There is a cell population that controls an excessive immune response in the large intestine, and regulatory T cells (Treg) are known as cells that play a central role in this population.Ulcerative colitis (UC) is one of the inflammatory bowel diseases caused by this Treg deficiency or dysfunction.It is an intractable disease of unknown cause with persistent / recurrent diarrhea / mucous stool / abdominal pain as the main symptoms and repeated rebound remission, and is increasing mainly among young people.The main focus is on treatments that suppress the activation of the immune response, but there are many cases in which none of these treatments are ineffective or cannot be used due to side effects.

　Therefore, the research group focused on the crude drug "Qingdao", which has been used as a folk remedy for various chronic inflammatory diseases in China for a long time. Although effective for UC patients, the mechanism of inflammation suppression was unclear.

　In a mouse study, Qingdao suppressed inflammation of the intestinal tract and increased Tregs expressing genes characteristic of the large intestine.An increase in Treg was also confirmed in the rectal mucosal tissue of patients taking Qingdao.It was revealed that Qingdao suppresses inflammation by inducing Tregs directly under the intestinal epithelium through intestinal epithelial cells in mice and humans.

　It is still unclear which component of Aomori is involved in this effect, and serious side effects of long-term administration of Aomori have also been reported.In the future, it is expected that detailed elucidation of the epithelial repair mechanism will lead to a new treatment method that is different from the conventional treatment for ulcerative colitis by immunosuppression.

Paper information:[Cell Reports] Aryl hydrocarbon receptor signals in epithelial cells govern the recruitment and location of Helios + Tregs in the gut