title: Natural killer cells and their receptors.
abstract: Natural killer (NK) cells have been known for a long time to be a very important component of the innate immune system. However, it is only during the last 10 years that knowledge of their receptors has emerged. Described in the present review are those receptor families killer inhibitory receptor (KIR) (belonging to the immunoglobulin superfamily), and killer lectin like receptor (KLR) CD94/NKG2, that both use HLA as a ligand and have inhibiting and activating types of receptors, and natural cytotoxic receptors (NCR) which do not associate with HLA. Association of the receptor gives rise to either an inhibiting or activating signal leading to either failure or success in lysing a target cell. The KIR receptors are very polymorphic both in the number of genes expressed in an individual and the alleles present for a gene. They would appear to have had a rapid evolution compared to the CD94/NKG2 receptors. The roles that NK cells and their receptors have with various facets of transplantation, disease, pregnancy and control of virus infection in humans are described.
authors.affiliation: Northern Ireland Regional Histocompatibility and Immunogenetics Laboratory, Belfast City Hospital, Belfast, UK. derek.middleton@bll.n-i.nhs.uk
authors.forename: Derek
authors.initials: D
authors.lastname: Middleton
authors.forename: Martin
authors.initials: M
authors.lastname: Curran
authors.forename: Lynne
authors.initials: L
authors.lastname: Maxwell
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics; D003602:Cytotoxicity, Immunologic; D019143:Evolution, Molecular; D005260:Female; D006680:HLA Antigens / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D015979:Killer Cells, Lymphokine-Activated / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type / Q000276:immunology; D008024:Ligands; D008213:Lymphocyte Activation; D051379:Mice; D008958:Models, Molecular; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011247:Pregnancy; D011487:Protein Conformation; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology*; D054340:Receptors, KIR; D055607:Receptors, Natural Killer Cell; D014181:Transplantation Immunology; D000097625:HLA-E Antigens
chemical_list: D015703:Antigens, CD; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; D037181:Lectins, C-Type; D008024:Ligands; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D055607:Receptors, Natural Killer Cell; D000097625:HLA-E Antigens; C527054:KLRC1 protein, human; C497869:KLRD1 protein, human; C497870:Klrd1 protein, mouse