AHR signaling in the development and function of intestinal immune cells and beyond.

The intestinal immune system is challenged daily with the task of recognizing and eliminating pathogens while simultaneously tolerating dietary and commensal antigens. All components must effectively coordinate to differentiate a continual barrage of environmental cues and mount appropriate responses dependent on the nature of the stimuli encountered. Playing a pivotal role, the aryl hydrocarbon receptor (AHR) is a chemical sensor that detects both dietary and microbial cues and is important for development, maintenance, and function of several types of intestinal immune cells, particularly innate lymphoid cells (ILCs) and T cells. In this review, we will highlight recent advances in our knowledge of the role of AHR signaling in ILCs, T cells, B cells, and dendritic cells.