1) Glomerulonephritis (GN) is inflammation of the glomeruli in the kidneys that can be caused by conditions like IgA nephropathy and systemic lupus erythematosus. There are currently no specific treatments available. 2) The document describes research into developing therapeutic antibodies for treating renal inflammation and GN by targeting the IgA receptor CD89. 3) One such therapeutic antibody, a Fab fragment against CD89, has shown promise in suppressing renal inflammation and reducing renal fibrosis in mouse models of GN. This antibody may be a potential new anti-inflammatory treatment for severe nephritis.

1. New therapeutic approaches for renal inflammation Renato Monteiro, MD, PhD Bichat Hospital – University Paris 7 - Inserm U699

3. Geneticfactors Inflammatory reaction and glomerulonephritis Fibrosis and decline in renal function Renal failure Glomerulonephritis Receptors IFN  TNF GM-CSF Antigen Neutrophil Mastcell Macrophage Dendriticcell T Lymphocyte B Lymphocyte TNF Chemokines TNF Histamines Trauma Antigens… Immune complexes Pathogens LESIONS Cell Signalling

5. HumanCD89 Humanized model for IgANephropathy CD11b promotor EGF Stop codon Transgene 83 96 73 Lines Tg CD89 CD11b Hematuria - + Launay et al J Exp Med 2000 Tg Lt CD89Tg IgA-N SCID S e rum: IgA/sCD89 IC SCID IgA-N Pathogenic role of sCD89

6. Mechanism of IgAdeposition in the kidneys Circulating IgA-complexes Mesangial IgA deposits TfR expression IgAN proliferation Moura et al J Exp Med 2001 Moura et al Blood 2004 1-Therapeutic antibody: the A24 mAb Mechanism of action Fe-Tf Transferrin receptor APOPTOSIS Patent WO 2005/111082

7. IgE- or IgG-IC FcRs Fab (clone A77) CD89 ITAM dependent renal inflammation 2-Therapeutic antibody: Fab anti-CD89 MAPKs activation MCP-1 GPCR TNFR TNF  Non- ITAM dependent renal inflammation Kanamaru et al J Immunol 2008 Pasquier et al Immunity 2005 SHP-1 Silva et al Nat Med 2007 Patent WO 2005/089798 Mechanism of action < < < < < < < < < < < < < < < < Ag < < < < < < < < Ag

8. Fab Anti-CD89 suppresses renal inflammation 0 1 2 320 A77 PBS 0 2 4 6 12 10 8 14 Proteinuria (g/dl) * * * Day Proteinuria Creatinine BUN (mmol/l) 60 40 20 0 d14 d7  mol/l) 40 20 0 * * * Renal parameter Experimental glomerulonephritis Immunohistochemistry Macrophages PBS 320 A77 T cells Injection of rabbit anti-GBM Ab Production of Autologous Ab IgG-IC GN Neutrophil influx Heterologous phase Autologous phase Protocol Tg hFc  RI mice Kanamaru et al. J Immunol 2008

9. Fab anti-CD89 reduces renal fibrosis UUO UUO Left Right A77 Fab ctr Fab (320) Left Right Kanamaru et al. J Immunol 2008 Tubular dilatation Tubular atrophy Cell infiltration 3 1 0 2 4 * 3 1 0 2 4 * 3 1 0 2 4 * Ligation (left kidney) PBS A77 Fab ctr Fab (320) PBS A77 Fab ctr Fab (320) Macrophages Collagen PBS A77 Fab Ctr Fab (320)

10. Other diseases with renal involvement: diabetes… TNF  (pg/ml) 0 500 1000 1500 2000 2500 LPS * Inflammatory renal disease: glomerulonephritis TNF  (pg/ml) 0 500 1000 1500 2000 2500 LPS * Kanamaruet al J Immunol 2008 LPS activation of blood cells Fab anti-CD89 reverses activation of patient cells PBS A77 320

11. Fab anti-CD89 : A new anti-inflammatory treatment For severe nephritis targeting macrophages Inhibition Activation

13. INATHER Y S Fusion Immunization Double Tags Plasmid Protein purification Generating therapeutic monoclonal Antibodies for clinical application Human Therapeutic Target In vivo Glomerulonephritis Blood Sample Ex vivo Multiple Screening Strategy Inflammatory Models NUDE Tg Cell proliferation Leads Optimization Sequence analysis Chimeric antibody production (ex A24 and A77) Western Blot Cytometry Hybridoma isolation Cell proliferation Extended period for screening