Scientists at Harvard Medical School have discovered that immune cells produced in the gut are involved in repairing damaged muscles and liver. Research published in the journal immunity.
Regulatory T cells (Treg) are highly specialized immune cells. They are found in various organs where they control local inflammation. Treg cells in the colon are essential to protect the body from food allergens, colon cancer and autoimmune conditions like colitis. Previous studies have shown that gut microbes control Treg production, but scientists believe it only affects the gut’s local immunity.
During routine work with immune cells in various organs, scientists found gut Tregs mixed with muscle cells. To find out how immune cells from the gut get into the muscles, the biologists tagged Treg with special light-emitting molecules in the mice’s colon. So they were able to follow the path of the Treg cells, starting in the gut. The scientists found that the cells migrated to other parts of the animal’s body, including the muscles and liver.
Other experiments showed that without these cells, damaged animal muscles healed much worse: a significant portion of healthy tissue was lost due to scarring. Scientists have also proven that destroying the intestinal microflora reduces the number of Treg cells. This highlights the importance of conscious use of antibiotics.
Treg cells are also involved in the immune response to fatty liver disease, a condition in which fat builds up in the liver and cells die. The scientists hope that their discovery will become the basis for the creation of drugs against skeletal muscle damage and fatty liver disease.