title: Triggering of natural killer cells by the costimulatory molecule CD80 (B7-1)
abstract: NK cell-mediated cytotoxicity is influenced by triggering as well as inhibitory signals. The identification of inhibitory signals provided by MHC class I molecules has recently attracted significant attention. Much less is known about putative triggering signals. Using purified populations of mouse NK cells, we demonstrate that the CD80 (B7-1) gene product functions as a triggering signal for NK cell-mediated cytotoxicity. The strength of this response is such that it overrides the protection mediated by MHC class I molecules. Triggering of mouse NK cells by B7-1 occurred even in the absence of CD28 and could not be blocked by either anti-CD28 or anti-CTLA-4 antibodies. NK cells may thus, at least in part, use receptors other than CD28 and CTLA-4 in their interaction with B7-1. Furthermore, we demonstrate that bone marrow-derived macrophages and dendritic cells are highly susceptible to lysis by autologous NK cells.
authors.affiliation: Microbiology and Tumor Biology Center, Karolinska Institute, Stockholm, Sweden.
authors.forename: B J
authors.initials: BJ
authors.lastname: Chambers
authors.forename: M
authors.initials: M
authors.lastname: Salcedo
authors.forename: H G
authors.initials: HG
authors.lastname: Ljunggren
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000276:immunology*; D001854:Bone Marrow Cells; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D051379:Mice; D015398:Signal Transduction
chemical_list: D018122:B7-1 Antigen; D015395:Histocompatibility Antigens Class I