Send to

Choose Destination
Immunity. 2018 Dec 18;49(6):1103-1115.e6. doi: 10.1016/j.immuni.2018.11.018.

Commensals Suppress Intestinal Epithelial Cell Retinoic Acid Synthesis to Regulate Interleukin-22 Activity and Prevent Microbial Dysbiosis.

Author information

Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA.
Department of Pharmaceutics, University of Washington, Seattle, WA 98195, USA.
Molecular Microbiology and Immunology, Brown University, Providence, RI 02912, USA. Electronic address:


Retinoic acid (RA), a vitamin A metabolite, regulates transcriptional programs that drive protective or pathogenic immune responses in the intestine, in a manner dependent on RA concentration. Vitamin A is obtained from diet and is metabolized by intestinal epithelial cells (IECs), which operate in intimate association with microbes and immune cells. Here we found that commensal bacteria belonging to class Clostridia modulate RA concentration in the gut by suppressing the expression of retinol dehydrogenase 7 (Rdh7) in IECs. Rdh7 expression and associated RA amounts were lower in the intestinal tissue of conventional mice, as compared to germ-free mice. Deletion of Rdh7 in IECs diminished RA signaling in immune cells, reduced the IL-22-dependent antimicrobial response, and enhanced resistance to colonization by Salmonella Typhimurium. Our findings define a regulatory circuit wherein bacterial regulation of IEC-intrinsic RA synthesis protects microbial communities in the gut from excessive immune activity, achieving a balance that prevents colonization by enteric pathogens.


IECs; IL-22; RA-signaling; Rdh7; antimicrobials; colonization resistance; commensal; dysbiosis; retinoic acid; vitamin A

[Available on 2019-12-18]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center