Humanized anti-CD4 antibody with immunosuppressive properties

Abstract

A humanized antibody derived from mouse monoclonal anti-CD4 antibody B-F5 is able to activate CD25+CD4+ regulatory T cells and is useful for preparing immunosuppressive compositions.

Claims

1. A humanized anti-CD4 antibody which is a humanized version of a mouse monoclonal anti-CD4 antibody, wherein the mouse monoclonal anti-CD4 antibody comprises a Vh region having SEQ ID NO: 9 and a Vk region having SEQ ID NO: 10, and wherein the humanized anti-CD4 antibody further comprises an IgG1 constant domain.

2. A humanized anti-CD4 antibody which comprises an L chain V domain having the complementarity-determining regions of SEQ ID NO: 2 shown in FIG. 3 and an H chain V domain having the complementarity-determining regions of SEQ ID NO: 1 shown in FIG. 4, wherein the H chain V domain further comprises a Leucine residue at the position 37, and wherein the humanized anti-CD4 antibody further comprises an IgG1 constant domain.

3. A humanized anti-CD4 antibody according to claim 2 which comprises an H chain V domain having SEQ ID NO: 1 and an L chain V domain having SEQ ID NO: 2, and wherein the humanized anti-CD4 antibody further comprises an IgG1 constant domain.

4. A therapeutic composition comprising the humanized anti-CD4 antibody of claim 1.

5. A method of making a humanized anti-CD4 antibody according to claim 3 comprising the steps of: culturing a host cell comprising a polynucleotide encoding SEQ ID NO: 1 and a polynucleotide encoding SEQ ID NO: 2, under conditions suitable for expression thereof, and recovering the expressed humanized anti-CD4 antibody.

6. A method according to claim 5 wherein the host cell is a mammalian cell.

7. A method according to claim 6 wherein the mammalian cell is a CHO cell.

8. A method according to claim 6 wherein the mammalian cell is a Sp2/0 cell.

9. A method according to claim 5 further comprising a step of purifying the expressed humanized anti-CD4 antibody by affinity chromatography using protein A Sepharose.

10. A method according to claim 7 further comprising a step of purifying the expressed humanized anti-CD4 antibody by affinity chromatography using protein A Sepharose.

11. A method according to claim 8 further comprising a step of purifying the expressed humanized anti-CD4 antibody by affinity chromatography using protein A Sepharose.

12. A method of treating a subject suffering from an autoimmune disease comprising administering to said subject an antibody according to claim 1.

13. A polynucleotide comprising a DNA molecule encoding the antibody of claim 1.

14. A method of using the humanized antibody of claim 1 to activate CD25+CD4+ regulatory T cells comprising contacting the humanized antibody with CD25.sup.+CD4.sup.+ regulatory T cells in vitro.

15. A method of preventing graft rejection in a subject comprising administering to said subject the therapeutic composition of claim 4.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts a DNA sequence encoding mouse B-F5 V.sub.H region (SEQ ID No. 5).

(2) FIG. 2 depicts a DNA sequence encoding mouse B-F5 V.sub.K region (SEQ ID No. 6).

(3) FIG. 3 shows an alignment of the polypeptide sequences of B-F5 (SEQ ID No. 10), FK-001 (SEQ ID Nos. 11, 12, 13, and 14, respectively, from left to right), L4L, and L4M (SEQ ID No. 2).

(4) FIG. 4 shows an alignment of the polypeptide sequences of B-F5 (SEQ ID No. 9, M26 (SEQ ID Nos. 15, 16, 17, and 18, respectively, from left to right), H37L, and H37V (SEQ ID No. 19).

(5) FIG. 5 depicts the fragment of the plasmid encoding the VH region of humanized BF-5; the complete nucleic acid sequence is SEQ ID No. 7, the underlined nucleic acid sequence is SEQ ID No. 3, the amino acid sequence is SEQ ID No. 19).

(6) FIG. 6 depicts the fragment of the plasmid encoding the VK region of humanized BF-5; the complete nucleic acid sequence is SEQ ID No. 8, the underlined nucleic acid sequence is SEQ ID No. 4, the amino acid sequence is SEQ ID No. 2).

