Resident mouse peritoneal macrophages (MΦ) produced significant amounts of superoxide anion (O2 -) in response to phagocytic stimuli. When MΦ were exposed in vitro for 20 hr to fibroblast interferon (IFN-β), their capacity to release O2 - was significantly reduced, such reduction being more evident with increasing IFN-β concentrations. In contrast, O2 - production by MΦ exposed for 20 hr to the lymphokine macrophage activating factor (MAF) or treated with either MAF or IFN-β for 4 hr was not significantly different from that of control cells. This pattern of activity closely followed that of MΦ-mediated suppression of lymphocyte proliferation, which was dramatically reduced by 20 hr exposure of MΦ to IFN-β, but unchanged by treatment with MAF. No correlation was however found between superoxide anion generation and enhancement of tumoricidal capacity in IFN-β-treated MΦ. We thus concluded that O2 - does not play a relevant role in IFN-β-induced MΦ cytolysis, whereas the reduction of O2 - production could be of major importance in the decrease of MΦ suppression induced by IFN-β.
|Number of pages||8|
|Publication status||Published - 1982|
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