title: Biology of T memory type 1 cells.
abstract: Engagement of inhibitory natural killer (NK) cell receptors for MHC class I molecules (NKR) can impair NK-cell activation programs. Inhibitory NKR thus confer to NK cells the capacity to discriminate between MHC class I+ and MHC class I- target cells, and are therefore involved in the control of NK-cell tolerance to self, as well as in the elimination of MHC class I- distressed cells by NK cells. In human and mouse, a subset of alphabeta T cells also express inhibitory NKR at their surface, but the biological function of inhibitory NKR on T cells remains to be precisely elucidated. We refer to these cells as T memory type 1 (Tm1) cells, and review here the phenotypic and functional features of this subset of memory-phenotype CD8+ alphabeta T cells. In vitro studies suggest that inhibitory NKR are involved in the peripheral control of T-cell self-tolerance. In vitro and in vivo analysis have revealed a novel biological function for inhibitory NKR when expressed on T cells. Indeed, engagement of inhibitory NKR on T cells provides them with survival signals against activation-induced cell death. Thus, sensing of self-MHC class I molecules by inhibitory NKR displayed on alphabeta T cells leads to the in vivo accumulation of Tm1 cells.
authors.affiliation: Centre d'Immunologie de Marseille-Luminy, CNRS-INSERM-Univ. Med., Marseille, France.
authors.forename: N
authors.initials: N
authors.lastname: Anfossi
authors.forename: V
authors.initials: V
authors.lastname: Pascal
authors.forename: E
authors.initials: E
authors.lastname: Vivier
authors.forename: S
authors.initials: S
authors.lastname: Ugolini
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D002454:Cell Differentiation; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D007156:Immunologic Memory; D007694:Killer Cells, Natural / Q000276:immunology; D051379:Mice; D008954:Models, Biological; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D011971:Receptors, Immunologic / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D017634:Self Tolerance; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*
chemical_list: D015395:Histocompatibility Antigens Class I; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2