Intestinal antigen handling at mucosal surfaces in health and disease: human and experimental studies

Intestinal uptake of antigenically intact food proteins was measured by a solid phase radioimmunoassay on serum samples after instillation of food proteins into a closed intestinal loop of adult Wistar rats. Compared to normal controls, rats fed protein deficient diets during five months had a higher macromolecular uptake. During the course of Nippostrongylus brasiliensis infection this uptake was decreased. In cholera toxin induced secretory states of the intestinal mucosa uptake of food proteins was increased. In human studies the uptake of Beta-Lactoglobulin after a milk meal was shown to be increased in premature compared to full-term neonates. In children suffering from intestinal helminth infection the macromolecular uptake was higher before treatment compared to that after treatment. These studies show that various pathological situations can alter the antigen handling at mucosal surfaces.