Mechanism of dc-mediated nk cell activation

The role of NK cells in anti-viral and anti-tumor immunity has been extensively studied, nevertheless the mechanisms involved in the activation of NK cells in an anti-bacterial remain to be fully understood. Recent studies have shown that activation of NK cells by various pathogens is indirect and is driven by accessory cells, particularly by DCs. (Cerwenka and Lanier 2001, Newman and Riley 2007). We have studied how DC can activate NK cells in the presence of LPS, the main component of the Gram-negative cell wall, which is recognized by TLR-4 (Akira 2006). We decided to focus our attention primerely on the production of IFN-γ by NK cells because their anti-bacterial effects are mainly mediated by this cytokine (Boehm, Klamp et al. 1997). Here we show the molecular mechanisms underlying the activation of NK cells mediated by DC (in vitro and in vivo) upon LPS exposure.