The aryl hydrocarbon receptor (AhR) ligand VAF347 selectively acts on monocytes and naïve CD4(+) Th cells to promote the development of IL-22-secreting Th cells.

The low molecular weight compound VAF347, and its pro-drug version VAG539, interact with the transcription factor aryl hydrocarbon receptor (AhR) on monocytes to mediate its anti-inflammatory activity in vitro and in vivo. AhR is a crucial factor for IL-22 production, which regulates skin and gut homeostasis. Here we investigated whether VAF347 might control the differentiation of naïve T cells into IL-22-secreting cells and/or regulate IL-22 production by memory T cells.