Interferon--secreting NK cells promote induction of dry eye disease

NK cells have been increasingly reported to be an im-portant effector in autoimmune diseases. However, nothing is known in this regard in DED, the most com-mon eye pathology, which is characterized by sus-tained inflammation on the ocular surface. In the pres-ent study, we have examined the profile of NK cells on the ocular surface as well as in the draining lymphoid tissues during the development of this disease. Our data demonstrate activated NK cells during the dis-ease-induction phase. Moreover, in vivo depletion of NK cells in mice results in reduced disease severity and diminished proinflammatory cytokines. Furthermore, we show that NK cells are also able to modulate the matu-ration of APCs, which is correlated with IFN- from NK cells. Together, our findings provide new in vivo evi-dence that IFN--secreting NK cells can promote induc-tion of DED via direct target tissue damage and indirect influence on the priming phase of an adaptive immune response in secondary lymphoid tissue. J. Leukoc. Biol. 89: 965–972; 2011