Purpose of review: The intestinal immune system is constantly exposed to foreign antigens, which for the most part should be tolerated, but the immune system retains the ability to react rapidly and effectively to eliminate pathogens. Dendritic cells are at the front line in maintaining intestinal integrity as they are widely distributed within the intestinal lamina propria, Peyer's patches and mesenteric lymph nodes.
Recent findings: The identification of dendritic cell subsets and phenotypic markers within the healthy and diseased intestine has progressed significantly, including improved identification of dendritic cell subsets within the human intestine. Recently, the role for dietary factors and the microbiome in modulating the intestinal dendritic cell functions has begun to be better investigated, resulting in a number of new findings relating to retinoic acid metabolism, pattern recognition receptor triggering and G-protein-coupled receptor activation. In addition, the interactions between goblet cells and mucin with intestinal dendritic cells are being better defined.
Summary: In this review, we discuss the recent findings relating to intestinal dendritic cells, in particular the importance of dendritic cells in sensing the intestinal microenvironment and the consequences for health and disease.