Agents, uses and methods

Abstract

The present invention relates to agents comprising a binding moiety with binding specificity for SRCR domain 1 of the CD163 receptor, for use in medicine. The invention also relates to methods, uses, kits and compositions comprising such agents.

Claims

1. An agent comprising a binding moiety with binding specificity for SRCR domain 1 of the CD163 receptor, wherein the agent comprises a cytotoxic moiety and/or a drug to be delivered to a cell having a CD163 receptor localized on its surface, wherein the agent is internalized into the cell when bound to the CD163 receptor, wherein said cytotoxic moiety and/or a drug is selected from the group consisting of an alkylating agent, an antimetabolite, an antimitotic, a topoisomerase inhibitor, a toxin, an immunosuppressive drug, an immunostimulatory drug, and a protein having biological activity having efficacy in the treatment of a condition or disorder affecting macrophage.

2. An agent according to claim 1 wherein the binding moiety with specificity for SRCR domain 1 of the CD163 receptor is selected from the group consisting of: (a) an antibody or an antigen-binding fragment thereof, or a variant, fusion or derivative of said antibody or an antigen-binding fragment, or a fusion of a said variant or derivative thereof, which retains the binding specificity for SRCR domain 1 of the CD163 receptor; (b) antibody mimics (for example, based on non-antibody scaffolds); (c) RNA aptamers; (d) small molecules; and (e) CovX-bodies.

3. An agent according to claim 1 wherein the CD163 receptor is a human CD163 receptor.

4. An agent according to claim 1 wherein the binding moiety is capable of binding to the consensus sequence: TABLE-US-00050 SEQ ID NO: 26 K-X.sub.1-VKVQEE-X.sub.2-R wherein: X.sub.1 represents Xaa.sub.5-8 (wherein Xaa represents any amino acid(s)); and; X.sub.2 is absent or represents Xaa.sub.38-42 (wherein Xaa represents any amino acid(s)).

5. An agent according to claim 1 wherein the binding moiety is capable of binding to the sequence: TABLE-US-00051 SEQ ID NO: 27 KCSGRVEVKVQEEWGTVCNNGWSMEAVSVICNQLGCPTAIKAPGWANSSAGSGR.

6. An agent according to claim 1 wherein the CD163 receptor is localised on the surface of a cell.

7. An agent according to claim 6 wherein the cell is a malignant cell, immune modulatory cell, inflamed cell or infected cell expressing the CD163 receptor.

8. An agent according to claim 6 wherein the cell is a monocyte and/or monocyte-derived cell.

9. An agent according to claim 1 wherein the binding moiety exhibits greater binding affinity for SRCR domain 1 of the CD163 receptor in the presence of calcium than in the absence of calcium.

10. An agent according to claim 2 wherein the binding moiety comprises an antibody or an antigen-binding fragment thereof, or a variant, fusion or derivative of said antibody or an antigen-binding fragment, or a fusion of a said variant or derivative thereof, which retains the binding specificity for SRCR domain 1 of the CD163 receptor.

11. An agent comprising a binding moiety with binding specificity for SRCR domain 1 of the CD163 receptor, wherein the agent is internalized into the cell when bound to the CD163 receptor, wherein the agent comprises a cytotoxic moiety and/or a drug to be delivered to a cell having a CD163 receptor localized on its surface, wherein the binding moiety comprises an antibody or an antigen-binding fragment thereof, or a variant, fusion or derivative of said antibody or an antigen-binding fragment, or a fusion of a said variant or derivative thereof, which retains the binding specificity for SRCR domain 1 of the CD163 receptor, wherein the antibody, antigen-binding fragment, variant, fusion or derivative thereof comprises: a heavy-chain variable (V.sub.H) region comprising SEQ ID NO: 20 and a light-chain variable (V.sub.L) region comprising SEQ ID NO: 21; or a heavy-chain variable (V.sub.H) region comprising SEQ ID NO: 22 and a light-chain variable (V.sub.L) region comprising SEQ ID NO: 23.

12. An agent according to claim 1 wherein said cytotoxic moiety and/or a drug is a immunosuppressive drug, an immunostimulatory drug, or a protein having biological activity having efficacy in the treatment of a condition or disorder affecting macrophage.

13. A pharmaceutical composition comprising an effective amount of an agent as defined in claim 1 and a pharmaceutically-acceptable diluent, carrier or excipient.

14. A kit comprising an agent as defined in claim 1.

15. An agent according to claim 1, wherein said cytotoxic moiety and/or a drug is selected from the group consisting of an alkylating agent, an antimetabolite, an antimitotic, a topoisomerase inhibitor, and a toxin.

16. An agent according to claim 15, wherein said cytotoxic moiety and/or a drug is an alkylating agent.

17. An agent according to claim 16, wherein said alkylating agent is cisplatin or carboplatin.

18. An agent according to claim 15, wherein said cytotoxic moiety and/or a drug is an antimetabolite.

19. An agent according to claim 18, wherein said antimetabolite is azathioprine or methotrexate.

20. An agent according to claim 15, wherein said cytotoxic moiety and/or a drug is an antimitotic.

21. An agent according to claim 20, wherein said antimitotic is vincristine.

22. An agent according to claim 15, wherein said cytotoxic moiety and/or a drug is a topoisomerase inhibitor.

23. An agent according to claim 22, wherein said topoisomerase inhibitor is doxorubicin or etoposide.

24. An agent according to claim 15, wherein said cytotoxic moiety and/or a drug is a toxin.

25. An agent according to claim 24, wherein said toxin is calicheamicin.

26. An agent according to claim 12, wherein said cytotoxic moiety and/or a drug is an immunosuppressive drug.

27. An agent according to claim 26, wherein said immunosuppressive drug is an anti-inflammatory drug, a glucocorticoid, methotrexate, cyclophosphamide, 6-mercaptopurin, cyclosporine, tacrolimus, mycophenolate mofetil, sirulimus, everolimus, an siRNA molecule inhibiting synthesis of proinflammatory cytokines, a non-steroidal anti-inflammatory drug (NSAIDs), a steroid, and a disease-modifying anti-rheumatic drug.

28. An agent according to claim 26, wherein said immunosuppressive drug is a glucocorticoid.

29. An agent according to claim 12, wherein said cytotoxic moiety and/or a drug is an immunostimulatory drug.

30. An agent according to claim 29, wherein said immunostimulatory drug is an siRNA molecule.

31. An agent according to claim 12, wherein said cytotoxic moiety and/or a drug is a protein having biological activity having efficacy in the treatment of a condition or disorder affecting macrophage.

32. An agent according to claim 31, wherein said protein having biological activity having efficacy in the treatment of a condition or disorder affecting macrophage is glucocerebrosidase.

Description

(1) Preferred, non-limiting examples which embody certain aspects of the invention will now be described, with reference to the following figures:

(2) FIGS. 1A-1D—Peripheral blood monocyte CD163 distribution in freshly drawn samples using different anti-CD163 clones. After gating monocytes in a forward scatter [FSC] versus side scatter [SSC], the gated cells were re-plotted with CD14 APC versus CD163 PE clone (FIG. 1A) MAC2-158, SRCR domain-1, (FIG. 1B) R-20, SRCR domain-4, (FIG. 1C) GHI/61, SRCR domain-7, and (FIG. 1D) RM3/1, SRCR domain-9.

(3) FIGS. 2A-2C—Monocytic cellular CD163 expression in blood samples under influence of various anticoagulants using different anti-CD163 clones. The influence of different extracellular calcium concentrations on monocyte surface CD163 expression determination was investigated in freshly drawn whole blood stabilized with three commonly used anticoagulants, (FIG. 2A) EDTA, (FIG. 2B) citrate, and (FIG. 2C) heparin. After gating monocytes in a forward scatter [FSC] versus side scatter [SSC], the gated cells were re-plotted with CD14 APC versus CD163 PE clone (left panels) MAC2-158, SRCR domain-1, (second panels) R-20, SRCR domain-4, (third panels) GHI/61, SRCR domain-7, and (right panels) RM3/1, SRCR domain-9.

(4) FIGS. 3A-3B—Schematic representation of the monocytic cellular CD163 expression in samples anti-coagulated with EDTA, citrate, and heparin using different CD163 mAbs. After gating monocytes in a forward scatter [FSC] versus side scatter [SSC], the gated cells were re-plotted with CD14 APC versus CD163 PE clone. Subsequently, (FIG. 3A) the fraction of CD163 positive monocytes and (FIG. 3B) the mean R-Phycoerythrin conjugated CD163 Abs bound per cell was estimated. Quantibrite PE beads were used to convert the FL2 linear fluorescence staining of cell population into the number of CD163 R-Phycoerythrin molecules bound per cell reflecting the receptor density. Results are expressed as mean±standard error (SE) of triplicate samples. The presented data are representative of several independently performed experiments.

(5) FIG. 4—mAbs binding to immobilized CD163 in either 2 mM free Ca.sup.2+ (solid line) or 10 mM EDTA (dotted line). Concentration of mAbs are 5 μg/ml, except for R-20 and 5C6-FAT (10 μg/ml) and GHI/61 (20 μg/ml)

(6) FIG. 5—Cellular binding and uptake of different .sup.125I-labeled clones of monoclonal CD163 antibodies. To compare the endocytic ability of different clones of monoclonal CD163 antibodies, CD163 transfected Flp-In CHO cells were incubated with different .sup.125I-labeled CD163 antibodies. The degree of cell-associated radioactivity detected in non-transfected Flp-In CHO cells was insignificant.

(7) FIG. 6—CD163 antibody binding and uptake in human macrophages. Monocyte-derived macrophages incubated for 0 or 30 minutes with immunofluorescent mAbs binding CD163, detected using fluorescent laser microscopy. As can be seen MAc2-158 exhibit both best binding and uptake.

(8) FIGS. 7A and 7B—CD163 antibody binding and uptake in CHO cells expressing CD163 and control CHO cells. Cells incubated for 0 or 30 minutes with immunofluorescent mAbs binding CD163, detected using confocal microscopy. As can be seen Mac2-48 and MAc2-158 exhibit both best binding and uptake.

(9) FIGS. 8A and 8B—Competition with Mac2-158. The small panel in FIG. 8A and FIG. 8B shows the entire sensorgram, whereas the zoom part shows the part of the sensorgram displaying binding of different mAbs to a Mac2-158 saturated CD163 chip. As can be seen in FIG. 8A, Mac2-158, Mac2-48, Ber-Mac3 and GHI/61 were not able to bind to a CD163-Fc saturated with Mac2-158 in a 2 mM free calcium buffer. All mAbs except GHI/61 bound to SRCR domain 1, and GHI/61 did not exhibit binding in a calcium-rich environment. The mAbs EdHU-1, Ki-M8, RM3/1 and R20 were all able to bind to the CD163-Fc regardless of the saturation and are thus not competing for binding to CD163 with Mac2-158.

(10) FIGS. 9A-9D—Identification of unknown tissue component expressing the macrophage scavenger receptor CD163. In a plot of forward scatter [FSC] versus CD163 PE, CD163 positive cells were gated (G1) (FIG. 9A), and the gated cells were re-plotted with CD14 APC versus CD163 PE. A gate (G2) was sat around the yet unidentified population of CD14-CD163+ cells (FIG. 9B) and re-plotted with CD163 PE versus HLA-DR FITC (FIG. 9C). Backgating analysis of CD14-HLA-DR+CD163+ cells (encircled dot plot overlay) in a FSC/SSC plot (FIG. 9D) revealed a relatively distinct cell population localized between lymphocytes and monocytes.

(11) FIGS. 10A-10E—Flow cytometric analysis of CD163 expression on dendritic cells in peripheral blood. In a forward scatter [FSC] versus side scatter [SSC], the mononuclear cell cluster was gated (G1) (FIG. 10A), and the gated cells were re-plotted with CD14 APC versus ILT3 PE-Cy5 (FIG. 10B), and a gate was sat around CD14-ILT3+ cells (dendritic cells; G2). The gated dendritic cells were re-plotted with CD163 PE versus HLA-DR FITC depicting two subsets of CD163+ dendritic cells (FIG. 10C). Backgating analysis of CD14-ILT3+HLA-DR+CD163+ cells (encircled dot plot overlay) in a FSC/SSC plot (FIG. 10D) revealed the expected localization of dendritic cells between lymphocytes and monocytes. Isotype matched non-specific PE-conjugated IgG1 served as a negative staining control (FIG. 10E).

(12) FIGS. 11A-11D—Flow cytometric analysis of peripheral blood dendritic cell CD163 expression using different CD163 mAbs. After gating of mononuclear cells and dendritic cells (CD14-ILT3+), gated cells were re-plotted with CD163 PE versus HLA-DR FITC using either GHI/61 (FIG. 11A) or MAC2-158 (FIG. 11C) clone of anti-CD163. Backgating analysis of CD14-ILT3+HLA-DR+CD163+ cells using MAC2-158 (grey dot plot overlay) in a FSC/SSC plot (FIG. 11D) showed a significantly higher fraction of CD163 expressing peripheral blood dendritic cells (32.3% [95% CI: 19.6-45.1%]) than when using GHI/61 (10.5% [95% CI: 8.0-12.5%]) (red dot plot overlay) in a FSC/SSC plot (FIG. 11B).

(13) FIGS. 12A-12E—Phenotyping CD163 expressing peripheral blood dendritic cells. Flow cytometric analysis of CD163, HLA-DR, ILT3, CD11c, CD16, and CD91 expression on dendritic cells in peripheral blood. After gating of mononuclear cells and dendritic cells (CD14-ILT3+), gated cells were re-plotted with CD163 PE versus: (FIG. 12A) HLA-DR PerCP, (FIG. 12B) ILT3 PE-Cy5, (FIG. 12C) CD11c FITC, (FIG. 12D) CD16 FITC, and (FIG. 12E) CD91 FITC.

(14) FIGS. 13A-13C—Dendritic cell CD163 expression in HIV-1 infection. Flow cytometric analysis of CD163 expression on dendritic cells in peripheral blood from HIV-1 patients compared to healthy adults. (FIG. 13A) Fraction of CD163+ dendritic cells in normal controls (n=31) and HIV-1 infected patients (n=15). Box plots indicate median, 25-75 percentiles, and range. (FIG. 13B) Level of expression of CD163 in CD163low and CD163high subsets in controls and HIV-1 infected patients. (FIG. 13C) Level of expression of CD163 in CD163low and CD163high subsets in controls and HIV-1 infected patients. Quantibrite PE beads were used to convert the FL2 linear fluorescence staining of cell population into the number of CD163 PE molecules bound per cell. Results are expressed as mean±standard error (SE). ***p<0.001.

(15) FIGS. 14A-14C—Representative plots of dendritic cell CD163 expression in HIV-1 infection. After gating of mononuclear cells and dendritic cells (CD14-ILT3+), gated cells were re-plotted with CD163 PE versus HLA-DR FITC (FIG. 14A), (FIG. 14B), and (FIG. 14C). The plots, originating from three different patients, are representative for the dendritic cell CD163 expression investigated in patients with HIV-1 infection (n=15).

(16) FIG. 14D—Overview of monocytic cellular CD163 expression in samples anti-coagulated with EDTA, citrate, and heparin using different CD163 mAbs. Monocytic cellular CD163 expression in heparin stabilized blood samples, which resembles physiological calcium levels, compared with samples anti-coagulated with calcium chelators; EDTA and citrate. Values are accompanied by 95% confidence intervals (95% CI) and differences between EDTA values and heparin and citrate values, respectively, are analysed for statistical significance with Student's t-test.

(17) FIG. 14E—Overview of monocytic cellular CD163 expression in samples anti-coagulated with EDTA, citrate, and heparin using different CD163 mAbs. Monocytic cellular CD163 expression in heparin stabilized blood samples, which resembles physiological calcium levels, compared with samples anti-coagulated with calcium chelators; EDTA and citrate. Values are accompanied by 95% confidence intervals (95% CI) and differences between heparin values and EDTA and citrate values, respectively, are analysed for statistical significance with Student's t-test.

(18) FIG. 15—Agarose gel of amplified fragments generated during humanisation procedure. A 1% agarose gel analysis shows that the PCRs for amplification of the variable regions worked. Left panel: Mac2-158 (100 bp Marker, heavy chain variable region, light chain variable region). Right panel: Mac2-48 (100 bp marker, 3× heavy chain variable region, 3× light chain variable region).

(19) FIG. 16—Sequence variants tested. Template for V.sub.H and V.sub.L is the best fit overall sequence and the Germline is the best fit in germline V-sequences. The other sequences are the sequences tested in expression and ELISA.

(20) FIG. 17—Comparison of reactivity of a heavy chain paired with either K8 light chain or NRY light chain. Apparent similar reactivities are obtained for cgamma(6)/K8 and cgamma(6)/NRY against CD163. The antibody sample cgamma(6)/K8 contained approximately twice as much antibody to obtain the same reactivity as did cgamma(6)/NRY.

(21) FIG. 18—Binding of humanized heavy chain variants. The humanised heavy chain variants KN2, KN1IN5, VR1, and DQ2 (all paired with the light chain NRY) had a comparable reactivity towards CD163. * or ** experiments done on the same ELISA plate.

(22) FIG. 19—Surface plasmon resonance detection of the binding of KN2/NRY and Mac2-158 to human CD163 immobilized on a Biacore chip. Virtually similar affinities for the two mAbs were displayed.

(23) FIG. 20—ELISA of fractions from the HisTrap™ purification of expressed scFv. A sample of each fraction was diluted 1:10 in 1% BSA, PBS. The diluted samples were subsequently added to CD163 coated wells.

(24) FIG. 21—ELISA of refolded scFv sample. The refolded scFv was added to the wells and 2 fold dilution series made. The refolded scFv bound to CD163 out to a 128 fold dilution in 1% BSA, PBS. The background of undiluted sample (scFv in buffer without BSA) was high (grey box to the left).

(25) FIG. 22—Cell culture supernatant tested directly in ELISA. The ELISA signal was very low even for the undiluted supernatant.

(26) FIG. 23—30× concentrated cell culture supernatant tested in ELISA. The ELISA signal of the 30× concentrated supernatant verified the presence of a Fab fragment. The intensity was comparable to the 100 ng/ml full length IgG4 antibody standard.

(27) FIG. 24—SDS-PAGE analysis of 65354. Lane M: MW marker (Cat. No. MM0900, GenScript); Lane 1, crude harvest; Lane 2, Flow through; Lane 3, Eluate of 50 mM imidazole; Lane 4-5, Eluate of 100 mM imidazole; Lane 6-8, Eluate of 250 mM imidazole; Lane 9, Eluate of 500 mM imidazole. The procedure produced about 6.0 mg of mouse CD163 soluble protein domain 1-3, with a purity of over 80% in SDS-PAGE analysis.

(28) FIG. 25—1% agarose gel electrophoresis of PCR product from V.sub.L PCR on cDNA beads. Lane M 100 bp marker. Lane 2 shows a product of ˜400 bp size. This band was purified by gel extraction and subsequently sequenced.

(29) FIG. 26—1% agarose gel electrophoresis of PCR product from V.sub.H PCR on cDNA beads. Lane M 100 bp marker. Lane 7 shows a product of ˜500 bp size. This band was purified by gel extraction and subsequently sequenced.

(30) FIGS. 27A-27E—Epitope mapping of KN2/NRY and Mac2-158, knock in and out of epitope

(31) FIG. 27A: Western blot of the following samples: SeeBlue plus2 prestained marker (lane 1); human CD163 wt (lane 2); human CD163 R60D (lane 3); human CD163 VKVQEE.fwdarw.LKIHEK (lane 4); human CD163 double mutant (lane 5); and negative transfection control (lane 6). Detection of protein expression was a done with polyclonal rabbit anti-human-CD163 and an anti-rabbit antibody conjugated with horse radish peroxidase as secondary antibody

(32) FIG. 27B: Western blot of the following samples: SeeBlue plus2 prestained marker (lane 1); human CD163 wt (lane 2); human CD163 R60D (lane 3); human CD163 VKVQEE.fwdarw.LKIHEK (lane 4); human CD163 double mutant (lane 5); and negative transfection control (lane 6). mac2-158 was used for detection of the epitope, with an anti-mouse antibody conjugated with horse radish peroxidase as secondary antibody.

(33) FIG. 27C: Western blot of the following samples: SeeBlue plus2 prestained marker (lane 1); human CD163 wt (lane 2); human CD163 R60D (lane 3); human CD163 VKVQEE.fwdarw.LKIHEK (lane 4); human CD163 double mutant (lane 5); and negative transfection control (lane 6). KN2/NRY-HRP was used for detection of the epitope.

(34) FIG. 27D: Western blot of the following samples: (lane 1) Mouse CD163 1-5 LKIHDK.fwdarw.VKVQEE, Y60R mutant, (lane 2) mouse CD163 1-5 wt, (lane 3) negative transfection control, (lane 4) SeeBlue plus2 pre-stained marker, (lane 5) positive blotting control (mouse CD163, recombinant with V5 tag). The primary antibody used was Anti-V5. Detection of bound primary antibody was done with an anti-mouse antibody conjugated with horse radish peroxidase as secondary antibody.

(35) FIG. 27E: Western blot of the following samples: (lane 1) Mouse CD163 1-5 LKIHDK.fwdarw.VKVQEE, Y60R mutant, (lane 2) mouse CD163 1-5 wt, (lane 3) negative transfection control, (lane 4) SeeBlue plus2 pre-stained marker, (5) positive blotting control (human CD163). The primary antibody used was Mac2-158. Detection of bound primary antibody was done with an anti-mouse antibody conjugated with horse radish peroxidase as secondary antibody.

(36) FIGS. 28A-28C—Chromatograms of dexamethasone and dexamethasone-NHS standard (FIG. 28A) and determination of free dexamethasone/dexamethasone-NHS (FIG. 28B) and total dexamethasone (FIG. 28C) in an ED2-dexamethasone conjugate sample. Dexamethasone-NHS is converted to dexamethasdone-hemisuccinate on the column, so there is no discrimination between dexamethasone-NHS and dexamethasone-hemisuccinate.

(37) FIG. 28D: Conjugation parameters of different antibody-corticosteroid-NHS-conjugates.

(38) FIG. 28E: Conjugation parameters of different antibody-MVCP-dexamethasone conjugations.

(39) FIGS. 29A-29F—

(40) FIG. 29A: SDS-PAGE of KN2/NRY and KN2/NRY-NHS-dexamethasone conjugate. Lane 1: Mw marker; lane 2: KN2/NRY; and lane 3: KN2/NRY-NHS-dexamethasone.

(41) FIG. 29B: Sensorgram showing CD163 binding of KN2/NRY and KN2/NRY-NHS-dexamethasone conjugate, conjugated to primary amines using NHS-dexamethasone.

(42) FIG. 29C: Schematic structure of the dexamethasone-NHS molecule used for conjugation to produce KN2/NRY-NHS-dexamethasone.

(43) FIG. 29D: Left SDS-PAGE of KN2/NRY and KN2/NRY-MVCP-dexamethasone conjugate. Lane 1: Mw marker; lane 2: KN2/NRY; and lane 4: reduced KN2/NRY; lane 5: KN2/NRY-MVCP (non-reduced).

(44) FIG. 29E: Sensorgram showing CD163 binding of KN2/NRY and KN2/NRY dexamethasone conjugate, conjugated to free SH groups of limited reduced KN2/NRY. Both A and B shows only very limited decrease in affinity upon conjugation and no increase in aggregation upon conjugation.

(45) FIG. 29F: Schematic structure of the dexamethasone-MVCP molecule used for conjugation to produce KN2/NRY-MVCP-dexamethasone.

(46) FIGS. 30A-30B—Effect of Haptoglobin dexamethasone conjugates on human monocytes

(47) FIG. 30A: Data showing the effect on human mononuclear cells isolated from buffy coats (outdated plasma) of haptoglobin coupled with dexamethasone and afterwards complexed with hemoglobin to induce CD163 binding of the conjugate. The effect measured is the induction of CD163 mRNA synthesis by dexamethasone. The number after Hp-dexa refers to different batches of Hp-dexa.

(48) FIG. 30B: Time study showing the effect of 10 nM dexamethasone on CD163 expression in human mononuclear cells isolated from buffy coats (outdated plasma).

(49) FIGS. 31A-31C—Mac2-158 dexamethasone conjugate effect on human macrophages.

(50) FIG. 31A: Data showing the effect on human in vitro matured macrophages cells isolated from buffy coats (outdated plasma) of Mac2-158 coupled with dexamethasone. The effect measured is the inhibition of LPS induction of TNF production.

(51) FIG. 31B: Time study showing the effect of 10 nM dexamethasone in the same set-up

(52) FIG. 32A-32D—Binding of KN2/NRY to human monocytes.

(53) FIG. 32A-32C) Human mononuclear cells isolated from buffy coats were stained with Mac2-158-FITC, anti-CD14-PE and KN2/NRY-Alexa Fluor647 and analyzed by flow cytometry FIG. 32D). A negative control staining with IgG-FITC and an irrelevant antibody conjugated with AlexaFluor647 (ATNP-Alexa Fluor647) was included.

(54) FIG. 33—Binding of KN2/NRY-dexamethasone to CD163 expressing CHO cells. CHO cells expressing human CD163 were incubated with KN2/NRY (grey histogram) or KN2/NRY-dexamethasone conjugate (black histogram), washed and stained with anti-human IgG-before flow cytometric analysis. White histogram represents negative control staining with anti-human IgG-FITC.

(55) FIG. 34—KN2/NRY-dexamethasone suppression of LPS mediated TNFα in vitro. Human mononuclear cells were cultured and incubated with serial dilutions of KN2/NRY—NHS-dexamethasone, KN2/NRY-MVCP-dexamethasone or free dexamethasone for 15 minutes, washed and incubated overnight. Cell supernatants were analyzed for TNFα after 4 hours of LPS stimulation.

(56) FIG. 35—Binding of ED2 to rat macrophages. Peritoneal macrophages were stained with anti-rat CD172a-PE (ED9) and anti-rat CD163-FITC (ED2) and analyzed by flow cytometry (left dotplot). The percentage of CD163-FITC positive macrophages are indicated in the upper right quadrant. A negative control staining with IgG-FITC was included (right dotplot).

(57) FIG. 36—Binding of ED2-dexamthasone to CD163 expressing CHO cells. CHO cells expressing rat CD163 were incubated with ED2 (grey histogram) or ED2-NHS-dexamethasone conjugate (black histogram), washed and stained with anti-mouse IgG-before flow cytometric analysis. White histogram represents negative control staining with anti-mouse IgG-FITC.

(58) FIG. 37—ED2-dexamethasone suppression of LPS mediated TNFα stimulation in vitro. Peritoneal rat macrophages and spleen cell suspensions were incubated with 1 μg/ml ED2-NHS-dexamethasone, dexamethasone, ED2 or PBS for 3 hours before LPS stimulation for 20 hours. The concentration of TNFα in cell culture supernatants (triplicates) was determined by the BD™ Cytometric Bead Array (CBA) Flex Set assay.

(59) FIGS. 38A-38C—Titration of LPS mediated TNFα induction of splenocytes. Rat spleen cells were cultured and incubated with serial dilutions of ED2-NHS-dexamethasone conjugate or free dexamethasone for (FIG. 38A) 15 minutes, (FIG. 38B) 30 minutes or (FIG. 38C) 60 minutes, washed and incubated overnight. Cell supernatants were analyzed for TNFα after 4 hours of LPS stimulation.

(60) FIG. 39A-39C—ED2-dexamethasone suppression of LPS mediated TNFα stimulation in vivo. Female Lewis rats were injected intravenously with ED2-NHS-dexamethasone (n=4), free dexamethasone (in the form of dexamethason-21-acetate to increase solubility, effect of dexamethasone and dexamethasone-21-acetate at similar concentrations are identical (result not shown)) (n=4) or vehicle (n=4) 20 hours before i.v. injection of LPS.

(61) FIG. 39A) The concentration of TNFα in serum samples were determined 2 hours post LPS injection. The serum samples were analyzed in triplicates in sandwich ELISA assay.

(62) FIG. 39B) Thymus weight 2 days post LPS injection.

(63) FIG. 39C) Spleen weight 2 days post LPS injection.

(64) FIGS. 40A-40D—ED2-dexamethasone suppression of LPS mediated TNFα stimulation in vivo, comparison of amino linked and Cys linked conjugation. (FIG. 40A) Rat spleen cells were cultured and incubated with serial dilutions of ED2-NHS-dexamethasone conjugate or free dexamethasone for 15 minutes, washed and incubated overnight. Cell supernatants were analyzed for TNFα after 4 hours of LPS stimulation, Female Lewis rats were injected intravenously with ED2-NHS-dexamethasone (n=5), ED2-MVCP-dexamethasone (n=5), free dexamethasone (in the form of dexamethason-21-acetate to increase solubility) (n=5) or vehicle (n=5) 20 hours before intravenous (i.v.) injection of LPS. (FIG. 40B) The concentration of TNFα in serum samples were determined 2 hours post LPS injection. The serum samples were analyzed in triplicates in sandwich ELISA assay. (FIG. 40C) Thymus weight 2 days post LPS injection. (FIG. 40D) Spleen weight 2 days post LPS injection. Statistically significant differences between groups are indicated, with p value.

(65) FIGS. 41A-41B—Effect of fluocinolone acetonoid and prednisolone coupled ED2 on LPS mediated TNFα production in vivo. Female Lewis rats were injected intravenously with ED2-fluocinolone acetonoid (n=4), ED2-prednisolone (n=4), free fluocinolone acetonoid (n=4), free prednisolone (n=4) or vehicle (n=4) 20 hours before intravenous (i.v.) injection of LPS. The concentration of TNFα in serum samples were determined 2 hours post LPS injection. The serum samples were analyzed in triplicates in sandwich ELISA assay.

(66) FIGS. 42A-42B—Effect of different 3E10810-dexamethasone conjugates in vitro and in vivo. (FIG. 42A) Mouse spleen cells were cultured and incubated with serial dilutions of 3E10B10-dexamethasone conjugate or free dexamethasone for 15 minutes, washed and incubated overnight. Cell supernatants were analyzed for TNFα after 4 hours of LPS stimulation. (FIG. 42B) Female Balbc/A mice were injected intravenously with 3E10B10—NHS-dexamethasone (n=5), 3E10B10-MVCP-dexamethasone (n=5), free dexamethasone (in the form of dexamethason-21-acetate to increase solubility) (n=5) or vehicle (n=5) 20 hours before intravenous (i.v.) injection of LPS. The concentration of TNFα in serum samples were determined 2 hours post LPS injection. The serum samples were analyzed in triplicates in sandwich ELISA assay.

(67) FIGS. 43A-43B—Effect of treatment of collagen antibody induced arthritis in mice. Rats were scored 6 times per week for signs of arthritis in each individual paw. (FIG. 43A) Total arthritis score was defined as the sum of score of all paws on each day. This figure shows the mean total clinical arthritis score versus time for all treatment groups. Each point represents the group mean (n=5). (FIG. 43B) The cumulative arthritis score was defined as the sum of the total clinical arthritis scores obtained from day 0 till day 14. * indicates p<0.05 for the methyl-prednisolone group versus vehicle group and # indicates p<0.05 for the methyl-prednisolone-3E10B10 group versus vehicle group.

(68) FIG. 44—Overview of synthesis route for Dexamethasone-MVCP

(69) FIG. 45—Overview of synthesis route for Dexamethasone-NHS

(70) FIG. 46—Comparison of CD163 sequences.

(71) FIG. 47—Effect of treatment on body weight.

(72) Individual rats were weighed six times per week and for each treatment group the mean weight was calculated. Each point represents the group mean (n=4). Note: The same vehicle and 0.01 mg/kg dexamethasone groups are presented in both panels.

(73) FIG. 48—Effect of treatment on day of disease onset.

(74) Day of onset is defined as the first day of three consecutive days on which a clinical score of >0 was observed. If rats did not develop disease during the experimental period, the day of onset was arbitrarily set to day 21. Each bar represents group mean±SD. * indicates p<0.05 versus vehicle group. Dexa=dexamethasone, Dexa-conj=dexamethasone-conjugate.

(75) FIG. 49—Effect of treatment on disease incidence. Disease was defined as a clinical score>0 on each day. This figure shows the incidence of disease versus time for all treatment groups.

