title: Differential activation of CD8+ tumor-specific Tc1 and Tc2 cells by an IL-10-producing murine plasmacytoma.
abstract: The involvement of counteractive CD8+ T-cell subsets during tumor-specific immune responses was analyzed in a syngeneic murine plasmacytoma model. CD8+ Tc cells against the immunogenic IL-10-producing BALB/c plasmacytoma ADJ-PC-5 can be easily induced by immunization of BALB/c mice with X-irradiated ADJ-PC-5 tumor cells in vivo and in vitro. However, the failure of recipient mice to mount a protective Tc response against the tumor during early stages of a real or simulated tumor growth is not due to immunological ignorance, but depends on the induction of tumor-specific tolerance, involving a population of tumor-induced CD8+ T cells that are able to inhibit the generation of tumor-specific Tc cells in a primary ADJ-PC-5-specific MLTC, using IFN-gamma as a suppressive factor. Whereas most long-term cultivated CD8+ ADJ-PC-5-specific Tc lines produce type-1 cytokines on stimulation, at least two of them, which were derived from a primary MLTC, display a type-2 cytokine spectrum. Furthermore, the primary in vitro Tc response against ADJ-PC-5 cells shows characteristics of a Tc2 response. The Tc response is strictly depending on tumor-derived IL-10. CD8+ Tc cells that are induced in a primary MLTC do not produce IFN-gamma, and the tumor-specific Tc response is enhanced by IL-4 but suppressed by IFN-gamma or IL-12. In contrast, ADJ-PC-5-specific CD8+ Tc cells from immunized mice are IFN-gamma producing Tc1 cells. Since the primary in vitro Tc response against the tumor is suppressed even by the smallest numbers of irradiated ADJ-PC-5-specific Tc1 cells via IFN-gamma, these Tc1 cells behave similar to the suppressive CD8+ T cells that are induced during early stages of ADJ-PC-5 tumorigenesis.
authors.affiliation: Institute for Immunology, University of Münster, Germany. specht@uni-muenster.de
authors.forename: C
authors.initials: C
authors.lastname: Specht
authors.forename: H G
authors.initials: HG
authors.lastname: Pauels
authors.forename: C
authors.initials: C
authors.lastname: Becker
authors.forename: E
authors.initials: E
authors.lastname: Kölsch
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry; D016130:Immunophenotyping; D007372:Interferons / Q000276:immunology; D016753:Interleukin-10 / Q000096:biosynthesis*; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D010954:Plasmacytoma / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology* / Q000378:metabolism
chemical_list: D016207:Cytokines; D016753:Interleukin-10; D007372:Interferons