IMMUNOMODULATION OF EPITHELIUM

many studies have provided evidence that the immune system is a key re gulatory system of intestinal function. The interaction of immune cell s with the gut epithelium plays an important role in host defence, act ing to eliminate pathogens, antigens and other noxious material from t he lumen of the gastrointestinal tract. During inflammatory conditions of the gut, the mucosa becomes packed with immune cells in close prox imity to the enterocytes. mediators released from these cells have pro found effects on epithelial functions. The two main functions of the i ntestinal epithelium are to transport nutrients, ions and water, and t o act as a barrier to prevent unimpeded uptake of antigenic material a nd microbes from the lumen. Both these functions are altered by immune reactions in response to various stimuli. topics discussed include ma st cells and epithelial function; mast cell-nerve interaction; mast ce ll activation; neutrophils, eosinophils and macrophages; T cells; and prostaglandins and immune cell activation.