(76) FIG. 50—Effect of treatment on total clinical arthritis score. Rats were scored 6 times per week for signs of arthritis in each individual paw. Total arthritis score was defined as the sum of score of all paws on each day. This figure shows the mean total clinical arthritis score versus time for all treatment groups. Each point represents the group mean (n=4). Note: The same vehicle and 0.01 mg/kg dexamethasone groups are presented in both panels.

(77) FIG. 51—Effect of treatment on cumulative arthritis score. This figure shows cumulative arthritis score which is defined as the sum of the total clinical arthritis scores obtained from day 0 till day 21. Each bar represents group means±SD. * indicates p<0.05 versus vehicle group and # indicates p<0.05 for the dexamethasone groups versus 0.01 mg/kg dexamethasone-conjugate. Dexa=dexamethasone, Dexa-conj=dexamethasone-conjugate.

(78) FIG. 52—Effect of treatment on left hind paw thickness. Thickness of the hind paws was measured employing a laser scan micrometer. The paw thickness was measured 5 times per week. Each point represents the group mean (n=4). Note: The same vehicle and 0.01 mg/kg dexamethasone groups are presented in both panels.

(79) FIG. 53—Effect of treatment on cumulative left hind paw swelling. This figure shows cumulative paw swelling which is defined as the sum of the delta thickness values from day 10 till 21 (delta thickness is paw thickness minus baseline value, which is the mean value of day 0 till 9). Each bar represents group means±SD. * indicates p<0.05 versus vehicle group. Dexa=dexamethasone, Dexa-conj=dexamethasone-conjugate.

(80) FIG. 54—Effect of treatment on right hind paw thickness. Thickness of the hind paws was measured employing a laser scan micrometer. The paw thickness was measured 5 times per week. Each point represents the group mean (n=4). Note: The same vehicle and 0.01 mg/kg dexamethasone groups are presented in both panels.

(81) FIG. 55—Effect of treatment on cumulative right hind paw swelling. This figure shows cumulative paw swelling which is defined as the sum of the delta thickness values from day 10 till 21 (delta thickness is paw thickness minus baseline value, which is the mean value of day 0 till 9). Each bar represents group means±SD. * indicates p<0.05 versus vehicle group and # indicates p<0.05 versus 0.01 mg/kg dexamethasone-conjugate. Dexa=dexamethasone, Dexa-conj=dexamethasone-conjugate.

(82) FIG. 56—Effect of treatment on organ weights. Spleen, thymus and liver were collected and weighed at sacrifice. Data were normalized for body weight. Each bar represents group means±SD. * indicates p<0.05 versus vehicle group and # indicates p<0.05 for the dexamethasone groups versus 0.01 mg/kg dexamethasone-conjugate. Dexa=dexamethasone, Dexa-conj=dexamethasone-conjugate.

EXAMPLES

Example 1—Antibodies to SRCR Domain 1 of the CD163 Receptor

(83) Introduction

(84) CD163 is a scavenging receptor consisting of nine extracellular scavenger receptor cysteine-rich (SRCR) type B domains. It mediates the clearance of the haptoglobin-hemoglobin (Hp-Hb) complexes formed when hemoglobin is librated to the circulation during intravascular hemolysis (1;2) and it is also involved in regulation of inflammatory processes (3;4). CD163 is considered to be expressed exclusively on the surface of the monocytic lineage. It is expressed by resident monocytes in the circulation (5;6) and upregulated during maturation to macrophages. It is highly expressed on tissue-resident macrophages (6-10), as well as on alternatively activated macrophages (M2) (11-14), and TIE2+ macrophages (15;16). Furthermore, CD163 has been shown to be expressed by a CD34.sup.+ subpopulation of hematopoietic stem/progenitor cells (17) and proposed to be expressed on a subset of myeloid dendritic cells (18;19).

(85) CD163 is cleaved from the cell membrane by a protease-mediated release mechanism in response to toll-like receptor (TLR) activation (20-22), forming soluble CD163 (sCD163) which in serum has been demonstrated to be useful in diagnosis of e.g. sepsis and hemophagocytosis (23-25).

(86) The restricted expression of CD163 limited to the monocytic/macrophage lineage has given rise to increased attention. A large body of evidence has now accumulated demonstrating significant changes in cellular and soluble CD163 levels in inflammatory, malignant, and infectious diseases (11;23;24;26-31). CD163 may be a diagnostic marker in conditions affecting the monocyte/macrophage system and as a therapeutic candidate.

(87) However, whereas the normal concentration range, biological variation, and molecular structure of sCD163 have been described in detail (21;32;33), limited studies exist systematically addressing monocytic CD163 expression. Importantly, using different anticoagulants, antibody clones, and general test conditions, flow cytometric studies continue to exhibit great discrepancy in the level of monocytic CD163 expression, which has been reported to vary from a few to 99% (3;5-7;34-41). Flow cytometric evaluations of monocytic CD163 expression were recently described to vary considerably according to the test conditions (38), and we have previously shown that dendritic cell CD163 expression may show a discrepancy when using different antibody clones (18). It is evident that the applicability of monocytic CD163 expression as a diagnostic tool and therapeutic candidate rests on comparable and reliable measurements in both pathological and physiological conditions.

(88) Materials and Methods

(89) Antibodies and Other Reagents.

(90) The following monoclonal antibodies (mAbs) were used in flow cytometry, immunofluorescence, SPR analysis, and endocytosis experiments with .sup.125I-labeled anti-CD163: Anti-CD163 (MAC2-158), APC-conjugated anti-CD14 (UCHM1), and R-PE-conjugated Mouse IgG.sub.1, k isotype control (MCG1) were obtained from IQ Products, Groningen, The Netherlands. Anti-CD163 (GHI/61) was obtained from BD Biosciences, CA, USA. Anti-CD163 (R-20) was obtained from Trillium Diagnostics, LLC, Scarborough, Me., USA. Anti-CD163 (RM3/1) was obtained from BioLegend, San Diego, Calif., USA. All CD163 mAbs clones were purchased purified and R-PE-conjugated. Goat anti-mouse-conjugated Alexa-Fluor® 488 was obtained from Molecular Probes, Invitrogen, Carlsbad, Calif., USA. Mouse anti Human CD163 Ki-M8 and 5C6-Fat were obtained from Acris Antibodies, Germany, (catalogue numbers BM4112 and BM4041, http://www.acris-antibodies.com/BM4112.htm, http://www.acris-antibodies.com/bm4041.htm). Mouse anti Human CD163 EDHu-1 was obtained from Acris Antibodies, Germany, (catalogue number SM2160P. http://www.acris-antibodies.com/SM2160P.htm). Anti CD163 antibody Mac2-48 was obtained from IQ Products, the Netherlands, catalogue number CD163-48U. http://www.igproducts.nl/catalog/index.php?pr=783). Mouse anti Human CD163 R20 was obtained from Trillium, Me., USA (catalogue number CD163-20U, http://trilliumdx.com/products/content.php?products id=33). Mouse anti Human CD163 Ber-Mac3 can be obtained from MBL, MA, USA, (catalogue number K-0147. http://www.mblintl.com/mbli/account/search_results.asp?search=K0147-3).

(91) Blood Samples and Preparation of PBMC.

(92) EDTA, citrate, and heparin stabilized peripheral blood samples were obtained by standard venipuncture from healthy donors in Venoject® vacutainers (Terumo Europe NV, Leuven, Belgium). Peripheral blood mononuclear cells (PBMC) were isolated from leukocyte-rich buffy coats by gradient separation centrifugation using Accuspin System Histopaque®—1077 (Sigma-Aldrich Denmark A/S, Broendby, Denmark). Buffy coats were prepared from units of whole blood (approximately 472 ml) anti-coagulated with CPD-A (Baxter, Munich, Germany) donated by healthy volunteers. Approval for the study was obtained from the regional ethical committee (j.nr. 20040068).

(93) Quantitative Flow Cytometry.

(94) Freshly drawn peripheral whole blood samples or PBMC (approx. 3×10.sup.6 cells) were stained with isotype-matched control antibody or a relevant antibody for one hour at 4° C. in the dark. When staining whole blood, erythrocytes were lysed for 15 min with 4° C. cold solution of ammonium chloride. When indirect immunofluoresence staining was required, cells were initially incubated with unconjugated primary CD163 antibody for one hour at 4° C., washed three times with D-PBS, pH 7.4, followed by incubation with goat anti-mouse-conjugated Alexa-Fluor® 488 (1:200 dilution; Molecular Probes, Invitrogen, Carlsbad, Calif., USA) for one hour at 4° C. in the dark. The stained cells were washed twice three D-PBS, pH 7.4, re-suspended in 400 μl FACSflow (Becton Dickinson, San Jose, Calif., USA), and kept on ice until analysis. All samples were analyzed using a FACSCalibur flow cytometer and compensated for spectral overlap using FlowJo for Macintosh software version 8.3 (TreeStar, San Carlos, Calif.). For CD163 density quantitation, flow cytometric estimation of antibodies bound/cell (ABCs) was performed using Quantibrite PE beads (Becton Dickinson, San Jose, Calif., USA) as recommended by the manufacturer. After the cells were stained, as detailed, a set of 4 pre-calibrated fluorescently labeled beads was used for standardization before the samples were acquired. The Quantibrite PE beads were run at the same instrument settings as the assay, and the linear regression obtained using the Quantibrite PE beads was used to convert the FL2 linear fluorescence staining of cell population into the number of (CD163) PE molecules bound per cell (ABC).

(95) Enzyme-Linked Immunosorbent Assay (ELISA).

(96) Soluble CD163 was measured using an in-house ELISA assay, as previously described (32).

(97) Preparation, Stimulation and Incubation of Human Monocyte-Derived Macrophages and Stably Transfected Chinese Hamster Ovary (CHO) Cells.

(98) Monocytes were isolated from PBMC by negative selection using magnetic beads from Dynal (Dynabeads® MyPure™ Monocyte Kit 2; Invitrogen A/S, Taastrup, Denmark) according to instructions provided by the manufacturer. Monocyte preparations were more than 95% (CD14.sup.+) pure determined by flow cytometry. The isolated cells were washed twice with phosphate-buffered saline. Monocyte-derived macrophages (MDMs) were prepared by cell culture of monocytes (approximately 1×10.sup.7 cells) for 4 days in 5% CO.sub.2 and 37° C. in RPMI 1640 media (RPMI 1640+25 mM HEPES+I-glutamine) (Invitrogen Corporation, Carlsbad, Calif., USA) with 20% FCS containing 100 ng/ml of M-CSF. MDMs were then detached from the flask by incubation with cell dissociation buffer (Invitrogen A/S, Taastrup, Denmark) for 30 minutes at 40□C, then flushed, and scraped. The cells were then cultured for 24 hours in RPMI 1640 media (RPMI 1640+25 mM HEPES+I-glutamine) (Invitrogen Corporation, Carlsbad, Calif., USA) supplemented with 20% FCS containing 100 ng/ml of M-CSF at 37° C. in 95% air and 5% CO in Lab-Tek™ Chamber Slides (Thermo Fisher Scientific, Roskilde, Denmark). 200 nM dexamethasone (Merck KGaA, Darmstadt, Germany) was added during culture to increase CD163 expression. Stably transfected Chinese hamster ovary (CHO) cells expressing the full-length human CD163, as described above, were cultured in serum-free CHO medium (HyQ-CCM, HyClone, Logan, Utah) containing 300 μg/ml Hygromycin B, as previously described (2).

(99) Cells were washed in were washed with 4° C. cold D-PBS, pH 7.4, re-suspended and stained for CD163 expression as described below.

(100) Cellular Binding and Uptake with Fluorescently Labeled CD163 Antibodies

(101) MDMs or CHO cells were washed with 4° C. cold D-PBS, pH 7.4, containing 1% BSA in Lab-Tek™ Chamber Slides (Thermo Fisher Scientific, Roskilde, Denmark). The cells were then incubated with 10 μg/ml different clones of anti-CD163 for one hour at 4° C. and then washed three times with D-PBS, pH 7.4, with 1% BSA. The cells were subsequently either fixated with 4% formaldehyde for one hour at 4° C. or incubated for 30 minutes at 3TC under a humidified atmosphere of 95% air and 5% CO. Cells incubated for 30 minutes were then washed 3 times with D-PBS, pH 7.4, containing 1% BSA and fixated for one hour at 4° C. with 4% formaldehyde. All cells were washed once with D-PBS, pH 7.4, and permeabilised with D-PBS, pH 7.4, containing 0.05% Triton X-100 (Merck) for 15 min at RT. Cells were then incubated with goat anti-mouse-conjugated Alexa-Fluor® 488 (1:200 dilution; Molecular Probes, Invitrogen, Carlsbad, Calif., USA) for one hour at RT washed five times with D-PBS, pH 7.4, containing 0.05% triton X-100. Slides were mounted with Vectashield® mounting medium with 4′,6′-diamidino-2-phenylindole (DAPI) to identify cell nucleus (Vector Laboratories, Burlingame, Calif., USA). Fluorescence was visualized using a Zeiss Axiovert 200M microscope (Carl Zeiss GmbH, Jena, Germany) with an ×100 oil-immersion objective. Representative images were acquired using a AxioCam MRm digital camera (Carl Zeiss GmbH, Jena, Germany). Alternatively, immunostained cells were analyzed by confocal immunofluorescence microscopy using a Zeiss LSM-510 confocal microscope (Carl Zeiss GmbH, Jena, Germany). Image processing was done using NIH ImageJ software (version 1.38w) and Adobe Photoshop CS4.

(102) Cellular Binding and Uptake of .sup.125I-Labeled Anti-CD163

(103) Endocytosis of .sup.125I-labeled anti-CD163 was investigated in CD163 transfected Flp-In Chinese hamster ovary (CHO) cells and mock-transfected Flp-In as described (Madsen, M., Moller, H. J., Nielsen, M. J., Jacobsen, C., Graversen, J. H., van den Berg, T. and Moestrup, S. K. (2004) Molecular characterization of the haptoglobin.hemoglobin receptor CD163. Ligand binding properties of the scavenger receptor cysteine-rich domain region. J. Biol. Chem., 279, 51561-51567.)

(104) Data and Statistical Analysis

(105) All estimates are accompanied by either range values or a 95% confidence interval. Differences between values were analysed for statistical significance with Student's t-test. For comparisons between smaller groups without Gaussian distribution of values, the non-parametric Mann-Whitney rank sum test was used. Differences were considered significant at p<0.05. Statistical calculations were carried out using the STATA statistical package version 10 for Windows.

(106) Surface Plasmon Resonance (SPR) Analysis of mAb CD163 Binding

(107) SPR analysis of the binding of mAbs to CD163 was carried out on a Biacore 2000 instrument (Biacore, Uppsala, Sweden). The Biacore sensor chips (type CM5) were activated with a 1:1 mixture of 0.2 M N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide and 0.05 M N-hydroxysuccimide in water. Purified recombinant CD163 were immobilized in 10 mM sodium acetate, pH 4.0, and the remaining binding sites were blocked with 1 M ethanolamine, pH 8.5. The SPR signal generated from immobilized recombinant CD163 proteins corresponded to 40-70 fmol of protein/mm.sup.2. Sensorgrams were generated using mAb concentrations ranging from 5-100 nM. The flow cells were regenerated with 1.6 M glycine-HCl, pH 3. The running buffer used for the experiment was either CaHBS 10 mM Hepes, 150 mM NaCl, 3.0 mM CaCl.sub.2, 1.0 mM EGTA, and 0.005% Tween 20, pH 7.4. or 10 mM Hepes, 150 mM NaCl, 3.0 mM EDTA, and 0.005% Tween 20, pH 7.4, mAb samples were dissolved in the same buffer as the running buffer used. All binding data were analyzed using the Biamolecular Interaction Analysis evaluation program version 3.1.

(108) Competition of Binding to Mac2-158 Epitope.

(109) To evaluate if there is competition in the binding of a range of mAbs to CD163 we first saturated the CD163-chip with Mac2-158 by injecting 50 μL of 50 μg/ml Mac2-158 and subsequently injecting relevant mAbs in 5 μg/ml. The binding buffer was CaHBS 10 mM Hepes, 150 mM NaCl, 3.0 mM CaCl.sub.2, 1.0 mM EGTA, and 0.005% Tween 20, pH 7.4.

(110) Results

(111) Surface CD163 Expression on Human Peripheral Blood Monocytes Determined Using Different Clones of Monoclonal Antibodies.

(112) Freshly drawn EDTA stabilized whole blood was stained with specific mAb defining monocytes as CD14.sup.+ cells to investigate monocyte surface CD163 expression using CD163 mAbs clones covering various SRCR domains. The MAC2-158 clone, which binds to SRCR domain 1, recognized a significantly larger fraction of peripheral blood monocytes (84.06% [95% CI: 76.20-91.92%]) (FIG. 1A) as compared with R-20 (75.93% [95% CI: 72.49-79.38%]; p<0.005) (FIG. 1B), GHI/61 (63.03% [95% CI: 54.34-71.73%]; p<0.001) (FIG. 1C), and RM3/1 (0.33% [95% CI: 0.068-0.59]; p<0.0001) (FIG. 1D), which bind to SRCR domain 4, 7, and 9, respectively. The measured density of CD163 receptors per monocyte was significantly higher when using MAC2-158 (17,725 [95% CI: 13,335-22,133]) (FIG. 1A) compared with R-20 (1,650 [95% CI: 1,139-2,163]; p<0.0001) (FIG. 1B), GHI/61 (1,030 [95% CI: 807-1,253]; p<0.0001) (FIG. 1C), and RM3/1 (101 [95% CI: 28-175]; p<0.0001) (FIG. 1D). For comparison, non specific binding was assessed using an isotype-matched non-specific IgG and showed low background staining (94 [95% CI: 76-112]) (not shown). A similar pattern of CD163 expression variation was observed when whole blood was stained using unconjugated primary CD163 antibody clones followed by Alexa Fluor® 488 secondary antibody conjugates (not shown).

(113) Monocytic Surface CD163 Expression on Peripheral Blood Mononuclear Cells Isolated by Density Gradient Centrifugation.

(114) Peripheral blood mononuclear cells were purified to assess the effect of the histopaque gradient isolation on the monocyte surface CD163 expression. Flow cytometric analysis revealed an analogous expression pattern of CD163 expression as observed utilizing freshly drawn EDTA stabilized whole blood. The fraction of CD14.sup.+ monocytes stained for CD163 was 81.10% [95% CI: 73.95-88.25%] when using MAC2-158 and 2.50% [95% CI: 0.29-4.71%] when using RM3/1 (2.50% [95% CI: 0.29-4.71%]) However, the fraction of CD14.sup.+ monocytes which stained positive for CD163 decreased significantly for the R-20 clone and the GHI/61 clone after density gradient centrifugation. After separation, 54.40% [95% CI: 29.10-79.70%] CD14.sup.+ monocytes stained positive for CD163 using R-20 which was significantly lower than in freshly drawn EDTA stabilized whole blood (p<0.05). The fraction of CD163 positive monocytes using GHI/61 diminished considerably and became almost undetectable (1.26% [95% CI: 0.91-1.61%]). The measured density of CD163 receptors per monocyte exhibited a similar pattern: MAC2-158 (11,417 [95% CI: 8,058-14,777]), p<0.01; R-20 (836.7 [95% CI: 654.4-1,019]; p<0.0001), GHI/61 (108.0 [95% CI: 81.71-134.3]; p<0.0001), and RM3/1 (132.3 [95% CI: 66.97-197.7]; p<0.05).

(115) Influence of Different Anticoagulants on Monocytic Surface CD163 Expression.

(116) To investigate the influence of different extracellular calcium concentrations on monocyte surface CD163 expression, CD163 levels were measured in freshly drawn whole blood samples stabilized with three commonly used anticoagulants and using different mAb clones (FIGS. 2, 3, and FIG. 14D). Using the MAC2-158 clone the fraction of CD14.sup.+ monocytes stained positive for CD163 was unaffected regardless the extracellular calcium concentration: 87.23% [95% CI: 81.10-93.37%] of CD14.sup.+ monocytes stained positive for CD163 when using EDTA as anticoagulant, 83.97% [95% CI: 80.52-87.41%] using citrate, and 84.43% [95% CI: 77.82-91.05%] when using heparin (left panel in FIG. 2; FIG. 3A, and FIG. 14D). The density of receptors per monocyte displayed a similar pattern, showing 17,725 [95% CI: 13,335-22,133] receptors using EDTA as anticoagulant, 17,726 [95% CI: 14,675-20,777] when using citrate, and 18,929 [95% CI: 14,261-23,597] when using heparin (left panel in FIG. 2, FIG. 3B, and FIG. 14D).

(117) CD163 staining with the R-20 clone, 75.93% [95% CI: 72.49-79.38%] of CD14.sup.+ monocytes stained positive for CD163 when using EDTA as anticoagulant, 74.73% [95% CI: 70.36-79.11%] when using citrate; however, significantly lower (63.03% [95% CI: 60.38-65.69%]; p<0.005) using heparin (middle left panel in FIG. 2; FIG. 3A, and FIG. 14D). The determined density of CD163 receptors per monocyte was 1,760 [95% CI: 1,600-1,920] in EDTA, 1,988 [95% CI: 1,750-2,226] in citrate, but, unexpectedly higher (3,019 [95% CI: 2,648-3,390]) in heparin stabilized samples (middle left panel in FIG. 2; FIG. 3B, and FIG. 14D).

(118) However, when using the GHI/61 clone the fraction of CD14.sup.+ monocytes stained for CD163 was clearly affected by the anticoagulant revealing a significant lower monocytic surface CD163 expression when using heparin as anticoagulant (0.82% [95% CI: 0.55-1.08%]) as compared with blood samples anti-coagulated with EDTA (63.03% [95% CI: 54.34-71.73%]; p<0.0001) and citrate (64.37% [95% CI: 58.17-70.56%]; p<0.0001) (middle right panel in FIG. 2; FIG. 3A, FIG. 14D). This finding was verified by the density of CD163 receptors per monocyte which was 58.33 [95% CI: 24.42-92.24] in heparin, whereas 1,030 [95% CI: 806.9-1,252] (p<0.0001) in EDTA, and 1,152 [95% CI: 962.9-1,342] (p<0.0001) in citrate stabilized samples (middle right panel in FIG. 2; FIG. 3B, and FIG. 14D).

(119) Using RM3/1, the flow cytometric analysis showed that a very little proportion of CD14.sup.+ monocytes stained positive for CD163 (0.33% [95% CI: 0.068-0.59%] in EDTA, 12.50% [95% CI: 9.57-15.43%] in citrate, and 3.33% [95% CI: 1.84-4.82%] in heparin [right panel in FIG. 2; and FIG. 3A]) stabilized blood samples. The determined monocyte surface CD163 expression was also extremely low (86.00 [95% CI: 66.28-105.7]) in EDTA, 207.0 [95% CI: 167.0-247.0] in citrate, and 210.3 [95% CI: 163.3-257.4] in heparin when the RM3/1 clone was used regardless the extracellular calcium concentration (right panel in FIG. 2; FIG. 3B, and FIG.14D).

(120) Variation in Detected Surface Expression is not Due to CD163 Shedding

(121) The levels of soluble CD163 (sCD163) were measured in the same freshly drawn whole blood samples stabilized with different anticoagulants. Adjusted for dilution during sample preparation sCD163 levels determined using ELISA were 832.1 μg/l in EDTA stabilized blood samples, 738.3 μg/l in citrate stabilized blood samples, and 897.8 μg/l in heparin stabilized blood samples suggesting that the anticoagulant used (and hence the presence of calcium) did not affect the shedding of sCD163.

(122) Binding to CD163.

(123) Mac2-48, Mac2-158, 5C6-Fat, Ki-M8, EdHu1 and BerMac3 all bound CD163 in both 2 mM free Ca.sup.2+ and 10 mM EDTA, however, exhibiting somewhat different affinity between the Ca.sup.2+ and EDTA buffer, but all affinities being in the nanomolar or sub-nanomolar range. The mAb designated GHI/61 did only exhibit very weak binding to CD163 in the calcium containing buffer, whereas it exhibited binding in 10 mM EDTA with an apparent K.sub.d of 29 nM. RM3/1 did not exhibit binding to CD163 in the EDTA buffer, whereas the apparent K.sub.d in 2 mM free Ca.sup.2+ was 0.6 nM. Typical sensorgrams are shown in FIG. 4, comparing binding in calcium and EDTA.

(124) Endocytosis of .sup.125I-Labeled CD163 Antibodies in Stable CD163 Transfected Flp-In CHO Cells.

(125) To compare endocytotic ability, the mAb clones were labelled with .sup.125I and incubated with CD163 expressing Flp-In CHO cells to increasing time points. As shown in FIG. 5A, the time course of cell-associated radioactivity (bound or internalized) reached a plateau after one hour of incubation for most of the antibodies, although the level of cell-associated radioactivity when using .sup.125I-labelled GHI/61 was at a low level suggesting reduced or no endocytosis. In contrast, when incubating with .sup.125I-labelled Mac2-48 and Mac2-158 the time course of cell-associated radioactivity did not reach a plateau after two, or even fout, hours of incubation. Using MAC2-158 the percentage of cell-associated radioactivity reached 61.27% [95% CI: 56.56-0.6597%] in stable CD163 transfected Flp-In CHO cells. For comparison, percentage of cell-associated radioactivity reached 1.37% [95% CI: 0.426-2.31%] in non-transfected Flp-In CHO cells using same mAb clone. The percentage of cell-associated radioactivity reached was lower using R-20 (18.97% [95% CI: 18.09-19.84%] vs. 0.97% [95% CI: 0.59-1.35%]), GHI/61 (1.23% [95% CI: 0.854-1.61%] vs. 1.23% [95% CI: 0.72-1.75%]), and RM3/1 (7.77% [95% CI: 4.11-11.43%] vs. 1.47% [95% CI: 0.099-2.84%]). As shown in FIG. 5B, the degree of cell-associated radioactivity detected in non-transfected Flp-In CHO cells was low for all monoclonal antibodies, as expected.

(126) Endocytosis of Fluorescent CD163 Antibodies in Human Monocyte-Derived Macrophages.

(127) Monocyte-derived human macrophages were prepared from peripheral blood monocytes and stimulated with 200 nM dexamethasone to assess binding and uptake of different CD163 mAbs. MAC2-158, R-20, GHI/61, and RM3/1 were able to bind the CD163 receptor on surface of human macrophages which was shown with immunofluorescent staining. However, fluorescence microscopy revealed that staining using MAC2-158 and R-20 exhibited a pronounced cell surface staining as compared with GHI/61 and RM3/1 (upper panels in FIG. 6).

(128) After incubation for 30 min, the immunofluorescent staining showed a distinct punctuate subcellular staining which was characteristic in all investigated clones of CD163 mAbs (lower panels in FIG. 6). However, the intensity of intracellular staining appered most prominent when using MAC2-158 as compared with R20, GHI/61, and RM3/1 (lower panels in FIG. 6), suggesting a more efficient uptake of MAC2-158. A similar pattern of surface staining and cellular uptake was observed in CD163-transfected Flp-In CHO cells by confocal laser scanning microscopic analysis (not shown).

(129) Similar experiments were made on CHO cells expressing CD163 screening a larger panel of mAbs using confocal microscopy (FIGS. 7a and 7b).

(130) Competition with Mac2-158

(131) FIG. 8 shows sensorgrams of binding of different CD163 mAbs to a CD163 sensorchip which has first been saturated with Mac2-158, meaning that virtually all epitopes for Mac2-158 has mAb bound, thus only mAbs binding in competition with Mac2-158 should not be able to bind to the CD163 immobilised on the chip, and induce a further increase in the response units measured, whereas mAb not binding in competition should be able to bind to the immobilised CD163 and thus increase the response units measured. As can be seen from FIG. 8, Mac2-158, Mac2-48, Ber-Mac3 and GHI/61 were not able to bind to a CD163-Fc saturated with Mac2-158 in a 2 mM free calcium buffer. All mAbs but GHI/61 are binding to SRCR domain 1 and GHI/61 is not exhibiting binding in a calcium rich environment. The mAbs EdHU-1, Ki-M8 and RM3/1 all where able to bind to the CD163-Fc regardless of the saturation and are thus not competing for binding to CD163 with Mac2-158. Thus, it appears that all monoclonal antibodies binding to domain 1 bind in competition with Mac2-158.

(132) Discussion

(133) An increasing focus on CD163 for diagnostic purposes led us to examine in detail factors influencing the detection of monocytic CD163 expression in peripheral blood by flow cytometry. Previous studies have reported varying results, from only a few to 99% of monocytes have been proposed to express CD163 (3;5-7;34-41). These studies have used various monoclonal CD163 antibody clones with specificity to different epitopes along the nine extracellular SRCR domains (42).

(134) We have previously demonstrated a higher monocytic and dendritic cell surface CD163 expression using MAC2-158, which recognizes an epitope in SRCR domain-1, than when using GHI/61, which recognizes SRCR domain-7 located in proximity to the cell membrane (18). This led us to hypothesize that the difference in reactivity may be due to steric hindrance when binding close to the cell membrane. We therefore selected four antibodies (MAC2-158, R-20, GHI/61, and RM3/1) on the basis of their diverse epitope-specificity (domain-1, -4, -7, and -9 respectively) (42), and investigated the performance in flow cytometry assessing peripheral blood monocytic cell surface CD163 expression.

(135) Indeed, we observed a SRCR domain dependent binding pattern which may explain the immense inconsistency in monocytic CD163 expression suggested by numerous investigators (3;5-7;34-41). Interestingly, a very small fraction of monocytes was stained when using RM3/1, which is known to recognize an epitope located in recognizes SRCR domain-9. Conversely, using the MAC2-158 clone, which recognizes SRCR domain-1, we were consistently able to identify a substantial proportion of circulating CD163 expressing monocytes (>80%). This observation was further substantiated by the receptor density investigated by flow cytometry, which showed a similar pattern. It is therefore tempting to speculate that the lower affinity of antibodies, which are raised against SRCR domain, located in proximity to the cell membrane, may partly reflect a steric hindrance which we have previously proposed (18).

(136) Nonetheless, there may be other explanations for the varying reactivity using different clones of CD163 mAbs. This phenomenon may simply suggest a difference in the degree of antibody labeling with fluorescent dye-protein conjugates. In order to maintain an optimal degree of conjugation to give maximum fluorescence intensity, all direct immunofluorescence staining was performed using commercial available primary conjugated anti-CD163. Nevertheless, the fluorescence intensity of a conjugated protein does not vary linearly with the degree of conjugation, but reach a maximum at a relatively low degree of conjugation. The lowest degree of conjugation which gives maximum fluorescence is therefore to be preferred as it will cause least changes in the physical and biological properties of the antibody (43-46). However, when indirect immunofluorescence staining was assessed using unconjugated primary CD163 antibody clones and same fluorescent secondary antibody conjugate, we observed a similar pattern of CD163 cell surface immunostaining by immunofluorescence microscopy and flow cytometry. Another plausible explanation of the decrease in monocytic CD163 expression when using antibodies raised against SRCR domain, located in proximity to the cell membrane, may be fluorescence quenching. In conventional organic fluorochromes, such as FITC and PE, intermolecular interactions and energy transfer between molecules can result in self-quenching of the fluorescence intensity causing loss of absorbed excitation energy and a reduction in fluorescence intensity (47).

(137) In a recent study the authors show, using two different clones of anti-CD163, a significantly higher monocytic CD163 cellular expression in blood samples anti-coagulated with EDTA than when anti-coagulated with heparin (38). To some extent, we observed similar pattern of determined monocytic CD163 expression in EDTA and heparin stabilized blood samples. The difference in proportion of CD14 positive monocytes stained positive for CD163 was most profound when using GHI/61. However, when using MAC2-158 the fraction of CD14 positive monocytes stained positive for CD163 was unaffected of anticoagulant used. CD163 is known to be cleaved from the cell membrane by matrix metallo-proteinases resulting in release of a soluble form of CD163 (20;48). Nonetheless, we excluded that the diversity in CD163 expression using different anticoagulants was due to shedding of CD163 by demonstrating that the levels of soluble CD163 was unaffected in the samples investigated. As heparin stabilized blood samples resembles physiological calcium levels, whereas free calcium is abrogated from EDTA stabilized blood samples, we hypothesized that the variation in CD163 expression may be due to loss of a calcium dependent binding affinity. This was clearly verified in SPR-analysis showing almost complete loss of ligand binding activity in the presence of calcium when using GHI/61. The reverse pattern was observed using RM3/1, which exhibited binding activity when calcium was present in the media. R-20 was slightly affected by calcium, whereas MAC2-158 showed binding activity regardless extracellular levels of calcium which was in accordance to observations when using flow cytometry.

