Murine autoimmune hemolytic anemia induced via xenogeneic erythrocyte immunixation. IV. Immunosuppression of the response

The immunization of mice with rat erythrocytes has been demonstrated to induce a direct antiglobulin-positive hemolytic anemia. This study was undertaken to evaluate the immunosuppressive effect of passive antibody and/or lymphoid subpopulation cell transfer on this induced autoimmune response. The passive transfer of IgG mouse antirat erythrocyte antibody was extremely effective in protecting against induction of antimouse red cell autoantibodies, whereas IgM mouse anti-rat erythrocyte antibody was ineffective. In contrast, transfer of spleen cells, singly primed with rat red blood cell (Rrbc), to syngeneic recipients enhanced development of a direct antiglobulin-positive hemolytic anemia. However, transfer of hyperimmunized spleen cells suppressed the response. Although Rrbc-specific suppressor T cells appeared to play a role in this suppression, anti-Rrbc antibody appears to be the major mediator of the inhibition. Indeed, the suppressive capacity of donor cells, in all transfer experiments, was proportional to the transfer of inhibitory anti-Rrbc antibody and related to the kinetics of autoantibody formation.