脓毒症大鼠肠系膜淋巴结细胞免疫功能的变化

目的 探讨脓毒症大鼠肠系膜淋巴结细胞免疫功能的变化.方法 雄性Wistar大鼠96只,体重200～250 g,随机分为假手术组(S组)和盲肠结扎穿孔致脓毒症组(CLP组),每组48只.分别于CLP后即刻、6、12、24、48、72 h(T_(1～5))时随机取8只大鼠抽取腹主动脉血,采用鲎试剂偶氮显色法测定血浆内毒素水平;取肠系膜淋巴结组织,流式细胞仪测定肠系膜淋巴结组织Th1/Th2比值和调节性T淋巴细胞(Treg)占CD4~+细胞的比例(Treg比例).结果 与S组比较,CLP组T_(2～5)时血浆内毒素水平升高,T_1时Th1/Th2比值升高,Treg比例降低,T_(2～5)时Th1/Th2比值降低,Treg比例升高(P<0.05或0.01);Th1/Th2比值与Treg比例呈负相关(r=-0.87,P<0.05).结论 脓毒症大鼠肠系膜淋巴结细胞免疫功能降低,其机制可能与肠源性内毒素介导Treg比例增加有关.

Variation in immune state of mesenteric lymph node induced by intra-abdominal infection in sepsis rats

Objective To investigate the variation in the immune state of mesenteric lymph node (MLN) during intra-abdominal infection in sepsis rats. Methods Ninety-six male Wistar rats weighing 200-250 g were randomly divided into 2 groups (n = 48 each): sham operation group and intra-abdominal infection group. Intra-abdominal infection was induced by cecum ligation and puncture (CLP). Eight rats in each group were killed after collection of blood and MLN samples at 0 (T_0), 6 (T_1), 12 (T_2), 24 (T_3),48 (T_4) and 72 h (T_5) after CLP. Plasma concentrations of endotoxin were detected. The ratio of T helper cells 1/T helper cells 2 (Th1/Th2) and the percentage of regulatory T cells (Treg) in CD4~+ T cells in MLN were determined by flow cytometry. Results The levels of endotoxin were significantly higher at T_2, T_3, T_4 and T_5 in group CLP than in sham operation group. The ratios of Th1/Th2 were significantly higher at T_1 and lower at T_2,T_3,T_4 and T_5 in group CLP than in sham operation group, while the percentage of Treg in CD4~+ T cells was significantly lower at T_1 and higher at T_2, T_3, T_4 and T_5 in group CLP than in sham operation group. There was a negative correlation between the ratio of Th1/Th2 and the percentage of Treg (r=-0.87, P<0.05). Conclusion Cellular immune function of MLN is suppressed during intra-abdominal infection by increasing the percentage of Treg in MLN.