(138) Calcium dependent ligand binding has also been observed for CD163 binding to its only known physiological relevant ligand; Hp-Hb complexes bind to SRCR domain-3 (42). The binding of the SRCR domain containing protein agglutinin to IgA is mediated in a calcium dependent manner by type B SRCR domains (49) and the structure of a type A SRCR domain from MARCO mediating calcium dependent ligand binding, has been determined (50). Three residues of the SRCR of MARCO were found to be of key importance for calcium ligation, Asp447, Asp 448 and Glu511. The calcium binding site of the domain was not interacting with the ligand, but calcium binding was suggested to have an effect of promoting the correct structural conformation to enable ligand binding (50). A sequence alignment of the SRCR domain of MARCO with the SRCR domains of CD163 (not shown) showed that SRCR domain-2, -3, -4, -7, and -9 of CD163 had a conservation of these three residues, whereas one or more of the three residues had a non-conservative substitution in SRCR domain-1, -5, -6, and -8. Though other residues in these four domains could substitute as ligands for divalent cations, the sequence observation is in concord with our observation of only a minor effect of calcium on the binding of a SRCR domain-1 binding mAb (MAC2-158) and a larger effect of calcium on mAb binding to domain-4, -7, and -9. Although the function and possible ligand of specific SRCR domains of CD163 other than SRCR domain-3 is not known, it is tempting to speculate on the role of calcium in these interactions, and that it may not be involved in ligand binding of SRCR domain-1, -5, -6, and -8.

(139) The CD163-mediated internalization of Hb-Hp complexes by macrophages have been proposed to be a possible a mechanism which could be exploited to target-specific drug delivery in CD163 expressing neoplastic cells of monocyte/macrophage lineage (51). Most studies addressing the cellular uptake have either been performed on stably CD163-transfected Flp-In CHO cells (2;4;42) or using fluorescence-conjugated Hb-Hp complexes (4;51). However, CD163-transfected cells do not resemble cells of monocyte/macrophage lineage and future drug-labeling may be more feasible using monoclonal antibodies rather than using Hb-Hp complexes. Therefore, we set out to investigate and evaluate the cellular uptake of different clones of monoclonal CD163 antibodies in monocyte-derived macrophages, which represent functional and immunocompetent CD163 expressing cells.

(140) Surprisingly, the immunofluorescence microscopy analysis revealed that the cellular uptake could be achieved using clones of CD163 mAbs regardless their SRCR domain recognition. However, in accordance with the flow cytometric analysis the proportion of stained cells, degree of fluorescence intensity, and cellular uptake appeared substantially superior using MAC2-158. This was confirmed by CD163 binding and cellular uptake experiments using CD163-transfected Flp-In CHO cells. A similar pattern of surface staining and cellular uptake was observed in CD163-transfected Flp-In CHO cells by confocal laser scanning microscopic analysis suggesting that the epitope recognized by MAC2-158 is more accessible or may likely emerge the correct conformation for antibody binding. This observation was further substantiated by investigating binding and endocytosis of different anti-CD163 clones labeled with .sup.125I in CD163-transfected Flp-In CHO cells. The time course of cell-associated radioactivity reached a plateau after one hour of incubation using R-20 and GHI/61 which is equivalent to the time course of cell-associated radioactivity when assessing .sup.125I-labelled Hp-Hb complexes (2). However, when incubating with .sup.125I-labelled MAC2-158 the time course of cell-associated radioactivity did not reach a plateau within the two hour incubation and exhibited a superior percentage-wise uptake as compared with other clones.

(141) Our findings may be significant since CD163 has been suggested as possible target for drug delivery in acute myeloid leukemia (51). Using flow cytometry, investigators have shown that approximately 5% (range: 0% to 38.5%) of leukemic blast cells of AML type M4 and 23% (range: 1% to 77%) of AML type M5 expressed CD163 (51;52). However, similar to the contradictory data on the cellular distribution of CD163 on monocytes and macrophages, discrepancy in CD163 expression on myelomonocytic neoplastic cells have been report reported. Using a different method and monoclonal antibody clone a recent study demonstrated CD163 immuno-reactivity in 49% of AML cases with monocytic differentiation (53). Taken the presented data to account it is tempting to speculate that a higher proportion of leukemic blasts in both myelomonocytic (M4) and monocytic (M5) subtypes of AML express CD163, suggesting the receptor as a potential candidate for targeted specific drug delivery in acute myeloid leukemia.

(142) In conclusion, we demonstrate that using the MAC2-158 clone, which recognizes SRCR domain-1, we are consistently able to identify a substantial proportion of circulating CD163 expressing monocytes. In addition, we show for the first time the ability of CD163-antibody-mediated cellular uptake in monocyte-derived macrophages which was most efficient when using MAC2-158. Our findings emphasize the clinical applicability of CD163 as a diagnostic tool and therapeutic candidate in diseases affecting the monocyte/macrophage system.

(143) Surprisingly we saw that the cellular uptake and binding of Mac2-158 and Mac2-48 to CD163-expressing cells is considerably higher than for the other tested antibodies (FIG. 5). This is not related to an increased affinity to CD163 of those antibodies compared to the other antibodies as such, since Biacore studies show that though Mac2-158 binds with high affinity to CD163, a number of the other mAbs bind with virtually similar strength, and for instance 5C6-Fat binds even more strongly.

(144) Neither is the increased uptake solely due to binding to domain 1 taking place, since for instance 5C6-Fat is also binding to domain 1, and stronger as judged by Biacore measurements (FIG. 4), yet binding to cell surfaces is weaker than that observed for Mac2-158 (FIGS. 5 and 6). In general, all the mAbs bind with virtually similar strength to CD163 displayed on cell surfaces (FIG. 5), irrespective of which SRCR domain of CD163 binding is taking place to, except for Mac2-48 and Mac2-158 which bind considerably more strongly, and GHI/61 which does not bind in calcium-containing medium. This strongly demonstrates that Mac2-158 binds to an epitope of specific interest, and that Mac2-48 is also binds strongly to cells, and, as can be seen from FIG. 8, binds in competition with Mac2-158.

REFERENCES FOR EXAMPLE 1

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Example 2—CD163-Positive Subsets of Dendritic Cells

(146) Materials and Methods

(147) Materials and Methods are as Described in Example 1.

(148) Quantitative Flow Cytometry

(149) Freshly drawn peripheral whole blood samples (approx. 3×10.sup.6 cells) were stained with isotype-matched control antibody (Mouse IgG.sub.1 PE, k isotype control, MOPC-21, BD Pharmingen™, San Diego, Calif., USA) or a relevant antibody (anti-CD3 FITC, UCHT1, BD Biosciences, San Diego, Calif., USA; anti-CD11c FITC, KB90, DAKO A/S, Glostrup, Denmark; anti-CD14 FITC, RMO52, IOTests®, Beckman and Coulter, Marseille, France; anti-CD16 FITC, 3G8, BD Biosciences, San Diego, Calif., USA; anti-CD19 FITC, SJ25C1, BD Biosciences, San Diego, Calif., USA; anti-CD20 FITC, CAT 13.6E12, Diatec.com A/S, Oslo, Norway; anti-CD56 FITC, NCAM16.2, BD Biosciences, San Diego, Calif., USA; anti-CD91 FITC, A2MR-a2, BD Biosciences, San Diego, Calif.; anti-HLA-DR FITC, EDU-1, Diatec.com A/S, Oslo, Norway; anti-CD163 PE, MAC2-158, IQ Products, Groningen, The Netherlands; anti-CD163 PE, GHI/61, BD Biosciences, CA, USA; anti-ILT3/CD85k PE-Cy5, ZM3.8, IOTests®, Beckman and Coulter, Marseille, France; anti-HLA-DR PerCP, L234, BD Biosciences, San Diego, Calif.; anti-CD4 APC, EDU-2, Diatec.com A/S, Oslo, Norway; anti-CD14 APC, 18D11, Diatec.com A/S, Oslo, Norway) for 15 minutes at room temperature in the dark. Erythrocytes were lysed for 15 minutes with 4° C. cold solution of ammonium chloride for 15 minutes. The stained cells were then washed twice with D-PBS, pH 7.4 and resuspended in 400 μl FACSflow (Becton Dickinson, San Jose, Calif., USA. All samples were analyzed using a BD FACSCalibur™ Flow Cytometer (Becton Dickinson, San Jose, Calif., USA) and compensated for spectral overlap using FlowJo for Macintosh software version 6.3 (TreeStar, San Carlos, Calif.). At least 100,000 events were acquired to ensure an adequate number of cells for analysis. All staining were controlled using non-specific mAbs. In a 2-parameter correlated Dot Plot of forward scatter [FSC] versus side scatter [SSC], a gate was set around the mononuclear cells (MNC) clusters. The gated MNC were re-plotted using two different 4-color staining protocols and cell definition strategies defining dendritic cells as either CD14.sup.−ILT3.sup.+HLA-DR.sup.+ or lineage[CD3,CD14,CD16,CD19,CD20,CD56].sup.−CD4.sup.+FILA-DR.sup.+. For CD163 density quantitation, flow cytometric estimation of antibodies bound/cell (ABCs) was performed using Quantibrite PE beads (Becton Dickinson, San Jose, Calif., USA) as recommended by the manufacturer. After the cells were stained, as detailed, a set of 4 precalibrated fluorescence labeled beads was used for standardization before the samples were acquired. The Quantibrite PE beads were run at the same instrument settings as the flow cytometric assay, and the linear regression obtained using the Quantibrite PE beads was used to convert the FL2 linear fluorescence staining of the cell population into the number of (CD163) PE molecules bound per cell.

(150) Results

(151) CD163 Positive Subsets of Blood Dendritic Cells: the Scavenging Macrophage Receptors CD163 and CD91 are Co-Expressed on Human Dendritic Cells and Monocytes

(152) Using a simple staining strategy, defining dendritic cells as CD14-CD163+, we identified a cell population expressing CD163 but not the monocytic marker CD14. In a plot of forward scatter [FSC] versus CD163 PE, CD163 expressing cells were gated (FIG. 9A). The gated cells were then re-plotted in a plot of CD14 APC versus CD163 PE identifying a small fraction (<1%) of CD14-cells expressing CD163 (FIG. 9B). This novel cell population also highly expressed HLA-DR (FIG. 9C) and the backgating analysis revealed CD14-CD163+ cells as a relatively distinct cell population localized between lymphocytes and monocytes (FIG. 9D).

(153) Defining dendritic cells as either CD14-ILT3+HLA-DRhigh (FIG. 10A-C) or lineage[CD3,CD14,CD16,CD19,CD20,CD56]-CD4+HLA-DR+ (not shown), flow cytometric analysis showed that 10.5% (95% CI: 8.0-12.5) of peripheral blood dendritic cells express CD163 (FIG. 10C). As shown in FIG. 10C, CD163 expressing peripheral blood dendritic cells can be subdivided into two populations; a subset expressing high levels of CD163 (CD163high, Ma 34.6 [95% CI: 30.5-40.7]) and a weaker staining subset (CD163low, MFI: 4.2 [95% CI: 3.7-5.1]). For comparison and consistent with paper I, virtually all CD14+ILT3+HLA-DR+ monocytes (88.0% [95% CI: 85.0-91.0%]) stained positive for CD163 (not shown). Backgating analysis demonstrated Lin-CD4+HLA-DR+CD163+ cells as a distinct cell population belonging to the expected localization of dendritic cells, between lymphocytes and monocytes (FIG. 10D). An isotype-matched non-specific IgG1 served as a negative staining control (MFI: 1.23 [95% CI: 1.14-1.46]) (FIG. 10E).

(154) To exclude unspecific cross-reactivity, the dendritic cell CD163 expression analysis was repeated utilizing the MAC-158 clone of anti-CD163. In accordance to paper I, the MAC2-158 clone binding SRCR domain 1, recognized a significantly higher fraction of peripheral blood dendritic cells (32.3% [95% CI: 19.6-45.1%]) (FIG. 11D) as compared with the GHI/61 clone (10.5% [95% CI: 8.0-12.5%]) (FIG. 11B) binding SRCR domain 7. The MFI, reflecting the amount of CD163 receptors per cell, was also significantly higher for the MAC2-158 antibody clone (107.5 [95% CI: 74.7-140.3]) (FIG. 11C) compared with GHI/61 (22.3 [95% CI: 19.2-25.4]) (FIG. 11A) suggesting that MAC2-158 was able to identify a higher quantity of CD163 receptors per cell.

(155) To assess the possible function of the two novel CD163 expressing subsets of peripheral blood cells with dendritic cell characteristics, further phenotyping was performed. The surface antigen assessment revealed that the subset expressing low levels of CD163 also expressed low levels of HLA-DR (FIG. 12A) and ILT3 (FIG. 12B), whereas the subset expressing high levels of CD163 highly expressed HLA-DR (FIG. 12A) and ILT3 (FIG. 12B). Both subsets expressed CD11c indicating relationship to the myeloid lineage (DC1) of dendritic cells (FIG. 12C). The CD163low subset was CD16+, whereas the CD163high subset was CD16− (FIG. 12D). However, both subsets were CD91+ (FIG. 12E), thereby constituting a subfraction of the recently described CD91+CD11c+ dendritic cell subset.

(156) Since evidence has accumulated showing that dendritic cells may be an important contributor to HIV-1 transmission and pathogenesis, we intended to investigate peripheral blood dendritic cell CD163 expression in HIV-1 patients. Generally, the fraction of CD163 expressing dendritic was significantly higher in HIV-1 patients (19.3% [95% CI: 14.7-26.3%]) compared with healthy patients (10.5% [95% CI: 8.0-12.5]) p<0.001 (FIG. 13A).

(157) All investigated HIV-1 infected patients expressed both subsets of CD163+ dendritic cells (CD163low and CD163high), whereas approximately half of the healthy controls only expressed either subset CD163low or CD163high (FIGS. 13B and 14A-C).

(158) Interestingly, the mean amount of CD163 receptors per cell estimated on the CD163high subset was significantly elevated in the HIV-1 patients compared with healthy controls (p<0.001) (FIG. 13C).

(159) Discussion

(160) Since the discovery of CD163 as a novel macrophage restricted marker, the receptor as been extensively investigated in pathophysiological conditions affecting the monocyte/macrophage system.

(161) CD163 may possess potential as a diagnostic marker of monocyte/macrophage activity in inflammatory conditions and as a therapeutic candidate. CD163 expression is tightly regulated by pro- and anti-inflammatory stimuli suggesting an immunoregulatory function of CD163, and CD163 cytoplasmic splice variants respond differently upon pro-inflammatory stimuli. Studies have also demonstrated significant changes in cellular and soluble CD163 conditions, such as inflammatory, malignant, and infectious diseases suggesting affection of the monocyte/macrophage system strongly implicating CD163. We have also shown that tumor-infiltrating macrophages highly express CD163 and that the density of CD163 expressing macrophages in tumor is associated with poor patient survival. In addition, a recent study has shown that TIE2+ macrophages, which are directly involved in angiogenesis, express high levels of CD163. CD163 has also been shown to be expressed on M4/M5 leukemic blast cells and on tumor cells in breast cancer.

(162) The cellular distribution of CD163 on both immune and malignant cells under physiological conditions remain unclear. The varying CD163 surface expression and great discrepancy reported by several investigators has compromised the applicability of CD163 as a diagnostic marker of monocyte/macrophage activity in inflammatory conditions and as a therapeutic candidate.

(163) In this (and the previous) Example, we report the development of a reliable multi-colour flow cytometry-based assay which consistently identifies a substantial proportion of circulating CD163 expressing monocytes (>80%). The CD163 expression has been a topic of debate in the literature for almost two decades. Using different anticoagulants, antibody clones, and general test conditions the level of monocytic CD163 expression has been reported to vary from a few to 99% (Venneri et al., 2007; Backe et al., 1991; Hogger et al. 1998; Philippidis et al. 2004; Sulahian et al., 2000; Van den Heuvel at al., 1999; Fabriek at al. 2005; Moniuszko et al. 2006; Kim et al. 2006; Davis et al. 2005; Buechler at al. 2000). However, we demonstrate a SRCR domain dependent binding pattern when utilizing various monoclonal antibody clones raised against different SRCR domains which may explain the immense inconsistency in monocytic CD163 expression suggested by numerous investigators.

(164) Using the MAC2-158 antibody clone, which recognizes SRCR domain 1, we showed that a significantly higher proportion of circulating monocytes expressed CD163 as compared with R-20 (SRCR domain 4), GHI/61 (SRCR domain 7), and RM3/1 (SRCR domain 9). This observation was further verified by the mean fluorescence intensity, which reflects the amount of CD163 receptors per cell. This phenomenon may simply suggest a significantly difference in antibody binding affinity; however, it seems more likely that this SRCR domain dependent binding pattern probably is partly due to steric hindrance for binding of antibodies, which are raised against SRCR domain, located in proximity to the cell membrane, whereas MAC2-158 recognizes a possible exposed SRCR domain 1.

(165) In a recent study, we have shown, using two different clones of anti-CD163, a significantly higher monocytic CD163 expression in blood samples anti-coagulated with EDTA than when anti-coagulated with heparin (Fabriek et al. 2005). To some extent, we observed similar pattern of CD163 expression in EDTA and heparin stabilized blood samples. The difference in proportion of CD14 positive monocytes stained for CD163 was most profound when using GHI/61. However, when using MAC2-158 the fraction of CD14 positive monocytes stained for CD163 was unaffected regardless anticoagulant used. We excluded that this diversity in CD163 expression using different anticoagulants was due to shedding of CD163, since the levels of soluble CD163 was unaffected in the samples investigated. As heparin stabilized blood samples resembles physiological calcium levels, whereas free calcium is abrogated from EDTA stabilized blood samples we hypothesize that the observed phenomenon may be due to the mechanism underlying the anticoagulant effect of EDTA, which is a calcium chelator, whereas heparin action is independent of calcium. We were not able to demonstrate same calcium dependent binding pattern using other monocyte/macrophage markers, such as CD36, CD91, and CD206. However, previously it has been suggested that some antibodies raised against calcium-binding proteins preferentially recognize specific calcium-induced protein conformational states (206), and that the immunoreactivity of these antibodies depends on the calcium-binding status (Gao et al., 1997).

(166) Some studies have shown that a high density of tumor-infiltrating macrophages is associated with poor prognosis in breast, bladder, and superficial esophageal cancers; however, in others in cancers such as gastrointestinal malignancies it appears that their infiltration correlates with a good prognosis. Most of these studies utilize CD68 as macrophage marker. Unfortunately, CD68 is a general marker which does not discriminate between different subpopulations, either tumor-suppressing or tumor-promoting macrophage populations, and the newly identified Tie2-expressing macrophages. As it is now well established that a variety of macrophage subpopulations exits within the tumor microenvironment of which some exhibit tumor-suppressing and others tumor-promoting capacity the usefulness of a general marker such as CD68 is seriously challenged. Studies suggesting that the correlation of macrophage infiltration with good prognosis may be controversial; thus, the common opinion is that macrophages are attracted to tumor sites and polarized by tumor cells to favor tumor growth and progression. The utility of an unsuitable marker for macrophages with tumor-promoting capacity may explain the observed discrepancy outcome of high density of tumor-infiltrating macrophages.

(167) Extensive immunohistochemical evaluation of CD163 expression has recognized the receptor as a novel marker of cells of monocyte/macrophage lineage in normal and neoplastic conditions using paraffin-embedded tissue samples (Shabo et al., 2008). However, when assessing CD163 immunoreactivity in hematopoietic disorders a study demonstrated that only 1 of 46 cases of acute monoblastic leukemia (AML-M5A) examined was CD163 positive. In addition, the investigators were not able to demonstrate any CD163 immunoreactivity in acute myelomonocytic leukemia (AML-M4) (Shabo et al., 2008). However, using flow cytometry later study showed that approximately 20% of leukemic blast cells of AML types M4 and M5 displays constitutive expression of CD163 (Lau et al., 2004). A recent study demonstrated CD163 immunoreactivity in 49% of AML cases with monocytic differentiation (18). However, these studies are hardly comparable since they utilize different methods and CD163 antibodies recognizing dissimilar SRCR domains.

(168) Based on our observation of SRCR domain dependent binding pattern using different antibody clones in flow cytometry we set out to evaluate immunohistochemical CD163 expression in paraffin-embedded tissue samples.

(169) Optimal immunoreactivity depends on epitope preservation. The composition, pH, type of heating, and amount of retrieval solution have a significant influence on the degree of epitope retrieval and preservation. An overwhelming body of evidence has demonstrated not all epitopes are equally unmasked during the process of epitope retrieval. More importantly from a clinical point of view, this suggests that the CD163 expression may be underestimated on both cells of monocyte/macrophage lineage in normal and neoplastic conditions, especially when performing immunohistochemistry.

(170) The CD163-mediated internalization of Hb-Hp complexes by macrophages may be a possible a mechanism which could be exploited to target-specific drug delivery in CD163 expressing neoplastic cells of monocyte/macrophage lineage. Most studies addressing the cellular uptake have either been performed on stably CD163-transfected Flp-In CHO cells (Bowen et al. 1997) or using fluorescence-conjugated Hb-Hp complexes (Lau et al., 2004). However, CD163-transfected CHO cells do not resemble cells of monocyte/macrophage lineage and future drug-labelling may be more feasible using monoclonal rather than using Hb-Hp complexes. Since CD163 only binds Hb and Hp in complex this suggest that a neo-epitope is presented and therefore it seems reasonable that only antibodies raised against SRCR domain 3, where Hb-Hp complexes are bound (Chakraborty et al., 2004), will be able to facilitate a CD163-mediated endocytosis. Therefore, we initially set out to investigate and evaluate the applicability of CD163 for future targeted therapy, assessing binding and cellular uptake of different clones of monoclonal CD163 antibodies in CD163-transfected FIp-In chinese hamster ovary.

(171) Interestingly, the confocal laser scanning microscopic analysis revealed that the cellular uptake could be achieved using clones of monoclonal CD163 antibodies regardless their SRCR domain recognition. In accordance with the flow cytometric analysis the proportion of stained cells, degree of fluorescence intensity, and cellular uptake appeared substantially superior using MAC2-158. As cells of monocyte/macrophage lineage represent functional and immunocompetent CD163 expressing cells, we then repeated these CD163 binding and cellular uptake experiments utilizing monocyte-derived macrophages. A similar pattern of surface staining and cellular uptake was observed in monocyte-derived macrophages signifying that MAC2-158 may potentially be the CD163 clone giving the most potent response if used for targeted specific drug delivery.

(172) CD163 has been considered to be expressed exclusively on the surface of monocytes and tissue macrophages (Radzun H J. Blood. 1987; Backé E. J Clin Pathol. 1991; Pulford K. Immunology. 1992). CD163 and CD91 are highly expressed during the differentiation of monocytes into the anti-inflammatory macrophage phenotype. CD91 has been shown to be expressed in monocyte-derived dendritic cells, where the receptor serves important functions in T-cell stimulation (Hart, J R J. Immunol. 2004). In addition, evidence has suggested that CD163 may be expressed by a yet unknown tissue component as monocyte CD163 expression and sCD163 levels did not correlate with the monocyte absolute count (Davis. Cytometry Part B Clinical cytometry. 2005; Zarev P V. Lab Hematol. 2004). The dual roles of both CD91 and CD163 in iron metabolism (Hvidberg, V. Blood. 2005; Kristiansen, M. Nature. 2001) and immunomodulation led us to hypothesize that CD163 like CD91 was expressed in dendritic cells in addition to other cells of myelomonocytic origin.

(173) Using a simple staining strategy, defining dendritic cells as CD14-CD163+, we identified a CD163 expressing cell population displaying dendritic cell phenotypic characteristics. This finding is in contrary to previous reports (Ritter. Pathobiology. 1999) and because of the well-known heterogeneity of dendritic cells we utilized two different staining strategies defining dendritic cells as either CD14-ILT3+HLA-DRhigh or lineage[CD3,CD14,CD19,CD20,CD56]-CD4+HLA-DR+ in order to verify our observation of CD163 expressing dendritic cells.

(174) Flow cytometric analysis revealed two distinct subsets of CD163 expressing dendritic cells, CD163low and CD163high, together constituting approximately 10.5% (95% CI: 8.0-12.5) of peripheral blood dendritic cells. However, in accordance with the previous Example, we demonstrated that using the MAC2-158 clone instead of GHI/61 we were able to identify a significantly higher proportion of CD163 expressing dendritic cells (32.3% [95% CI: 19.6-45.1%]) suggesting that up to almost half of circulating peripheral blood dendritic cells may express the hemoglobin scavenger receptor. An extensive phenotyping characterized both subsets of CD163 expressing dendritic cells as CD91+CD11c+, thus representing a subpopulation of the recently described CD91+CD11c+ myeloid lineage (DC1) of dendritic cells (Hart, J P. J. Immunol. 2004). Since CD91 and CD163 are co-expressed on monocytes, their co-expression on a subfraction of peripheral blood dendritic cells emphasizes the relation between the two receptors. Interestingly, further phenotyping revealed that the subset expressing high levels of CD163 also highly expressed HLA-DR and ILT3 suggesting that this subset possesses both inflammatory and tolerogenic abilities. On the contrary, the subset expressing low levels of CD163, was CD16+ and expressed low levels of HLA-DR and ILT3. This subset has been reported to constitute a significant proportion of myeloid DC (MacDonald K P. Blood. 2002), and micro array analysis has proposed that toll-like receptor 8 (TLR8) is predominant in these cells (Lindstedt M. J Immunol. 2005), suggesting a primary role in ssRNA responses. CD16 (FcγRIII) was originally identified as a NK-cell restricted receptor; however, it is also expressed by monocytes/macrophages, granulocytes, and dendritic cells (Schakel K. Eur J Immunol. 1998). CD16 expressing dendritic cells are shown to exhibit greater phagocytic and oxidative activity than CD16 negative dendritic cells, including produce significant amounts of cytokines (Almeida J. Clin Immunol. 2001), and have a marked capability to activate naïve T-cells (Schakel K. Eur J Immunol. 1998).

(175) Myeloid dendritic cells are potent antigen-presenting cells and play critical roles in host defence. These cells with a partial activation phenotype are known to accumulate in lymphoid tissue during asymptomatic chronic HIV1 infection. Dendritic cells may be an important contributor to HIV-1 transmission and pathogenesis. This led us to investigate peripheral blood dendritic cell CD163 expression in HIV-1 patients.

(176) Surprisingly, CD163 expressing dendritic was significantly higher in HIV-1 patients (19.3% [95% CI: 14.7-26.3%]) compared with healthy individuals (10.5% [95% CI: 8.0-12.5]) p<0.001. These findings are consistent with a recent study showing increased frequency of CD163+CD16+ monocytes in HIV-1-infected patients compared with seronegative individuals. CD163+CD16+ monocytes may therefore be a useful biomarker for HIV-1 infection and a possible target for therapeutic intervention.

(177) In addition, another recent study demonstrate that inflammatory myeloid dermal dendritic cells, which are known to play a significant role in the pathogenesis of psoriasis and accumulate in chronically inflamed tissues, may arise from CD163 expressing peripheral blood dendritic cell precursors (CD11c+HLA-DR+CD16+). The authors speculate that these “pre-inflammatory dendritic cells” may migrate into the skin in response to a chemokine gradient or other stimulus. Hence, it is suggested that these inducing inflammatory dendritic cells may represent novel therapeutic target in psoriasis (Zaba. J Invest Dermatol. 2009).

(178) Direct targeting of dendritic cells via specific surface receptors is a promising method to enhance immunogenicity of vaccines (Gamvrellis. Immunol. Cell Biol. 2004). The restricted expression of CD163 on dendritic cells and other antigen presenting cells emphasize the applicability of CD163 as a diagnostic tool and putative candidate for targeted specific drug delivery. Solid tumors contain not only malignant cells, but also a number of inflammatory, infiltrating cells including macrophages, which are residents in the microenvironment of both primary and secondary tumors (Albini A. Nat Rev Cancer. 2007).

(179) In conclusion, this (and the previous) Example has led to the identification of the unknown tissue component expressing the hemoglobin scavenger receptor CD163 consisting of two distinct subsets of CD163 expressing dendritic cells, CD163low and CD163high, together constituting up to 50% of peripheral blood dendritic cells. One of the identified subsets of CD163 expressing dendritic cells (ILT3highCD163high) potentially possesses inflammatory and tolerogenic characteristics. We show that CD163 expressing dendritic was significantly elevated in HIV-1-infected patients compared with sero-negative individuals further supporting the suggested immunomodulatory role of CD163. Furthermore, we demonstrate that using the MAC2-158 clone, which recognises SRCR domain 1, we are consistently able to identify a substantial proportion of circulating CD163 expressing monocytes (>80%). In addition, we show the ability of CD163-antibody-mediated cellular uptake in both CD163-transfected CHO cells and monocyte-derived macrophages with was most pronounced when using MAC2-158.

(180) Our data propose clinical applicability of CD163 as a diagnostic tool in pathophysiological conditions involving the monocyte/macrophage system which is emphasized by the restricted CD163 expression on monocytes, macrophages, dendritic cells. The CD163 expression on tumor-promoting macrophages and malignant cells depicts the hemoglobin scavenger receptor CD163 as a double-edged sword in malignant disease by suggesting usability of CD163 as a putative candidate for targeted specific drug delivery in hematological malignancies and solid tumors, as well as other diseases involving the monocyte/macrophage system. Our data also implies that the expected adverse effect profile using CD163 as target is potential clinically insignificant compared with comparable treatments currently available.

