Preliminary studies on NADPH oxidase mediated bacterial killing by splenic dendritic cells

Dendritic cells (DCs) continuously scavenge their environment to capture invading pathogens for presentation to T cells. To increase the antigen presentation potential, DCs are equipped with several mechanisms that reduce antigen degradation. Alkalization of the endosomal and phagosomal compartments by reactive oxygen species (ROS) produced by NADPH oxidases is one of these mechanisms. In neutrophils, the respiratory burst mediated by NADPH oxidase results in effective bacterial killing, but whether DCs also eliminate bacteria via NADPH oxidase activity is not clear. Here we show that murine splenic DC subsets differentially express NADPH oxidase subunits and differentially produce ROS. Furthermore, preliminary data indicate that killing of Salmonella typhimurium by DCs is dependent on NADPH oxidase activity. These results suggest that DCs may utilize NADPH oxidase activity to eliminate phagocytosed bacteria.