Natural killer cells: versatile roles in autoimmune and infectious diseases.
Natural killer (NK) cells are essential members of innate immunity and they rapidly respond to a variety of insults via cytokine secretion and cytolytic activity. Effector functions of NK cells form an important first line of innate immunity against viral, bacterial and parasitic infections, as well as an important bridge for the activation of adaptive immune responses. The control of NK-cell activation and killing is now understood to be a highly complex system of diverse inhibitory and activatory receptor-ligand interactions, sensing changes in MHC expression. NK cells have a functional role in innate immunity as the primary source of NK-cell-derived immunoregulatory cytokines, which have been identified in target organs of patients suffering from autoimmune diseases, and play a critical role in early defense against infectious agents. This review focuses on recent research of NK cells, summarizing their potential immunoregulatory role in modulating autoimmunity and infectious diseases.
Aktas
Esin
E
Department of Immunology, Institute of Experimental Medicine (DETAE), Istanbul University, 34393 Istanbul, Turkey. esinaktas@yahoo.com
Erten
Gaye
G
Kucuksezer
Umut Can
UC
Deniz
Gunnur
G