REFERENCES FOR EXAMPLE 2

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Immunol Cell Biol 2004 October; 82(5):506-16. 6. Hart J P, Gunn M D, Pizzo S V. A CD91-positive subset of CD11c+ blood dendritic cells: characterization of the APC that functions to enhance adaptive immune responses against CD91-targeted antigens. J Immunol 2004 Jan. 1; 172(1):70-8. 7. Hvidberg V, Maniecki M B, Jacobsen C, Hojrup P, Moller H J, Moestrup S K. Identification of the receptor scavenging hemopexin-heme complexes. Blood 2005 Oct. 1; 106(7):2572-9. 8. Kristiansen M, Graversen J H, Jacobsen C, Sonne O, Hoffman H J, Law S K, et al. Identification of the haemoglobin scavenger receptor. Nature 2001 Jan. 11; 409(6817):198-201. 9. Lindstedt M, Lundberg K, Borrebaeck C A. Gene family clustering identifies functionally associated subsets of human in vivo blood and tonsillar dendritic cells. J Immunol 2005 Oct. 15; 175(8):4839-46. 10. MacDonald K P, Munster D J, Clark G J, Dzionek A, Schmitz J, Hart D N. Characterization of human blood dendritic cell subsets. Blood 2002 Dec. 15; 100(13):4512-20. 11. Radzun H J, Kreipe H, Bodewadt S, Hausmann M L, Barth J, Parwaresch M R. Ki-M8 monoclonal antibody reactive with an intracytoplasmic antigen of monocyte/macrophage lineage. Blood 1987 May; 69(5):1320-7. 12. Backe E, Schwarting R, Gerdes J, Ernst M, Stein H. Ber-MAC3: new monoclonal antibody that defines human monocyte/macrophage differentiation antigen. J Clin Pathol 1991 November; 44(11):936-45. 13. Pulford K, Micklem K, McCarthy S, Cordell J, Jones M, Mason D Y. A monocyte/macrophage antigen recognized by the four antibodies GHI/61, Ber-MAC3, Ki-M8 and SM4. Immunology 1992 April; 75(4):588-95. 14. Ritter M, Buechler C, Langmann T, Schmitz G. Genomic organization and chromosomal localization of the human CD163 (M130) gene: a member of the scavenger receptor cysteine-rich superfamily. Biochem Biophys Res Commun 1999 Jul. 5; 260(2):466-74. 15. Schakel K, Mayer E, Federle C, Schmitz M, Riethmuller G, Rieber E P. A novel dendritic cell population in human blood: one-step immunomagnetic isolation by a specific mAb (M-DC8) and in vitro priming of cytotoxic T lymphocytes. Eur J Immunol 1998 December; 28(12):4084-93. 16. Zaba L C, Krueger J G, Lowes M A. Resident and “inflammatory” dendritic cells in human skin. J Invest Dermatol 2009 February; 129(2):302-8. 17. Shabo I, Stal O, Olsson H, Dore S, Svanvik J. Breast cancer expression of CD163, a macrophage scavenger receptor, is related to early distant recurrence and reduced patient survival. Int J Cancer 2008 Aug. 15; 123(4):780-6. 18. Lau S K, Chu P G, Weiss L M. CD163: a specific marker of macrophages in paraffin-embedded tissue samples. Am J Clin Pathol 2004 November; 122(5):794-801. 19. Venneri M A, De P M, Ponzoni M, Pucci F, Scielzo C, Zonari E, et al. Identification of proangiogenic TIE2-expressing monocytes (TEMs) in human peripheral blood and cancer. Blood 2007 Jun. 15; 109(12):5276-85. 20. Backe E, Schwarting R, Gerdes J, Ernst M, Stein H. Ber-MAC3: new monoclonal antibody that defines human monocyte/macrophage differentiation antigen. J Clin Pathol 1991 November; 44(11):936-45. 21. Hogger P, Dreier J, Droste A, Buck F, Sorg C. Identification of the integral membrane protein RM3/1 on human monocytes as a glucocorticoid-inducible member of the scavenger receptor cysteine-rich family (CD163). J Immunol 1998 Aug. 15; 161(4):1883-90. 22. Philippidis P, Mason J C, Evans B J, Nadra I, Taylor K M, Haskard D O, et al. Hemoglobin scavenger receptor CD163 mediates interleukin-10 release and heme oxygenase-1 synthesis: antiinflammatory monocyte-macrophage responses in vitro, in resolving skin blisters in vivo, and after cardiopulmonary bypass surgery. Circ Res 2004 Jan. 9; 94(1):119-26. 23. Sulahian T H, Hogger P, Wahner A E, Wardwell K, Goulding N J, Sorg C, et al. Human monocytes express CD163, which is upregulated by IL-10 and identical to p155. Cytokine 2000 September; 12(9):1312-21. 24. Van den Heuvel M M, Tensen C P, van As J H, Van den Berg T K, Fluitsma D M, Dijkstra C D, et al. Regulation of CD 163 on human macrophages: cross-linking of CD163 induces signaling and activation. J Leukoc Biol 1999 November; 66(5):858-66. 25. Fabriek B O, Dijkstra C D, Van den Berg T K. The macrophage scavenger receptor CD163. Immunobiology 2005; 210(2-4):153-60. 26. Moniuszko M, Kowal K, Rusak M, Pietruczuk M, Dabrowska M, Bodzenta-Lukaszyk A. Monocyte CD163 and CD36 expression in human whole blood and isolated mononuclear cell samples: influence of different anticoagulants. Clin Vaccine Immunol 2006 June; 13(6):704-7. 27. Kim W K, Alvarez X, Fisher J, Bronfin B, Westmoreland S, McLaurin J, et al. CD163 identifies perivascular macrophages in normal and viral encephalitic brains and potential precursors to perivascular macrophages in blood. Am J Pathol 2006 March; 168(3):822-34. 28. Davis B H, Zarev P V. Human monocyte CD163 expression inversely correlates with soluble CD163 plasma levels. Cytometry B Clin Cytom 2005 January; 63(1):16-22. 29. Buechler C, Ritter M, Orso E, Langmann T, Klucken J, Schmitz G. Regulation of scavenger receptor CD163 expression in human monocytes and macrophages by pro- and antiinflammatory stimuli. J Leukoc Biol 2000 January; 67(1):97-103. 30. Bowen M A, Whitney G S, Neubauer M, Starling G C, Palmer D, Zhang J, et al. Structure and chromosomal location of the human CD6 gene: detection of five human CD6 isoforms. J Immunol 1997 Feb. 1; 158(3):1149-56. 31. Direkze N C, Hodivala-Dilke K, Jeffery R, Hunt T, Poulsom R, Oukrif D, et al. Bone marrow contribution to tumor-associated myofibroblasts and fibroblasts. Cancer Res 2004 Dec. 1; 64(23):8492-5. 32. Chakraborty A, Lazova R, Davies S, Backvall H, Ponten F, Brash D, et al. Donor DNA in a renal cell carcinoma metastasis from a bone marrow transplant recipient. Bone Marrow Transplant 2004 July; 34(2):183-6. 33. Gao et al., Neurone-specific enolase and Sangtex 100 assays during cardiac surgery: Part I—The effects of heparin, protamine and propofol. Perfusion (1997), 12(3), 163-165.

Example 3—Humanisation of CD163 Antibodies

(182) Materials and Methods

(183) Obtaining Hybridoma:

(184) The hybridoma clones (Mac2-158 and Mac2-48) were obtained from Trillium Diagnostics LCC, Maine, USA (http://www.trilliumdx.com/). The cells were thawed and allowed to amplify a few rounds.

(185) Primers:

(186) Primers used for PCR amplification and sequencing of the variable heavy and light chain regions of the hybridoma clones Mac2-158 and Mac2-48 were as described in (1)), but adapting the 5′ (GAGG-directional) and 3′ (blunt end) sequences for TOPO directional cloning. All primers were obtained from TAG Copenhagen (Copenhagen, Denmark).

(187) List of Primers:

(188) TABLE-US-00019 Leader and constant region primers VK6 leader VK6leader tgaagtcacagacccagg [SEQ ID NO: 32] VKconstant VKconstant gcacctccagatgttaactg [SEQ ID NO: 33] VHgconstant VHgconstant agggaaataRcccttgaccag (R = a/g) [SEQ ID NO: 34] VH leader2 VHleader2 atgagagtgctgattcttttg [SEQ ID NO: 35] Primers for generation of chimeric heavy chain VHfor VHfor gatgtccagcttcaggag [SEQ ID NO: 36] LeaderbackH leaderbackH ctcctgaagctggacatcagacagcacccacctgg [SEQ ID NO: 37] CHfor CHfor gcagcgccagcaccaag [SEQ ID NO: 38] VHback VHback cttggtgctggcgctgctgactgtgagagcggtgc [SEQ ID NO: 39] Expression vector cloning primers  Light chain Lfor1 gccATGGACATGAGAGTGCCTG [SEQ ID NO: 40] forward Light chain Lback1 tcaGCACTCGCCCCTGTTG [SEQ ID NO: 41] reverse Heavy chain Hfor1 gccATGAAGCACCTGTGGTTC [SEQ ID NO: 42] forward Heavy chain Hback1 tcaCTTGCCCAGGCTCAGGC [SEQ ID NO: 43] reverse Heavy chain SLIM primers K43-N43, S50- K-N F TCACCTACAGCGGCAGC [SEQ ID NO: 44] Y50, Y52-T52 K-N FT TGGAGTGGATGGGCTACA TCACCTACAGCGGCAGC [SEQ ID NO: 45] K-N RT tgtagcccatccactcca gcttgttgccggggaac [SEQ ID NO: 46] K-N R Gcttgttgccggggaac [SEQ ID NO: 47] S56-I56, Y58-N58 SY-IN FT gcggcatcaccaacta caaccccagcctgaag [SEQ ID NO: 48] SY-IN F Caaccccagcctgaag [SEQ ID NO: 49] SY-IN RT tagttggtgatgccgc tgtaggtgatgtagcc [SEQ ID NO: 50] SY-IN R Tgtaggtgatgtagcc [SEQ ID NO: 51] V71-R71 V-R F Caagaaccagttcagcctg [SEQ ID NO: 52] V-R FT tcagcgaggacaccag caagaaccagttcagc [SEQ ID NO: 53] V-R RT ctggtgtcctcgctga tggtcaccctgctctt [SEQ ID NO: 54] V-R R Tggtcaccctgctcttcag [SEQ ID NO: 55] Q1-D1 Q-D F Gagtctggaccaggacc [SEQ ID NO: 56] Q-D R Gacagcacccacctgg [SEQ ID NO: 57] Q-D FT1 tgacgtgcagctgcag gagtctggaccaggac [SEQ ID NO: 58] Q-D RT1 ctgcagctgcacgtca gacagcacccacctgg [SEQ ID NO: 59] Light chain SLIM primers P46L P-L FT Ggcaagagccccaagctcctgatctactatgccagc [SEQ ID NO: 60] P-L F Ctgatctactatgccagc[SEQ ID NO: 61] P-L RT Gagcttggggctcttgccgggcttctgctggaacc [SEQ ID NO: 62] P-L R Gggcttctgctggaacc[SEQ ID NO: 63] G89-Q89, T93-S93 GT-QS FT Ccagcaggactactccagccctaggaccttcggtg [SEQ ID NO: 64] GT-QS F Ccctaggaccttcggtg[SEQ ID NO: 65] GT-QS RT Ctggagtagtcctgctggcagaagtacacggcgaag [SEQ ID NO: 66] GT-QS R Cagaagtacacggcgaag[SEQ ID NO: 67] Light chain Quick change primers Primers SLQ-NRY SLQ-NRY for gatctactatgccagcaaccggtactctggagtgcccagc [SEQ ID NO: 68] SLQ-NRY gctgggcactccagagtaccggttgctggcatagtagatc back [SEQ ID NO: 69] Sequencing primers CMV primer cmv for Caaatgggcggtaggcgtg [SEQ ID NO: 70] TK poly A TKPA rev Ccttccgtgtttcagttagc [SEQ ID NO: 71] EMCV IRES EMCV ires Ccttattccaagcggcttc [SEQ ID NO: 72] rev
Sequencing:

(189) Sequencing was performed at Eurofins MWG operon (Ebersberg, Germany) as a Value Read Tube Service. All plasmid preparations and mutations were verified by sequencing.

(190) Extracting Total RNA:

(191) 2×10.sup.6 cells of each hybridoma cell line were used for extracting total RNA by QIAamp blood RNA kit (QIAGEN Corporation, Copenhagen, Denmark) according to the instructions of the manufacturer. Briefly, the cells were re-suspended in 600 μl buffer RLT (QIAGEN) and homogenized by passing it through a syringe mounted with a 21-G (0.8 mm) needle at least 5 times. 600 μl of 70% ethanol (EtOH) was added and mixed by pipetting. The suspension was applied to the QIAamp spin column and load by multiple centrifugations. The column was washed with 750 μl RW1 (Qiagen) and 750 μl RPE (QIAGEN). The RNA was eluted with 2×50 μl RNase free water (QIAGEN).

(192) Preparation of Buffers for cDNA Synthesis

(193) All buffers for the cDNA synthesis was prepared with Ultra pure or molecular biology grade chemicals and diethyl pyrocarbonat (DEPC)-treated water. DEPC-treated water was prepared by adding DEPC (Sigma-Aldrich, Brøondby, Denmark) to a final concentration of 0.1% and the solution was stirred over night followed by autoclaving. Tris and EDTA stock solutions were made by adding the chemicals to DEPC-treated water followed by autoclaving. Buffers containing LiCl were made by dissolve LiCl in MQ water, add DEPC to 0.1% and stir over night. Subsequently, the solutions were autoclaved and Tris and EDTA solutions where added to appropriate concentrations, pH was adjusted and the solutions were autoclaved again.

(194) cDNA Synthesis:

(195) cDNA was synthesized by Omniscript Reverse Transcriptase (QIAGEN, Copenhagen, Denmark). All buffers were DEPC treated and mixed with molecular biology grade chemicals. Briefly: Secondary structures in the RNA were disrupted by heating to 65° C. for 2 min. 100 μl Dynalbeads Oligo (dT).sub.25 (Invitrogen, Taastrup, Denmark) were washed twice in 1 ml binding buffer (20 mM Tris, 1 M LiCl, 2 mM EDTA) and re-suspended in 100 μl binding buffer. The heated purified RNA sample was added to the beads and incubated at room temp. for 3-5 min with rotation for annealing. Subsequently the beads are washed twice in 1 ml buffer B (10 mM Tris, 0.15 M LiCl, 1 mM EDTA) and twice in 1 ml ice-cold DEPC-water. The captured mRNA is reverse transcribed with Omniscript Reverse Transcriptase (Omniscript RT kit, QIAGEN, Copenhagen, Denmark) in a total volume of 80 μl of: 4 units ORT, 8 μl 10× buffer (supplied by Qiagen), 0.5 mM dNTPs, 40 units RNase inhibitor (RiboLock, Fermentas, St. Leon-Rot, Germany), by incubation at 37° C. for 2 h with gentle shaking. Finally the synthesized cDNA was washed twice in 1 ml TE buffer (20 mM Tris, 1 mM EDTA).

(196) PCR Amplification of the Variable Regions of the Light and Heavy Chains:

(197) Primers for amplification of the variable genes were designed according to the degenerate primer sequences of Zhou and co-workers (1). Primer mixes were made with a 100 μM total primer concentration. V.sub.H Forward primer mix was 25 μM in each primer and the V.sub.H Back primer mix was 10 μM in each primer. The V.sub.L Forward mix was 20 μM in each primer concentration and the V.sub.L Back primer mix was 10 μM in each primer concentration.

(198) 100 μl PCR reaction was made for amplification of each clone V.sub.H as well as for V.sub.L. The reactions contained the following: 10 μl Pfu Buffer with MgSO.sub.4; 2 μl 10 mM dNTP mix; 10 μl Forward primer mix (either V.sub.H or V.sub.L); 10 μl Back primer mix (either V.sub.H or V.sub.L); 67 μl autoclaved water; 1 μl Pfu (2.5 units); and half of the cDNA containing beads from a clone.

(199) The cycling was as follows: Initial denaturation of 3 min at 95° C. and 30 cycles of 50 s at 95° C., 50 s at 55° C., and 3 min at 72° C. The amplified DNA is checked on a 1% agarose gel stained with EtBr and purified by gelextraction kit (Machery-Nagel, AH-Diagnostics, Aarhus, Denmark).

(200) Sequencing:

(201) Each PCR product (V.sub.H or V.sub.L) was sequenced as (Value Read Tube premixed with primer) with the Forward primer mix (V.sub.H or V.sub.L) or the Back primer mix (V.sub.H or V.sub.L). Both were 1 μM in each primer as final concentration. Received sequences were aligned with ClustalW2 (http://www.ebi.ac.uk/Tools/clustalw2/index.html)(2).

(202) Sequences of V.sub.H inserts in pcDNA3.3 was verified with the primers CMV and TK polyA. Sequences of V.sub.L inserts in pOptiVec was verified with the primers CMV and EMCV IRES.

(203) Secondary PCR Primer Design:

(204) To evaluate if any essential amino acids have been mutated due to primer design a pair of secondary PCR primers were designed. The leader primers (VK6 leader and VH leader2) were based on sequences found in (3) and the gamma and kappa primers (VHgconstant and VKconstant) were adapted after (4). PCR products were amplified by standard PCR with the primer pairs (VK6 leader and VKconstant) and (VH leader2 and VHgconstant). The PCR products were purified and sequenced forward and reverse with the primers used to generate the PCR products.

(205) Sequence Analysis and Donor Framework Design:

(206) The following servers and programs were used for analysis of the variable regions: http://www.bioinf.org.uk/abs/, http://www.ncbi.nlm.nih.gov/igblast/, http://blast.ncbi.nlm.nih.gov/Blast.cgi, http://swissmodel.expasy.org//, and Swiss PDB Viewer.

(207) The humanization was performed as a CDR grafting onto human frameworks. Overall strategy was according to (5). The “best fit complete sequence” for V.sub.H or V.sub.L were used as acceptor frameworks. Complete hypervariable loops were grafted onto the chosen acceptor frameworks. Backmutations are the V.sub.H-V.sub.L interface, which were retained to ensure correct orientation of the variable domains (defined as in Morea et al. Table 2) and the mouse residues at key positions important for the canonical structures of the hypervariable loops were retained (according to Morea et al. Table 1).

(208) The acceptor frameworks for the heavy chain was dbj|BAG64279.1| and germline IGHV4-b*01. The acceptor frameworks for the light chain was emb|CAD43020.1| and germline IGKV1D-39*01. The complete sequences for a humanized gamma 4 variant and a humanized Kappa variant were designed after sequences from NCBI BLAST (sp|P01861.1|IGHG4_HUMAN and dbj|BAC01725.1|) and synthesized at GenScript (Piscataway, N.J., USA)).

(209) Generation of Chimeric Heavy Chain

(210) A chimeric heavy chain was generated by splicing by overlap (SOE) extension PCR (6). Three standard PCR reactions where made to generate the templates for the SOE-PCR: (1) Primers Hfor1 and leaderbackH in a PCR reaction on the synthesized gamma4 sequence from GenScript, (2) primers CHfor and Hback1 in a PCR reaction on the synthesized gamma4 sequence from GenScript, and (3) primers VHfor and VHback in a PCR reaction on the beads containing the Mac2-158 cDNA. The PCR products were purified by gel extraction kit (Macherey-Nagel, AH-Diagnostic, Aarhus, Denmark). The SOE-PCR was made as a standard PCR reaction with the primers Hfor1 and Hback1. 2 μl of each of the template PCR products (1-3) was added to the reaction. An approximate 1500 bp band was purified by gel extraction. The purified SOE-PCR product was inserted into the pcDNA3.3 Topo vector from the OptiCHO protein express kit (invitrogen, Taastrup, Denmark) according to manufacturers instructions. The sequence was verified by sequencing with the primers CMV and TK polyA.

(211) Construction of Expression Plasmids:

(212) The synthesized sequences from GenScript were inserted into the expression vectors from the OptiCHO protein express kit (Invitrogen, Taastrup Denmark). The kappa chain was amplified by standard PCR with the Lfor1 and Lback1 primers, and the gamma4 chain was amplified with the Hfor1 and Hback1 primers. The light and heavy chain PCR products were inserted into the pOptiVec (light chain) and pcDNA3.3 (heavy chain) Topo vectors from the OptiCHO protein express kit according to manufacturers instructions.

(213) Site Directed Mutagenesis:

(214) Three mutations were introduced by quick change site directed mutagenesis. In the light chain 53SLQ55 were back-mutated to NRY. The mutagenesis was performed as a standard mutagenesis according to the Stratagene protocol (http://www.stratagene.com/manuals/200518.pdf) with the primers SLQ-NRY for and back. Template was the plasmid pOptiVec-Kappa 8.

(215) SLIM Mutagenesis:

(216) For the remaining mutants the Site-directed Ligation Independent Mutagenesis (SLIM) method was used (7). Primers are listed in the primer table. The templates were for the K-N primers pcDNA3.3-gamma n1 heavy chain, for the SY-IN primers the pcDNA3.3-KN1 plasmid, for the remaining heavy chain mutations the template was pcDNA3.3-KN1IN5. The template for the additional humanization in the light chain was the plasmid pOptiVec-NRY. This was done by two consecutive rounds of SLIM on pOptiVec-NRY with the primer sets P46L (first round) and G89Q, T93S (second round).

(217) Expression of Antibody:

(218) The humanized antibody and a chimeric mouse/human antibody in the IgG4 format were cloned into vectors supplied with OptiCHO protein express kit from invitrogen (pcDNA3.3 and pOptiVec). The expression plasmids were heat shocked into Top10 cells and plated on LB plates containing amp. Colonies were picked to over night cultures and plasmids were prepared from the cultures with the Nucleobond plasmid kit with finalizer (Macherey-Nagel, AH-Diagnostic, Aarhus, Denmark). The sequences of all plasmids were verified by sequencing.

(219) The various mutants and different combinations of antibodies were expressed transient in CHO—S cells as follows:

(220) 20 μg of pcDNA3.3 containing a heavy chain was mixed with 20 μg of pOptiVec containing a light chain. The DNA was diluted in OptiCHOPro SFM (8 mM L-glutamine) to a total volume of 0.6 ml. The DNA is gently mixed with 0.6 ml OptiCHOPro SFM containing 40 μl FreeStyle MAX transfection reagent (Invitrogen, Taastrup, Denmark). After 10 min of incubation at room temperature the DNA-FreeStyle MAX mix was added to 1×10.sup.6 cells/ml in 25 ml. 3 days later the supernatant was harvested by centrifugation and analysed by ELISA.

(221) ELISA Antibody Reactivity Comparison

(222) A nunc maxisorp plate was coated with the following (50 μl/well) over night at 4° C.: 4 μg/ml goat anti-human kappa chain antibody (AbD Serotec, Oxford, UK) and ˜4 μg/ml human CD163 (purified as described in 8). Buffer was carbonate buffer, pH 9.0. Each measurement was made in duplicate.

(223) The ELISA steps are as follows

(224) 1) The ELISA was washed 3 times in PBS

(225) 2) The plate was blocked with PBS containing 3% BSA for 1 h.

(226) 3) Optionally, step 1 was repeated

(227) 4) After blocking, the primary antibody was added (100 μl per well).

(228) Samples

(229) Undiluted supernatant from transfected cells added to the wells (100 μl/well)

(230) Standards

(231) 100 ng/ml human IgG/kappa (Sigma) antibody diluted in PBS containing 1% BSA;

(232) 100 ng/ml Mac2-158 diluted in PBS containing 1% BSA;

(233) 2 fold dilution series were made on all samples and standards. Dilution in PBS containing 1% BSA.

(234) The samples were incubated on the plate for 1 hour.

(235) 5) Step 1 is repeated

(236) 6) Addition of secondary antibody (100 μl/well)

(237) For Anti-Kappa/Anti-Gamma ELISA 100 μl/well of goat anti human IgG gamma chain specific HRP 1:6000 in PBS containing 1% BSA.

(238) For CD163 ELISA 100 μl/well of goat anti human IgG (H&L) HRP 1:6000 in PBS containing 1% BSA. For Mac2-158 goat anti-mouse HRP 1:2000 in PBS containing 1% BSA is added to the wells
7) Step 1 was repeated
8) The ELISA was developed by adding 75 μl of TMB substrate to each well. Incubation was performed for 3 min.
9) The reaction was stopped by adding 30 μl 2 NH.sub.2SO.sub.4 to the wells.
10) The plate was read in an ELISA reader at 450 nm.

(239) Background was measured on wells with no coating and wells with no primary antibody.

(240) Results

(241) PCR Amplification of the Variable Genes:

(242) A 1% agarose gel analysis show that the mRNA purifications, cDNA productions, and PCRs for amplification of the variable regions worked (see FIG. 15).

(243) Sequences of PCR Products:

(244) Sequencing of the purified PCR product (V.sub.H and V.sub.L) from PCR on the generated cDNA (Mac2-48 and Mac2-158) was done at Eurofins MWG Operon (Ebersberg, Germany). The sequences were aligned.

(245) TABLE-US-00020 VL48 TDIVMTQTPKFLLVSAGDRVTITCKASQSVSHDVSWFQQKPGQSPKLLIYYTSNRYTGVPDRFTGSGYGT VL158 -DIVMTQSPKSLLISIGDRVTITCKASQSVSSDVAWFQQKPGQSPKPLIYYASNRYTGVPDRFTGSGYGT VL48 DFTFTISTVQAEDLAIYFCQQDYSSPRTFGGGTKLEIKRA VL158 DFTFTISSVQAEDLAVYFCGQDYTSPRTFGGGTKLEIKRA VH48 DVKLQESGPGLVKPSQSLSLTCTVTGYSITSDYAWNWIRQFPGNKLEWMGFISYSGITSYNPSLKSRISITRD VH158 DVKLQESGPGLVKPSQSLSLTCTVTGYSITSDYAWNWIRQFPGNKLEWMGYITYSGITNYNPSLKSQISITRD VH48 TSKNQFFLQLNSVTTEDSATYYCVSGTYYFDYWGQGTTLTVSS VH158 TSKNQFFLQLNSVTTEDTATYYCVSGTYYFDYWGQGTTLTVSS

(246) The secondary PCR products verified the overall sequences of the V.sub.H and V.sub.L. The few differences found were:

(247) TABLE-US-00021 VL158: N-term SVVMTQT VL48: N-term SIVMTQT VH158: N-term DVQLQ VH48: N-term DVQLQ

(248) The V in position 2 in VL158 might be important for the function of the light chain. Additional the linkers to both the kappa constant and gamma constant domains were found to be normal IgG1 linkers.

(249) Design of Humanized Antibody:

(250) The frameworks chosen as acceptor for the CDR grafting were for the heavy chain: dbjIBAG64279.1 and germline IGHV4-b*01 and for the light chain: embICAD43020.1 and germline IGKV1D-39*01. The light chain as a full length kappa chain with a leader peptide and the heavy chain as a full length gamma 4 with a leader peptide are show as DNA and protein sequences:

(251) TABLE-US-00022 Light chain DNA sequence [SEQ ID NO: 73] Atggacatgagagtgcctgctcagctgctgggactgctgctgctgtggctgcctggagctaggtgtgacatc gtgatgacacagtctcccagcagcctgagcgcctctgtgggcgacagggtgaccatcacctgcagggctagc cagagcgtgagcagcgacgtggcctggttccagcagaagcccggcaagagccccaagcccctgatctactat gccagcagcctgcagtctggagtgcccagcaggttcagcggcagcggcagcggaacagacttcaccctgacc atcagcagcctgcaggccgaggacttcgccgtgtacttctgcggccaggactacaccagccctaggaccttc ggtggcggaaccaagctggagatcaagaggaccgtggccgcccccagcgtgttcatcttccctccaagcgac gagcagctgaagagcggcaccgccagcgtggtgtgcctgctgaacaacttctaccccagggaggccaaggtg cagtggaaggtggacaacgccctgcagagcggcaacagccaggagagcgtgaccgagcaggacagcaaggac agcacctacagcctgagcagcaccctgaccctgagcaaggccgactacgagaagcacaaggtgtacgcctgc gaggtgacccaccagggcctgagcagccccgtgaccaagagcttcaacaggggcgagtgc Protein sequence [SEQ ID NO: 74] MDMRVPAQLLGLLLLWLPGARCDIVMTQSPSSLSASVGDRVTITCRASQSVSSDVAWFQQKPGKSPKPLIYY ASSLQSGVPSRFSGSGSGTDFTLTISSLQAEDFAVYFCGQDYTSPRTFGGGTKLEIKRTVAAPSVFIFPPSD EQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYAC EVTHQGLSSPVTKSFNRGEC Heavy chain DNA sequence [SEQ ID NO: 75] atgaagcacctgtggttcttcctgctgctggtggctgcccccaggtgggtgctgtctcaggtgcagctgcag gagtctggaccaggactggtgaagccatctgagaccctgagcctgacctgcaccgtgagcggctacagcatc accagcgactacgcctggaactggatcaggcagttccccggcaagaagctggagtggatgggcagcatctac tacagcggcagcacctactacaaccccagcctgaagagcagggtgaccatcagcgtggacaccagcaagaac cagttcagcctgaagctgagcagcgtgaccgccgccgacaccgccacctactactgcgtgagcggcacctac tacttcgactactggggccagggcaccaccctgaccgtgagcagcgccagcaccaagggaccaagcgtgttc ccactggctccatgcagcaggagcaccagcgagagcacagccgccctgggatgcctggtgaaggactacttc cctgagcctgtgaccgtgagctggaattctggcgccctgaccagcggagtgcacaccttcccagccgtgctg cagagctctggactgtacagcctgagcagcgtggtgaccgtgccttcttccagcctgggcaccaagacctac acctgcaacgtggaccacaagcccagcaacaccaaggtggacaagagggtggagtctaagtatggacctcca tgcccaagctgtcctgctcctgagttcctgggcggcccaagcgtgttcctgttccctccaaagccaaaggac accctgatgatcagcaggacccctgaggtgacctgcgtggtggtggacgtgagccaggaggaccccgaggtg cagttcaactggtacgtggacggcgtggaggtgcacaacgccaagaccaagcccagggaggagcagttcaac agcacctacagggtggtgagcgtgctgaccgtgctgcaccaggactggctgaacggcaaggagtacaagtgc aaggtgagcaacaagggcctgcccagcagcatcgagaagaccatcagcaaggccaagggccagcccagggag ccccaggtgtacaccctgcctccaagccaggaggagatgaccaagaaccaggtgagcctgacctgcctggtg aagggettctaccccagcgacatcgccgtggagtgggagagcaacggccagcccgagaacaactacaagacc acccctccagtgctggacagcgacggcagcttcttcctgtacagcaggctgaccgtggacaagagcaggtgg caggagggcaacgtgttcagctgcagcgtgatgcacgaggccctgcacaaccactacacccagaagagcctg agcctgagcctgggcaag Protein sequence [SEQ ID NO: 76] MKHLWFFLLLVAAPRWVLSQVQLQESGPGLVKPSETLSLTCTVSGYSITSDYAWNWIRQFPGKKLEWMGSIY YSGSTYYNPSLKSRVTISVDTSKNQFSLKLSSVTAADTATYYCVSGTYYFDYWGQGTTLTVSSASTKGPSVF PLAPCSRSTSESTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTKTY TCNVDHKPSNTKVDKRVESKYGPPCPSCPAPEFLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQEDPEV QFNWYVDGVEVHNAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPRE PQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRW QEGNVFSCSVMHEALHNHYTQKSLSLSLGK
Cloning and Mutagenesis:

(252) The cloning of the sequences obtained from GenScript produced a light chain Kappa 8 (K8) and a heavy chain gamma n1 with correct sequences.

(253) Heavy chain variants: The constructs produces by SLIM reactions where gamma n1 is the template for the first reaction with the primers producing the K43N, S50Y, and Y52T mutations. This generated the pcDNA3.3 plasmids KN1 and KN2. Plasmid KN1 was used as template for the S561 and Y58N mutations. This generated KN11N5 which served as template for the last two single mutations V71R (plasmid VR1) and Q1D (QD2). Subsequent sequencing showed that KN1 had a mis-mutation (N) in position 19, and that the V71R mutation turned out to be a V71E mutation. Clone KN2 had the correct sequence.

(254) Light chain variants: The construct produced by Quick Change Mutagenesis resulted in the light chain plasmid pOptiVec-NRY with correct sequence. Analysis of the plasmids after the two consecutive SLIM mutagenesis reaction (P46L and G89Q, T93S) showed that only two of the mutations where present (P46L and T93S) in the plasmid d3.

(255) mAb ELISA Reactivity

(256) The sequences of the different humanized variant heavy and light chains tested in ELISA are shown in FIG. 16. Three different light chains K8, NRY, and d3 and five different heavy chains chimeric cgamma(6), KN2, KN1IN5, QD2, and VR1 were tested.

(257) The first ELISA comparison was made between two variants of the light chain (K8 and NRY) all paired with the chimeric heavy chain cgamma(6). The result of the ELISA is shown in FIG. 17. cgamma(6)/K8 exhibited the highest expression level and cgamma(6)/NRY the lowest. The exhibited reactivity of the two variants towards CD163 were almost identical. So when including expression level in the comparison of reactivity the light chain NRY is better than the K8 light chain.

(258) FIG. 18 shows a comparison of the humanized heavy chain variants with additional back-mutations all paired with the light chain NRY. The ELISA showed that all combinations more or less displayed similar reactivity towards the antigen CD163. A reactivity which was also comparable with the Mac2-158 reactivity towards CD163.

(259) A few forward mutations were introduced into the light chain NRY to generate a more humanized version of the light chain (d3).

