共刺激分子B7-H1和受体PD-1在溃疡性结肠炎患者结肠黏膜中的表达及意义

摘要

目的 研究共刺激分子B7-H1和受体PD-1在溃疡性结肠炎患者结肠黏膜中的表达,探讨二者在结肠黏膜炎症反应中的作用及意义.方法 收集溃疡性结肠炎患者45例及正常对照者10例,结肠镜下活检结肠黏膜行免疫组织化学染色,检测结肠黏膜中B7-H1和PD-1的表达,以阳性细胞的累积光密度值(IOD值)为评价指标,比较各组差异.结果 B7-H1和PD-1主要在结肠黏膜固有层单个核细胞中表达.UC活动期患者炎症最重部位及炎症不明显部位、UC缓解期患者原炎症部位B7-H1和PD-1的表达强度(IOD值)均明显高于正常对照组.其中B7-H1表达强度最高的为UC活动期患者炎症最重部位,其后依次为UC活动期患者炎症不明显部位和UC缓解期患者原炎症部位,各组间比较差异均有统计学意义(P<0.05);PD-1表达强度最高的为UC活动期患者炎症不明显部位,其后依次为UC活动期患者炎症最重部位和UC缓解期患者原炎症部位,各组间比较差异均有统计学意义(P<0.05).结论 UC患者结肠黏膜中B7-H1和受体PD-1表达上调,且表达水平与炎症程度有关,提示二者参与了肠道的炎症反应.%Objective To investigate the expression of co-stimulators of B7-H1 and PD-1 in colon mucosa of patients with ulcerative colitis and explore their roles in intestinal inflammatory responses.Methods Biopsy specimens of colon mucosa were obtained from 45 patients with UC and 10 healthy adults who underwent colonoscopy.Immunohistochemistry technique was employed to detect the expression of B7-H1 and PD-1 in colon mucosa, and the intensity was evaluated by integrated optical density (IOD) in positive cells of each specimen.Results B7-H1 and PD-1 were mostly localized in lamina propria mononuclear cells.The expression of B7-H1 and PD-1 significantly enhanced in colonic mucosa of patients with UC in active stage ( including mucosa with severe inflammation and without obvious inflammation)and colonic mucosa (which was the original sites of lesion in active stage) of patients with UC in remission, compared with healthy controls.The expression of B7-H1 was highest in colonic mucosa with severe inflammation of patients with UC in active stage, followed by colonic mucosa without obvious inflammation of patients with UC in active stage and then mucosa ( which was the original sites of lesion in active stage) of patients with UC in remission (P ＜ 0.05 ).While the expression of PD-1 was highest in colonic mucosa without obvious inflammation of patients with UC in active stage, followed by colonic mucosa with severe inflammation of patients with UC in active stage and then mucosa ( which was the original sites of lesion in active stage) of patients with UC in remission (P ＜ 0.05).Conclusion The expression of costimulators of B7-H1 and PD-1 are up-regulated in colon mucosa of ulcerative colitis, and the intensity is correlated with the severity of UC, which demonstrates B7-H1 and PD-1 may participate in intestinal inflammatory responses.