title: Synergistic action of gamma interferon and catalase to reverse the suppressive effect of peritoneal macrophages on concanavalin A-induced lymphocyte proliferation.
abstract: The suppressive effect of normal rat peritoneal exudate cells (PEC) on concanavalin A (Con-A)-induced lymphocyte proliferation was studied. Partial suppression of proliferation was obtained by adding 3% PEC and complete suppression was observed with 6% PEC. The suppressive effect was mediated by W3/25+ plastic-adherent macrophages, which constitute about 60% of normal PEC. Addition of PEC prior to, simultaneously with, or 24 h after, but not 48 h after, the stimulation of lymphocytes with Con A resulted in suppression. Suppressed cultures produced normal or slightly increased amounts of interleukin 2 (IL-2), but the expression of the IL-2 receptor on lymphocytes was decreased. Pre-exposure of PEC to gamma interferon (IFN-gamma) resulted in decreased suppression, whereas IFN-gamma added simultaneously with the lymphocytes had no effect. Catalase reversed PEC-induced suppression and significant synergistic effects were recorded when combined with IFN-gamma. Even completely suppressed cultures were effectively protected from suppression. Indomethacin and combinations of indomethacin with catalase or IFN-gamma did not result in additional protection from PEC-mediated suppression.
mesh_terms: D000818:Animals; D002374:Catalase / Q000494:pharmacology*; D003208:Concanavalin A / Q000494:pharmacology; D004357:Drug Synergism; D005260:Female; D007108:Immune Tolerance; D007371:Interferon-gamma / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D008264:Macrophages / Q000145:classification / Q000276:immunology*; D010529:Peritoneal Cavity / Q000166:cytology; D051381:Rats; D011920:Rats, Inbred WF
chemical_list: D007376:Interleukin-2; D003208:Concanavalin A; D007371:Interferon-gamma; D002374:Catalase