(260) Development of Stable CHO-DG44 Cell Line for KN2/NRY Production and Small Scale Expression

(261) The OptiCHO Antibody Express Kit (Invitrogen, Taastrup, Denmark) was used for cloning and expression of the humanized IgG4 antibody designated KN2/NRY. The pcDNA3.3 gamma KN2 and pOptiVEC kappa NRY plasmids (Example 3) were liniearized and transfected into dihydrofolate reductase (DHFR)-negative CHO-DG44 cells (cGMP banked) according to the manufacturer's protocol. Two days post transfection, the CHO DG44 cells were selected for stable transfection of the OptiVEC kappa NRY plasmid in CD OptiCHO Medium supplemented with 8 mM L-glutamine. Every 2-3 days, the cells were centrifuged at 1100 rpm for 10 min, the medium was removed by aspiration and complete CD OptiCHO medium added to a final volume of 25 ml. Following 3 weeks of selection, the cell viability was 100% and the cells were further propagated in complete CD OptiCHO medium with 500 ug/ml Geneticin (G418) to select for CHO-DG44 cells stably transfected with the pOptiVEC kappa NRY and pcDNA3.3 gamma KN2 plasmids. The cells were selected for 2 weeks as described above. When the cell viability reached 100%, the cells were clonally selected in minipools by limiting dilution in 96 well culture plates (10 cells/well). The resulting minipools were analyzed for KN2/NRY expression in a protein-specific ELISA and high producers were propagated before genomic amplification by methotrexate (MTX). Several rounds of MTX selection (50-2000 mM MTX) was performed according to the manufacturer's instructions before the stably transfected and MTX amplified cells were single cell cloned by limiting dilution. Finally, clonally selected cells were analyzed by ELISA and high producing clones were propagated for smale scale production of KN2/NRY. Small scale productions were seeded at 0.5×10.sup.6 cells/ml in 150-200 ml complete CD OptiCHO medium with 500 ug/ml Geneticin (G418) Medium in Triple layer tissue culture flasks (Nalge-Nunc) for 4 days, medium supernatant was isolated by centrifugation and filtration.

(262) Purification of KN2/NRY

(263) The supernatant from the KN2/NRY expressing CHO cells are added Tris-HCl pH 8.0 buffer to a final concentration of 50 mM, filtered trough a 0.22 μm filter, and loaded on a HiTrap MabSelct SuRe column (Ge Healtcare, Brøondby, Denmark). After loading the column is washed with 10 volumes of PBS pH 7.4 and protein eluted with a 0.1 M Na-Citrate buffer pH 3.2 into fraction tubes filled with 1/10 of the final fraction volume of 1 M Tris-HCl pH 8.0. The protein is buffer gelfiltrated into the final buffer for use. Using Sephadex G-25 (Ge Healtcare, Brøondby, Denmark).

(264) Biacore Affinity Testing of KN2/NRY Binding to CD163

(265) KN2/NRY has been tested for binding to CD163 immobilized on a Biacore chip and compared to the binding of Mac2-158 to the same CD163 chip.

(266) SPR analysis of the binding of mAbs to CD163 was carried out on a Biacore 2000 instrument (Biacore, Uppsala, Sweden). The Biacore sensor chips (type CM5) were activated with a 1:1 mixture of 0.2 M N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide and 0.05 M N-hydroxysuccimide in water. Purified recombinant CD163 were immobilized in 10 mM sodium acetate, pH 4.0, and the remaining binding sites were blocked with 1 M ethanolamine, pH 8.5. The SPR signal generated from immobilized recombinant CD163 proteins corresponded to 40-70 fmol of protein/mm.sup.2. Sensorgrams were generated using mAb concentrations ranging from 5-100 nM. The flow cells were regenerated with 1.6 M glycine-HCl, pH 3. The running buffer used for the experiment was either CaHBS 10 mM Hepes, 150 mM NaCl, 3.0 mM CaCl.sub.2, 1.0 mM EGTA, and 0.005% Tween 20, pH 7.4. or 10 mM Hepes, 150 mM NaCl, 3.0 mM EDTA, and 0.005% Tween 20, pH 7.4, KN2/NRY and Mac-158 samples were dissolved in the same buffer as the running buffer used at a concentration of 5 μg/ml. All binding data were analyzed using the Biamolecular Interaction Analysis evaluation program version 3.1.

(267) The result is shown in FIG. 19, and shows that the affinities of the two monoclonal antibodies for CD163 is virtually identical. Both exhibit sub nM dissociation constants, though exact fitting is difficult due to the high affinity.

REFERENCES FOR EXAMPLE 3

(268) 1. Zhou, H., Fisher, R. J. & Papas, T. S. (1994). Optimization of primer sequences for mouse scFv repertoire display library construction. Nucleic Acids Res 22, 888-9. 2. Larkin M. A. et al. (2007). Clustal W and Clustal X version 2.0. Bioinformatics, 23 (21):2947-8. 3. Lefranc, M.-P. et al. (2005), Nucleic Acids Res, 33, D593-D597. 4. Rohatgi, S., et al. (2008). J Immunol Meth, 339, 205-219. 5. Morea, V., et al. (2000). Antibody modeling: implications for engineering and design. Methods 20(3): 267-79. 6. Horton et al. (1989). Engineering hybrid genes without the use of restriction enzymes: gene splicing by overlap extension. Gene 77: 61-8. 7. Chiu et al. (2004). Site-directed, Ligase-Independent Mutagenesis (SLIM): a single-tube methodology approaching 100% efficiency in 4 h. Nucleic Acid Res, 32 (21): e174. 8. Kristiansen M. et al. (2001). Identification of the haemoglobin scavenger receptor. Nature 11:409(6817): 198-201.

Example 4—Single Chain Expression, Refolding, and Function

(269) Materials and Methods

(270) Obtaining the scFv Sequence:

(271) The sequence of the scFv (V.sub.H-15 residue linker-V.sub.L) was synthesized at GenScript and cloned into pET20b at GenScript via the cloning sites NcoI/XhoI. Linker is chosen as the 15 residue linker described in (1). Protein and DNA sequences are shown below

(272) TABLE-US-00023 Protein [SEQ ID NO: 77] MDQVQLQESGPGLVKPSETLSLTCTVSGYSITSDYAWNWIRQFPGNKLEW MGYITYSGSTYYNPSLKSRVTISVDTSKNQFSLKLSSVTAADTATYYCVS GTYYFDYWGQGTTLTVSSGGGGSGGGGSGGGGSDIVMTQSPSSLSASVGD RVTITCRASQSVSSDVAWFQQKPGKSPKPLIYYASNRYSGVPSRFSGSGS GTDFTLTISSLQAEDFAVYFCGQDYTSPRTFGGGTKLEIKREQKLISEED L DNA [SEQ ID NO: 78] CCATGGACCAGGTGCAGCTGCAGGAAAGCGGCCCGGGCCTGGTGAAACCG AGCGAAACCCTGAGCCTGACCTGCACCGTGAGCGGCTATAGCATTACCAG CGATTATGCGTGGAACTGGATTCGTCAGTTTCCGGGCAACAAACTGGAAT GGATGGGCTACATTACTTATAGCGGCAGCACCTATTATAACCCGAGCCTG AAAAGCCGTGTGACCATTAGCGTGGATACCAGCAAAAACCAGTTTAGCCT GAAACTGAGCAGCGTGACCGCGGCGGATACCGCGACCTATTATTGCGTGA GCGGCACCTATTATTTTGATTATTGGGGCCAGGGTACCACCCTGACCGTG TCTAGCGGTGGGGGCGGAAGCGGGGGCGGTGGAAGCGGGGGCGGTGGATC TGATATTGTGATGACCCAGAGCCCGAGCAGCCTGAGCGCGAGCGTGGGCG ATCGTGTGACCATTACCTGCCGTGCGAGCCAGAGCGTGAGCAGCGATGTG GCGTGGITTCAGCAGAAACCGGGCAAAAGCCCGAAACCGCTGATTTATTA TGCGAGCAACCGGTATAGCGGTGTGCCGAGCCGTTTTAGCGGTAGCGGTA GCGGTACCGATTTTACCCTGACCATTAGCAGCCTGCAGGCGGAAGATTTT GCGGTGTATTTTTGCGGCCAGGATTATACCAGCCCGCGTACCTTTGGTGG CGGAACCAAACTGGAAATTAAACGTGAACAGAAACTGATTAGCGAAGAAG ATCTGCTCGAG
scFv Expression and Purification:

(273) The pET20b-scFv plasmid were transformed into BL21 DE3 star cells (Invitrogen, Taastrup, Denmark) by heat shock, and the transformed cells were plated on agar plates with LB media and 0.1 mg/ml ampicilin. A starter culture was made in LB media supplemented with 0.1 mg/ml ampicilin and 1% glucose by transferring one colony from the plate to the media. The starter culture was incubated over night at 30° C. with shaking.

(274) Expression of the scFv in inclusion bodies was done at 37° C. with shaking as follows: 500 ml LB media (supplemented with ampicillin and 0.1% glucose) was inoculated with 1:100 of the starter culture. At OD.sub.600˜0.6 the culture was induced with 2 mM IPTG and the expression was allowed to continue for 4 hours. Subsequently, the bacteria were harvested by centrifugation, solubilized in PBS, sonicated and centrifuged again. The supernatant was aspired and the pellet was washed in PBS and centrifuged again.

(275) The pellet was solubilized in 20 ml 20 mM Tris pH 8, 7 M urea, and bacteria remnants were spun down. The 20 ml supernatant was dialysed over night at 4° C. against 1 liter 20 mM Tris, 3 M urea. The dialysed sample was centrifuged. His tag containing scFv was purified from the supernatant on a 1 ml HisTrap™ HP (GE Healthcare, Brøondby, Denmark) and eluted with 20 mM Tris, 3 M urea, 50 mM EDTA. Eluate was collected in 0.4 ml fractions.

(276) scFv Refolding:

(277) The HisTrap purified protein was refolded as follows: 3 ml protein in 20 mM Tris pH 8, 3 M urea, 50 mM EDTA in a dialysis bag was dialysed against 100 ml buffer B (20 mM Tris pH 8, 3 M urea). A peristaltic pump (0.2 ml/min) loaded 900 ml of buffer C (20 mM Tris pH 8) into buffer B. The dialysis was left for approx. 90 hours.

(278) scFv ELISA:

(279) A nunc Maxisorp ELISA plate (NUNC, Roskilde, Denmark) was coated with 50 μl/well of 2 μg/ml of CD163 (purified as described in (2)) over night at 4° C. The coated plate was washed 3 times in PBS and blocked for 1 hour with 3% BSA in PBS. Fractions from scFv purification were tested by adding 100 μl/well of a 1:10 dilution of each sample in 1% BSA, PBS. The refolded protein sample was added directly to the wells (100 μl/well) and two-fold dilution series was made with dilution in 1% BSA in PBS. After 1 hour incubation at 4° C. the plate was washed 3 times in PBS again. Secondary detection was made with a 1 hour incubation of a HRP conjugated anti-His antibody (Sigma-Aldrich, Brøondby, Denmark) (1:4000 diluted in 1% BSA, PBS). After washing 3 times in PBS the ELISA was developed with 75 μg/well TMB substrate (Invitrogen, Taastrup, Denmark). The reaction was stopped with 40 μl/well of 1 M H.sub.2SO.sub.4 and the plate was read in an ELISA reader at 450 nm.

(280) Results

(281) Expression and Purification:

(282) The dialysis of solubilized pellet resulted in heavy precipitation in the dialysis bag. The majority of the His-tagged protein was not precipitated as evaluated by western blot (data not shown). After HisTrap™ purification the fractions were evaluated in ELISA. To mediate protein refolding a sample of each fraction was diluted a 10 fold in 1% BSA which results in an end concentration of 0.3 M urea which should render the protein in a folded state. The diluted samples were analysed for binding to CD163 in ELISA (FIG. 20). ELISA signal was mainly found in the fractions 9-14. Fractions 9-16 were pooled. This gave approx. 3 ml purified protein.

(283) Refolding:

(284) A slow refolding was made by dialysis over 90 hours. The end volume was 4 ml and the concentration of urea was 0.3 M. The dialysis resulted in an insignificant pellet after centrifugation. The supernatant was tested in ELISA.

(285) ELISA with Refolded Protein:

(286) The ELISA of the refolded scFv showed binding to CD163. Signals were detected at dilutions down to a 128 fold (FIG. 21). The undiluted sample (sample in buffer without BSA) did though show a high background binding to BSA. As the sample contained an ensemble of folded protein and misfolded protein, which were not separated, it was not surprising that the presence of misfolded protein resulted in unspecific binding. At a 64 or 128 fold dilution in 1% BSA, PBS the background binding to BSA would be neglectable and it still gave rise to signals of 0.29 or 0.15, respectively, clearly showing binding of refolded scFv to CD163 (FIG. 21).

REFERENCES FOR EXAMPLE 4

(287) 1. Todorovska et al. (2001). Design and application of diabodies, triabodies and tetrabodies for cancer targeting. J Immunol Methods 248, 47-66. 2. Kristiansen M. et al. (2001). Identification of the haemoglobin scavenger receptor. Nature 11:409(6817): 198-201.

Example 5—Generation, Production and Testing of a Fab Fragment

(288) Materials and Methods

(289) Primers:

(290) TABLE-US-00024 Fab P-->stop [SEQ ID NO: 79] 5′-acaagagggtggagtctaagtatggatagccatgcccaagctg-3′ Fab P-->stop anti [SEQ ID NO: 80] 5′-cagcttgggcatggctatccatacttagactccaccctcttgt-3′

(291) Primers were obtained from TAG Copenhagen (Copenhagen, Denmark).

(292) Sequencing:

(293) Sequencing was performed at Eurofins MWG operon (Ebersberg, Germany) as a Value Read Tube Service. The primer used for sequencing was CMV primer from Eurofins MWG operon.

(294) Quick Change Site Directed Mutagenesis:

(295) A stop codon was introduced by quick change site directed mutagenesis, using the QuickChange kit from Stratagene (USA). The mutagenesis was performed as a standard mutagenesis according to the manufactureres protocol. In the heavy chain P220 was mutated to a stop codon. with the primers Fab P.fwdarw.stop and Fab P.fwdarw.stop anti. Template was the plasmid pcDNA3.3-KN2. Sequence of mutant was verified by sequencing.

(296) Expression of Fab Fragment:

(297) The expression plasmids were heat shocked into Top10 cells and plated on LB plates containing amp. Colonies were picked to over night cultures and plasmids were prepared from the cultures with the Nucleobond plasmid kit with finalizer (Macherey-Nagel, AH-Diagnostic, Aarhus, Denmark). The sequences of all plasmids were verified by sequencing.

(298) The Fab fragment was expressed transient in CHO—S cells as follows:

(299) 20 μg of pcDNA3.3-Fab1 was mixed with 20 μg of pOptiVec-NRY. The DNA was diluted in OptiCHOPro SFM (8 mM L-glutamine) to a total volume of 0.6 ml. The DNA is gently mixed with 0.6 ml OptiCHOPro SFM containing 40 μl FreeStyle MAX transfection reagent (Invitrogen, Taastrup, Denmark). After 10 min of incubation at room temperature the DNA-FreeStyle MAX mix was added to 1×10.sup.6 cells/ml in 25 ml. 3 days later the supernatant was harvested by centrifugation and analysed by ELISA.

(300) Fab Fragment Activity Measured by ELISA

(301) A nunc maxisorp plate was coated with ˜1 μg/ml human CD163 (purified as described by Kristiansen, M. et al. ((2001). Identification of the haemoglobin scavenger receptor. Nature 11:409(6817): 198-201)) was added at 50 μl/well and incubated over night at 4° C. Buffer for coating was carbonate, pH 9.0. Each measurement was made in duplicates.

(302) The primary antibody samples used in ELISA was undiluted supernatant or 30 times concentrated supernatant from transfected cells or antibody standard 100 ng/ml KN2/NRY antibody diluted in PBS containing 1% BSA. The supernatant was concentrated on VIVAspin centrifugal concentrator (10.000 MWCO) (Sigma-Aldrich, Brøondby, Denmark).

(303) The ELISA steps were as follows: ELISA plates were washed 3 times in PBS and blocked with PBS containing 3% BSA for 1 h. After blocking the primary antibody samples were added to the wells (100 μl/well). 2 fold dilution series were made on all samples and standards (dilutions in PBS containing 1% BSA). The samples were incubated on the plates for 1 h. Subsequently, the plates were washed 3 times in PBS and secondary antibody goat anti human kappa chain HRP (AbD Serotec, Oxford, UK) 1:4000 in PBS containing 1% BSA (100 μl/well) was added to the wells. After 1 hour incubation the wells were washed 3 times in PBS and the ELISA was developed by adding 75 μl of TMB substrate to each well. The reaction was stopped after 10 min by adding 40 μl 1 M H.sub.2SO.sub.4 to the wells. The plates were read in an ELISA reader at 450 nm.

(304) Background was measured on both wells with no coating and wells with no primary antibody.

(305) Results

(306) Site Directed Mutagenesis

(307) The DNA sequence of the purified plasmid after mutagenesis and the corresponding protein sequence is shown below:

(308) TABLE-US-00025 DNA [SEQ ID NO: 81] caggtgcagctgcaggagtctggaccaggactggtgaagccatctgagac cctgagcctgacctgcaccgtgagcggctacagcatcaccagcgactacg cctggaactggatcaggcagttccccggcaacaagctggagtggatgggc tacatcacctacagcggcagcacctactacaaccccagcctgaagagcag ggtgaccatcagcgtggacaccagcaagaaccagttcagcctgaagctga gcagcgtgaccgccgccgacaccgccacctactactgcgtgagcggcacc tactacttcgactactggggccagggcaccaccctgaccgtgagcagcgc cagcaccaagggaccaagcgtgttcccactggctccatgcagcaggagca ccagcgagagcacagccgccctgggatgcctggtgaaggactacttccct gagcctgtgaccgtgagctggaattctggcgccctgaccagcggagtgca caccttcccagccgtgctgcagagctctggactgtacagcctgagcagcg tggtgaccgtgccttcttccagcctgggcaccaagacctacacctgcaac gtggaccacaagcccagcaacaccaaggtggacaagagggtggagtctaa gtatggatag Protein [SEQ ID NO: 82] QVQLQESGPGLVKPSETLSLTCTVSGYSITSDYAWNWIRQFPGNKLEWMG YITYSGSTYYNPSLKSRVTISVDTSKNQFSLKLSSVTAADTATYYCVSGT YYFDYWGQGTTLIVSSASTKGPSVFPLAPCSRSTSESTAALGCLVKDYFP EPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTKTYTCN VDHKPSNTKVDKRVESKYG(stop)
ELISA Testing of Fab:

(309) The undiluted and the non-concentrated supernatant gave rise to a measurable but very small signal in ELISA (FIG. 22). The 30× concentrated supernatant gave rise to a larger ELISA signal. The intensity of the signal and dilution series was comparable to the standard dilution series (100 ng/ml), clealrly showing binding of Fab fragment to CD163 (FIG. 23).

Example 6: Generation and Characterization of a Rat Anti Murine CD163 Monoclonal Antibody

(310) The hybridoma clone rat anti-mouse E10B10 (IgG2a) was generated by GenScript (Piscataway, N.J., USA). As follows:

(311) The mouse CD163 domain 1-3 was used as immunogen and 3 rats were immunized. All rats showedimmune response and the rat with highest response was used for cell fusion and hybridoma production using standard techniques. Total 18 hybridoma cell lines derived from 9 parental clones were produced and screened

(312) Murine CD163 domain 1-3 was produced as follows

(313) 1. Subcloning

(314) Target DNA sequence of mouse CD163 domain 1-3 was optimized and synthesized with C-terminal his tag, and subcloned into mammalian expression vector for transient transfection and production.

(315) 2. Evaluation of Mouse CD163 Domain 1-3 Expression and Purification

(316) 1 L of 293 cell culture were harvested and processed by one-step purification procedure using HiTrap Chelating column. The target protein was primarily eluted in the fraction of 250 mM Imidazole. Eluted material was analyzed by SDS-PAGE for the protein of interest, see FIG. 24. We obtained about 6.0 mg of protein after affinity purification.

(317) Screening of Clones

(318) The clones were screened by testing binding of supernatants to murine CD163 in solubilized murine spleen loaded on a SDS-PAGE and western blotted, using standard techniques. The clone displaying highest signal upon binding to non-reduced CD163 was chosen, the clone is named E10B10.

(319) The hybridoma cells were thawed and allowed to amplify a few rounds. Genscript obtained the hybridoma using standard techniques after immunization of two rats with recombinant murine CD163.

(320) Primers:

(321) Primers used for primary PCR amplification and sequencing of the variable light chain region of the hybridoma clone were as described in (1), but adapting the 5′ (GAGG-directional) and 3′ (blunt end) sequences for TOPO directional cloning. PCR amplification of the heavy chain variable region was done with the primers:

(322) TABLE-US-00026 [SEQ ID NO: 83] 3b 5′-AGGT(C/G)(A/C)AACTGCAG(C/G)AGTC(A/T)GG-3′ [SEQ ID NO: 84] 4 5′-CCAGGGGCCAGTGGATAGACAAGCTTGGGTGTCGTTTT-3′
as described in (2).

(323) All primers were obtained from TAG Copenhagen (Copenhagen, Denmark).

(324) Sequencing:

(325) Sequencing was performed at Eurofins MWG operon (Ebersberg, Germany) as a Value Read Tube Service.

(326) Extracting Total RNA:

(327) 2×10.sup.6 cells of the hybridoma cell line were used for extracting total RNA by QIAamp blood RNA kit (QIAGEN, Copenhagen, Denmark) according to the instructions of the manufacturer. Briefly, the cells were re-suspended in 600 μl buffer RLT and homogenized by passing it through a syringe mounted with a 21-G (0.8 mm) needle at least 5 times. 600 μl of 70% ethanol was added and mixed by pipetting. The suspension was applied to the QIAamp spin column and load by multiple centrifugations. The column was washed with 750 μl RW1 and 750 μl RPE. The RNA was eluted with 2×50 μl RNase free water.

(328) Preparation of Buffers for cDNA Synthesis

(329) All buffers for the cDNA synthesis was prepared with Ultra pure or mol. bio. grade chemicals and DEPC-treated water. DEPC-treated water was prepared by adding DEPC (Sigma-Aldrich, Brøondby, Denmark) to 0.1% and the solution was stirred over night followed by autoclaving. Tris and EDTA stock solutions were made by adding the chemicals to DEPC-treated water followed by autoclaving. Buffers containing LiCl were made by dissolve LiCl in MQ water, add DEPC to 0.1% and stir over night. Subsequently, the solutions were autoclaved and Tris and EDTA solutions where added to appropriate concentrations, pH was adjusted and the solutions were autoclaved again.

(330) cDNA Synthesis:

(331) cDNA was synthesized by Omniscript Reverse Transcriptase (QIAGEN, Copenhagen Denmark). All buffers were DEPC treated and mixed with molecular biology grade chemicals. Briefly: Secondary structures in the RNA were disrupted by heating to 65° C. for 2 min. 100 μl Dynalbeads Oligo (dT).sub.25 (Invitrogen, Taastrup, Denmark) were washed twice in 1 ml binding buffer (20 mM Tris, 1 M LiCl, 2 mM EDTA) and re-suspended in 100 μl binding buffer. The heated purified RNA sample was added to the beads and incubated at room temp. for 3-5 min with rotation for annealing. Subsequently the beads were washed twice in 1 ml buffer B (10 mM Tris, 0.15 M LiCl, 1 mM EDTA) and twice in 1 ml ice-cold DEPC-water. The captured mRNA was reverse transcribed with Omniscript Reverse Transcriptase (Omniscript RT kit, QIAGEN, Copenhagen, Denmark) in a total volume of 80 μl of: 4 units ORT, 8 μl 10× buffer, 0.5 mM dNTPs, 40 units RNase inhibitor (RiboLock, Fermentas, St. Leon-Rot, Germany), by incubation at 37° C. for 2 h with gentle shaking. Finally the synthesized cDNA was washed twice in 1 ml TE buffer (20 mM Tris, 1 mM EDTA).

(332) PCR Amplification of the Variable Regions of the Light and Heavy Chains:

(333) Primers for amplification of the light chain variable gene were designed according to the degenerate primer sequences of Zhou and co-workers (1). Primer mixes were made with a 100 μM total primer concentration. The V.sub.L Forward mix was 20 μM in each primer concentration and the V.sub.L Back primer mix was 10 μM in each primer concentration. Primers (3b and 4) for amplification of the heavy chain variable gene were designed according DUbel et al. (2)

(334) 100 μl PCR reaction was made for amplification of V.sub.H as well as for V.sub.L. The reactions contained the following: 10 μl Pfu Buffer with MgSO.sub.4; 2 μl 10 mM dNTP mix; 5 μl Forward primer mix (V.sub.L) or 5 pMol primer 3b (V.sub.H); 5 μl Back primer mix (V.sub.L) or 5 pMol primer 4 (V.sub.H); 77 μl autoclaved water; 1 μl Pfu (2.5 units); and half of the cDNA containing beads from the E10B10 clone.

(335) The cycling was as follows: Initial denaturation of 3 min at 95° C. and 30 cycles of 50 s at 95° C., 50 s at 55 (54 for V.sub.H) ° C., and 3 min at 72° C. The amplified DNA is checked on a 1% agarose gel stained with EtBr and purified by gelextraction kit (Machery-Nagel, AH-Diagnostics, Aarhus, Denmark).

(336) Sequencing:

(337) Each purified PCR product (V.sub.H or V.sub.L) was sequenced as (Value Read Tube premixed with primer) with the Forward and Back primer mix (V.sub.L) or the primers 3 and 4(V.sub.H). All were 1 μM in each primer as final concentration.

(338) Results

(339) PCR Amplification of Variable Genes

(340) 1% agarose gel analysis's showed that the mRNA purifications, cDNA productions, and PCRs for amplification of the variable regions worked (see FIGS. 25 and 26).

(341) Sequences

(342) The products from the PCR amplification of the variable regions were purified by gel extraction and send for sequencing. Both the VH and the VL were successfully sequenced. The obtained DNA and corresponding protein sequences are shown below:

(343) TABLE-US-00027 DNA VH [SEQ ID NO: 85] caggtcaaactgcaggagtctggtggaggattggtgcagcctaaggagtc tttgaaaatctcatgtgcagcctctggattcaccttcagtactgctgcca tgtactgggtccgccaggctccaggaaagggtctggattgggttgctcgc ataagaactaaacctgataattatgcaacatattaccctgcttcagtgaa aggcagattcaccatctccagagatgattcaaagggcatggtctacctac aaatggataacttaaagactgaggacacagccatttattactgtacagca gcttattactatgatggccgctttgattactggggccaaggagtcatggt cacagtcgcctcagctgaaacgacacccaagcttgtctatccactggccc ctggaaaacactcg VL [SEQ ID NO: 86] gacattgtgatgacccagactccatcctcccaggctgtgtcagcagggga gagggtcactatgaggtgcaagtccagtcagagtcttttatacagtgaaa acaaaaagaactacttggcctggtaccaacagaaaccagggcagtctcct aaactgttgatttcctgggcatccactagggaatctggggtccctgatcg cttcataggcagtggatctgggacagatttcactctgaccatcagcagtg tgcaggcagaagacctggctgtttattactgtgaccagtattatgatcct ccattcacgttcggctcagggacgaagttggaaataaaacgggctgatgc tgcaccaactgtatcc Protein VH [SEQ ID NO: 87] QVKLQESGGGLVQPKESLKISCAASGFTFSTAAMYWVRQAPGKGLDWVAR IRTKPDNYATYYPASVKGRFTISRDDSKGMVYLQMDNLKTEDTAIYYCTA AYYYDGRFDYWGQGVMVTVASAETTPKLVYPLAPGKHS VL [SEQ ID NO: 88] DIVMTQTPSSQAVSAGERVTMRCKSSQSLLYSENKKNYLAWYQQKPGQSP KLLISWASTRESGVPDRFIGSGSGTDFTLTISSVQAEDLAVYYCDQYYDP PFTFGSGTKLEIKRADAAPTVS 
Production of 3E10B10

(344) The rat hybridoma 3E10B10 (Genscript, New Jersey, USA) producing anti-mouse CD163 (domain 1-3) were adapted to serum Hybridoma-SFM serum free medium (GIBCO, Invitrogen, Denmark, Taastrup, Denmark) and antibody production was verified in a sandwich ELISA assay. Smale scale productions were seeded at 0.2×10.sup.6 cells/ml in 15-200 ml Hybridoma-SFM medium in Triple layer tissue culture flasks (Nalge-Nunc, Roskilde, Denmark) for 5-6 days.

(345) Purification of E10B10

(346) The supernatant from the E10B10 expressing hybridoma cells are added Tris-HCl pH 8.0 buffer to a final concentration of 50 mM, filtered trough a 0.22 μm filter, and loaded on a Protein G-resin column (Genscript, New Jersey, USA). After loading the column is washed with 10 volumes of PBS pH 7.4 and protein eluted with a 0.1 M Na-Citrate buffer pH 3.2 into fraction tubes filled with 1/10 of the final fraction volume of 1 M Tris-HCl pH 8.0. The protein is buffer gelfiltrated into the final buffer for use. Using Sephadex G-25 (Ge Healtcare, Brøondby, Denmark)

REFERENCES FOR EXAMPLE 6

(347) 1. Zhou, H., Fisher, R. J. & Papas, T. S. (1994). Optimization of primer sequences for mouse scFv repertoire display library construction. Nucleic Acids Res 22, 888-9. 2. Dübel et al. (1994). Isolation of IgG antibody Fv-DNA from various mouse and rat hybridoma cell lines using the polymerase chain reaction with a simple set of primers. J Immunol Methods:175; 89-95

Example 7—Mac2-158 and KN2/NRY Epitope Mapping

(348) Materials and Methods

(349) Primers:

(350) Primers used for SLIM mutagenesis of human CD163 to map the epitope of Mac2-158 and KN2/NRY. Primers were obtained from TAG Copenhagen (Copenhagen, Denmark).

(351) List of Primers:

(352) TABLE-US-00028 VKVQEE-->LKIHEK LKI FT [SEQ ID NO: 89] attgaaaatccacgagaagtggggaacggtgtgtaataatg LKI F [SEQ ID NO: 90] gtggggaacggtgtgtaataatg LKI RT [SEQ ID NO: 91] ttctcgtggattttcaattccactctcccgctacac LKI R [SEQ ID NO: 92] tccactctcccgctacac R60D R60D FT [SEQ ID NO: 93] gttctggagacatttggatggatcatgtttcttgtcgtg R60D F [SEQ ID NO: 94] tggatcatgtttcttgtcgtg R60D RT [SEQ ID NO: 95] tccaaatgtctccagaacctgcactggaattagcccatc R60D R [SEQ ID NO: 96] ctgcactggaattagcccatc
Sequencing:

(353) Sequencing was performed at Eurofins MWG operon (Ebersberg, Germany) as a Value Read Tube Service. The primer used for sequencing was CMV primer from Eurofins MWG operon. The plasmids were considered sequenced when at least domain 1 was correctly sequenced.

(354) SLIM Mutagenesis:

(355) For the mutant generation the Site-directed Ligation Independent Mutagenesis (SLIM) method was used (1). Primers are listed in the primer table. The template for the generation of the two first mutants was a pcDNA5-FRT-humanCD163 plasmid harboring the full length human CD163 cDNA. The primers LKI FT, RT, F, and R were used to generate the mutant plasmid pcDNA5-FRT-humanCD163 (VKVQEE.fwdarw.LKIHEK). The primers R60D FT, RT, F, and R were used to generate the mutant plasmid pcDNA5-FRT-humanCD163 (R60D). Generation of a double mutant was done by performing a SLIM reaction on pcDNA5-FRT-humanCD163 (VKVQEE.fwdarw.LKIHEK) with the primers R60D FT, RT, F, and R.

(356) Expression of Human CD163 and Mutants:

(357) The expression plasmids were heat shocked into DH5a cells and plated on LB plates containing amp. Colonies were picked to over night cultures and plasmids were prepared from the cultures with the Nucleobond plasmid kit with finalizer (Macherey-Nagel, AH-Diagnostic, Aarhus, Denmark). The sequences of all plasmids were verified by sequencing.

(358) The human CD163 wt and the three mutants were expressed transient in HEK 293 cells as follows:

(359) 8 μg of the DNA was diluted in OptiCHOPro SFM (8 mM L-glutamine) to a total volume of 0.15 ml. The DNA was gently mixed with 0.15 ml OptiCHOPro SFM containing 8 μl FreeStyle MAX transfection reagent (Invitrogen, Taastrup, Denmark). After 10 min of incubation at room temperature the DNA-FreeStyle MAX mix was added to 1×10.sup.6 cells/ml in 5 ml. 3 days later the cells were harvested by centrifugation.

