ISSN: 1305-385X
About: It is published as special issues.
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Nk And Nkt Cells
Dr. Günnur DENİZa
aİmmünoloji ABD, İstanbul Üniversitesi Deneysel Tıp Araştırma Enstitüsü, İSTANBUL
Bone marrow derived Natural Killer (NK) cells are large granular lymphocytes playing a role in the innate immunity. By contrast, T and B lymphocytes are important cells of the adaptive immune system. NK cells exert potent spontanous cytolytic activity against tumour cells and pathogens, and compose 15% of the peripheral lymphocytes. These cells can be found in peripheral tissues such as liver, peritoneal cavity and placenta. It has been shown that in vivo depletion of the NK cells, having killing capacity of certain tumour cells in vitro, give rise to increased tumour development in mice models. The existence of human NK1 and NK2 subsets, similar to T helper 1 (Th1) and Th2 cells, was also shown in in vivo and in vitro studies. Recent studies demonstrate that circulating NK cells can differentiate into effector NK cell subtypes with different cytokine profiles and gain various inflammatory properties. Although NK cells do not express CD3 antigens, cells expressing CD3 antigen and many of the NK cell receptors are called “NKT cells”. NKT cells are a cell subgroup sharing properties of NK and conventional T lymphocytes, playing regulatory roles in immediate immunity, tumour rejection, immune surveillance and autoimmune diseases. Many studies demonstrated the importance of NKT cells, which have effects in most pathological conditions, in the regulation of in vivo viral infections and control of tumour growth.Keywords: NK, NKT, KIR, KAR, cytotoxcity, cytokinesTurkiye Klinikleri J Int Med Sci 2007, 3(43):18-25
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