Dendritic cell subsets in primary and secondary T cell responses at body surfaces.

We examine the role of dendritic cells subsets in immunity to peripheral infections, with emphasis on the differences in the regulation of primary and secondary T cell responses to viruses. Our major focus is on new developments in the understanding of immunity to infections of the skin and lung, which are crucial entry points for a variety of infectious pathogens. Initially we describe a diverse network of dendritic cell subsets, but then we argue for a more generalized model of reduced complexity.