Treatment of arthritis in Lewis rats by a monoclonal antibody against alpha beta T cell receptor: differential sensitivity of Yersinia-induced arthritis versus adjuvant arthritis.

Lewis rats experimentally infected with Yersinia enterocolitica develop sterile arthritis similar to Yersinia-associated reactive arthritis in humans. To investigate the putative role of alpha beta T cells in the pathogenesis of Yersinia-induced arthritis (YIA) rats were treated with the monoclonal antibody (mAb) R73 mAb directed against the rat alpha beta T cell receptor. In spite of reduction of alpha beta T cells in peripheral blood and in liver lesions of Yersinia-infected rats this serotherapy had no suppressive effect on YIA. Moreover, R73 mAb treatment had no influence on the number of alpha beta T cells in the inflammed synovial tissue. In contrast, R73 mAb serotherapy in Mycobaterium tuberculosis-immunized rats blocked development of adjuvant arthritis (AA) and suppressed the presence of alpha beta T cells in the synovial tissue. These results suggest fundamental differences between the immunopatho-mechanism of YIA caused by bacterial infection and AA induced by bacterial immunization and known to be T cell mediated. These data might have consequences for putative serotherapy of arthritis in humans.