The role of suppressor T cells in the expression of autoimmune haemolytic anaemia in NZB mice.

The course of haemolytic anaemia in NZB mice has been altered by injection of spleen cells from diseased mice into younger ones before the onset of clinical disease. Recipients greater than 6 weeks of age developed early-onset autoimmune disease, recipients less than 6 weeks of age developed early-onset autoimmune disease, recipients less than 6 weeks of age recovered from early induced disease and showed a delay in the onset of spontaneous disease as compared with untreated NZB mice. This delay was due to the induction in the young mice of splenic suppressor cells. These cells were non-adherent to nylon wool and suppressed autoantibody formation on transfer to old Coombs-positive recipients. Suppressor cells active against autoantibody formation on transfer to old Coombs-positive recipients. Suppressor cells active against autoantibody-producing cells may be present in young untreated NZB mice, but not in sufficient numbers to suppress autoantibody production on adoptive transfer to Coombs-positive; however, when Ig-negative cells from the spleens of very young NZB mice were transferred together with Ig-positive cells from Coombs-positive donor mice to irradiated NZB recipients, the autoantibody production of the transferred B cells was suppressed in some cases. Suppressor cell activity could also be induced by co-culture of spleen cells from old Coombs-positive and young Coombs-negative NZB mice in vitro.