(7) FIG. 7 shows the results of the ELISA assays, wherein murine and hB-F5s could moderately inhibit ConA-induced proliferation, but the activities varied from antibody to antibody and/or from donor to donor.

(8) FIG. 8 shows the results of the ELISA assays, wherein murine and hB-F5s were able to inhibit Ag-specific PBMC proliferation induced by PPD.

(9) FIG. 9 shows a test of suppressive activity, wherein the negative control (no activation) is preCD25; 0.5 μg/ml OKT-3 (positive control, full activation) is preCD25-CD3; 5 μg/ml hB-F5 (Test 1) is preCD25-CD4; 30 μg/ml hB-F5 (Test 2) is preCD25-CD4.

DETAILED DESCRIPTION OF THE INVENTION

(10) The inventors have however attempted the humanization of mouse B-F5, and have succeeded in producing humanized B-F5 (hereinafter referred to as hB-F5) having the same CD4 binding properties than parent mouse B-F5.

(11) Furthermore, they have found that, surprisingly, hB-F5 has an in vivo optimal immunosuppressive effect at far lower doses than those previously used with parent B-F5, and than those currently used with other anti-CD4 monoclonal antibodies.

(12) Actually, the inventors have observed that hB-F5 provided an effective immunosuppression, reflected by a positive clinical effect in rheumatoid arthritis patients, when used in a 10 days treatment at a dose as low as 1 mg/day, and preferably at a dose of 5 mg every second day.

(13) The present invention provides a humanized antibody (hB-F5) derived from mouseB-F5 MAb, wherein said hB-F5 antibody has V domains defined by the following polypeptide sequences:

(14) TABLE-US-00001 - H chain V domain: (SEQ ID NO: 1) EEQLVESGGGLVKPGGSLRLSCAASGFSFSDCRMYWLRQA PGKGLEWIGVISVKSENYGANYAESVRGRFTISRDDSKNTVYLQMNSLKTEDTAVYYCS ASYYRYDVGAWFAYWGQGTLVTVSS  - L chain V domain: (SEQ ID NO: 2) DIVMTQSPDSLAVSLGERATINCRASKSVSTSGYSYIYWYQQ KPGQPPKLLIYLASILESGVPDRFSGSGSGTDFTLTISSLQAEDVAVYYCQHSRELPWTFG QGTKVEIK.

(15) Generally, ahB-F5 antibody of the invention further comprises a human constant region (Fc). This constant region can be selected among constant domains from any class of immunoglobulins, including IgM, IgG, IgD, IgA and IgE, and any isotype, including IgG1, IgG2, IgG3 and IgG4. Preferred constant regions are selected among constant domains of IgG, in particular IgG1.

(16) The present invention also includes any fragment of an hB-F5 antibody comprising the V regions thereof. This comprises in particular Fab, Fab′, F (ab)′2, Fv andscFv fragments.

(17) The invention also encompasses a polynucleotide selected among:

(18) a polynucleotide encoding a polypeptide of SEQ ID NO: 1

(19) a polynucleotide encoding a polypeptide of SEQ ID NO: 2.

(20) Preferably, said polynucleotide is selected among:

(21) a polynucleotide of SEQ ID NO: 3;

(22) a polynucleotide of SEQ ID NO: 4.

(23) Polynucleotides of the invention can easily be obtained by the well-known methods of recombinant DNA technology and/or of chemical DNA synthesis.

(24) A polynucleotide encoding the V domain of the H chain or of the L chain of a hB-F5 antibody may be fused with a polynucleotide coding for the constant region of a human H or L chain, for the purpose of expressing the complete H and L chains obtained in this way; a sequence coding a signal peptide allowing the secretion of the protein can also be added. These recombinant polynucleotides are also part of the invention.

(25) The invention also provides expression cassettes wherein a polynucleotide of the invention is linked to appropriate control sequences allowing the regulation of its transcription and translation in a chosen host cell, and recombinant vectors comprising a polynucleotide or an expression cassette of the invention.

