title: Co-stimulation in T cell responses.
abstract: Antigen-specific T cell responses have primarily been considered in terms of activation signals delivered through the TCR and the co-stimulatory molecule CD28. In the past few years, studies have demonstrated the critical importance of inhibitory signals for regulating lymphocyte activation. CD28 and its homologue cytotoxic T lymphocyte antigen-4 (CTLA-4) share the same counter-receptors on antigen-presenting cells, but recent experiments have shown that CD28 and CTLA-4 have opposite effects on T cell activation. The mechanisms responsible for integrating these activation and inhibitory signals at the cellular and molecular levels are just beginning to be elucidated.
authors.affiliation: Department of Molecular and Cellular Biology, Cancer Research Laboratory, University of California, Berkeley, CA 94720, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Chambers
authors.forename: J P
authors.initials: JP
authors.lastname: Allison
mesh_terms: D000069594:Abatacept; D000818:Animals; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology*; D018106:CD28 Antigens / Q000276:immunology*; D060908:CTLA-4 Antigen; D006801:Humans; D018796:Immunoconjugates; D008213:Lymphocyte Activation / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015703:Antigens, CD; D000943:Antigens, Differentiation; D018106:CD28 Antigens; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D018796:Immunoconjugates; D000069594:Abatacept