cDCs have been long known to be specialized in antigen processing and presentation to naïve T cells leading to the induction of specific adaptive cellular immune responses. By contrast, until recently, pDCs had often been reported to be poor activators of naïve T cells, owing to their purported lower efficiency to take up, process and present exogenous antigens (reviewed in [117] ). However, detailed and kinetic analyses of the expression of MHC class I and II in DC subsets upon activation have shown contrasting responses of pDCs as compared to cDCs, suggesting that these cell types function in a distinct and complementary fashion for the induction and maintenance of adaptive cellular immune responses.