Experimental erythrocyte autoimmunity prevented by suppressor T cells in mice treated with Cyclosporin-A.

Mice injected with rat erythrocytes produce erythrocyte autoantibodies and suppressor cells that inhibit autoantibody production without inhibiting the net production of antibodies against rat RBC. Here it is shown that injecting mice with Cyclosporin-A daily for up to 13 days during the course of injections of rat RBC significantly inhibits autoantibody production. Antibody production against rat RBC was also inhibited. The Cyclosporin-A-treated mice that did not produce autoantibodies produced suppressor cells that inhibited autoantibody production in adoptive transfer experiments. These suppressor cells, which did not inhibit antibody production against rat RBC, were destroyed by treatment with anti-Thy 1.2 serum and complement. From the results, it is suggested that in this experimentally induced autoimmune disease, suppressor T cells may be activated and/or preferentially spared in Cyclosporin-A-treated mice.