Inhibition of macrophage-induced, antigen-specific T-cell proliferation by poly I:C role of suppressor macrophages.
Poly I:C treatment can inhibit the ability of macrophages (M phi) to induce antigen-specific T-cell proliferation. This study investigated whether this inhibition is the result of suppressor or cytotoxic activity. Pretreatment of M phi with indomethacin in vivo, in vitro or both failed to reverse the inhibition of T-cell proliferation induced by poly I:C-treated, keyhole limpet haemocyanin (KLH)-pulsed M phi, suggesting that prostaglandin production does not mediate the inhibition of T-cell proliferation. The transfer of supernatants from cultures containing poly I:C-treated, KLH-pulsed M phi to cultures containing saline-treated, KLH-pulsed M phi and T cells did not inhibit T-cell proliferation, suggesting that the inhibition of T-cell proliferation by poly I:C is not mediated by the production of soluble suppressor factors. As addition of poly I:C-treated, KLH-pulsed M phi to cultures containing saline-treated, KLH-pulsed M phi did not significantly inhibit KLH-specific T-cell proliferation, the inhibition of T-cell proliferation is also not mediated by direct cell contact or short-range soluble suppressor factors. In addition, poly I:C-treated, KLH-pulsed M phi did not induce cytolysis of syngeneic T cells. These results indicate that cytotoxic or suppressor effector functions of M phi are not involved in the mechanism by which poly I:C inhibits M phi-induced, antigen-specific T-cell proliferation.
Kirschmann
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Department of Microbiology and Immunology, Medical College of Pennsylvania, Philadelphia.
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Murasko
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D000818:Animals; D002450:Cell Communication / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D000939:Epitopes / Q000276:immunology; D007108:Immune Tolerance / Q000187:drug effects*; D007213:Indomethacin / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D011070:Poly I-C / Q000494:pharmacology*; D013491:Suppressor Factors, Immunologic / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000939:Epitopes; D013491:Suppressor Factors, Immunologic; D011070:Poly I-C; D007213:Indomethacin