(26) These recombinant DNA constructs can be obtained and introduced in host cells by the well-known techniques of recombinant DNA and genetic engineering.

(27) The invention also comprises a host cell, transformed by a polynucleotide of the invention.

(28) Useful host-cells within the framework of the present invention can be prokaryotic or eukaryotic cells. Among suitable eukaryotic cells, one will mention, by way of example, plant cells, cells of yeasts such as Saccharomyces, cells of insects such as Drosophila, or Spodoptera, and mammal cells such as HeLa, CHO, 3T3, C127, BHK, COS, etc. . . .

(29) The construction of expression vectors of the invention, and the transformation of host-cells can be made by the standard techniques of molecular biology.

(30) An hB-F5 antibody of the invention can be obtained by culturing a host cell containing an expression vector comprising a nucleic acid sequence encoding said antibody, under conditions suitable for the expression thereof, and recovering said antibody from the host cell culture.

(31) The present invention also comprises a therapeutic composition comprising a hB-F5 antibody of the invention or a fragment thereof, as defined above.

(32) Preferably, said composition is a composition for parenteral administration, formulated to allow the administration of a dose of from 0.1 to 10 mg, advantageously of from 1 to 5 mg of hB-F5.

(33) More specifically, the invention encompasses the use of an hB-F5 antibody of the invention or a fragment thereof, for preparing an immunosuppressive composition. Said immunosuppressive composition is useful in particular for the treatment or prevention of diseases such as graft rejection, graft-versus-host reaction or host-versus-graft reaction, or autoimmune diseases including for instance myocarditis, diabetes mellitus, psoriasis, lupus erythematosus, Crohn's disease, multiple sclerosis, rheumatoid arthritis, etc.

(34) Moreover, the inventors have found out that hB-F5 was able to activate a particular subset of T CD4+ cells, namely CD4+CD25+ cells.

(35) CD25+CD4+ regulatory T cells (Treg cells) constitute 5-10% of peripheral CD4+ T cells. They were first described in 1995 by Sakaguchi et al. (J. Immunol., 155: 1151-1164) as regulatory cells in mice. When activated, these cells are able to suppress both CD4+ and CD8+ T cell activation and proliferation. Later, CD25+CD4+ suppressor T cells have also been found in humans (Jonuleit et al., J. Exp. Med. 193, 1285-1294, 2001; Levings et al., J. Exp. Med. 193, 1295-1302, 2001; Dieckmann et al., J. Exp. Med. 193, 1303-1310 2001). Numerous articles have been published describing the immunosuppressive role of these cells in different autoimmune disease models and in vitro systems (for review, see for instance Shevach, J. Exp. Med., 193, 11, 41-46, 2001). Ex vivo activated CD4+CD25+ Treg cells have also been shown to be effective at preventing graft-versus-host disease (Taylor et al., Blood, 99, 3493-3499, 2002; Cohen et al., J. Exp. Med. 196, 401-406, 2002; Hoffmann et al., J. Exp. Med. 196, 389-399, 2002). Thus, providing means for activating CD4+CD25+ Treg cells is of great interest.

(36) The invention also relates to the use of the hB-F5 antibody of the invention, or of the parent antibody B-F5, to activate in vitro CD25+CD4+ regulatory T cells.

(37) Preferably, the hB-F5 antibody of the invention is added to the CD25+CD4+ regulatory T cells at a concentration 1 μg/ml from 10 μg/ml.

EXAMPLES

(38) The present invention will be further illustrated by the following additional description, which refers to examples illustrating the properties of hB-F5 antibodies of the invention. It should be understood however that these examples are given only by way of illustration of the invention and do not constitute in any way a limitation thereof.