(360) HRP Conjugation of KN2/NRY

(361) HRP (P6782, Sigma-Aldrich, Brøndby, Denmark) was conjugated to MabSelect Sure purified KN2/NRY by periodate oxidation essentially as described in (2). Separation of unconjugated HRP from conjugate KN2/NRY-HRP was done by ultrafiltration on VIVAspin centrifugal concentrator (100.000 MWCO) (Sigma-Aldrich, Brøndby, Denmark). The buffer was exchanged 1000 times to PBS containing 10 mM glycine and finally BSA was added to 10 mg/ml and the conjugate was stored at 4° C. ELISA determined working dilution to 1:100-1:2000.

(362) Western Blotting of Human CD163 and Knock Out Mutants.

(363) Each cell pellet was added 1 ml lysis buffer (10 mM Tris pH 8, 140 mM NaCl, 15 mM MgSO.sub.4 1% Triton X-100) and incubated for 15 min at 4 □C with rotation. After centrifugation for 30 min at 6000 rpm the supernatants were sterile filtered.

(364) 90 μl of each of the supernatants were added 30 μl of 4×LDS sample buffer. 3×20 μl samples of each supernatant and 8 μl SeeBlue plus2 prestained marker were loaded on NuPage 4-12% Bis-Tris-Gels (Invitrogen, Taastrup, Denmark) and the SDS-PAGEs were run with MOPS running buffer according to instructions of the manufacturer (200 V constant for 50 min). Blotting to PVDF membranes (Invitrogen, Taastrup, Denmark) was done on an iBLOT device according to instructions of the manufacturer. After blotting the membranes were washed briefly in 1×PBS 0.1% Tween and blocked for 30 min in 1×PBS 2% Tween at room temperature with shaking. After blocking the membranes were washed 3×5 min in 1×PBS 0.1% Tween and incubated 1 hour with: (1) 10 ml 1 μg/ml polyclonal rabbit anti-human CD163; (2) 10 ml 1 μg/ml Mac2-158; (3) 10 ml 1:500 KN2/NRY-HRP all diluted in 1×PBS 0.1% Tween. The membranes were washed with 3×5 min 1×PBS 0.1% Tween again and incubated with: (1) 10 ml Goat anti-rabbit-HRP 1:1000 (AbD Serotec, Oxford, UK); or (2) 10 ml Goat anti-mouse-HRP 1:1000 (Dako, Glostrup, Denmark) for 1 hour. The membranes were washed 3×5 min in 1×PBS 0.1% Tween and were developed with Novex HRP chromogenic substrate by briefly washing the membranes in MilliQ water and adding 10 ml substrate to each blot. The precipitation of the chromogen was stopped by washing twice in MilliQ water.

(365) Results

(366) Site Directed Mutagenesis

(367) The DNA sequences of the purified plasmids after mutagenesis and the corresponding protein sequences are shown below:

(368) TABLE-US-00029 DNA VKVQEE-->LKIHEK mutant [SEQ ID NO: 97] Atgagcaaactcagaatggtgctacttgaagactctggatctgctgacttcagaagacat tttgtcaacctgagtcccttcaccattactgtggtcttacttctcagtgcctgttttgtc accagttctcttggaggaacagacaaggagctgaggctagtggatggtgaaaacaagtgt agcgggagagtggaattgaaaatccacgagaagtggggaacggtgtgtaataatggctgg agcatggaagcggtctctgtgatttgtaaccagctgggatgtccaactgctatcaaagcc cctggatgggctaattccagtgcaggttctggacgcatttggatggatcatgtttcttgt cgtgggaatgagtcagctctttgggattgcaaacatgatggatggggaaagcatagtaac tgtactcaccaacaagatgctggagtgacctgctcagatggatccaatttggaaatgagg ctgacgcgtggagggaatatgtgttctggaagaatagagatcaaattccaaggacggtgg ggaacagtgtgtgatgataacttcaacatagatcatgcatctgtcatttgtagacaactt gaatgtggaagtgctgtcagtttctctggttcatctaattttggagaaggctctggacca atctggtttgatgatcttatatgcaacggaaatgagtcagctctctggaactgcaaacat caaggatggggaaagcataactgtgatcatgctgaggatgctggagtgatttgctcaaag ggagcagatctgagcctgagactggtagatggagtcactgaatgttca R60D [SEQ ID NO: 98] Atgagcaaactcagaatggtgctacttgaagactctggatctgctgacttcagaagacat tttgtcaacctgagtcccttcaccattactgtggtcttacttctcagtgcctgttttgtc accagttctcttggaggaacagacaaggagctgaggctagtggatggtgaaaacaagtgt agcgggagagtggaagtgaaagtccaggaggagtggggaacggtgtgtaataatggctgg agcatggaagcggtctctgtgatttgtaaccagctgggatgtccaactgctatcaaagcc cctggatgggctaattccagtgcaggttctggagacatttggatggatcatgtttcttgt cgtgggaatgagtcagctctttgggattgcaaacatgatggatggggaaagcatagtaac tgtactcaccaacaagatgctggagtgacctgctcagatggatccaatttggaaatgagg ctgacgcgtggagggaatatgtgttctggaagaatagagatcaaattccaaggacggtgg ggaacagtgtgtgatgataacttcaacatagatcatgcatctgtcatttgtagacaactt gaatgtggaagtgctgtcagtttctctggttcatctaattttggagaaggctctggacca atc Double mutant [SEQ ID NO: 99] Atgagcaaactcagaatggtgctacttgaagactctggatctgctgacttcagaagacat tttgtcaacctgagtcccttcaccattactgtggtcttacttctcagtgcctgttttgtc accagttctcttggaggaacagacaaggagctgaggctagtggatggtgaaaacaagtgt agcgggagagtggaattgaaaatccacgagaagtggggaacggtgtgtaataatggctgg agcatggaagcggtctctgtgatttgtaaccagctgggatgtccaactgctatcaaagcc cctggatgggctaattccagtgcaggttctggagacatttggatggatcatgtttcttgt cgtgggaatgagtcagctctttgggattgcaaacatgatggatggggaaagcatagtaac tgtactcaccaacaagatgctggagtgacctgctcagatggatccaatttggaaatgagg ctgacgcgtggagggaatatgtgttctggaagaatagagatcaaattccaaggacggtgg ggaacagtgtgtgatgataacttcaacatagatcatgcatctgtcatttgtagacaactt gaatgtggaagtgctgtcagtttctct Protein VKVQEE-->LKIHEK mutant [SEQ ID NO: 100] MSKLRMVLLEDSGSADFRRHFVNLSPFTITVVLLLSACFVTSSLGGTDKELRLVDGENKCSGRVE LKIHEKWGTVCNNGWSMEAVSVICNQLGCPTAIKAPGWANSSAGSGRIWMDHVSCRGNESAL WDCKHDGWGKHSNCTHQQDAGVTCSDGSNLEMRLTRGGNMCSGRIEIKFQGRWGTVCDDNF NIDHASVICRQLECGSAVSFSGSSNFGEGSGPIWFDDLICNGNESALWNCKHQGWGKHNCDHA EDAGVICSKGADLSLRLVDGVTECS R60D [SEQ ID NO: 101] MSKLRMVLLEDSGSADFRRHFVNLSPFTITVVLLLSACFVTSSLGGTDKELRLVDGENKCSGRVE VKVQEEWGTVCNNGWSMEAVSVICNQLGCPTAIKAPGWANSSAGSGDIWMDHVSCRGNESAL WDCKHDGWGKHSNCTHQQDAGVTCSDGSNLEMRLTRGGNMCSGRIEIKFQGRWGTVCDDNF NIDHASVICRQLECGSAVSFSGSSNFGEGSGPI Double mutant [SEQ ID NO: 102] MSKLRMVLLEDSGSADFRRHFVNLSPFTITVVLLLSACFVTSSLGGTDKELRLVDGENKCSGRVE LKIHEKWGTVCNNGWSMEAVSVICNQLGCPTAIKAPGWANSSAGSGDIWMDHVSCRGNESAL WDCKHDGWGKHSNCTHQQDAGVTCSDGSNLEMRLTRGGNMCSGRIEIKFQGRWGTVCDDNF NIDHASVICRQLECGSAVSFS
Western Blotting of Mutants:

(369) Three western blots were made. The SDS-PAGE had in all blots the following loaded: SeeBlue plus2 prestained marker (lane 1); human CD163 wt (lane 2); human CD163 R60D (lane 3); human CD163 VKVQEE.fwdarw.LKIHEK (lane 4); human CD163 double mutant (lane 5); and negative transfection control (lane 6). Western blotting with polyclonal rabbit anti-CD163 was used to estimate the protein expression level. This western blot (FIG. 27 A) showed that the mutant R60D was not expressed to the same extend as was the wild type human CD163, the VKVQEE.fwdarw.LKIHEK mutant, or the double mutant (which were al expressed to the same extent), but still at a detectable level. FIG. 27 B shows the testing of Mac2-158 on the different mutants. Mac2-158 bound to the human CD163 wt and the R60D mutant. Binding to the R60D mutant was very weak. No binding was detected to any of the LKIHEK containing mutants. The humanized antibody KN2/NRY-HRP conjugated showed only binding to the human CD163 wt (FIG. 27 C). Binding to the R60D mutant could for this antibody not be detected.

(370) This showed that we could knock-out binding of Mac2-158 and KN2/NRY with the same mutants, identifying at least part of the binding epitope for these mAbs.

(371) Knock in Mac2-158 and KN2/NRY Epitope.

(372) Materials and Methods

(373) Plasmids:

(374) A midiprep of pEF4N5/His vector (Invitrogen, Taastrup, Denmark) containing mouse CD163 domain 1-5 was used for expression of mouse CD163 domain 1-5N5/His. A mutant (LKIHDK.fwdarw.VKVQEE, Y60R) in domain 1 of mouse CD163 1-5 was ordered as midiprep at GenScript (Piscataway, N.J., USA). Sequences DNA and protein of mutants are show below (mutant only domain 1).

(375) HRP Conjugation of KN2/NRY

(376) HRP (P6782, Sigma-Aldrich, Brøondby, Denmark) was conjugated to MabSelect Sure purified KN2/NRY by periodate oxidation essentially as described in (2). Separation of unconjugated HRP from conjugate KN2/NRY-HRP was done by ultrafiltration on VIVAspin centrifugal concentrator (100.000 MWCO) (Sigma-Aldrich, Brøondby, Denmark). The buffer was exchanged 1000 times to PBS containing 10 mM glycine and finally BSA was added to 10 mg/ml and the conjugate was stored at 4° C. ELISA determined working dilution to 1:100-1:2000 (data not shown).

(377) TABLE-US-00030 DNA mouse CD163 1-5 wt [SEQ ID NO: 103] atgggtggacacagaatggttcttcttggaggtgctggatctcctggttgtaaaaggttt gtccatctaggtttctttgttgtggctgtgagctcacttctcagtgcctctgctgtcact aacgctcctggagaaatgaagaaggaactgagactggcgggtggtgaaaacaactgtagt gggagagtggaacttaagatccatgacaagtggggcacagtgtgcagtaacggctggagc atgaatgaagtgtccgtggtttgccagcagctgggatgcccaacttctattaaagccctt ggatgggctaactccagcgccggctctggatatatctggatggacaaagtttcttgtaca gggaatgagtcagctctttgggactgcaaacatgatgggtggggaaagcataactgtacc catgaaaaagatgctggagtgacctgctcagatggatctaatttggagatgagactggtg aacagtgcgggccaccgatgcttaggaagagtagaaataaagttccagggaaagtggggg acggtgtgtgacgacaacttcagcaaagatcacgcttctgtgatttgtaaacagcttgga tgtggaagtgccattagtttctctggctcagctaaattgggagctggttctggaccaatc tggctcgatgacctggcatgcaatggaaatgagtcagctctctgggactgcaaacaccgg ggatggggcaagcataactgtgaccatgctgaggatgtcggtgtgatttgcttagaggga gcagatctgagcctgagactagtggatggagtgtccagatgttcaggaagattggaagtg agattccaaggagaatgggggaccgtgtgtgatgataactgggatctccgggatgcttct gtggtgtgcaagcaactgggatgtccaactgccatcagtgccattggtcgagttaatgcc agtgagggatctggacagatttggcttgacaacatttcatgcgaaggacatgaggcaact ctttgggagtgtaaacaccaagagtggggaaagcattactgtcatcatagagaagacgct ggcgtgacatgttctgatggagcagatctggaacttagacttgtaggtggaggcagtcgc tgtgctggcattgtggaggtggagattcagaagctgactgggaagatgtgtagccgaggc tggacactggcagatgcggatgtggtttgcagacagcttggatgtggatctgcgcttcaa acccaggctaagatctactctaaaactggggcaacaaatacgtggctctttcctggatct tgtaatggaaatgaaactactttttggcaatgcaaaaactggcagtggggcggcctttcc tgtgataatttcgaagaagccaaagttacctgctcaggccacagggaacccagactggtt ggaggagaaatcccatgctctggtcgtgtggaagtgaaacacggagacgtgtggggctcc gtctgtgattttgacttgtctctggaagctgccagtgtggtgtgcagggaattacaatgt ggaacagtcgtctctatcctagggggagcacattttggagaaggaagtggacagatctgg ggtgaagaattccagtgtagtggggatgagtcccatctttcactatgctcagtggcgccc ccgctagacagaacttgtacccacagcagggatgtcagcgtagtctgctcaaatctagag ggcccgcggttcgaaggtaagcctatccctaaccctctcctcggtctcgattctacgcgt accggtcatcatcaccatcaccattga Mouse CD163 1-5 LKIHDK-->VKVQEE, Y60R mutant [SEQ ID NO: 104] Atgggtggacacagaatggttcttcttggaggtgctggatctcctggttgtaaaaggttt gtccatctaggtttctttgttgtggctgtgagctcacttctcagtgcctctgctgtcact aacgctcctggagaaatgaagaaggaactgagactggcgggtggtgaaaacaactgtagt gggagagtggaagtgaaggtgcaggaggagtggggcacagtgtgcagtaacggctggagc atgaatgaagtgtccgtggtttgccagcagctgggatgcccaacttctattaaagccctt ggatgggctaactccagcgccggctctggacggatctggatggacaaagtttcttgtaca gggaatgagtcagctctttgggactgcaaacatgatgggtggggaaagcataactgtacc catgaaaaagatgctggagtgacctgctcagatggatctaatttggagatgagactggtg aacagtgcgggccaccgatgcttaggaagagtagaaataaagttccagggaaagtggggg acggtgtgtgacgacaacttcagcaaagatcacgcttctgtgatttgtaaacagcttgga tgtggaagtgccattagtttctctggctcagctaaattgggagctggttctggaccaatc tggctcgatgac Protein Mouse CD163 1-5 wt [SEQ ID NO: 105] MGGHRMVLLGGAGSPGCKRFVHLGFFVVAVSSLLSASAVTNAPGEMKKELRLAGGENNCS GRVELKIHDKWGTVCSNGWSMNEVSVVCQQLGCPTSIKALGWANSSAGSGYIWMDKVSCT GNESALWDCKHDGWGKHNCTHEKDAGVTCSDGSNLEMRLVNSAGHRCLGRVEIKFQGKWG TVCDDNFSKDHASVICKQLGCGSAISFSGSAKLGAGSGPIWLDDLACNGNESALWDCKHR GWGKHNCDHAEDVGVICLEGADLSLRLVDGVSRCSGRLEVRFQGEWGTVCDDNWDLRDAS VVCKQLGCPTAISAIGRVNASEGSGQIWLDNISCEGHEATLWECKHQEWGKHYCHHREDA GVTCSDGADLELRLVGGGSRCAGIVEVEIQKLTGKMCSRGWTLADADVVCRQLGCGSALQ TQAKIYSKTGATNTWLFPGSCNGNETTFWQCKNWQWGGLSCDNFEEAKVTCSGHREPRLV GGEIPCSGRVEVKHGDVWGSVCDFDLSLEAASVVCRELQCGTVVSILGGAHFGEGSGQIW GEEFQCSGDESHLSLCSVAPPLDRTCTHSRDVSVVCSNLEGPRFEGKPIPNPLLGLDSTR TGHHHHHH Mouse CD163 1-5 LKIHDK-->2VKVQEE, Y60R mutant [SEQ ID NO: 106] MGGHRMVLLGGAGSPGCKRFVHLGFFVVAVSSLLSASAVTNAPGEMKKELRLAGGENNCS GRVEVKVQEEWGTVCSNGWSMNEVSVVCQQLGCPTSIKALGWANSSAGSGRIWMDKVSCT GNESALWDCKHDGWGKHNCTHEKDAGVTCSDGSNLEMRLVNSAGHRCLGRVEIKFQGKWG TVCDDNFSKDHASVICKQLGCGSAISFSGSAKLGAGSGPIWLDD
Expression of Mouse CD163 1-5 and Mutant:

(378) The mouse CD163 1-5 and the mouse CD163 domain 1 mutant were expressed transient in Lenti-X 293T cells as follows: 1.5 μg of the DNA was diluted in OptiCHOPro SFM (8 mM L-glutamine) to a total volume of 50 μl. The DNA was gently mixed with 50 μl of OptiCHOPro SFM containing 1.5 μl Freestyle MAX transfection reagent (Invitrogen, Taastrup, Denmark). After 10 min of incubation at room temperature the complexes were added to 1×10.sup.6 cells in 1 ml. Three days later, the cell supernatants were harvested by centrifugation.

(379) Western Blotting of Mouse CD163 and Knock in Mutant.

(380) Ni-NTA His-bind resin (Merck-Chemicals, Darmstadt, Germany) was washed in 50 mM Tris pH 8 buffer, and cell culture supernatants were added 60 μl of Ni-NTA His-bind resin slurry. After 1 hour shaking at 4° C. the supernatants were aspired and each of the purifications were eluted with 90 μl 50 mM Tris pH 8, 25 mM EDTA buffer.

(381) 90 μl of each of the eluates were added 30 μl of 4×LDS sample buffer. 20 μl samples of each supernatant and 8 μl SeeBlue plus2 prestained marker were loaded on NuPage 4-12% Bis-Tris-Gels (Invitrogen, Taastrup, Denmark) and the SDS-PAGEs were run with MOPS running buffer according to instructions of the manufacturer (200 V constant for 50 min). Blotting to PVDF membranes (Invitrogen, Taastrup, Denmark) was done on an iBLOT device according to instructions of the manufacturer. After blotting the membranes were washed briefly in 1×PBS 0.1% Tween and blocked for 30 min in 1×PBS 2% Tween at room temperature with shaking. After blocking the membranes were washed 3×5 min in 1×PBS 0.1% Tween and incubated 1 hour with: (1) 1:5000 Anti-V5 (Invitrogen, Taastrup, Denmark); or (2) 1 μg/ml Mac2-158. The membranes were washed with 3×5 min 1×PBS 0.1% Tween again and incubated with: Goat anti-mouse-HRP 1:2000 (Dako, Glostrup, Denmark) for 1 hour. The membranes were washed 3×5 min in 1×PBS 0.1% Tween and developed with Novex HRP chromogenic substrate (Invitrogen, Taastrup, Denmark) by briefly washing the membranes in MilliQ water and adding 10 ml substrate to each blot. The precipitation of the chromogen was stopped by washing twice in MilliQ water.

(382) Results

(383) Sequences of the Mouse CD163 Domain 1-5 wt and Mutants:

(384) TABLE-US-00031 DNA mouse CD163 1-5 wt [SEQ ID NO: 107] atgggtggacacagaatggttcttcttggaggtgctggatctcctggttgtaaaaggttt gtccatctaggtttctttgttgtggctgtgagctcacttctcagtgcctctgctgtcact aacgctcctggagaaatgaagaaggaactgagactggcgggtggtgaaaacaactgtagt gggagagtggaacttaagatccatgacaagtggggcacagtgtgcagtaacggctggagc atgaatgaagtgtccgtggtttgccagcagctgggatgcccaacttctattaaagccctt ggatgggctaactccagcgccggctctggatatatctggatggacaaagtttcttgtaca gggaatgagtcagctctttgggactgcaaacatgatgggtggggaaagcataactgtacc catgaaaaagatgctggagtgacctgctcagatggatctaatttggagatgagactggtg aacagtgcgggccaccgatgcttaggaagagtagaaataaagttccagggaaagtggggg acggtgtgtgacgacaacttcagcaaagatcacgcttctgtgatttgtaaacagcttgga tgtggaagtgccattagtttctctggctcagccaaattgggagctggttctggaccaatc tggctcgatgacctggcatgcaatggaaatgagtcagctctctgggactgcaaacaccgg ggatggggcaagcataactgtgaccatgctgaggatgtcggtgtgatttgcttagaggga gcagatctgagcctgagactagtggatggagtgtccagatgttcaggaagattggaagtg agattccaaggagaatgggggaccgtgtgtgatgataactgggatctccgggatgcttct gtggtgcgcaagcaactgggatgtccaactgccatcagtgccattggtcgagttaatgcc agtgagggatctggacagattcggcttgacaacatctcatgcgaaggacatgaggcaact ctttgggagtgtaaacaccaagagtggggsaagcattactgtcatcatagagaagacgct ggcgcgacatgttctgatggagcagatctcgaacteagacttgtaggtggaggcagtcgc tgtgctggcattgcggaggtggagattcacaagctgactgggaagatgtgtagccgaggc tggacactggcagatgcggatgtggtttgcagacagcttggatgtggacctgcgcttcaa acccaggctaagatctactctaaaactggcgcaacaaatacgcggctccttcccggacct tgtaatggaaatgaaactactttttggcaatgcaaaaactggcagtggggcggcctttcc tgtgataatttcgaagaagccaaagttacctgctcaggccacagggaacccagactggtt ggaggagaaatcccacgctctggtcgtgtcgaagtgaaacacggagacgtgtggggctcc gtctgtgattttgacttgtctctggaagctgccagtgtggtgtgcagggaattacaatgt ggaacagtcgtctctatcctagggggagcscatcttggagaaggaagtggacagatctgg ggtgaagaattccagcgtagtggggatgacccccatctttcactatgctcagtggcgccc ccgctagacagaacttgtacccacagcagggatgtcagcgtagtctgctcaaatctagag ggcccgcggttcgaaggtaagcctatccctaaccctctcctcggtctcgattctacgcgt accggtcatcatcaccatcaccattga Mouse CD163 1-5 LKIHDK-->VKVQEE, Y60D mutant [SEQ ID NO: 108] Atgggtggacacagaatggttcttcttgcsggtgctggatctcctggttgtaaaaggttt gtccatctaggtttctttgttgtggctgtcagctcacttctcagtgcctctgctgtcact aacgctcctggagaaatgaagaaggaactcagactggcgggtggtgaaaacaactgtagc gggagagtggaagtgaaggtgcaggaggactggggcacagtgtgcagtaacggctggagc atgaatgaagtgtccgtggcttgccagcacctgggatgcccaacttctattaaagccctt ggatgggctaactccagcgccggctctggacggatctggatggacaaagtttcttgtaca gggaatgagtcagctctttgggactgcaaacatgatgggtggggaaagcataactgtacc catgaaaaagatgctggagtgacccgctcagacggatctaatttggagatgagactggtg aacagtgcgggccaccgatgcttaggaagagtagaaataaagttccagggaaagtggggg acggtgtgtgacgacaacttcagcaaagatcacgcttctgtgatttgtaaacagcttgga tgtggaagtgccattagtttctctggctcagctaaattgggagctggttctggaccaatc tggctcgatgac Protein Mouse CD163 1-5 wt [SEQ ID NO: 109] MGGHRMVLLGGAGSPGCKRFVHLGFFVVAVSSLLSASAVTNAPGEMKKELRLAGGENNCS GRVELKIHDKWGTVCSNGWSMNEVSVVCQQLGCPTSIKALGWANSSAGSGYIWMDKVSCT GNESALWDCKHDGWGKHNCTHEKDAGVTCSDGSNLEMRLVNSAGHRCLGRVEIKFQGKWG TVCDDNFSKDHASVICKQLGCGSAISFSGSAKLGAGSGPIWLDDLACNGNESALWDCKHR GWGKHNCDHAEDVGVICLEGADLSLRLVDGVSRCSGRLEVRFQGEWGTVCDDNWDLRDAS VVCKQLGCPTAISAIGRVNASEGSGQIWLDNISCEGHEATLWECKHQEWGKHYCHHREDA GVTCSDGADLELRLVGGGSRCAGIVEVEIQKLTGKMCSRGWTLADADVVCRQLGCGSALQ TQAKIYSKTGATNTWLFPGSCNGNETTFWQCKNWQWGGLSCDNFEEAKVTCSGHREPRLV GGEIPCSGRVEVKHGDVWGSVCDFDLSLEAASVVCRELQCGTVVSILGGAHFGEGSGQIW GEEFQCSGDESHLSLCSVAPPLDRTCTHSRDVSVVCSNLEGPRFEGKPIPNPLLGLDSTR TGHHHHHH Mouse CD163 1-5 LKIHDK-->VKVQEE, Y60R mutant [SEQ ID NO: 110] MGGHRMVLLGGAGSPGCKRFVHLGFFVVAVSSLLSASAVTNAPGEMKKELRLAGGENNCS GRVEVKVQEEWGTVCSNGWSMNEVSVVCQQLGCPTSIKALGWANSSAGSGRIWMDKVSCT GNESALWDCKHDGWGKHNCTHEKDAGVTCSDGSNLEMRLVNSAGHRCLGRVEIKFQGKWG TVCDDNFSKDHASVICKQLGCGSAISFSGSAKLGAGSGPIWLDD
Western Blotting of Mutants:

(385) SDS-PAGE gels had the following loaded: (1) Mouse CD163 1-5 LKIHDK.fwdarw.VKVQEE, Y60R mutant, (2) mouse CD163 1-5 wt, (3) negative transfection control, (4) SeeBlue plus2 pre-stained marker, (5) positive blotting control (mouse CD163 (D) or human CD163 (E)) (FIG. 27). The V5 antibody was used to confirm and estimate protein expression. This showed that both the wt mouse CD163 1-5 and the mutant were expressed at reasonable level. The blot incubated with Mac2-158 showed that Mac2-158 did not bind to the wt mouse CD163 1-5 but that Mac2-158 did bind to the mutant mouse CD163 1-5 LKIHDK.fwdarw.VKVQEE, Y60R. A similar but faint band could be seen in the blots developed using Kn22NRY-HRP (not shown). Thus we can insert the hypotized KN2/NRY and Mac2-158 epitope onto a murine CD163 framework, showing that it is indeed, at least part of, the epitope.

REFERENCES FOR EXAMPLE 7

(386) 1. Chiu et al. (2004). Site-directed Ligase Independent Mutagenesis (SLIM): a single-tube methodology approaching 100% efficiency in 4 h. Nucleic Acids Res 32(21): e174. 2. Boorsma and Streefkerk (1979). Periodate or glutaraldehyde for preparing peroxidase conjugates. J Immunol. Methods 30: 245-55.

Example 8—Preparation of Corticosteroid Conjugated Antibodies

(387) Origin of Antibodies and Haptoglobin to be Conjugated

(388) Anti-human CD163 murine mAbs Mac2-48 and Mac 2-158, from IQ-products, the Netherlands. The humanized CD163 antibody KN2/NRY described in example 3. Anti-rat CD163 ED2, purchased from AbD-Serotec, the Netherlands, product number MCA342R and described by Dijkstra et al. (Immunology (1985), 54:589-99) E10B10 a rat anti-mouse CD163 antibody described in example 6. Haptoglobin of phenotype 1-1 (Hp) was purchaced from Sigma-Aldrich (St. Louis, Mo., USA, product number H9762).

(389) Details concerning dexamethasone-MVCP and dexamethasone-NHS, and their preparation, are given in the accompanying Examples (such as Example 10).

(390) Determination of Free and Protein-Conjugated Corticosteroids by HPLC

(391) Material and Methods

(392) This method is used to measure the amount of free corticosteroids (Dexamethasone, Dexamethasone-phosphate, Dexamethasone-acetate, Prednisolone, Methyl-Prednisolone or Fluocinolone-Acetonide) and corticosteroid-hemisuccinate (Dexamethasone-hemisuccinate, Prednisolone-hemisuccinate, Methylprednisolone-hemisuccinate or Fluocinolone-Acetonide-hemisuccinate) in aqueous samples as well as the amount of total corticosteroids in protein-corticosteroid-conjugates.

(393) Sample Preparation for Free Corticosteroids and Corticosteroid-Hemisuccinate

(394) HPLC at pH 5

(395) About 100 μl of sample or diluted sample are filtered through 0.45 μm RC membrane syringe filters (Phenomenex, Danmark) directly into HPLC vials.

(396) HPLC at pH 2

(397) Spin filters (30 kD cut off, 500 μl volume, Millipore, Danmark) are rinsed by spinning twice with 500 μl water for 10 minutes each. Water is discarded, 50 μl of sample or diluted sample are filtered through and filter is rinsed with 50 μl of the respective sample buffer. Volume of filtrate is determined and filtrate transferred to HPLC vials.

(398) Total Corticosteroid in Protein-Corticosteroid-Conjugates

(399) 20 μl samples of protein-corticosteroid-conjugates are hydrolyzed by incubation with 50 μl 0.1 M sodium hydroxide for 15 minutes at room temperature. The pH is adjusted afterwards with 50 μl 0.1 M hydrochloric acid. Samples are filtered through 0.45 μm syringe filters (Phenomenex, Danmark) into HPLC vials.

(400) Total Corticosteroid in Corticosteroid Loaded Liposomes

(401) 20 μl samples of corticosteroid loaded liposome are diluted with a 10% ethanole solution and loaded into HPLC vials and injected directly on the column. The 40% acetonitrile in the running buffer disintegrates the liposomes, as verified by light scatter measurements (not shown).

(402) HPLC Analysis of Samples

(403) 1 to 50 μl samples are run over an C18 column (Hyperclone C18, 3 μm, 150×460, Phenomenex, Danmark) in an Shimadzu 10 A HPLC System (Shimadzu, Japan) and eluted isocratically with either 40% acetonitril (HPLC-grade, Scharlau, Germany) in 50 mM potassium-acetate buffer, pH 5.0 or 40% acetonitril, 0.005% Trifluoracetic Acid (Sigma-Aldrich, Danmark) (pH 2) at 0.5 ml/min. Peaks are detected by absorption measurement at 240 nm by a Shimadzu SPD 10A VP detector. Run time per injection is between 15 and 30 minutes, depending on retention time of the corticosteroid analyzed. Column heater is set to 30° C. and autosampler/vial holder to 4° C.

(404) All solvents are filtered through 0.45 μm RC-membrane filters (Whatman, RC 55) and degassed under vacuum.

(405) Calibration of HPLC for Corticosteroids and Corticosteroid-Hemisuccinate

(406) A 2 ug/ml solution of corticosteroid, respectively corticosteroid-hemisuccinate, in 10% EtOH (Dexamethasone for HPLC; Dexamethasone-21-phosphate disodium salt 98%, Dexamethasone-21-acetate 99%, Prednisolone 99%, Prednisolone 21-hemisuccinate sodium salt, Fluocinolone acetonide 98%, 6α-Methylprednisolone 21-hemisuccinate sodium salt, all Sigma-Aldrich, Danmark; is used in triplicate at different injection volumes to obtain a linear calibration curve.

(407) Amount of corticosteroid or corticosteroid-hemisuccinate in sample injected is calculated by integration of peak area and calculating the amount according to the respective calibration curve by LC Solution software (Shimadzu, Japan).

(408) Estimation of Residual MVCP-Dexamethasone

(409) To estimate amount of residual MVCP-dexamethasone in the conjugates, MVCP-dexamethasone (10 mg/ml in DMSO) is diluted 25 times in 50 mM borate buffer and mixture run over HPLC as described above. Area of all peaks in conjugate samples corresponding to peaks in MVCP-dexamethasone chromatogram (3 peaks) is summarized and amount of MVCP-dexamethasone estimated according to dexamethasone-calibration curve.

(410) FIG. 28 shows a typical chromatogram from a determination of free dexamethasone/dexamethasone-hemisuccinate and total dexamethasone in a conjugate sample (ED2-dexamethasone). Samples between 0.02 mg/l and 3 mg/l corticosteroid or corticosteroid-hemisuccinate can reliably be analyzed by this HPLC method. Mean standard deviation in concentration of samples injected three times from the same vial is 3.6%, (max. 17.3%, min. 0%, median 1.5%, n=56*3 runs). Mean standard deviation in concentration of total dexamethasone in two independent determinations (two times alcalic hydrolysis) of one sample is 3.4% (max. 8.1%, min. 0%, median 2.9%, n=46*2 runs).

