ENHANCED CD3 MONOCLONAL-ANTIBODY INDUCED PROLIFERATION OF COLONIC MUCOSAL T-LYMPHOCYTES IN CROHNS-DISEASE PATIENTS FREE OF CORTICOSTEROID OR IMMUNOSUPPRESSOR TREATMENT

Mucosal lymphocytes are increasingly activated in Crohn's disease. In order to investigate this phenomenon we tested the response of culture d colonic mucosal T lymphocytes to CD3 activation. These lymphocytes w ere obtained by biopsy from control subjects and Crohn's disease patie nts. T cells from mucosa involved in Crohn's disease showed a higher C D3-induced proliferative response compared to control T lymphocytes (P < 0.01). T cells from uninvolved areas showed a wide range of respons e, ranging from normal to very high proliferative indices. Our results suggest that the exaggerated response of mucosal T lymphocytes, due t o the impairment of the downregulation of the CD3-dependent signaling process, may contribute to the pathogenesis of Crohn's disease. (C) 19 96 Academic Press Inc.