Regulation ofin vitrocytotoxic T lymphocyte generation. II. Demonstration of noncytotoxic alloantigen‐specific suppressor T lymphocytes

摘要

AbstractBoth allospecific suppressor T lymphocytes (TsS) and nonspecific suppressor T lymphocytes (TsN) are activated in alloantigen‐stimulated mixed leukocyte cultures (MLC). TsS and TsN can suppress cytotoxic T lymphocyte (CTL) induction upon transfer to fresh (second) MLC stimulated by the same alloantigens as in the first MLC (TsS or TsN) or by third‐party alloantigens (TsN only). Evidence that TsS and TsN functions are performed by different T cell sets has been restricted to radioresistance of the former but not the latter. Separation of TsS from CTL has proven even more difficult. Methods are reported here which have allowedin vitroinduction and functional separation of TsS from CTL and TsN in a totally allogeneic system. TsS are resistant to combined exposure to pyrilamine, a histamine1antagonist and local anesthetic, during suppressor cell induction, and to X or γ irradiation thereafter, while CTL precursors (CTL‐P) and TsN are more sensitive to such treatments. This allowed us to use these treatments to generate TsS that are not contaminated with functional CTL, CTL‐P or TsN. These data show that TsS regulate CTL induction by interacting with responding cell populations, rather than by cytotoxic depletion of stimulat