title: T:T antigen presentation by activated murine CD8+ T cells induces anergy and apoptosis.
abstract: Using an IL-2-secreting, noncytolytic, H-Y-specific, CD8+ T cell clone, the functional consequences of Ag presentation by T cells to T cells were investigated. Incubation of the T cells with H-Y-soluble peptide led to nonresponsiveness to Ag rechallenge. This was due to the simultaneous induction of apoptosis, involving approximately 40% of the T cells, and of anergy in the surviving cells. These effects were strictly dependent upon bidirectional T:T presentation, in that exposure of C6 cells to peptide-pulsed T cells from the same clone induced proliferation but not apoptosis or anergy. The inhibitory effects of T:T presentation were not due to a lack of costimulation, since the T cells expressed levels of CD80 and CD86 higher than those detected on cultured dendritic cells and equipped them to function as efficient APCs for primary CD8+ T cell responses. Following incubation with soluble peptide, CD80 expression increased, and high levels of CTLA-4 (CD152) expression were induced. Although addition of anti-CTLA-4 Ab augmented proliferation in response to soluble peptide, no protection from apoptosis or anergy was observed. Neither Fas nor TNF-alpha was expressed/produced by the C6 cells, and coligation of MHC class I molecules and TCR failed to reproduce the effects of T:T presentation. Taken together, these data suggest that T:T Ag presentation induces anergy and apoptosis in murine CD8+ T cells and may reflect the regulatory consequences of T:T interactions in the course of clonal expansion in vivo.
authors.affiliation: Department of Immunology, Hammersmith Hospital, Imperial College of Science, Technology, and Medicine, London, United Kingdom.
authors.forename: J G
authors.initials: JG
authors.lastname: Chai
authors.forename: I
authors.initials: I
authors.lastname: Bartok
authors.forename: D
authors.initials: D
authors.lastname: Scott
authors.forename: J
authors.initials: J
authors.lastname: Dyson
authors.forename: R
authors.initials: R
authors.lastname: Lechler
mesh_terms: D000069594:Abatacept; D000818:Animals; D017951:Antigen Presentation; D015703:Antigens, CD / Q000378:metabolism; D000943:Antigens, Differentiation / Q000378:metabolism; D017209:Apoptosis / Q000276:immunology; D018122:B7-1 Antigen / Q000378:metabolism; D051940:B7-2 Antigen; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D060908:CTLA-4 Antigen; D017635:Clonal Anergy; D002999:Clone Cells; D005260:Female; D006182:H-Y Antigen; D018796:Immunoconjugates; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D060908:CTLA-4 Antigen; C497965:Cd86 protein, mouse; C556707:Ctla4 protein, mouse; D006182:H-Y Antigen; D018796:Immunoconjugates; D008562:Membrane Glycoproteins; D018124:Receptors, Tumor Necrosis Factor; D019014:fas Receptor; D000069594:Abatacept