anti-inflammatory metabolite. Without being limited by mechanism, these features represent two possible modalities by which TNFR2 agonist antibodies of the disclosure may be used to treat diseases associated with an aberrant immune response against self antigens.

Other Embodiments

[0591] All publications, patents, and patent applications mentioned in this specification are incorporated herein by reference to the same extent as if each independent publication or patent application was specifically and individually indicated to be incorporated by reference.

[0592] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations described herein following, in general, the principles described herein and including such departures from the invention that come within known or customary practice within the art to which the invention pertains and may be applied to the essential features hereinbefore set forth, and follows in the scope of the claims.

[0593] Other embodiments are within the claims.