Interferon gamma produced by mitogen-activated T lymphocytes does not directly mediate lymphoproliferation.
Human interferon gamma (IFN-gamma) endogenously produced during mitogenic stimulation of human peripheral blood mononuclear cells or human T lymphocyte-enriched cultures was neutralized in situ by the addition of a polyclonal antiserum (anti-L) raised in a rabbit against partially purified natural IFN-gamma derived from peripheral blood mononuclear cells. Small decreases in mitogen-induced [3H]thymidine incorporation (lymphoproliferation) were demonstrated under these conditions. However, an antiserum (anti-G) raised in a sheep against highly purified recombinant IFN-gamma (E. coli-derived) which strongly neutralized the antiviral effect of IFN-gamma either had little effect on mitogen-induced lymphoproliferation or caused slight enhancement of mitogenesis. The interleukin 2 responsiveness of activated T lymphocytes following mitogenic stimulation was not found to be different in the presence of anti-G to that of control cultures incubated in the presence of normal sheep serum. These results suggest that IFN-gamma is not a direct requirement for lymphoproliferation.
D000906:Antibodies / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000276:immunology*; D007376:Interleukin-2 / Q000276:immunology; D008213:Lymphocyte Activation; D008934:Mitogens / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000276:immunology*
D000906:Antibodies; D007376:Interleukin-2; D008934:Mitogens; D007371:Interferon-gamma