Previous studies demonstrated that nonresponder (DBA/1)-derived suppressor factor specific for the random copolymer L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT-TsF) failed to suppress responder strain mice when administred at the same time as antigen (GAT) challenge. The present study demonstrates that if responder (BALB/c or A/J) spleen cells are preincubated with nonresponder GAT-TsF for 2 days in vitro, suppressor T cells (Ts2) are induced that can suppress syngeneic GAT plaque-forming cell responses in vivo or in vitro. This finding is in accord with Ts2 induction in nonresponder mice with the same GAT-TsF. Further, administration of nonresponder GAT-TsF to responder mice 7 days before in vivo antigen challenge suppressed subsequent GAT-PFC responses in these mice. Finally, the Ts2 induced in the same strain of mice (BALB/c) by GAT-TsF and by L-glutamic acid50-L-tyrosine50 (GT)-specific TsF were shown to be able to suppress only the response to the inducing antigen, demonstrating the fine specificity of these Ts2. The implications of this demonstration of nonresponder TsF activity in responder mice for an antigen under strict Ir gene control are discussed.
This work was supported by Grant AI-09920 from the National Institute of Allergy and Infectious Diseases and Grant CA-09130 from the National Cancer Institute.