IFN-beta-induced reduction of superoxide anion generation by macrophages.
Resident mouse peritoneal macrophages (M phi) produced significant amounts of superoxide anion (O2-) in response to phagocytic stimuli. When M phi were exposed in vitro for 20 hr to fibroblast interferon (IFN-beta), their capacity to release O2- was significantly reduced, such reduction being more evident with increasing IFN-beta concentrations. In contrast, O2- production by M phi exposed for 20 hr to the lymphokine macrophage activating factor (MAF) or treated with either MAF or IFN-beta for 4 hr was not significantly different from that of control cells. This pattern of activity closely followed that of M phi-mediated suppression of lymphocyte proliferation, which was dramatically reduced by 20 hr exposure of M phi to IFN-beta, but unchanged by treatment with MAF. No correlation was however found between superoxide anion generation and enhancement of tumoricidal capacity in IFN-beta-treated M phi. We thus concluded that O2- does not play a relevant role in IFN-beta-induced M phi cytolysis, whereas the reduction of O2- production could be of major importance in the decrease of M phi suppression induced by IFN-beta.
D000818:Animals; D003602:Cytotoxicity, Immunologic; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D007372:Interferons / Q000494:pharmacology*; D008222:Lymphokines / Q000494:pharmacology; D016215:Macrophage-Activating Factors; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H; D010100:Oxygen / Q000096:biosynthesis*; D013481:Superoxides / Q000096:biosynthesis*
D008222:Lymphokines; D016215:Macrophage-Activating Factors; D013481:Superoxides; D007372:Interferons; D010100:Oxygen