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

Lymphocytes responsible for the production of IFN-gamma (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-gamma in response to H-2 alloantigens. The data indicate that (a) in primary mixed lymphocyte reactions, IFN-gamma 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-gamma and (c) the production of IFN-gamma does not correlate with either proliferation or the generation of cytotoxic lymphocytes.