title: A bispecific single-chain antibody fusion protein for targeted depletion of autoreactive B cells via unstimulated human T lymphocytes.
abstract: Autoantigen-specific B cells are culprits in the pathogenesis of many autoimmune diseases either through the production of autoreactive antibodies or as very effective antigen-presenting cells. A general depletion of B cells by a CD20-specific monoclonal IgG1 antibody has recently been validated as an effective strategy for treating rheumatoid arthritis. However, general elimination of B cells can lead to immunosuppression and increased risk of infection. In search for a more specific approach, we have generated a fusion protein for the antigen-specific targeting of autoreactive B cells for re-directed lysis by resting human T lymphocytes. We describe the design, purification and characterization of MOGxanti-CD3, a single-chain bispecific antibody fusion protein recognizing B cell receptors specific for the human myelin oligodendrocyte glycoprotein (MOG) and to CD3 on human T cells. MOGxAnti-CD3 induced selective and very efficient redirected lysis of MOG-reactive B cells through freshly isolated, unstimulated human T cells. Fusions between autoantigens and an anti-CD3 single-chain antibody may be suitable to develop very specific therapeutic approaches for the selective depletion of autoreactive B cells in autoimmune diseases.
authors.affiliation: Micromet AG, Staffelseestr. 2, 81477 Munich, Germany. marcel.zocher@roche.com
authors.forename: Marcel
authors.initials: M
authors.lastname: Zocher
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Baeuerle
mesh_terms: D000906:Antibodies / Q000737:chemistry / Q000276:immunology*; D018033:Antibodies, Bispecific; D000918:Antibody Specificity; D001324:Autoantigens; D015551:Autoimmunity; D001402:B-Lymphocytes / Q000276:immunology*; D017252:CD3 Complex / Q000276:immunology; D015195:Drug Design; D006801:Humans; D008212:Lymphocyte Depletion / Q000379:methods*; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein / Q000276:immunology; D063308:Myelin-Oligodendrocyte Glycoprotein; D011993:Recombinant Fusion Proteins / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000906:Antibodies; D018033:Antibodies, Bispecific; D001324:Autoantigens; D017252:CD3 Complex; C571326:MOG protein, human; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D063308:Myelin-Oligodendrocyte Glycoprotein; D011993:Recombinant Fusion Proteins