Production of immune interferon is regulated by more than one T cell subset: Lyt-1,2,3 and Qat-5 phenotypes of murine T lymphocytes involved in IFN-γ production in primary and secondary mixed lymphocyte reaction

Lymphocytes responsible for the production of IFN-γ (immune interferon) in primary and secondary mixed lymphocyte reactions have been characterized with antisera specific for the Lyt-1,2,3 and Qat-5 alloantigens. A comparison was made between selected T cell subsets with respect to their ability to proliferate, generate cytolytic activity and produce IFN-γ in response to H-2 alloantigens. The data indicate that (a) in primary mixed lymphocyte reactions, IFN-γ is produced by Lyt-1⁺, Qat-5⁺ and by Lyt-123⁺, Qat-5⁺ T cells, (b) in secondary mixed lymphocyte reactions, an additional T cell subset, which is Lyt-23⁺, Qat-5^?, participates in the generation of IFN-γ and (c) the production of IFN-γ does not correlate with either proliferation or the generation of cytotoxic lymphocytes.