title: Innate or adaptive immunity? The example of natural killer cells.
abstract: Natural killer (NK) cells were originally defined as effector lymphocytes of innate immunity endowed with constitutive cytolytic functions. More recently, a more nuanced view of NK cells has emerged. NK cells are now recognized to express a repertoire of activating and inhibitory receptors that is calibrated to ensure self-tolerance while allowing efficacy against assaults such as viral infection and tumor development. Moreover, NK cells do not react in an invariant manner but rather adapt to their environment. Finally, recent studies have unveiled that NK cells can also mount a form of antigen-specific immunologic memory. NK cells thus exert sophisticated biological functions that are attributes of both innate and adaptive immunity, blurring the functional borders between these two arms of the immune response.
authors.affiliation: Centre d'Immunologie de Marseille-Luminy (CIML), Université de la Méditerranée UM 631, Campus de Luminy, 13288 Marseille, France. vivier@ciml.univ-mrs.fr
authors.forename: Eric
authors.initials: E
authors.lastname: Vivier
authors.forename: David H
authors.initials: DH
authors.lastname: Raulet
authors.forename: Alessandro
authors.initials: A
authors.lastname: Moretta
authors.forename: Michael A
authors.initials: MA
authors.lastname: Caligiuri
authors.forename: Laurence
authors.initials: L
authors.lastname: Zitvogel
authors.forename: Lewis L
authors.initials: LL
authors.lastname: Lanier
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Yokoyama
authors.forename: Sophie
authors.initials: S
authors.lastname: Ugolini
mesh_terms: D056704:Adaptive Immunity; D000818:Animals; D006801:Humans; D007113:Immunity, Innate; D007156:Immunologic Memory; D007694:Killer Cells, Natural / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology / Q000628:therapy; D011971:Receptors, Immunologic / Q000276:immunology / Q000378:metabolism; D017634:Self Tolerance; D014777:Virus Diseases / Q000276:immunology
chemical_list: D011971:Receptors, Immunologic