动物实验,刮伤皮肤 z-bo 2020-11-23 348

　　According to research conducted in mice, scratching the skin triggers a series of immune responses, which ultimately leads to more activated mast cells-immune cells involved in allergic reactions-in the small intestine. This newly discovered skin-intestinal communication helps clarify the relationship between food allergies and atopic dermatitis (a type of eczema), a disease characterized by dry, itchy skin. The research was supported by the National Institute of Allergy and Infectious Diseases (NIAID), which is part of the National Institutes of Health and led by researchers at Boston Children's Hospital.

　　Atopic dermatitis is a strong risk factor for food allergy, but the exact relationship between the two conditions remains unclear. Since itching is the main symptom of atopic dermatitis, people with this disease, especially babies, often scratch their skin. Current research suggests that scraping the skin causes the expansion of intestinal mast cells.

　　Researchers have discovered that some cells in the skin respond to scratches-mimicking by smearing and removing small strips on mouse skin-by producing a cell signaling protein called IL-33 into the blood. When IL-33 reaches the intestine, it acts synergistically with IL-25, which is a protein secreted by cells in the lining of the intestine to activate type 2 innate lymphoid cells (ILC2s). Activated ILC2 produces two additional cell signaling proteins, IL-13 and IL-4, which have been found to be responsible for the expansion of intestinal mast cells.

　　Researchers also found that as mast cells expand, the lining of the intestine becomes more permeable, making it easier for allergens to enter the tissues. It is worth noting that the mice that received the tape stripping had a more severe reaction to food allergens than the mice that had not been exposed. Finally, the researchers found that the intestinal biopsies of four children with atopic dermatitis contained more mast cells than the four unaffected children.

　　Although more work is needed to determine the relevance of the research results to humans, the researchers believe that interventions that limit itching may reduce the severity of food allergies in patients with atopic dermatitis.