Example 1: Construction of Humanized B-F5

(39) Design of Humanized B-F5 VH and VK Regions

(40) DNA sequences encoding mouse B-F5 V.sub.H and V.sub.K regions are respectively shown in FIG. 1 and FIG. 2 and under sequence identifiers SEQ ID NO: 5 and SEQ IN ISO: 6. The human V.sub.H and V.sub.K on which the mouse CDRs are grafted were selected by searching databases for human VH most like the original mouse B-F5 V.sub.H and V.sub.K. V.sub.H region of a human antibody (M26; Accession Number A36006) had the highest homology with B-F5 V.sub.H. V.sub.K region of another human antibody (FK-001; NAKATANI et al., Biotechnology, 7 (1989), 805-810)) had the highest homology with B-F5 V.sub.K.

(41) Two types of V.sub.K differing between them in that the 4th residue was Leucine or Methionine were constructed and designated as L4L and L4M. Two types of VH differing between them in that the 37th amino acid residue was Leucine or Valine, were constructed and designated as H37L and H37V. The alignment of the polypeptide sequences of B-F5, FK-001, L4L, and L4M is shown in FIG. 3. The alignment of the polypeptide sequences of B-F5, M26, H37L, and H37V is shown in FIG. 4. The FR residues previously reported to be important for the packing of CDRs (Chothia et al., Nature, 342 (1989), 877; Foote et al., J. Mol. Biol., 224 (1992), 487) are boxed.

(42) By combining these VH and VK, 4 versions of V regions were designed.

(43) Expression of Humanized B-F5

(44) The subsequent steps for production of humanized B-F5 were the same as those disclosed in U.S. Pat. No. 5,886,152 for humanizedB-B10.

(45) Briefly, expression plasmids for the H chain (VH humanized region fused to the constant region of a humany-1 chain (TAKAHASHI et al., Cell, 29 (1982), 671-679)) and the L chain (VK humanized region fused to the constant region of FK-001K chain) of humanized B-F5 were constructed separately. In these plasmids, the expression of humanized B-F5 is driven by the promoter/enhancer of the gene of human monoclonal IgM, FK-001. FIGS. 5 and 6 respectively show the fragments of the plasmids encoding the VH and VK regions of humanized BF-5. The sequences encoding the V region are underlined and the corresponding polypeptide sequences are indicated above the nucleotide sequence. Both plasmids and pSV2neo were simultaneously introduced into mouse myeloma Sp2/0 (ATCC CRL-1581) using Lipofectin. Transfectomas producing human IgG were selected by ELISA, using an anti-human IgG (y chain) antibody and an anti-human Ig K chain antibody.

Example 2: Characterisation of the Different Versions of Humanized

(46) B-F5 Estimation of CD4 Binding Activity

(47) Culture supernatants of transfectomas producing the four versions of hB-F5 were collected, and concentrated. The different antibodies were purified from culture supernatants by affinity chromatography using protein A Sepharose and assessed for their CD4 binding activity by measuring, by means of competitive ELISA, their inhibitory activities against the binding of biotinylated mB-F5 to soluble CD4 coated on microtiter plates. Incubation time is 2 hours for 37 C and overnight for 4 C.

(48) The relative binding activities of hB-F5s (binding activity of mB-F5 was taken as 100%) are shown in Table I below

(49) TABLE-US-00002 TABLE I Relative binding activity Antibody Temp (° C.) (% of mB-F5) H37L/L4L 4 80 37 30 H37L/L4M 4 80 37 30 H37V/L4L 4 10-20 37 10 H37V/L4M 4 10-20 37 10

(50) From the results shown in Table I, it appears that the 37th residue of V.sub.H, Leucine, is critical to maintain CD4 binding activity of hB-F5 because the CD4 binding activity is several-fold reduced by conversion of .sup.37Leu to .sup.37Val. On the contrary, the 4.sup.th residue of V is found to be not so important for the CD4 binding activity. As the structural difference between .sup.37Leu and .sup.37Val of V.sub.H is not clearly demonstrated by molecular modeling, the superiority of H37L to H37V in CD4 binding activity was unexpected.

(51) H37L/L4L and H37L/L4M were chosen for evaluating the in vitro biological activities.

(52) Investigation of the In Vitro Biological Activities of Humanized B-F5

(53) The in vitro biological activities of mouse B-F5 and humanized B-F5s (H37L/L4M IgG1 and H37L/L4L IgG 1) were evaluated. Humanized B-F5s of IgG2 type (H37L/L4M IgG2 and H37L/L4L IgG2) were also tested.

