title: Ly49A expression on T cells alters T cell selection.
abstract: Ly49 receptors are inhibitory receptors expressed on subsets of both NK cells and NK1.1(+) T cells. The function of these receptors on NK cells is believed to be important in maintaining self-tolerance, yet their role on T cells is unclear. In this report we investigated how an Ly49A transgene alters T and NK cell development in an in vivo environment, where a ligand for Ly49A is expressed. Ly49A transgenic mice that co-expressed an MHC ligand for Ly49A, H-2D(d), developed a severe inflammatory disorder that resulted in death within the first weeks of age. T cells expressing forbidden TCR V(beta) chains were found both in the thymus and periphery of transgenic mice, while non-transgenic littermates had successfully deleted these T cell subsets. These data indicate that the expression of Ly49A on T cells could alter T cell selection and allow survival of potentially self-reactive T cells.
authors.affiliation: Umeå Center for Molecular Pathogenesis and Department of Pathology, Umeå University, 901 87 Umeå, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Fahlén
authors.forename: L
authors.initials: L
authors.lastname: Oberg
authors.forename: T
authors.initials: T
authors.lastname: Brännström
authors.forename: N K
authors.initials: NK
authors.lastname: Khoo
authors.forename: U
authors.initials: U
authors.lastname: Lendahl
authors.forename: C L
authors.initials: CL
authors.lastname: Sentman
mesh_terms: D000818:Animals; D000950:Antigens, Ly; D006183:H-2 Antigens / Q000276:immunology / Q000378:metabolism; D064532:Histocompatibility Antigen H-2D; D007249:Inflammation / Q000276:immunology / Q000473:pathology; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008099:Liver / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009206:Myocardium / Q000473:pathology; D055650:NK Cell Lectin-Like Receptor Subfamily A; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000502:physiology*; D055630:Receptors, NK Cell Lectin-Like; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology; D019076:Transgenes
chemical_list: D000950:Antigens, Ly; D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; C527088:Klra1 protein, mouse; D037181:Lectins, C-Type; D055650:NK Cell Lectin-Like Receptor Subfamily A; D016693:Receptors, Antigen, T-Cell, alpha-beta; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like