title: Selective induction of apoptosis in mature T lymphocytes by variant T cell receptor ligands.
abstract: Activation, anergy, and apoptosis are all possible outcomes of T cell receptor (TCR) engagement. The first leads to proliferation and effector function, whereas the others can lead to partial or complete immunological tolerance. Structural variants of immunizing peptide-major histocompatibility complex molecule ligands that induce selective lymphokine secretion or anergy in mature T cells in association with altered intracellular signaling events have been described. Here we describe altered ligands for mature mouse CD4(+) T helper 1 cells that lead to T cell apoptosis by the selective expression of Fas ligand (FasL) and tumor necrosis factor (TNF) without concomitant IL-2, IL-3, or interferon gamma production. All ligands that stimulated cell death were found to induce FasL and TNF mRNA expression and TCR aggregation ("capping") at the cell surface, but did not elicit a common pattern of tyrosine phosphorylation of the TCR-associated signal transduction chains. Thus, TCR ligands that uniquely trigger T cell apoptosis without inducing cytokines that are normally associated with activation can be identified.
authors.affiliation: Molecular Development of the Immune System Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: B
authors.initials: B
authors.lastname: Combadière
authors.forename: C
authors.initials: C
authors.lastname: Reis e Sousa
authors.forename: R N
authors.initials: RN
authors.lastname: Germain
authors.forename: M J
authors.initials: MJ
authors.lastname: Lenardo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D010856:Columbidae; D003574:Cytochrome c Group; D016207:Cytokines / Q000032:analysis / Q000378:metabolism; D053222:Fas Ligand Protein; D005786:Gene Expression Regulation / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism; D008024:Ligands; D008562:Membrane Glycoproteins / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology; D019000:Phosphotyrosine / Q000032:analysis / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D003574:Cytochrome c Group; D016207:Cytokines; D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D008024:Ligands; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; D014409:Tumor Necrosis Factor-alpha; D019000:Phosphotyrosine