Mechanism and regulation of natural cytotoxicity. Minireview on cancer research.
Natural killer (NK) cells comprise a heterogeneous population of effector cells functionally and phenotypically distinct from B cells and mature antigen-sensitive T cells, with the capacity to spontaneously lyse target cells of widely different tissue provenance in a genetically unrestricted fashion. As such they have been widely implicated in immunosurveillance against neoplastic and virus-infected cells, as well as in the homeostasis of haematopoietic differentiation and regulation of immune function. In common with cytotoxic T cells, the lytic mechanism may be resolved into several discrete stages. Target cell recognition appears to involve several chemical entities, while susceptibility is also influenced by a multiplicity of factors operative at post-recognition stages of the lytic process. NK activity is subject to both positive and negative regulation. The potentiating effects of interferons and interleukin-2, products of activated T cells, indicate a possible pathway by which adaptive immune responses may augment natural cytotoxicity under local physiological conditions. Negative regulation is mediated by certain prostaglandins and a variety of cell types including macrophages, granulocytes and thymocytes as well as subsets of peripheral blood lymphocytes.
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Moore
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D000818:Animals; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007108:Immune Tolerance; D007113:Immunity, Innate; D007372:Interferons / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology*; D008247:Lysosomes / Q000201:enzymology; D010447:Peptide Hydrolases / Q000276:immunology; D011971:Receptors, Immunologic / Q000276:immunology
D011971:Receptors, Immunologic; D007372:Interferons; D010447:Peptide Hydrolases