Inhibition of autoimmune T cell responses in the DA rat by bone marrow-derived NK cells in vitro: implications for autoimmunity.

Regulation of the immune response is critical to homeostasis. While innate immunity can influence the development of adaptive immune responses, its role in regulation is less well understood. Recently, NK cells have been implicated in the control of experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis. In this report, we show that rat bone marrow-derived NK cells exhibited potent inhibitory effects on T cell proliferation to both Con A as well as the central nervous system Ag myelin basic protein. There was also a significant decrease in both IFN-gamma and IL-10 production in vitro, whereas levels of the beta-chemokine monocyte chemoattractant protein-1 were significantly elevated. Flow cytometry studies suggest that the NK cells may play an important role in regulating both normal and autoimmune T cell responses by exerting a direct effect on activated, autoantigen-specific T cells.