IL-18在结肠炎小鼠结肠粘膜中的表达及作用探讨

目的 研究白细胞介素18（IL-18）在小鼠葡聚糖硫酸钠（DSS）结肠炎结肠粘膜中的表达及作用。方法 免疫组化染色检测IL-18在小鼠DSS结肠炎中的表达。ELISA检测DSS结肠炎结肠上皮细胞（IEC）裂解液或培养上清液对脾单个核细胞（SMC）IL-2、IFN-γ分泌的作用。Western Blot检测IEC裂解液或培养上清液中IL-18的表达。结果 DSS结肠炎IEC及部分固有膜单个核细胞表达IL-18。刺激实验及Western Blot显示IEC裂解液或培养上清液中均含IL-18阳性蛋白，IL-18诱导IFN-γ的产生。结论 DSS结肠炎IEC表达和分泌前体IL-18及活性IL-18，可能在DSS结肠炎的发病中起重要作用。

Expression and Function of Interleukin-18 in Mouse Dextran Sulfate Sodium Colitis

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.