IMMUNOREGULATORY EFFECTS OF CYTOKINES ON NATURAL-KILLER-CELLS

Natural killer (NK) cells are able to kill tumour cells or virus-infec ted cells spontaneously and independent of classical MHC-restriction, The activities of these cells can be regulated by different cytokines. Interleukin-2 has been shown to be a potent stimulatory factor for NK cells, inducing proliferation, cytokine production and increased cyto toxic activity. During recent years, the influence of various cytokine s on NK cells have been studied, like interferons, IL-1, IL-6, IL-4 an d TGF-beta. Recently, new cytokines like IL-7 and IL-12 have been show n to possess direct and potent stimulatory effects on NK cells. Furthe rmore, endogenous production of TNF seems to play an important role in mediating effects induced by several stimulatory cytokines. Here, an overview of the different regulatory effects of these cytokines on NK cells are presented.