PRODUCTION OF INTERFERON-GAMMA BY INVIVO TUMOR-SENSITIZED T-CELLS - ASSOCIATION WITH ACTIVE ANTITUMOR IMMUNITY

The state of active immunity to Meth A fibrosarcoma in mice immunized with an admixture of Meth A cells and Propionibacterium acnes is associated with possession by the host of spleen cells capable of producing interferon-γ (IFN-γ) upon in vitro restimulation with irradiated tumor cells. The ability of spleen cells from immunized mice to produce IFN-γ in response to irradiated Meth A cells decays as active antitumor immunity is replaced by a state of immunological memory. The IFN-producing cells are L3T4+Ly2+, cyclophosphamide-sensitive and radiosensitive T cells, as determined by their sensitivity to corresponding monoclonal antibodies and complement. The induction of IFN-γ production by in vivo tumor-sensitized T cells is tumor specific, in that spleen cells from mice immunized against Meth A fibrosarcoma can produce IFN in response to irradiated Meth A cells but not in response to another syngeneic tumor M109 lung carcinoma. © 1991, Mary Ann Liebert, Inc. All rights reserved.