The puzzle of intestinal lamina propria dendritic cells and macrophages.

A specialized network of immune cells is positioned directly in the mucosa of the intestinal tract. In this Viewpoint, we discuss the nature and function of DC and macrophages occupying the intestinal lamina propria of mice. DC and macrophages share phenotypic traits and functional plasticity, properties that preclude simple classification of the two cell types. Nevertheless, the information available appears to have reached "critical mass" to allow for a clear demarcation between intestinal macrophages and DC.