Intestinal macrophages and dendritic cells: what's the difference?

Mononuclear phagocytes (MPs) in the murine intestine, comprising dendritic cells (DCs) and macrophages (M phi s), perform disparate yet complementary immunological functions. Functional analyses of these distinct MP subsets have been complicated by the substantial overlap in their surface phenotypes. Here, we review recent findings that have enabled more accurate definition of these MP subsets. We discuss these recent advances in the context of the current understanding of the functions of DCs and M phi s in the maintenance of intestinal homeostasis, and how their functions may alter when homeostasis is disrupted.