Presence and anatomic location of species and organ-specific intestinal antigens.

Several groups of antigens were detected in the ileum of rabbits, rats, and guinea pigs. An antigen present in the cytoplasm of the epithelial cells is shared by these species, but is not tissue-specific because it can be absorbed by the liver. Organ-specific ileum antigens are present in the goblet cell mucus. There are different ileum-specific antigens in the three species and they do not elicit autoantibody formation. Additional antigens are located in the basement membrane and some basement membrane antigens are derived from exogenous sources.