title: Perforin-deficient CD8+ T cells provide immunity to Listeria monocytogenes by a mechanism that is independent of CD95 and IFN-gamma but requires TNF-alpha.
abstract: CD8+ T cells are effective mediators of immunity against Listeria monocytogenes, but the mechanisms by which they provide antilisterial immunity are poorly understood. CD8+ T cells efficiently lyse target cells in vitro by at least two independent pathways. To test the hypothesis that CD8+ T cell-mediated immunity to L. monocytogenes is dependent on perforin or CD95 (Fas, Apo-1), we used C57BI/6 (B6) and perforin-deficient (PO) mice to generate CD8+ T cell lines specific for the L. mono cytogenes-encoded Ag listeriolysin O (LLO). Both lines specifically produce IFN-gamma and TNF-alpha, and mediate target cell lysis in vitro. Cytolysis mediated by the PO-derived CD8+ T cell line is delayed relative to the B6-derived line and is completely inhibited by anti-CD95 Abs. In vivo, PO-derived CD8+ T cells provide specific antilisterial immunity in B6 hosts, CD95-deficient hosts, and IFN-gamma-depleted hosts. However, PO-derived CD8+ T cells fail to provide antilisterial immunity in hosts depleted of TNF-alpha. These results indicate that single Ag-specific CD8+ T cells derived from PO mice can mediate antilisterial immunity by a mechanism that is independent of CD95 or IFN-gamma, but requires TNF-alpha.
authors.affiliation: Interdisciplinary Graduate Program in Immunology, University of Iowa, Iowa City 52242, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: White
authors.forename: J T
authors.initials: JT
authors.lastname: Harty
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001427:Bacterial Toxins; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000637:transplantation; D003601:Cytotoxicity Tests, Immunologic; D003602:Cytotoxicity, Immunologic; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D006360:Heat-Shock Proteins / Q000276:immunology; D006460:Hemolysin Proteins; D007371:Interferon-gamma / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D008089:Listeria monocytogenes / Q000276:immunology; D008088:Listeriosis / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000172:deficiency* / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D019463:Mice, Inbred MRL lpr; D018345:Mice, Knockout; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013154:Spleen / Q000166:cytology / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D019014:fas Receptor / Q000502:physiology*
chemical_list: D001427:Bacterial Toxins; D018984:Epitopes, T-Lymphocyte; D006360:Heat-Shock Proteins; D006460:Hemolysin Proteins; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor; D054353:Perforin; D007371:Interferon-gamma; C038705:hlyA protein, Listeria monocytogenes