Antigen specific, suppressor cells induced by the immunomodulator FCE 20696 in aged NZB/WF1 mice.

FCE 20696 is a new synthetic immunomodulating agent, active on some manifestations of the autoimmune disease of NZB/WF1 mice, in which a disorder of T suppressor cells (SC) has been described to be of pathogenetic relevance. The ability of FCE 20969 to induce SC in NZB/WF1 mice, which are then able to specifically inhibit the production of anti autologous red blood cells antibodies (aRBC Ab), was investigated. NZB/WF1 mice were chronically treated with the compound starting from the ninth week of age, sacrificed at different times and their spleen cells transferred to 9 weeks old, syngeneic mice. In donor animals SC were induced by rat RBC, whereas in the recipients the suppressive activity of transferred cells was evaluated from the appearance of aRBC Ab induced by the same antigen. The results show that antigen specific SC were present in both FCE 20696 treated and control young animals. In older controls, SC couldn't be induced, whereas in treated animals SC were present and able to transfer suppression into the recipients. FCE 20696 was active at 1.5 mg/Kg.