The dialogue between human natural killer cells and dendritic cells

The interaction of NK cells with dendritic cells (DCs) appears to play an important role in both innate and adaptive immune responses to pathogens. In peripheral inflamed tissues the simultaneous engagement of receptors for danger (e.g. Toll-like receptors), which are expressed by both NK cells and DCs, results in cell activation and the acquisition of functional properties necessary for controlling, and possibly rapidly eliminating, pathogens by innate effector mechanisms. Moreover, NK cells are needed to select the most appropriate DCs that display the functional properties suitable for subsequent T-cell priming. This NK-cell-mediated programming of DC maturation is modulated by cytokines released during the early stages of inflammatory responses (i.e. IL-12, IFN-γ, IL-4). NK cells and DCs continue their interactions in secondary lymphoid organs where both cell types play a role in the control of T-cell priming.