REGULATORY MECHANISMS IN CELL-MEDIATED IMMUNE-RESPONSES .2. COMPARISON OF CULTURE-INDUCED AND ALLOANTIGEN-INDUCED SUPPRESSOR CELLS IN MLR AND CML

Abstract

Two antigen-nonspecific [mouse] T [thymus-derived] cell-dependent suppressor systems were compared for their effects upon CML [cell mediated lympholysis] and MLR [mixed lymphocyte responses]. Suppressor cells generated by an in vitro culture of spleen cells were compared with suppressor cells generated by in vivo priming with alloantigen. Culture-induced suppressor cells were themselves unable to respond in CML or MLR; were able to actively suppress the CML and MLR responses of untreated responding cells; were mitomycin-sensitive; and produced no easily demonstrable suppressive supernatant. Alloantigen-primed cells were able to respond in CML and MLR; could suppress proliferation in MLR, but were able to suppress CML only after mitomycin treatment; and produced suppressive supernatants active in suppressing CML and MLR. In addition to cataloging the differences and similarities between these suppressor populations, the data were used to analyze the mechanisms by which suppression occurs in CML and MLR.