(411) The described method for the determination of free and protein-conjugated corticosteroids by HPLC works well for a range of corticosteroids and corticosteroid-hemisuccinate tested. It is fast, sensitive and highly reproducible.

(412) Synthesis of Antibody-Corticosteroid-Conjugates

(413) 1. Synthesis by Aminocoupling to Corticosteroid-NHS

(414) Materials and Methods

(415) Corticosteroid-NHS preparations (Dexamethasone-NHS, Prednisolone-NHS, Fluocinolone-Acetonide-NHS, all freeze-dried) were stored at −20° C. and a 1 mg/ml solution in DMSO prepared freshly for each conjugation reaction.

(416) Antibody and protein solutions were used in a final concentration of 1 mg/ml in 50 mM borate buffer, pH 8.3.

(417) Typically, 50 μl of the 1 mg/ml Corticosteroid-NHS solution in DMSO per mg protein were added slowly to the protein/antibody solution while gently stirring the solution on a laboratory mixer. This gives a final ratio of conjugated corticosteroid to protein (M/M, with ED2 as antibody) of 4-5, but ratio can be adjusted by in-/decreasing volume of Corticosteroid-NHS solution per mg antibody.

(418) Reaction mix was then incubated for 15 minutes at 25° C. on a thermomixer (Thermomixer comfort, Eppendorf Ag) while gently agitating.

(419) To stop the conjugation reaction 100 μl 5 mM Glycin in 50 mM borate buffer pH 8.3 were added per ml reaction mix and incubated at 25° C. for further 30 minutes with gentle agitation. Reaction mixture were then diafiltered in spin filters (Amicon-Ultra, 30K, Millipore Corp.) into storage buffer, typically PBS (Gibco, Invitrogen)+2.5% EtOH or 10 mM Citrat buffer, 144 mM NaCl, 2.5% EtOH, pH 6.0 or 25 mM Citrat buffer, 125 mM NaCl, 2.5% EtOH, pH 5.0. Conjugates were sterile filtered and analyzed for protein concentration and amount of free and total (free+bound) corticosteroid. They were diluted to desired concentration in respective buffer and stored either at 4° C. or in liquid nitrogen.

(420) FIG. 28D shows typical conjugation parameters of different NHS-conjugates. In all different kinds of conjugates percentage of free corticosteroid-HS after coupling is very low (under 3%), which indicates a good conjugation efficiency.

(421) Aminocoupling of antibodies to Corticosteroid-NHS has been tested for the antibodies ED2, E10B10, Mac2-158 and KN2NRY and to the natural CD163 protein ligand haptoglobin and with the corticosteroids. Dexamethasone, Prednisolone and Fluocinolone-acetonide. Our data show, that it is an efficient and, with regard to ratio, reproducible method for conjugation of corticosteroids to antibodies. The degree of reactivity seems to depend as well on the type of corticosteroid used as on antibody characteristics. Conjugates are stored frozen.

(422) 2. Synthesis by Reduction of Protein Disulfide-Bonds and Conjugation with MVCP-Corticosteroid

(423) Materials and Methods

(424) MVCP-dexamethasone preparations (freeze-dried) were dissolved in DMSO at 10 mg/ml and stored at −20° C. Antibody solutions were obtained either from purification of cell culture supernatants prepared in house (3E10B10, KN2NRY) or from AbD Serotec (ED2) and were used in a final concentration of 1 mg/ml in 50 mM borate buffer, pH 8.3.

(425) Reduction of Antibody

(426) Typically, 70 μl of a 100 mM DTT (Fluka, >99%) solution were added per mg of protein and mixture was incubated for 30 minutes at 25° C. with gentle agitation on a thermomixer (Thermomixer comfort, Eppendorf AG). This leads to complete reduction of interchain disulphide bridges of the antibody. To achieve lower conjugation ratios, incomplete reduction can be achieved by lowering the amount of DTT added.

(427) To remove DTT, reaction mix was run over a gel filtration column (Sephadex G 25, GE Heathcare), which was previously sanitized by running with 0.5 M NaOH+ 0.5 M NaCl for one hour and afterwards equilibrated in PBS+5 mM EDTA. Protein was eluted with PBS+5 mM EDTA to preserve reduced Cysteins and protein-containing fractions were pooled. Protein concentration in pool was determined by OD.sub.280 measurement (Nanodrop ND-1000, Nanodrop Technologies).

(428) Conjugation of Antibody to MVCP-Dexamethasone

(429) MVCP-dexa is added in a 150 fold molar excess. In practice, 40 μl of the 10 mg/ml MVCP-dexamethasone solution in DMSO per mg of antibody were slowly added to antibody solution while gently stirring on a laboratory mixer. Reaction mix was incubated for 1 hour at 25 1 C with gentle agitation on a thermomixer. Reaction mixture was then diafiltered in spin filters (Amicon-Ultra, 30K, Millipore Corp.) into storage buffer, typically PBS (10×PBS; Gibco, Invitrogen)+2.5% EtOH. Conjugates were sterile filtered and analyzed for protein concentration and amount of free and total (free+bound) dexamethasone. They were diluted to desired concentration in respective buffer and stored either at 4° C. or in liquid nitrogen.

(430) Results

(431) FIG. 28E shows typical conjugation parameters of different MVCP-conjugations. A ratio of about 8-12 is generally achieved. Coupling of corticosteroids to reduced antibodies via Cysteine-linker has been tested with MVCP-dexamethasone and the antibodies ED2, 3E10B10 and KN2NRY. Our results show, that this method of conjugation works reproducible with different antibodies.

(432) Affinity Testing of Conjugated KN2/NRY

(433) NHS-dexamethasone and MVCP-dexamethasone conjugated KN2/NRY has been tested for binding to CD163 immobilized on a Biacore chip. The binding experiment was conducted as for example 1. The result is shown in FIGS. 29B and E, and shows that only a minimal reduction in affinity was induced by the conjugations, regardless of the method used.

(434) Formation of Stealth-Liposomes

(435) Methylprednisolone hemisuccinate (MPS-HS, Sigma) was loaded into liposomes using the remote loading method described by Avnir et. al (Avnir et al. Amphipathic weak acid glucocorticoid prodrugs remote-loaded into sterically stabilized nanoliposomes evaluated in arthritic rats and in a Beagle dog: a novel approach to treating autoimmune arthritis. Arthritis Rheum (2008) vol. 58 (1) pp. 119-29) and briefly explained here. Liposomes were prepared using the ethanol-injection method from a mixture of HSPC, mPEG2000-PE and Cholesterol (molar ratio of 55:40:5) (all Avanti polar lipids, Alabaster, Ala., USA). Lipids were dissolved in 100 μl EtOH at ˜65□C for 15 min and hydrated in 900 ul of aqueous buffer to from MLV's. Liposomes were sized by extrusion 25 times through a 100 nm filter and dialysed twice against 150 mM NaCl (0.9% NaCl) with second dialysis being over might at 4□C to generate a transmembrane calcium gradient. For loading of liposomes with methylprednisolone-hemisuccinate, methyl-rednisolone hemisuccinate (preparred as described in example 10) is incubated with liposomes for 15 min at 60° C. (molar drug:lipid ratio 1:20). Finaly MPS-loaded liposomes were cooled to 4° C. and dialysed against 150 mM NaCl to remove excess drug. Liposome size was estimated using a Wyatt minidawn light scatter (Wyatt Technologies, Santa Barbara, Calif., USA).

(436) Attachment of Protein to pNP-PEG2000-PE.

(437) For attachment of protein or antibody to liposomes antibodies was initially modified by pNP-PEG2000-PE (NGPE). NGPE was synthesized an described by Torchilin et. al. (Torchilin et al. p-Nitrophenylcarbonyl-PEG-PE-liposomes: fast and simple attachment of specific ligands, including monoclonal antibodies, to distal ends of PEG chains via p-nitrophenylcarbonyl groups. (Biochim Biophys Acta (2001) vol. 1511 (2) pp. 397-411)). NGPE were dried by argon from chloroform and then solubilzed in 50 μl of CBS pH 5.0 (5 mM NaCltrate, 140 mM NaCl)+5 mg/ml Octyl glucoside. Protein was added to solubilized NGPE (1:40 molar ratio) and pH was adjusted to 8.5 using PBS pH 8.5 and 0.1 M NaOH, the mixture was incubated over night at 4□C. Modified antibody or protein was then added to preformed liposomes incubated over night at 4□C and finaly purified by dialysis in a spectrum dialysis tube (MWCO 250 kDa)(SpectrumLaboratories, California, USA) overnight against 150 mM NaCl at 4□C. Protein concentration was measured using the PIERCE BCA protein micro assay (Fisher denmark, Slangerup, Denmark), and lipid concentration was measured using the Stewart Assay (Stewart, J. C. M. (1980). Anal Biochem, 104:10). The amount of methylprednisolone in the prepared liposomes was determined using the HPLC method described above.

Example 9: In Vitro and In Vivo Experiments Using Corticosteroid Conjugates Targeted to CD163

(438) Materials and Methods

(439) Isolation and Cultivation of Human Mono Nuclear Cells (MNC)

(440) Outdated buffy coats were obtained from the blood bank at Skejby University Hospital. MNC were isolated with Accuspin System Histopaque®—1077 (Sigma-Aldrich Denmark A/S, Broendby, Denmark) according to the manufacturer's instructions and cultured in RMPI 1640, 10% fetal calf serum (FCS), penicillin/streptomycin (pen/strep) in Tissue culture flasks at 37° C. and 5% CO.sub.2. MNC were detached from the flasks by flushing.

(441) Dexamethasone Treatment of Mono Nuclear Cells (MNC)

(442) The cultured MNCs were incubated with the indicated dexamethasone constructs and concentrations by addition of the reagents to the media and incubation for specified time at 37° C. and CD163 mRNA level was measured.

(443) Gaining cDNA and Real-Time, Quantitative PCR Analysis of CD163 mRNA

(444) Total cellular RNA was extracted from MNC and macrophages after RLT buffer fixation with QUIAamp RNA blood Minin (Qiagen, Albertslund, Denmark) according to the manufacturer's protocol and stored at −80° C. until further use.

(445) Reverse transcription was performed by adding 1 μl of the extracted mRNA to a reaction mixture consisting of 2 μl 10×PCR buffer II (Applied Biosystems, Naerum, Denmark) supplemented with 6.3 mM MgCl.sub.2, 0.3 mM of each of the four deoxyribonucleoside triphosphates (dATP, dTTP, dGTP, dCTP), 2.5 mM 16mer oligo dT nucleotide, 20 U RNase inhibitor, and 50 U MULV reverse transcriptase in a total volume of 20 μl (All reagents from Applied Biosystems, Naerum, Denmark). The cDNA synthesis was carried out in a GeneAmp® PCR System 9700 Thermal Cycler (Applied Biosystems, Naerum, Denmark) at 42° C. for 30 min followed by 99° C. for 5 min. The resulting cDNA provided template for the real-time qPCR assay. The synthesized cDNA was stored at −20° C.

(446) Two μl of cDNA were used as template for real-time qPCR in a reaction mixture containing 10 pmol of each primer being either (CD163 WT; forward primer 5′-ACA TAG ATC ATG CAT CTG TCA TTT G-3′; reverse primer 5′-CAT TCT CCT TGG AAT CTC ACT TCT A-3′; MWG Biotech AG, Edersberg, Germany) ore (TNF-alpha; forward primer 5′-TGG GGT GGA GCT GAG AGA-3′ reverse primer 5′-GCA ATG ATC CCA AAG TAG ACC T-3′), 1.0 μl LightCycler® FastStart DNA Master.sup.PLUS SYBR Green I (Roche Diagnostics, Hvidovre, Denmark), containing FastStart Taq DNA Polymerase, reaction buffer, deoxyribonucleoside triphosphates (dATP, dUTP, dGTP, dCTP), SYBR Green I dye, and 10 mM of MgCl.sub.2. The volume was adjusted to 10 μl with nuclease-free H.sub.2O. The real-time hot-start qPCR was performed in a LightCycler® System (Roche Diagnostics, Hvidovre, Denmark) with an initial denaturation step of 95° C. for 15 min, then 50 cycles with a 95° C. denaturation for 10 s. followed by 65° C. annealing for 10 s and 72° C. extension for 5 s. Amplification specificity was checked by melting curve analysis.

(447) Monocyte Isolation and Macrophage In Vitro Maturation

(448) Monocytes were obtained from MNC after isolation using Dynal Monocyte Negative Isolation Kit (Invitrogen) according to the manufacturer's instructions. Monocytes were collected by negative selection in a magnetic field. The effluent was collected as a negative fraction representing highly enriched monocytes.

(449) Maturing the Monocytes to Macrophages:

(450) Monocytes were resuspended in RMPI 1640 medium (Sigma-Aldrich, Brondby, Denmark) containing 20% fetal calf serum (FCS) supplemented with 100 ng/ml M-CSF (GenScript Corporation, New Jersey, USA) and pencillin/streptomycin (pen/strep) for 7 days. The first 3 days in Tissue Culture Flasks at 37° C. and 5% CO.sub.2. The monocytes were then detached from the flask by flushing and scraping. The monocytes were divided into smaller portions and further grown for four days. 0.9>10.sup.5 cells per well were grown in 96 well tissue culture plates for TNF CBA use.

(451) Activating Macrophages into Proinflammatory Subtype:

(452) Subsequently, the macrophages were activated in RMPI 1640 containing 5% FCS, 1 ug/ml lipopolysaccaride (LPS) (Sigma-Aldrich, Brøondby, Denmark) and 20 ng/ml INF-gamma (Genscript Corporation, New Jersey, USA) for 18 hours making them pro-inflammatory.

(453) Dexamethasone Treatment of Cultivated Pro-Inflammatory Macrophages

(454) The pro-inflammatory macrophages were stimulated with RMPI160, 5% FCS, 1 ug/ml LPS and 20 ng/ml INF-gamma containing either dexamethasone, Ab-dexamethasone or no drug.

(455) Cytometry Bead Array (BD) Determination of Soluble TNF Concentration

(456) To detect the change in soluble TNF-alpha concentration we used the Cytometry Bead Array Kit (BD Biosciences, New Jersey, USA). The media from the in vitro stimulated macrophages (described earlier) grown in 96 well tissue culture plates were analyzed according to the manufacturer's protocol.

(457) Flow Cytometry

(458) The cell suspensions were washed in PBS pH 7.4 (0.1% NaN.sub.3) and the cell density adjusted to 3-5×10.sup.6/ml. The cells were incubated at 0.3-0.5×10.sup.6/ml with primary mAb (0.1-0.5 μg) in 100 μl PBS pH 7.4 (0.1% NaN3 and 2% FBS) for one hour at 4° C. Subsequently, the cells were washed in PBS (0.1% NaN3) and incubated with secondary Ab (anti-mouse IgG-FITC or anti-human IgG-FITC (both AbD-Serotec Dusseldorf, Germany)) for 30 min at 4° C. The stained cells were washed twice in PBS pH 7.4 (0.1% NaN.sub.3 and 2 FBS) by centrifugation at 1200 rpm for 5 min, 4° C. before analysis on a FACSCalibur (BD Biosciences, New Jersey, USA). The data were further analyzed using the FlowJo7 software package (Tri Star, Origon, USA).

(459) The Human, Rat and Mouse In Vitro LPS Models

(460) Rat or mouse peritoneal or spleen cell suspensions were prepared from female Lewis rats (Harlan) or BaIB/cA mice (Taconic). Human mononuclear cells were isolated from buffycoats (Skejby University Hospital) as described above. The purified cells were suspended in RPMI medium supplemented with 10% FCS and 2 mM L-glutamine and cultured (2×10.sup.5 per well) overnight in 96-well flat bottomed plates (125 μl per well) at 37° C. and 5% CO.sub.2. Glucocorticoid conjugates (Example 8), free glucocorticoids or PBS were serial diluted in supplemented RPMI medium and added (100 μl) to the overnight cell cultures at final concentrations ranging from 1-10.sup.−7 μg glucocorticoid/ml. After incubation for a specific time ranging from 30 min-24 hours, 150 μl supernatant was carefully aspirated and 150 μl supplemented RPMI medium added to the wells before further incubation overnight. Each incubation condition was tested in duplicates or triplicates. After 16-20 hours, the cells were challenged with lipopolysaccaride (LPS) (250 ng/ml) for 4 hours before supernatant was aspirated from each well and frozen at −20° C. The supernatants were analyzed for the presence of TNFα using the human, rat or mouse CytoSet Antibody Pairs (Invitrogen, Taastrup, Denmark) in a sandwich ELISA according to the manufacturer's instructions.

(461) The Rat and Mouse In Vivo LPS Models

(462) Female Lewis rats (9-11 weeks) or female Balb/cA mice (8-9 weeks) were injected intravenously with either free glucocorticoid, glucocorticoid-conjugates or vehicle (PBS pH 7.4 2.5% ethanol). After 18-20 hours, lipopolysaccharide (LPS) (0.9 mg/kg) was injected intravenously. Blood samples were collected at the following time points: before glucocorticoid injection, 2 hours post LPS injection, and again after 24 hours. Serum samples were analyzed for TNFα using the rat or mouse CytoSet Antibody Pairs (Invitrogen, Taastrup, Denmark) in a sandwich ELISA according to the manufacturer's instructions the. Two days post LPS challenge, the animals were sacrificed and thymus and spleen were dissected and weighed.

(463) Induction of Collagen Antibody Induced Arthritis (CAIA) and Treatment Schedule.

(464) Female Balb/cA mice (7-8 weeks) were injected intravenously with 1 mg of a cocktail of 5 monoclonal antibodies (Chondrex) at day zero. Three days later, the mice were injected intravenously with 35 μg LPS from E. Coli 0111:B4 to induce higher severity and a longer period of active inflammatory arthritis. On the first day of disease onset at day four, the mice were divided into treatment groups. Treatment with methyl-prednisolone, liposome-methyl-prednisolone, liposome-methyl-prednisolone coated with 3E10B10 or vehicle (PBS pH 7.4 2.5% ethanol). were initiated on day four and repeated every second-third day with a total of 4 treatments over 10 days. Changes in ankle size and body weight were monitored during the treatment process. Clinical severity of CAIA was determined by swelling of individual joints and the number of affected joints in the front and rear paws. Each paw was scored from 1 to 4, so the maximum clinical score, including all four paws was 16. On day 14, all animals were sacrificed and spleen and liver were dissected and weighed.

(465) Results

(466) Mac2-158-Dexamethasone Conjugates

(467) FIG. 30A shows the effect on human mononuclear cells isolated from buffy coats (outdated plasma) of haptoglobin coupled with dexamethasone and afterwards complexed with hemoglobin to induce CD163 expression. The effect measured is the induction of CD163 mRNA synthesis by dexamethasone. The number after Hp-dexa refers to different batches of Hp-dexa.

(468) FIG. 30B shows the results of a time study showing the effect of 10 nM dexamethasone on CD163 expression in human mononuclear cells isolated from buffy coats (outdated plasma).

(469) To enable the measurement of changes in TNF synthesis of the cell in the assay, the isolated monocytes were maturated into pro-inflammatory macrophages, which produce TNF. Furthermore, dexamethasone was conjugated to a CD163 mAb (Mac2-158). The macrophages were then incubated with increasing concentrations of dexamethasone, either conjugated to Mac2-158 or as free dexamethasone. For cells not treated with dexamethasone conjugate the TNF concentration measured was 112 pg/ml (FIG. 31A).

(470) The concentration of 10 nM dexamethasone was then used in a time study on the same pro-inflammatory macrophage cell type (FIG. 31B). As can be seen, the conjugated dexamethasone is as efficient as free dexamethasone whether the conjugation is to a monoclonal Ab or Hp. Mac2-158 without dexamethasone was also tested on macrophages with no effect different from buffer (results not shown).

(471) KN2/NRY-Dexamethasone Conjugates

(472) Binding of the humanized KN2/NRY antibody to human monocytes was initially analyzed by flow cytometric analysis of mononuclear cells isolated from buffycoat. FIG. 32 demonstrates specific binding of KN2/NRY to CD14 positive monocytes. Approximately, 70% of the peripheral monocytes showed co-binding of KN2/NRY and Mac2-158 suggesting specific binding to CD163.

(473) The effect of conjugation of KN2/NRY to dexamethasone using the activated NHS ester method was analyzed in a flow cytometric binding analysis of CD163-expressing CHO cells (FIG. 33) and revealed that dexamethasone conjugation had no or very little effect on binding to CD163 displayed on CHO cells.

(474) The ability of the KN2/NRY-conjugates to inhibit LPS mediated TNFα stimulation of human mononuclear cells was analyzed in vitro and FIG. 34 demonstrates similar effect of free dexamethasone and KN2/NRY-dexamethasone conjugates in suppression of LPS mediated TNFα stimulation.

(475) Overall the human cell data corresponds with our results from rat macrophages, indicating that conjugate drugs will be equally effective in both organisms. However, access to matured spleen derived human macrophages are obviously very difficult and experiments on macrophages have thus only been conducted on rat and mice macrophages.

(476) ED2-Dexamethasone Conjugates

(477) Binding of the rat CD163 specific antibody ED2 to rat macrophages was demonstrated by flow cytometric analysis of peritoneal macrophages and revealed that approximately 42% of the peritoneal macrophages were CD163 positive (FIG. 35). The effect of dexmathasone conjugation to ED2 was analyzed in a similar binding assay using CHO cells expressing rat CD163 (FIG. 36) and it was shown that binding of non-conjugated ED2 was comparable to CD163 binding of the ED2-dexamethasone conjugate.

(478) Lipopolysaccaride (LPS) Mediated TNFα Stimulation of Rat Macrophages In Vitro

(479) The ED2-NHS-dexamethasone conjugate was analyzed for the ability to inhibit TNFα stimulation of rat macrophages in vitro, ED2-NHS-dexamethasone conjugates and free dexamethasone (1 μg/ml) prevented LPS mediated stimulation of rat macrophages, whereas ED2 alone had no effect on TNFα secretion. The concentration of TNFα was approximately 10 fold higher in cell supernatants from macrophages stimulated for 20 hours without dexamethasone or ED2-dexamethasone conjugate (ED2 or PBS) (FIG. 37). The dose effects of dexamethasone and ED2-dexamethasone were comparable using the incubation conditions described above and similar titration curves were observed (data not shown). In a timestudy, the dose effect of dexamethasone and ED2-NHS-dexamethasone was compared over a time period from 15 minutes to 24 hours (FIG. 38 and data not shown) and revealed that after 15 minutes of incubation, the level of TNFα suppression of the ED2-NHS-dexamethasone conjugate (1e-4 to 1e-5 μg/ml dexamethasone) was 2 fold higher compared to free dexamethasone. Thus, the rat in vitro model was considered as a valuable method to evaluate the effect of ED2-dexamethasone conjugates before proceeding to animal studies and clearly showed the effect of increased efficacy of conjugates. It is not to be expected that extensive incubation time should yield different results for free and conjugated dexamethasone, since the free dexamethasone will eventually end up in the cells.

(480) The Rat In Vivo LPS Model

(481) The LPS model was established in Lewis rats to obtain an in vivo model for further characterization of macrophage targeting of dexamethasone, using ED2-dexamethasone.conjugates. Free dexamethasone, dexamethasone conjugate or vehicle was injected intravenously 20 hours before injection of LPS (FIG. 39). Two hours after LPS administration, the level of TNFα was 2 fold lower in rats injected with dexamethasone compared to vehicle (FIG. 39A). The level of TNFα was comparable in rats injected with conjugate and free dexamethasone, at a total dexamethasone concentration 100 fold lower for the conjugate. After 24 hours the TNFα level had returned to normal levels for all groups (data not shown). Thus dexamethasone conjugate formulated as ED2-dexamethasone was significantly more efficient than free dexamethasone in lowering the TNFα level. The avoidance of the systemic side-effects of dexamethasone by administrating it as a ED-2-dexamethasone conjugate was also indicated by spleen and thymus weight, which was significantly lower in rats injected with dexamethasone than for rats injected with ED2-dexamethasone (FIGS. 39B and C), indicating that leukocytes has been directed towards apoptosis by free dexamethasone, but not by the conjugated form.

(482) Having established the rat LPS model, different formulations of ED2-dexamethasone conjugates were analyzed using both the in vitro and in vivo LPS models. FIG. 40 shows the effect of the ED2-NHS-demethasone and ED2-MVCP-dexamethasone conjugates. In vitro (FIG. 40A), the suppressive effect of ED2-MVCP-dexamethasone was 3 fold higher compared to free dexamethasone and the effect of ED2-NHS-dexamethasone was about 2 fold higher at dexamethasone concentrations ranging from 1e-3 to 1e-6 μg/ml. Overall, the titration curves suggest a 100-1000 fold higher dexamethasone potency of the ED2 conjugates compared to free dexametasone. When injected into rats, the suppressive effect of both formulations was significantly higher compared to free dexamethasone. Two hours post LPS admiinistration, the TNFα level was 2 fold lower in rats injected with dexamethasone conjugate formulations compared to free dexamethasone at a total dexamethasone dose 50 times higher than conjugate (FIG. 40B). Again, systemic effect in the form of reduced weight of organs (presumably due to induction of apoptosis of lymphocytes of free dexamethasone) was not observed since there was no significant difference between organ weight for vehicle and conjugate groups, whereas the free dexamethasone group was significantly different from free dexamethasone using the conjugated dexamethasone preparations (FIGS. 40C and D). Thus efficacy is increased more than 50 fold and adverse effects avoided.

(483) In sum, these results show selective targeting of the ED2-dexamethasone conjugate to CD163 expressing macrophages. Furthermore, the suppressive effect of the conjugates demonstrated in vivo indicate up to at least a 100 fold higher potency of the conjugates compared to free dexamethasone.

(484) ED2-Prednislone and ED2-Fluocinolone Conjugations.

(485) The effect of targeting of other glucocorticoids to macrophages was analyzed using ED2-prednisolone and ED2-fluocinolone-acetoniode conjugates. FIG. 41 shows the suppressive effect of free fluocinolone, free prednislone, ED2-NHS-fluocinolone-acetonide and ED2-NHS-prednisolone in vitro (A) and in vivo (B). The suppressive in vitro effect of fluocinolone-acetoniode was significantly higher compared to prednisolone. and the dose effect ED2 conjugated prednisolone and fluocinolone-acetoniode was comparable to free prednisolone and fluocinoloneacetonoide, respectively. The TNFα level was 5 times lower in rats injected intravenously with free prednislone and fluocinolone and challenged with LPS compared to vehicle. Injected intravenously into rats both ED2 glucocorticoid conjugates prevented LPS mediated TNFα stimulation at least 10 times more efficiently compared to free glucocorticoids.

(486) In sum, targeting of macrophages using ED2-glucocorticoid formulations was demonstrated to be significantly more efficient than free glucocortiods in suppressing LPS mediated TNFα stimulation of macrophages in vivo. Repeated experiments suggest that the ED2-dexamethasone formulations are up to 100 times more potent than free dexamethasone. The non-significant impact on thymas and other organ weights of conjugated glucocortioid as compared to free glucocorticoid clearly demonstrates that adverse systemic effects are avoided upon macrophage targeted delivery of glucocorticoids.

(487) 3E10B10-Dexamethasone Conjugations

(488) The CD163 specific mouse antibody, 3E10B10, was conjugated to dexamethasone and the conjugates were analyzed in pilot experiments.

(489) The Mouse In Vitro and In Vivo LPS Models

(490) The suppressive effect of the 3E10B10-NHS-dexamethasone conjugate on LPS mediated TNFα production in splenocytes is shown in FIG. 42). The dose effect was comparable to free dexamethasone or eventually slightly higher. The ED2-NHS-dexamthasone, ED2-MVCP-dexamethasone conjugates, free dexamethasone or vehicle were injected intravenously into mice and serum TNFα levels were analyzed 2 hours post LPS challenge. The TNFα level was 2 fold lower in rats injected with dexamethasone compared to vehicle (FIG. 42). The suppressive effect of 3E10B10-NHS-dexamethasone was low or absent whereas the effect of 3E10B10-MVCP-dexamethasone was comparable to free dexamethasone at a total dexamethasone dose 50 times higher than conjugate. The difference between E10B10-NHS-dexamethasone and E10B10-MVCP-dexamethasone is due to the fact, that modification of the amino groups of E10B10 greatly diminished the binding to murine macrophages in FACS and isolated murine CD163 immobilized on a Biacore chip (results not shown).

(491) 3E10B10-Liposome Conjugations

(492) The CAIA Model

(493) The collagen antibody induced arthritis (CAIA) animal model was established to analyze the treatment effect of 3E10B10-glucocorticoid formulations on development of arthritis in mice. CAIA was induced by injecting Balb/cA mice with 1 mg of anti-collagen antibodies, followed by 35 μg LPS 3 days later. Treatment with intravenous injections of methyl-prednisolone, liposome-methyl-prednisolone, liposome-prednisolone-3E10B10 or vehicle was initiated at day 4. At this timepoint, at least one animal in each treatment group showed clinical signs of arthritis. At day 7, disease incidence was 97%. The disease severity (mean clinical score as well as cumulative score) was significantly lower in CAIA mice treated with methyl-prednisolone and liposome-methyl-prednisolone-3E10B10 compared to vehicle-treated CAIA mice (FIG. 43). Furthermore, the clinical score as well as the cumulative score was comparable in mice treated with liposome-methylprednisolone-3E10B10 compared to free prednisolone at a total prednisolone dose 50 times higher than conjugate. Arthritis in CAIA mice treated with liposome-methyl-prednisolone without coated 3E10B10 was not significantly different from arthritis in the vehicle group. Thus, when administrated systemically in the mouse CAIA model, selective targeting of 3E10B10 coated liposomes to macrophages seems to require a lower prednisolone treatment dose compared to free prednisolone and liposome-prednisolone.

Conclusion

(494) Data obtained from the in vitro LPS model, the in vivo LPS model as well as the CAIA model suggest that targeting of macrophages using conjugate-glucocorticid formulations results in drug conjugates with a significantly higher glucorticoid potency compared to free glucorticoid. In several experiments, the rat in vivo LPS model indicate up to a 100 fold higher suppression effect of ED2-dexamethasone compared to free dexametasone. Other ED2-glucocorticoid conjugates were also demonstrated to have an suppressive effect higher than free glucocortiod in the rat in vivo LPS model. In the CAIA model, liposome-methyl-prednisolone coated with the mouse antibody 3E10B10 was shown to have a significant treatment effect on development of arthritis. This study also indicate selective targeting of 3E10B10 coated liposomes to macrophages as well as lower dose requirements compared to free glucocortiod. Furthermore, all the studies using conjugated glucocorticoids demonstrated that the adverse systemic effects, otherwise seen upon using free glucocorticoids at a dose having a pharmacologic effect, are avoided in terms of reduced weight of organs.

Example 10—Synthesis of Activated Glucocorticoid for Protein Conjugation

(495) Preparation of Dexamethasone-MVCP

(496) Dexamethasone.-MVCP also called Mal-Val-Cit-PABC-dexamethasone, for conjugation to free SH groups of proteins were prepared as described in the following. All numbers refer to FIG. 44.

(497) Fmoc-Cit-PABA (2)

(498) HOBt (2.19 g, 16.21 mmol) and EDC (1.26 g, 8.12 mmol) were added to a stirred suspension of 4-aminobenzylalcohol (1, 1.00 g, 8.12 mmol) and Fmoc-Cit-OH (3.23 g, 8.13 mmol) in 150 ml dry DCM at rt. The mixture quickly became clear followed by formation of a white precipitate. After 2 hours, TLC analysis showed only small amounts of remaining 4-aminobenzylalcohol. The reaction mixture was filtered and the residue was washed multiple times with DCM. The filtrate was dissolved in EtOH/DCM (9:1) and filtered. The solvents was removed in vacuo giving 2 (3.51 g, 86%) as a yellow solid sufficient pure to be used in the following reaction without further purification.

