The genetic and evolutionary balances in human NK cell receptor diversity.
In primates and cattle two ancient killer-cell immunoglobulin-like receptor (KIR) lineages independently evolved to become diverse NK cell receptors. In mice, KIR genes were sidelined to the X chromosome, a possible consequence of pathogen-mediated selection on the receptor for IgA-Fc. In humans, KIR uniquely form two omnipresent haplotype groups (A and B), postulated here to play complementary and necessary roles in immune defense and reproduction. The basis of KIR3DL1/S1 polymorphism is three ancient lineages maintained by long-term balancing selection and present in all human populations. Conserved and variable NK cell receptors produce structurally diverse NK cell receptor repertoires within a defined range of missing-self-response.
Parham
Peter
P
Department of Structural Biology, Stanford University School of Medicine, 299 Campus Drive West, Stanford, CA 94305, USA. peropa@stanford.edu
D000818:Animals; D015703:Antigens, CD / Q000502:physiology; D019143:Evolution, Molecular; D014644:Genetic Variation / Q000276:immunology; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D011961:Receptors, Fc / Q000502:physiology; D054340:Receptors, KIR / Q000502:physiology; D054341:Receptors, KIR3DL1 / Q000502:physiology; D055607:Receptors, Natural Killer Cell / Q000235:genetics* / Q000276:immunology*; D012098:Reproduction / Q000502:physiology
D015703:Antigens, CD; C036832:Fc(alpha) receptor; D011961:Receptors, Fc; D054340:Receptors, KIR; D054341:Receptors, KIR3DL1; D055607:Receptors, Natural Killer Cell