Generation of suppressor cells in the autologous mixed lymphocyte reaction.

When challenged with HLA-A, B and DR incompatible cells, T cells which have been primed in an autologous mixed lymphocyte response (AMLR) show an accelerated (day 2) component of their proliferative response, as well as the expected primary-style response at day 5. This early response of AMLR-primed cells to allogeneic stimulation, like the response to rechallenge with autologous cells, is abolished by treatment of the primary culture with BUdR and light. These results suggest that priming in the AMLR is not solely to MHC-private specificities, and that an antigenic element common to autologous and allogeneic cells is recognized. The AMLR also generates cells with suppressor activities. AMLR-primed cells suppress the proliferative responses of fresh T cells from the same donor to autologous or allogeneic stimulation. Limiting numbers of suppressor cells are more effective suppressors of the autologous, than of the allogeneic response. Suppressor activity is reduced but not abolished by treatment with mitomycin C. AMLR-primed cells also suppress pokeweed mitogen-induced antibody production by fresh peripheral blood lymphocytes. In some experiments, specific antigen-induced antibody production is also suppressed.