First described in 1973 by Ralf Steinman, dendritic cells have since attracted considerable attention. Their properties of antigen capture, presentation and T cell activation, place them both as a key bridge between the innate and adaptive immunity, as well as a switch between tolerance and immunity. Although, the human and mouse DC network share many similarities, one subset was discovered in mouse that had not yet found its equivalent in human: the CD8+ DC characterised by their ability produce IL-12, but most particularly to uptake dead cells and “cross-present” these exogenous antigens on MHC class I molecules. This function has been shown to be essential in the immune defense against many viruses, intracellular bacteria and tumors as well as for the maintenance of self tolerance. Four studies in J. Exp. Med provide insight into a potential human homologue to the mouse cross-presentation specialist CD8+ DC
A nice minireview from two DC experts: Villadangos and Shortman