(499) Boc-Val-Cit-PABA (3)

(500) Fmoc-Cit-PABA (2, 2.00 g, 3.98 mmol) was dissolved in 10 ml DMF containing 20% piperidine. The mixture was stirred for 30 min at rt and the solvent was removed in vacuo. The remaining solid was dissolved in 5 ml dry DMF.

(501) Boc-Val-OH (865 mg, 3.98 mmol) was dissolved in 10 ml dry DCM and cooled to 4° C. in an ice bath. HOBt (1.08 g, 7.99 mmol) and EDC (618 mg, 3.98 mmol) were added and the mixture was stirred at 4° C. for 20 min. The solution of deprotected Cit-PABA in DMF was added, the ice bath was removed and the reaction was stirred overnight at rt. The solvent was removed and without further workup the product was purified by flash chromatography (DCM-MeOH; 18:2.fwdarw.17:3). This gave 3 (782 mg, 41%) as a slightly yellow solid.

(502) Boc-Val-Cit-PABC-Dexamethasone (5)

(503) Boc-Val-Cit-PABA (200 mg, 0.417 mmol) was dissolved in 5 ml DMF-DCM (3:7), dexamethasone 21-(p-nitrocarbonate) (prepared following the procedure of Ponpipom, M. M.; Bugianesi, R. L.; Robbins, J. C.; Doebber, T. W.; Shen, T. Y., J. Med. Chem., 1981, 24:1388-1395) (4, 698 mg, 1.25 mmol), pyridine (67 μl, 0.828 mmol) and DMAP (255 mg, 2.09 mmol) were added and the mixture was stirred overnight at room temperature (rt). The solvent was removed in vacuo and the product was purified by flash chromatography (DCM-MeOH; 19:1.fwdarw.23:2). This gave 5 (116 mg, 31%) as a white solid.

(504) Mal-Val-Cit-PABC-Dexamethasone (6)

(505) Boc-Val-Cit-PABA-dexamethasone (6, 116 mg, 0.129 mmol) was stirred in 5 ml DCM containing 20% TFA. After TLC analysis showed full conversion of the starting material (10-30 min) the solvent was removed in vacuo. The resulting free amine was dissolved in 5 ml dry DCM/DMF (1:1) followed by addition of 6-maleimidoproproionic acid (prepared following the procedure of Figueiredo, R. M. de; Oczipka, P.; Froehlich, R.; Christmann, M. Synthesis, 2008, 8:1316-1318) (33 mg, 0.195 mmol), TEA (125 μl, 0.900 mmol) and EDC (40 mg, 0.258 mmol). After stirring at rt for 6 hours, the solvent was removed in vacuo and the product purified by flash chromatography (DCM-MeOH; 19:1.fwdarw.9:1). The obtained white solid was washed three times with DCM (5-10 ml), giving the desired product 6 (34 mg, 28%) as a white solid.

(506) Preparation of Glucocorticoid-NHS

(507) Glucocorticoid-NHS for conjugation to primary amino groups of proteins were generally prepared as described in the following for dexamethasone-NHS, also called dexamethasone-hs-NHS. All numbers refer to FIG. 45.

(508) The example shown is for dexamethasone, but other glucocorticoids can also be used. Using the same method methylprednisolone, prednisolone and fluocinolone acetonoid hemisuccinate were also prepared.

(509) Dexamethasone-hs (7)

(510) Dexamethasone (1.00 g, 2.55 mmol) and succinic anhydride (1.27 g, 12.69 mmol) was stirred overnight at it in 15 ml pyridine. The solution was poured into a mixture of 50 g ice and 20 ml conc. hydrochloric acid, filtered and the obtained precipitate was washed twice with 20 ml ice cold HCl (4 M). The precipitate was dissolved in THF and transferred to a round bottom flask and evaporated three times with toluene. This gave 7 (1.25 g, 97%) as a white solid.

(511) Dexamethasone-hs-NHS (8)

(512) Dexamethasone-hs (7, 500 mg, 0.988 mol) was dissolved in 20 ml dry THF. N-hydroxysuccinimide (171 mg, 1.48 mmol) and EDC (200 mg, 1.29 mg) was added and the reaction was stirred overnight at rt. The solvent was removed in vacuo and the product was purified by flash chromatography (pentane-EtOAc; 1:1) giving 8 (376 mg, 63%) as a white solid.

Abbreviations

(513) Boc tert-butyloxycarbonyl;

(514) Cit Citruline

(515) DCM Dichloromethane

(516) DMF Dimethylformaide

(517) EDC N-ethyl-N′-(3-dimethylaminopropyl)carbodiimide

(518) Fmoc Fluorenylmethyloxycarbonyl

(519) HOBt 1-Hydroxybenzotriazole

(520) hs Hemisuccinate

(521) MC 6-maleimidocaproic acid

(522) NHS N-hydroxysuccinimide

(523) PAPA para-Aminobenzylalcohol

(524) PABC para-Aminobenzylcarbonate

(525) TEA Triethylamine

(526) TFA Triluoroacetic acid

(527) THF Tetrahydrofuran

(528) Val Valine

Example 11—Further Experiments Using Dexamethasone Conjugates

(529) Introduction

(530) Summary

(531) The rat collagen-induced arthritis (CIA) model was performed successfully in this study as judged by the 100% disease incidence in the vehicle group in conjunction with increasing total clinical score over time, reaching a value of 6.3 a.u. at the end of the study. Dexamethasone suppressed clinical signs of arthritis in a dose-dependent manner, showing significance at the 0.1 and 1 mg/kg dose level. Administration of 0.01 mg/kg dexamethasone resulted in a lower total clinical score and reduced paw swelling compared to vehicle. Administration of conjugated dexamethasone resulted in a significant reduction of the total clinical score and paw swelling, indicating that the conjugated form is more effective than the non-conjugated form. At the 0.01 mg/kg dose level, no effect of dexamethasone or dexamethasone-conjugate on thymus weight was observed, while higher dosages of dexamethasone reduced thymus weight. In summary, this pilot study showed that at a dose level of 0.01 mg/kg suppression of clinical symptoms in the rat CIA model by dexamethasone treatment is minimal and that the dexamethasone-conjugate is significantly more effective in suppressing clinical signs of arthritis at the same dose level.

(532) Aim

(533) This study was designed to determine the effect of escalating doses of intravenously administered dexamethasone on the development of experimental arthritis. The aim of the study was to determine a dexamethasone dose with minimal or no suppressive effect on arthritis to be able to show superiority of a dexamethasone conjugate at the same dose level in the main study. In this study, a group treated with dexamethasone-conjugate was included to obtain an indication of the efficacy of this conjugate compared to dexamethasone in suppressing arthritis.

(534) For this purpose the model of collagen-induced arthritis (CIA) in the Lewis rat was used. Lewis rats are highly susceptible for the induction of arthritis by intradermal injection of bovine type II collagen. The main pathological features of CIA include infiltration of the joints with inflammatory cells, cartilage degradation, erosion of bone tissue and fibrosis. These pathological features result in clinical signs including less loading of the paws and thickening of the paws.

(535) Study Design

(536) The effect of dexamethasone on arthritis development in the rat CIA model was tested at three dosages (0.01, 0.1 and 1 mg/kg). Dexamethasone was administered intravenously on day 10 (day of disease onset), 13, 16 and 19. Dexamethasone conjugate produced as described in Example 5 was tested at 0.01 mg/kg using the same treatment regimen as for dexamethasone. Treatment with vehicle (PBS/2.5% EtOH) served as negative control. Rats were sacrificed 21 days after immunization.

(537) TABLE-US-00032 Study groups [1] Vehicle n = 4 day 10, 13, 16, 19 [2] Dexamethasone 0.01 mg/kg n = 4 day 10, 13, 16, 19 [3] Dexamethasone  0.1 mg/kg n = 4 day 10, 13, 16, 19 [4] Dexamethasone   1 mg/kg n = 4 day 10, 13, 16, 19 [5] Dexamethasone-conjugate 0.01 mg/kg n = 4 day 10, 13, 16, 19
Outcome Parameters Individual body weight (6× per week) Clinical arthritis score (6× per week) Hind paw swelling (5× per week) Disease incidence Day of disease incidence Spleen, thymus and liver weights at sacrifice
Sample Storage Serum collection before immunization (day −4) Serum collection at sacrifice Storage of hind paws for histological analysis
Materials and Methods
Reagents Incomplete Freunds Adjuvant, Chondrex, lot no. 080292 Bovine type II collagen, Chondrex, lot no. 080280
Test Compounds Dexamethasone, Sigma, lot no. 078H1176 Phosphate buffered saline (PBS), Braun, lot no. 8344A162 Ethanol, Merck, lot no. K37694210732 Dexamethasone-conjugate, supplied by Cytoguide ApS as ready-to-use solution of 0.01 mg/ml PBS/2.5% EtOH. Vials (containing 1.25 ml of compound solution) were stored at −20° C. until use.

(538) Manufacture of the dexamethasone-conjugate is described in the accompanying Examples.

(539) Dexamethasone and dexamethasone-conjugate were dissolved in PBS/2.5% EtOH for i.v. administration. Dexamethasone was freshly prepared once a week. Rats were dosed at 1 ml/kg using the following scheme:

(540) 126-175 gram body weight: 150 μl dosing volume

(541) 176-225 gram body weight: 200 μl dosing volume

(542) 225-275 gram body weight: 250 μl dosing volume

(543) Animals

(544) Female Lewis rats were purchased from Charles River laboratories at an age of 7 weeks and a body weight range of maximal 10%. Animals were housed under clean conventional conditions at 21±3° C., relative humidity of 55±15% and a light/dark cycle of 12 hours. Rats had free access to rodent chow-diet (SSNIFF, Bio-Services, The Netherlands). Before start of the experiment rats were handled for a 2-weeks period. Rats were housed in pairs. Individual animals were identified by marking on their tails.

(545) Induction of Arthritis

(546) Collagen arthritis was induced in 9 weeks old female Lewis rats using a two-step immunization protocol. On day 0, all mice were immunized by intradermal injection of 1 mg/ml bovine type II collagen emulsified in Incomplete Freund's adjuvant at several sites at the back. Arthritis development was accelerated by an intradermal boost in the back and tail-base with 100 Sg bovine type II collagen in IFA on day 7. In order to perform immunization and intradermal boost, rats were anesthetized by inhalation of 3-4% isoflurane in a mixture of oxygen and N2O.

(547) Read-Out Parameters

(548) Body Weights

(549) Body weight of each individual rat was measured 6 times per week (once during weekends).

(550) Disease Incidence

(551) Disease incidence is defined as the percentage of mice within one group that have a clinical arthritis score above 0.

(552) Clinical Arthritis Score

(553) Rats were evaluated 6 times per week (once during weekends) for arthritis severity using a macroscopic scoring system of 0-4 for each paw as detailed below: 0=no signs of arthritis 0.5=unloading of the paw and/or light redness of ankle joint 1=redness and mild swelling of the ankle joint 2=redness and swelling of paw 3=severe redness and swelling of entire paw including digits 4=maximally swollen paw, often involvement of multiple joints and extending towards knee joint.

(554) The total clinical score of an individual rat is defined as the sum of the clinical scores of all four paws for each day. At the end of the study, the cumulative arthritis score was calculated for each rat. This cumulative arthritis score is defined as the sum of the total clinical scores obtained from day 0 till day 21.

(555) Day of Disease Onset

(556) The day of disease is defined as the first day of three consecutive days on which a total arthritis score of more than 0 was observed.

(557) Hind Paw Swelling

(558) The swelling of the hind paws was measured during weekdays with a laser scan micrometer (Mitutoyo, LSM-503S/6200). At the end of the study, the cumulative paw swelling was calculated for each rat as follows: a baseline value was determined by averaging the paw thickness values of day 0-9 when no signs of arthritis were visible. Next, increase in paw thickness was calculated by subtracting the baseline value from the paw thickness values obtained on day 10-21 (delta value). Cumulative paw swelling is defined as the sum of the delta paw thickness values from day 10 till 21.

(559) Organ Weights

(560) Spleen, thymus and liver were isolated and weighed at sacrifice. Weights were normalized for body weight.

(561) Sample Storage

(562) Serum was collected before immunization (day −4) by tail vein puncture (±100 μl) and at sacrifice by heart punction (±500 μl) and stored at −80° C. Hind paws were collected at sacrifice and fixed in 4% formalin to enable future histological analysis.

(563) Deviations from the Protocol

(564) Baseline serum samples were collected at day −4 instead of day 0 as mentioned in the study protocol. At day 0 serum collection would be performed when the rats were under anaesthesia for immunisation. However, anaesthetics might interfere with parameters to be determined in the serum and therefore it was decided to collect baseline serum samples at day −4.

(565) Rat #4 of the 0.01 mg/kg dexamethasone-conjugate group received only 180 μl of compound instead of 200 μl on the first day of treatment (day 10).

(566) Production of Dexamethasone Coupled mAbs

(567) Anti-human CD163 murine mAbs Mac2-48 and Mac 2-158 were conjugated as described (Melgert), we found that exchanging the solvent for the activated dexamethasone upon addition to haptoglobin from DMSO to ethanol significantly increased the affinity for CD163, as judged by Biacore. Different ratios between mAb and activated dexamethasone was tested, and the optimal final ratio for a conserved CD163 affinity and avoidance of aggregation was 3-5 dexamethasones per mAb.

(568) Dose Study of Dexamethasone in the Rat Collagen-Induced Arthritis Model (TNO)

(569) Collagen-induced arthrtitis (CIA) was induced in female Lewis rats (9 weeks of age) by intradermal injection of approximately 1 mg bovine type II collagen (Chondrex) emulsified in Incomplete Freund's adjuvant (IFA). The rats were immunized at several sites at the back under isoflurane anaesthesia (day 0) and boosted intradermal at the back and tail-base with 100 μg bovine type II collagen in IFA at day 7. The rats were scored 6 times per weeks for clinical signs of arthritis. Clinical severity of CIA was determined by swelling of individual joints and the number of affected joints in the front and rear paws. Each paw was scored from 1 to 4, so the maximum clinical score, including all four paws was 16.

(570) A total of 20 rats were divided into five treatment groups (4 rats each). Three groups were injected intravenously with dexamethasone (1.0, 0.1 or 0.01 mg/kg), one group with ED2-dexamethasone (0.01 mg/kg) and one group with vehicle. Treatment of CIA was initiated at disease onset (the day the first animal showed signs arthritis) and repeated every third day with a total of 4 treatments. Changes in ankle size and body weight were monitored during the treatment process. On day 21, all animals were sacrificed and joint tissue, spleen, liver and thymus were dissected.

(571) Results

(572) Preamble

(573) Data Presentation

(574) The presentation of outcome parameters is organized as follows: The clinical data are presented as line graphs for the time-dependent outcome parameters in two separate panels. In the left panel, data of the vehicle and the dexamethasone groups are presented. In the right panel, data of the vehicle group and the 0.01 mg/kg dexamethasone and dexamethasone-conjugate groups are presented. Changes in body weight, disease incidence, total clinical arthritis score and paw thickness are shown in FIGS. 47, 49, 50, 52 and 54. Group means are depicted. Non time-dependent outcome parameters are shown as bar graphs. The cumulative arthritis score, day of disease onset, cumulative paw swelling and organ weight are presented in FIGS. 48, 51, 53, 55 and 56. Group data are presented as mean±standard deviation (SD).
Statistical Analysis

(575) All statistical analyses were performed using the statistical software program SPSS 14.0 for Windows (SPSS Inc. Chicago, USA). During the weekends the body weights and the arthritis score were determined once. For these missing data points the mean of the day before and the day of the respective time point was used.

(576) Basic statistical analyses were performed as follows: The significance of differences between the treatment groups in the non-time dependent outcome parameters were tested using Kruskall Wallis H followed by Mann-Whitney U post hoc testing to evaluate significance of difference between each treatment group and the control (vehicle) group. Interpretation of p-values: p≦0.05 indicates statistically significant differences p>0.05 is considered not significant
Characterization of the Test Model: Vehicle-Treated Rats

(577) In an adequate CIA model, the vehicle-treated group must show an increase in total clinical score over time together with a high disease incidence (i.e. the vehicle-treated rats must have developed arthritis). The current study fulfils these criteria as shown by the following observations: After an initial increase of body weight due to the growth of the animals, there was a moderate decrease in body weight from day 10 onwards, which is expected for rats developing arthritis (FIG. 47). First clinical signs of arthritis were observed on day 10, which is in line with historical data. Mean day of disease onset was 10.3±0.5 days (mean±SD, FIG. 48) Within one day after the first rats showed clinical features of arthritis, all rats in the vehicle group developed arthritis. Disease incidence remained 100% throughout the study in this group (FIG. 49). The total clinical score steadily increased up to a value of 6.3 a.u. at the end of the study (day 21, FIG. 50). Theoretically, a maximal score of 16 a.u. per rat can be reached, but front paws are hardly affected within the timeframe of this CIA model. The mean cumulative arthritis score reached a value of 51.6±14.9 a.u. (mean±SD, FIG. 51). The development of arthritis was reflected by swelling of the hind paws. Swelling of the hind paws started around day 10, reaching a maximum on day 15 (FIGS. 52 and 54). Mean values of spleen, thymus and liver weights were 2.31±0.13, 2.28±0.40, 43.62±2.60 mg/g body weight, respectively in the vehicle group.
Effect of Treatment with Escalating Doses of Dexamethasone

(578) Intravenous administration of dexamethasone with a frequency of once every three days dose-dependently suppressed clinical signs of arthritis in this study. This is based on the following observations: As for the vehicle group, first clinical signs of arthritis were also observed on day 10, since a therapeutic treatment regimen was used. However, definite disease onset as defined by three consecutive days of arthritis is significantly delayed in the 0.1 and 1 mg/kg dexamethasone groups (13.8±1.0 days; p=0.017 and 18.3±2.1 days; p=0.017, respectively, FIG. 48). Disease incidence of 100% was reached in the 0.01 and 0.1 mg/kg groups, however, at a later stage in the study than the vehicle group. The 1 mg/kg dexamethasone group never reached 100% disease incidence (FIG. 49). Severity of arthritis as judged by the total clinical score was suppressed in all dexamethasone groups throughout the study (FIG. 50). Cumulative arthritis scores were 39%, 69% and 91% reduced with respect to the vehicle group. Significant differences in cumulative arthritis score were observed for the 0.1 and 1 mg/kg groups (p=0.021 for both groups, FIG. 51). Thickness of the hind paws in the dexamethasone groups was reduced throughout the study (FIGS. 52 and 54) and significant differences in hind paw swelling were observed for the 0.1 and 1 mg/kg groups (p=0.021 and 0.021 for the left paw, respectively and p=0.043 and 0.043 for the right paw, respectively, FIGS. 53 and 55).
Additional Observations: Body weight of the rats decreased gradually after initiation of the dexamethasone treatment (FIG. 47), irrespectively of arthritis development. This effect of dexamethasone treatment is always observed in rat arthritis studies and is due to the corticosteroid treatment rather than the development of arthritis. A relationship between body weight loss and increasing dexamethasone dose is evident from FIG. 47. No significant differences were observed for spleen and liver weights in the dexamethasone groups compared to the vehicle group (FIG. 56). Thymus weight, on the other hand, was significantly decreased in the 0.1 and 1 mg/kg groups (p=0.043 and p=0.021, respectively).
Effect of Treatment with 0.01 mg/kg Dexamethasone-Conjugate

(579) Intravenous administration of 0.01 mg/kg dexamethasone-conjugate with a frequency of once every three days was more effective in suppressing clinical signs of arthritis than dexamethasone at the same dose level. This is based on the following observations: First clinical signs of arthritis were observed on day 10, which is comparable to the vehicle group since a therapeutic treatment regimen was used. However, definite disease onset as defined by three consecutive days of arthritis is significantly delayed in the dexamethasone-conjugate group (13.8±3.0 days; p=0.025, FIG. 48). This delay was similar to the 0.1 mg/kg dexamethasone group. Disease incidence of 100% was reached, but at a much later stage (day 18) in the study than the vehicle group (FIG. 49). In comparison, the 0.01 mg/kg dexamethasone group reached 100% incidence already at day 14. Total clinical score in the 0.01 mg/kg dexamethasone-conjugate group was reduced to a large extent. As a result, the cumulative arthritis score was significantly decreased as compared to the vehicle group (p=0.021). Suppression of arthritis severity by dexamethasone-conjugate was superior to dexamethasone at the same dose level (p=0.021, FIGS. 50 and 51). The effect of 0.01 mg/kg dexamethasone conjugate on cumulative score was in between the effect of the 0.1 and 1 mg/kg dexamethasone group (FIG. 51). Thickness of the hind paws in the 0.01 mg/kg dexamethasone-conjugate group was reduced throughout the study (FIGS. 52 and 54). Hind paw swelling was significantly decreased with respect to the vehicle group (p=0.021 (left) and p=0.043 (right), FIGS. 53 and 55). No significant differences were observed between the dexamethasone-conjugate group and the different dexamethasone dose groups.
Additional Observations: Body weight of the 0.01 mg/kg dexamethasone-conjugate group remained more or less the same after initiation of the treatment, which is different from the 0.01 mg/kg dexamethasone group which still showed a certain degree of body weight loss (FIG. 47). No significant differences were observed for spleen, thymus and liver weights in the dexamethasone-conjugate group compared to the vehicle group or compared to the 0.01 mg/kg dexamethasone group (FIG. 56).

(580) Treatment with intravenous injections of dexamethasone or ED2-dexamethasone was initiated at day 10. At this timepoint, at least one animal in each treatment group showed clinical signs of arthritis. Further disease onset was delayed in rats treated with dexamethasone and ED2-dexamethasone compared to the control group injected with vehicle (FIGS. 48 and 49).

(581) The disease severity (total clinical arthritis score as well as cumulative arthritis score) was correlated to free dexamethasone dose (FIGS. 50 and 51). Interestingly, the suppressive effect of 0.01 mg/kg ED2-dexamethasone was higher than the effect of 0.01 mg/kg free dexamethasone (p=0.004) and not statically different from the effect of higher doses of free dexamethasone.

(582) In sum, these data show that significantly lower doses of ED2-dexamethasone compared to free dexamethasone delay and prevent severe arthritis in the rat CIA mode.

(583) At day 21, the mean body weight of rats in the ED2-dexamethasone treatment group was higher compared to vehicle and dexamethasone treatment groups (data not shown). Thymus weight in the ED2-dexamethasone group was similar to thymus weight in the control group (FIG. 56), whereas thymus weight was significantly lower in rats treated with free dexamethasone doses (0.1 mg/kg) showing clinical effect s comparable to ED2-dexamethasone (p=0.005).

(584) Thus, when administrated systemically in the rat CIA model, selective targeting of ED2-dexamethasone to macrophages requires a lower dexamethasone treatment dose and also seems to reduce adverse side effects observed with free dexamethasone, including suppression of thymus as well as growth retardation.

(585) Discussion

(586) In the current rat collagen-induced arthritis study, all vehicle-treated rats developed arthritis, indicating a successful induction of arthritis. Escalating doses of dexamethasone were intravenously administered every three days starting at disease onset to determine a minimal effective dose for future comparison with dexamethasone conjugate, which is expected to be superior due to the macrophage-targeting aspects of this compound. At a dose level of 0.01 mg/kg dexamethasone, suppression of clinical signs of arthritis (clinical score and paw swelling) was observed. At higher dose levels, dexamethasone reduced disease severity to a larger extent and the total clinical score showed a dose-dependent relationship between the dexamethasone dose and suppression of arthritis. In addition, one group was incorporated in this study that was treated with dexamethasone-conjugate at a dose level of 0.01 mg/kg. Increased efficacy of this compound compared to non-conjugated dexamethasone was demonstrated. Cumulative arthritis score was suppressed by 83% versus 39% of dexamethasone at the same dose level. Also, reduced paw swelling was observed, but this effect was not significant. Overall, the same effect on arthritis development can be obtained with 10-100 times lower concentrations of dexamethasone-conjugate. No significant effect on thymus weight was observed in the 0.01 mg/kg dexamethasone-conjugate group, which was also observed for the same dose level of dexamethasone. Increased concentrations of dexamethasone resulted in decreased weight of the thymus, indicating that at the same efficacy level there is less effect on thymus weight of the conjugate.

(587) In summary, dexamethasone concentrations were determined at which sub-maximal suppression of clinical signs of arthritis is observed. In addition, this study yielded valuable information on the performance of dexamethasone-conjugate, which was significantly more effective in suppressing arthritis compared to dexamethasone at the same dose level.

Example 12: Exemplary Pharmaceutical Formulations

(588) Whilst it is possible for an agent of the invention to be administered alone, it is preferable to present it as a medicament or pharmaceutical formulation, together with one or more acceptable carriers. The carrier(s) must be “acceptable” in the sense of being compatible with the agent of the invention and not deleterious to the recipients thereof. Typically, the carriers will be water or saline which will be sterile and pyrogen-free.

(589) The following examples illustrate medicaments and pharmaceutical compositions according to the invention in which the active ingredient is an agent of the invention.

(590) Preferably, the agent of the invention is provided in an amount from 5 mg to 1400 mg (for example, from 7 mg to 1400 mg, or 5 mg to 1000 mg), preferably 5 mg to 200 mg. It will be appreciated that the following exemplary medicaments and pharmaceutical compositions may be prepared containing an amount of the agent from 5 mg to 1400 mg or from 7 mg to 1400 mg, or 5 mg to 1000 mg and preferably 5 mg to 200 mg.

(591) For example, the agent may be present in a 10.sup.th or 100.sup.th or 200.sup.th or 500.sup.th of the amount shown in the following exemplary medicaments and pharmaceutical compositions with the amounts of the remaining ingredients changed accordingly.

(592) Thus, for example, the tablets or capsules of the medicaments and pharmaceutical compositions of the invention may contain active agent for administration singly or two or more at a time, as appropriate.

Example A: Tablet

(593) TABLE-US-00033 Active ingredient 1 mg Lactose 200 mg  Starch 50 mg  Polyvinylpyrrolidone 5 mg Magnesium stearate 4 mg

(594) Tablets are prepared from the foregoing ingredients by wet granulation followed by compression.

Example B: Ophthalmic Solution

(595) TABLE-US-00034 Active ingredient 1 mg Sodium chloride, analytical grade 0.9 g Thiomersal 0.001 g Purified water to 100 ml pH adjusted to 7.5

Example C: Tablet Formulations

(596) The following formulations A and B are prepared by wet granulation of the ingredients with a solution of povidone, followed by addition of magnesium stearate and compression.

(597) TABLE-US-00035 Formulation A mg/tablet mg/tablet (a) Active ingredient 1 1 (b) Lactose B.P. 210 26 (c) Povidone B.P. 15 9 (d) Sodium Starch Glycolate 20 12 (e) Magnesium Stearate 5 3 251 51

(598) TABLE-US-00036 Formulation B mg/tablet mg/tablet (a) Active ingredient 1 1 (b) Lactose 150 — (c) Avicel PH 101 ® 60 26 (d) Povidone B.P. 15 9 (e) Sodium Starch Glycolate 20 12 (f) Magnesium Stearate 5 3 251 51

(599) TABLE-US-00037 Formulation C mg/tablet Active ingredient 1 Lactose 200 Starch 50 Povidone 5 Magnesium stearate 4 260

(600) The following formulations, D and E, are prepared by direct compression of the admixed ingredients. The lactose used in formulation E is of the direction compression type.

(601) TABLE-US-00038 Formulation D mg/capsule Active Ingredient 1 Pregelatinised Starch NF15 150 151

(602) TABLE-US-00039 Formulation E mg/capsule Active Ingredient 1 Lactose 150 Avicel ® 100 251
Formulation F (Controlled Release Formulation)

(603) The formulation is prepared by wet granulation of the ingredients (below) with a solution of povidone followed by the addition of magnesium stearate and compression.

(604) TABLE-US-00040 mg/tablet (a) Active Ingredient 1 (b) Hydroxypropylmethylcellulose 112 (Methocel K4M Premium) ® (c) Lactose B.P. 53 (d) Povidone B.P.C. 28 (e) Magnesium Stearate 7 201

(605) Drug release takes place over a period of about 6-8 hours and was complete after 12 hours.

Example D: Capsule Formulations

(606) Formulation A

(607) A capsule formulation is prepared by admixing the ingredients of Formulation D in Example C above and filling into a two-part hard gelatin capsule. Formulation B (infra) is prepared in a similar manner.

(608) TABLE-US-00041 Formulation B mg/capsule (a) Active ingredient 1 (b) Lactose B.P. 143 (c) Sodium Starch Glycolate 25 (d) Magnesium Stearate 2 171

(609) TABLE-US-00042 Formulation C mg/capsule (a) Active ingredient 1 (b) Macrogol 4000 BP 350 351

(610) Capsules are prepared by melting the Macrogol 4000 BP, dispersing the active ingredient in the melt and filling the melt into a two-part hard gelatin capsule.

(611) TABLE-US-00043 Formulation D mg/capsule Active ingredient 1 Lecithin 100 Arachis Oil 100 201

(612) Capsules are prepared by dispersing the active ingredient in the lecithin and arachis oil and filling the dispersion into soft, elastic gelatin capsules.

(613) Formulation E (Controlled Release Capsule)

(614) The following controlled release capsule formulation is prepared by extruding ingredients a, b, and c using an extruder, followed by spheronisation of the extrudate and drying. The dried pellets are then coated with release-controlling membrane (d) and filled into a two-piece, hard gelatin capsule.

(615) TABLE-US-00044 mg/capsule (a) Active ingredient 1 (b) Microcrystalline Cellulose 125 (c) Lactose BP 125 (d) Ethyl Cellulose 13 264

Example E: Injectable Formulation

(616) TABLE-US-00045 Active ingredient 1 mg Sterile, pyrogen free phosphate buffer (pH 7.0) to 10 ml

(617) The active ingredient is dissolved in most of the phosphate buffer (35-40° C.), then made up to volume and filtered through a sterile micropore filter into a sterile 10 ml amber glass vial (type 1) and sealed with sterile closures and overseals.

Example F: Intramuscular Infection

(618) TABLE-US-00046 Active ingredient 1 mg Benzyl Alcohol 0.10 g Glucofurol 75 ® 1.45 g Water for Injection q.s. to 3.00 ml

(619) The active ingredient is dissolved in the glycofurol. The benzyl alcohol is then added and dissolved, and water added to 3 ml. The mixture is then filtered through a sterile micropore filter and sealed in sterile 3 ml glass vials (type 1).

Example G: Syrup Suspension

(620) TABLE-US-00047 Active ingredient 1 mg Sorbitol Solution 1.5000 g Glycerol 2.0000 g Dispersible Cellulose 0.0750 g Sodium Benzoate 0.0050 g Flavour, Peach 17.42.3169 0.0125 ml Purified Water q.s. to 5.0000 ml

(621) The sodium benzoate is dissolved in a portion of the purified water and the sorbitol solution added. The active ingredient is added and dispersed. In the glycerol is dispersed the thickener (dispersible cellulose). The two dispersions are mixed and made up to the required volume with the purified water. Further thickening is achieved as required by extra shearing of the suspension.

Example H: Suppository

(622) TABLE-US-00048 mg/suppository Active ingredient (63 μm)* 1 Hard Fat, BP (Witepsol H15 - Dynamit Nobel) 1770 1771 *The active ingredient is used as a powder wherein at least 90% of the particles are of 63 μm diameter or less.

(623) One fifth of the Witepsol H15 is melted in a steam-jacketed pan at 45° C. maximum. The active ingredient is sifted through a 200 μm sieve and added to the molten base with mixing, using a silverson fitted with a cutting head, until a smooth dispersion is achieved. Maintaining the mixture at 45° C., the remaining Witepsol H15 is added to the suspension and stirred to ensure a homogenous mix. The entire suspension is passed through a 250 μm stainless steel screen and, with continuous stirring, is allowed to cool to 40° C. At a temperature of 38° C. to 40° C. 2.02 g of the mixture is filled into suitable plastic moulds. The suppositories are allowed to cool to room temperature.

Example I: Pessaries

(624) TABLE-US-00049 mg/pessary Active ingredient 1 Anhydrate Dextrose 380 Potato Starch 363 Magnesium Stearate 7 751

(625) The above ingredients are mixed directly and pessaries prepared by direct compression of the resulting mixture.