CD16 cross-linking induces increased expression of CD56 and production of IL-12 in peripheral NK cells

Abstract

Human NK cells are classified into two populations according to the intensity of CD56 surface expression, as well as possession of CD16, FcRIII. CD56(dim)CD16(bright) make up 90% circulating NK cells, whereas CD56(bright)CD16(-/dim) comprises the remaining 10%. Here we report that peripheral NK cells upon CD16 cross-linking up-regulates the expression of activating markers and receptors such as CD25, CD69, NKp44, NKp30, CD40L and the intensity of CD56 expression. Additionally, co-culturing immature DCs with CD16 activated NK cells was found to significantly increase the expression of maturation markers on DCs. These results suggest that CD16 cross-linking on resting peripheral blood NK cells triggers the activation of these cells and induces the appearance of CD56(bright) NK cells. The latter were found capable of producing pro-inflammatory cytokines, IFN-gamma and TNF-alpha and notably IL-12.