NK cells in innate immunity.

NK cells have an important role in innate immune responses, particularly in anti-viral immunity. Recent studies have revealed a molecular basis for NK cell recognition of virus-infected cells, implicating the activating KIR and Ly49 receptors and NKG2D in this process. Additionally, mutual cooperation between NK cells and dendritic cells suggests that these innate cells can shape the nature of an adaptive immune response. These findings, as well as advances in understanding NK cell development and homeostasis, indicate that NK cell biology is more sophisticated than previously appreciated.