A Novel BLyS Peptibody Down-Regulates B Cell and T Helper Cell Subsets In Vivo and Ameliorates Collagen-Induced Arthritis

B lymphocyte stimulator (BLyS), a member of tumor necrosis factor (TNF) family, contributes to the development of autoimmune disease, and BLyS antagonists have been developed for the treatment of autoimmune disorders. Recently, we constructed a novel BLyS antagonist, TC-Fc peptibody. The study was performed to investigate the efficiency of TC-Fc peptibody on collagen-induced arthritis (CIA). CIA mice were randomly divided into three groups, treated with TC-Fc, Fc, and phosphate-buffered saline (PBS), respectively. Clinical scores associated with the severity of arthritis were assessed on alternate day from first day. Histopathological scores, B and T cell changes, and autoantibodies levels were measured at the end of the experiment. CIA mice treated with TC-Fc peptibody had lower clinical and histological scores. Compared with Fc group, TC-Fc treatment resulted in reduction of B cell and T help cell subsets, significantly alleviated the swelling of paws, and suppressed articular tissue degeneration. These results demonstrated that TC-Fc could inhibit the progression of CIA and might have therapeutic effect on rheumatoid arthritis.