PREVENTION OF COLLAGEN-INDUCED ARTHRITIS WITH AN ANTIBODY TO GP39, THE LIGAND FOR CD40

The ligand for the CD40 antigen is a 39-kilodalton protein, gp39, expr essed on the surface of activated CD4+ T cells and is essential for th ymus-dependent humoral immunity. The role of gp39-CD40 interactions in autoimmune disease was investigated in vivo with the use of an antibo dy that blocks their interactions (anti-gp39). Arthritis induced in mi ce by immunization with type II collagen was inhibited by anti-gp39. A nti-gp39 blocked the development of joint inflammation, serum antibody titers to collagen, the infiltration of inflammatory cells into the s ubsynovial tissue, and the erosion of cartilage and bone. Thus, interf erence with gp39-CD40 interactions may have therapeutic potential in t he treatment of autoimmune disease.