Experimental erythrocyte autoimmunity. II. Autoantibody-specific suppressor cells present in blood.

Mice injected with rat RBC produce RBC autoantibodies and spleen cells that delay autoantibody production. In this report it is shown that transfer of 5 X 10(6) blood leukocytes from mice producing autoantibodies to syngeneic recipients before the injections of rat RBC were started, significantly delayed autoantibody production. These circulating suppressor cells were effective if transferred up to 3 weeks before the first injection of rat RBC and were destroyed by 2,000 rad of irradiation before transfer.