Interleukin 2-mediated immune interferon (IFN-gamma) production by human T cells and T cell subsets.
Human interleukin 2 (IL 2, or T cell growth factor), which was free of lectin and interferon activity (IFN), induced human peripheral T lymphocytes to produce immune IFN (IFN-gamma). In contrast, non-T cells and macrophages did not produce IFN-gamma in response to IL 2. IL 2 acted directly on unstimulated T cells to induce IFN-gamma production, and also acted in synergy with a suboptimal dose (2 micrograms/ml) of concanavalin A (Con A) to enhance IFN-gamma production. The IFN-gamma-inducing activity of partially purified IL 2 was absorbed along with the IL 2 activity by murine IL 2-dependent CT-6 cell line cells. This further supports the view that IFN-gamma-inducing activity is identical to IL 2. When T cells were separated further into helper/inducer T4+ and suppressor/cytotoxic T8+ subsets by negative selection with monoclonal antibody and complement, both T4+ and T8+-enriched cells produced significant levels of IFN-gamma in response to IL 2. Complete removal of macrophages from purified T lymphocyte populations by treatment of OKM1 plus complement consistently reduced IFN-gamma production in response to IL 2 to a limited degree; readdition of macrophages restored IFN-gamma production by both T cell subsets. This observation that IL 2 contributes to the production of IFN-gamma by human lymphocytes suggests that a cascade of lymphocyte-cell interactions participates in human immune responses.
D000042:Absorption; D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D002460:Cell Line; D002469:Cell Separation; D003208:Concanavalin A / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D004357:Drug Synergism; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D007376:Interleukin-2 / Q000502:physiology*; D007700:Kinetics; D051379:Mice; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
D000911:Antibodies, Monoclonal; D007376:Interleukin-2; D003208:Concanavalin A; D007371:Interferon-gamma