(54) The in vitro biological activities of mB-F5 and the four types of hB-F5s were evaluated using peripheral blood mononuclear cells (PBMCs) from healthy donors. PBMCs were activated by ConA (2.5 μg/ml, 3 days) of PPD (10 μg/ml, 4 days) in the presence of murine or hB-F5s, and were monitored for their proliferative responses by .sup.3H-thymidine incorporation.

(55) The results are shown in FIGS. 7 and 8. Murine and hB-F5s could moderately inhibit ConA-induced proliferation, but the activities varied from antibody to antibody and/or from donor to donor (FIG. 7). Also, murine and hB-F5s were able to inhibit Ag-specific PBMC proliferation induced by PPD (FIG. 8).

(56) IgG1 type of hB-F5 inhibited PPD-induced proliferation more effectively (as high as 70% inhibition, FIGS. 7 and 8) than Mb-F5. IgG1 type seemed to be more effective than IgG2 type of which inhibitory activity was almost the same as mB-F5. For IgG2 type of H37L/L4M and H37L/L4L inhibitory activities of B-F5s against PPD-induced PMBC proliferation were as follows: H37L/L4M IgG1>H37L/L4L IgG1>H37L/L4M IgG2=H37L/L4L IgG2=mB-F5.

(57) Considering the efficacy of the in vitro biological activity and the smaller number of mouse amino acids, H37L/L4M IgG1 was chosen for further evaluation.

Example 3: Preliminary Evaluation of the Effect of Hb-F50N Patients with Reheumatoid Arthritis (RA)

(58) The Effect of hB-F5 (H37L/L4M IgG1) was Tested on RA Patients.

(59) The conditions of the assay are as follows:

(60) Each patient received a 10 days treatment consisting of 5 injections of 5 mg of hB-F5 (an injection every 2nd day).

(61) The results for 3 different patients are shown in Tables II-IV below:

(62) Patient 1 (Table II):

(63) Diagnosis: Rheumatoid Arthritis, Activity 2

(64) Rheumatoid factor: 2; Stage: 2

(65) Sex: F; Age: 65; Onset of the disease: 1965

(66) Additional therapy: Diclophenac 150 mg/day

(67) TABLE-US-00003 TABLE II After treatment Before During treatment (days) (weeks) Clinical Investigations Treatment 2 4 6 8 10 4 Estimation of pain in joints 4.5 2 2 1.5 3 2.2 3.5 (0-10) Morning stiffness in minutes 360 0 0 90 90 120 20 Severity of Physician 3 3 3 2.5 3 3 3 condition (1-5) Patient 3 3 3 3 3 3 3 Number of swollen joints 6 6 4 3 2 2 7 Number of painful joints 25 12 6 7 13 13 23 Swelling index (0-30) 8 6 4 2 3 9 Power in hand Right 17 15 20 22 12 20 15 Left 10 10 10 15 12 19 12 Estimation of tiredness (0-10) 7.7 4 2.3 2 2.3 3.1 3 Estimation of Patent 3 3 4 3 5 2 treatment Physician 3 3 4 3 5 2 effects Erythrocyte sedimentation 35 34 25 rate C-Reactive Protein 4.0 2 2.5

(68) Patient 2 (Table III):

(69) Diagnosis: Rheumatoid Arthritis, Activity 3

(70) Rheumatoid factor: 2; Stage: 2

(71) Sex: F; age: 48 Onset of the disease: 2000

(72) Additional therapy. Diclophenac 150 mg/day

(73) TABLE-US-00004 TABLE III After treatment Before During treatment (days) (weeks) Clinical Investigations Treatment 2 4 6 8 10 4 Estimation of pain in joints 8.2 8.2 5 2.9 2.2 0.6 (0-10) Morning stiffness in minutes 240 120 120 60 20 10 Severity of Physician 4 3 3 3 3 2 condition (1-5) Patient 4 4 3 3 3 2 Number of swollen joints 13 12 11 11 5 5 Number of painful joints 22 22 16 15 13 7 Swelling index (0-30) 15 14 12 11 5 5 Power in hand Right 30 30 28 34 36 40 Left 22 20 18 18 22 28 Estimation of tiredness (0-10) 8.7 5.1 2.2 2.2 1.1 0.7 Estimation of Patent 3 4 4 4/5 5 treatment Physician 3 2 3 4/5 5 effects Erythrocyte sedimentation 35 38 35 rate C-Reactive Protein 1.2 0.2 0.8

