title: [Antigen-recognition mechanism of T cells].
abstract: The antigen-recognition mechanism of T cells was reviewed from the standpoint of MHC-restriction. T cells recognize antigens presented by antigen-presenting cells in a MHC-restricted manner. CD4+ helper T cells recognize antigens with the context of MHC class II molecules, and CD8+ cytotoxic T cells recognize antigens with MHC class I molecules. The MHC class I molecule is composed of alpha-chain and beta 2-microglobulin, and MHC class II molecule is composed of alpha-chain and beta-chain. The T cell antigen receptor is composed of alpha-chain and beta-chain, or gamma-chain and delta-chain, and CD3 complex. Antigens are processed and presented by antigen-presenting cells to T cells in the context of MHC molecules. Furthermore, costimulatory factors such as adhesion molecules and cytokines are required for the full activation of T cells. The biological significance of the T cell antigen recognition mechanism is discussed from the standpoint of clinical application.
authors.affiliation: Department of Immunology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: U
authors.initials: U
authors.lastname: Yamashita
mesh_terms: D000938:Antigen-Presenting Cells; D000941:Antigens / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000737:chemistry; D000949:Histocompatibility Antigens Class II / Q000737:chemistry; D006801:Humans; D011948:Receptors, Antigen, T-Cell; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000941:Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D011948:Receptors, Antigen, T-Cell