INTESTINAL EPITHELIAL-CELLS EXPRESS THE CD23 FC-EPSILON-RII MOLECULE - ENHANCED EXPRESSION IN ENTEROPATHIES/

Immunohistochemical analysis of normal human intestine revealed that t wo anti-CD23 monoclonal antibodies (mAb), EBVCS 1 and EBVCS 2, reacted with human intestinal epithelial cells. Both mAb exhibited an exclusi ve reactivity with epithelial cells of the small and large bowels. Sta ining with both EBVCS 1 and EBVCS 2 was localized on the apical and ba sal sides of enterocytes. Enhanced expression of CD23 on gut epithelia l cells was found in inflammatory bowel diseases, in children with foo d intolerance to cows' milk proteins and in a young infant with severe autoimmune enteropathy. Western blot analysis of anti-CD23 mAb reacti vity with gut epithelial cell extracts showed the presence of a non-re ducible 42,000-45,000 M(r) polypeptide compatible with the membrane fo rm of the intact CD23 molecule. These data show that CD23 is constitut ively expressed by intestinal epithelial cells and that its expression is enhanced in enteropathies.