LYMPHOCYTE-T STIMULATION OF HUMAN SMALL INTESTINAL GLYCOPROTEIN-BIOSYNTHESIS - EFFECTS OF ANTI-CD3 ANTIBODY ON NORMAL AND CELIAC MUCOSA

The effects of mucosal T-cell activation on human small intestinal glycoprotein biosynthesis have been examined during short-term culture in vitro. The incorporation of H-3-glucosamine into tissue and secreted glycoproteins was determined. Activation of mucosal T lymphocytes of normal duodenal biopsies with the monoclonal anti-CD3 antibody significantly increased both the total glucosamine incorporation into glycoproteins (p < 0.01) and the secretion of in vitro radiolabelled glycoproteins (p < 0.001). This effect was inhibited by ciclosporin. Secretion of glycoproteins was also stimulated by culture with pokeweed mitogen. In patients with coeliac disease, culture of small intestinal biopsies with anti-CD3 antibody significantly increased (p < 0.05) glycoprotein biosynthesis in treated patients, but had no stimulatory effect in untreated patients with villous atrophy. These results show that activation of mucosal T lymphocytes induces quantitative changes in intestinal glycoprotein synthesis and secretion and T lymphocytes therefore have an important role in non-specific intestinal defences. The results are consistent with the suggestion that increased glycoprotein synthesis and secretion in untreated coeliac mucosa result from T-cell activation.