title: Natural killer lymphocytes: "null cells" no more.
abstract: Natural Killer (NK) lymphocytes were initially described as potent effector cells that, unlike T lymphocytes, were able to kill targets in the absence of a priori stimulation and without specific recognition mechanisms. Over the past ten years however, it has been clearly demonstrated that NK cell function is regulated by a number of surface receptors that bind specific ligands expressed by target cells. Some of these receptors display inhibitory functions and recognize MHC class I molecules expressed by normal autologous cells that, as a consequence, are spared from indiscriminate NK-mediated killing. Other receptors are involved in NK cell activation against allogeneic cells or cells that, upon viral infection or tumor transformation, down-regulate MHC Class I expression. Altogether these data provide important advances toward the understanding of the complexity of the molecular mechanisms that regulate NK-mediated functions.
authors: Dipartimento di Medicina Sperimentale, Sezione di Istologia, Università di Genova, Italy. alemoret@unige.it
authors: A
authors: A
authors: Moretta
authors: C
authors: C
authors: Bottino
authors: S
authors: S
authors: Sivori
authors: E
authors: E
authors: Marcenaro
authors: R
authors: R
authors: Castriconi
authors: M
authors: M
authors: Della Chiesa
authors: S
authors: S
authors: Carlomagno
authors: R
authors: R
authors: Augugliaro
authors: M
authors: M
authors: Nanni
authors: M
authors: M
authors: Vitale
authors: R
authors: R
authors: Millo
mesh_terms: D003602:Cytotoxicity, Immunologic; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D011971:Receptors, Immunologic / Q000276:immunology
chemical_list: D011971:Receptors, Immunologic