Cytokine Induction in Experimental and Ulcerative Colitis

Abstract

In order to delineate the role of cytokines in inflammatory bowel disease, we studied induction of these mediators in an acetic acid-induced rat model for colitis. In this model, IL-1β mRNA induction was detected early after induction of acute colitis. Using in situ hybridization techniques, enterocytes were identified as the predominant source of IL-1β mRNA. TNFα mRNA was detected with in situ hybridization in cells located in the lamina propria and in the submucosa. Immunofluorescent techniques showed cells with the same localisation producing TNFα protein. Cultured human colon biopsies from patients with ulcerative colitis secreted large amounts of interleukin-1 but only modest quantities of tumor necrosis factor. Thus, interleukin-1 is synthesized in experimental as well as ulcerative colitis, and may be causally related to its pathogenesis. These findings open new possibilities for development of intervention strategies in ulcerative colitis.