RESUMO
OBJECTIVE: Interleukin-18 (IL-18) is a proinflammatory cytokine that induces Th1 cytokines production and may play a role in the pathogenesis of inflammatory bowel diseases. This study was aimed at detecting the expression and role of IL-18 in colonic mucosa of dextran sulfate sodium (DSS) colitic mice. METHODS: Expression of IL-18 in colon of DSS colitis was determined by immunohistochemistry. Extract and supernatant of intestinal epithelial cells (IEC) from colon of DSS colitis mice were used to stimulate splenic mononuclear cells (SMC); IFN-gamma and IL-2 concentrations in supernatant of SMC were measured by ELISA. The levels of expression of IL-18 in extract or supernatant of IEC were examined by Western blot. RESULTS: Colon epithelial cells and part of lamina propria mononuclear cells were stained positive for IL-18 antibody. Stimulation assay and Western blot indicated that IL-18 positive proteins were present in both IEC extract and supernatant. CONCLUSION: Colon epithelial cells in mice with DSS colitis express and secret pro IL-18 and active IL-18.
