title: Immune down-regulation and peripheral deletion of CD8 T cells does not require TNF receptor-ligand interactions nor CD95 (Fas, APO-1).
abstract: TNF receptor-ligand interactions and CD95 (Fas / APO-1) have been demonstrated to be involved in activation-induced death of mature T cells. Here, we examined the role of these molecules in the murine model of lymphocytic choriomeningitis virus (LCMV) infection using LCMV TCR transgenic (tg) mice lacking TNF, TNF receptor I (TNFR1), CD95 or both TNFR1 and CD95. This report demonstrates that neither TNF receptor-ligand interactions nor CD95 was required for down-regulation of LCMV-specific CD8 T cells following acute LCMV infection in vivo. Even LCMV-specific CD8 T cells lacking both TNFR1 and CD95 molecules declined after the acute phase of the infection with normal kinetics. Furthermore, peripheral deletion of LCMV-specific CD8 T cells induced by LCMV peptide injection or by adoptive transfer of tg spleen cells expressing the corresponding LCMV epitope was not impaired in mice lacking TNF, TNFR1 and / or CD95. Our data speak against an indispensable role of these molecules in antigen-induced apoptosis of CD8 T cells in vivo and suggest that T cell homeostasis after antigen challenge is controlled by additional mechanisms.
authors.affiliation: Institut für Medizinische Mikrobiologie und Hygiene, University of Freiburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Reich
authors.forename: H
authors.initials: H
authors.lastname: Körner
authors.forename: J D
authors.initials: JD
authors.lastname: Sedgwick
authors.forename: H
authors.initials: H
authors.lastname: Pircher
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology*; D017209:Apoptosis / Q000235:genetics / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D015536:Down-Regulation / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D018124:Receptors, Tumor Necrosis Factor / Q000276:immunology*; D047888:Receptors, Tumor Necrosis Factor, Type I; D015398:Signal Transduction / Q000276:immunology; D019014:fas Receptor / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D011948:Receptors, Antigen, T-Cell; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D019014:fas Receptor