(74) Patient 3 (Table IV):

(75) Diagnosis: Rheumatoid Arthritis, Activity 3

(76) Rheumatoid factor: 3; Stage: 2

(77) Sex: F; Age: 49; Onset of the disease: 1989

(78) Additional therapy. Diclophenac 150 mg/day

(79) TABLE-US-00005 TABLE IV After treatment Before During treatment (days) (weeks) Clinical Investigations Treatment 2 4 6 8 10 1 2 Estimation of pain in joints 7.9 7.6 7.6 7.2 5.0 3.0 1.5 1.3 (0-10) Morning stiffness in 360 0 0 0 0 0 0 minutes Severity of Physician 4 3 3 3 3 3 2 2 condition (1-5) Patient 5 4 4 3 3 2 2 Number of swollen joints 10 7 7 6 5 5 5 5 Number of painful joints 30 24 24 15 11 11 10 9 Swelling index (0-30) 15 12 12 9 7 7 6 Power in hand Right 24 30 30 36 48 48 50 50 Left 24 30 30 38 40 34 40 42 Estimation of tiredness (0-10) 8.5 7.2 5.2 0 0 0 0 0 Estimation of Patent 3 3 3 5 5 5 treatment Physician 3 4/3 4 4 5 5 5 effects Erythrocyte sedimentation 61 53 42 45 41 rate C-Reactive Protein 8 3.7 3.3

Example 4: Activation of CD4+CD25+ Treg Cells by hB-F5

(80) Isolation of T cells:

(81) 1) T regulatory Cells (Tregs):

(82) CD25+ cells are isolated using CD25 microbeads;

(83) Depletion of contaminations: CD14−, CD8−, CD19− positive cells is made with CD14/CD8/CD19DYNALbeads;

(84) Depletion of CD45RA+ cells is made with CD45RA mAb+anti-mouse DYNALbeads: purity: >95% CD4+CD25+ Tregs

(85) 2) Effector Cells

(86) CD4+ T cells are isolated using CD4 microbeads

(87) Depletion of CD45RO+ cells is made with CD45RO+mAb+anti-mouse DYNALbeads; purity: >98% CD4/CD45RA+, CD25− effector T cells

(88) 3) Test System:

(89) CD25+ Tregs from donor A are cocultured for 2 days with syngenic CD2-depleted PBMC, without additions (negative control=no activation=no suppressive activity), or in the presence of 0.5 μg/ml anti-CD3 (OKT-3=positive control=full activation of Tregs), or in the presence of 5 μg/ml or 30 μg/ml hB-F5.

(90) After extensive washing of pre-cultured cells, CD25+ Tregs cells are isolated and treated by y-radiation (3000 rad).

(91) 4) Test of Suppressive Activity:

(92) Pre-cultured CD25+ Tregs cells are cocultured for 4 days with freshly isolated CD4+ effector T cells (1:1) from donor B in the presence of APC's (CD2-depleted PBMC) from donor A (syngenic for pre-cultured T cells (no additional activation), allogeneic for effector T cells (=allogeneic mixed lymphocyte reaction). Then, cells are incubated for 16 h with 3H Thymidine, and proliferation of effector T cells is detected.

(93) The results are shown in FIG. 9.

(94) Legend of FIG. 9:

(95) negative control (no activation)=preCD25;

(96) 0.5 μg/ml OKT-3 (positive control, full activation)=preCD25-CD3;

(97) 5 μg/ml hB-F5(Test-1)=preCD25-CD4;

(98) 30 μg/ml hB-F5 (Test-2)=preCD25-CD4.