Intestinal processing of soluble protein antigen

Food and environmental antigens entering the intestine are processed at several levels before interacting with class II molecules and, ultimately, with the antigen receptors of T cells which will regulate the appropriate immune response. Thus: intraluminal digestive enzymes; epithelial transcytosis mechanisms; lysosomal activity of lamina propria macrophages; and mechanisms acting downstream of the mucosa may all have a modifying effect.