American Journal of Clinical Nutrition, Vol 27, 1434-1440, Copyright © 1974 by The American Society for Clinical Nutrition, Inc.

Immunologic control of soluble protein absorption from the small intestine: a gut-surface phenomenon

¹ From The Gastrointestinal, Clinical Immunology and Arthritis Units of the Children's and Medical Services, Massachusetts General Hospital and the Departments of Pediatrics and Medicine, Harvard Medical School, Boston, Massachusetts 02114

The mechanism of antibody control of soluble antigen absorption has been studied. Evidence suggests that antigen uptake is inhibited after specific immunization. Based on the data presented, the following sequence of events may occur on the gut surface: initial exposure of gut sacs from immunized rats to soluble antigen in vitro leads to association of antigen with local antibodies on the mucosal surface; at this location, enhanced breakdown of antigen seems to occur. It seems likely that based on this mechanism, less antigen is available for transport from the mucosal to the serosal surface. Recent preliminary studies suggest that the site of antibody interference with antigen uptake may be within the mucous coat of the gut. These studies suggest that increased breakdown of antigen may account for the decrease in antigen uptake by the small intestine of immunized animals.