中文摘要：

目的探讨脓毒症大鼠CD4^＋CD25^＋调节性T细胞（Treg）凋亡对辅助性T细胞（Th）漂移的影响及血必净注射液的干预作用。方法将Wistar大鼠随机分为正常组、假手术组、模型组、血必净组，每组8只。行盲肠结扎穿孔术（CLP）制备脓毒症大鼠模型。于第3日采用免疫磁珠法分选各组CD4^＋CD25^＋Treg并培养12h，用流式细胞仪检测Treg凋亡率及叉头翼状螺旋转录因子（Foxp3）和T淋巴细胞毒性相关抗原4（CTLA-4）的表达，用酶联免疫吸附法（ELISA）检测白细胞介素-10（IL-10）的分泌量；再将CD4^＋CD25^＋Treg与CD4^＋CD25^-T细胞1：1共培养，刀豆素A刺激68h，ELISA检测Th1、Th2、Th17分泌的γ-干扰素（IFN-γ）、IL-4、IL-17水平。结果正常组Treg凋亡率[（12．03±0．89）%]与假手术组[（9．48±2．17）％]比较差异无统计学意义；模型组Treg凋亡率[（5．87±0．44）％]明显低于正常组和假手术组；而血必净组的Treg凋亡率[（27．29±2．48）％]显著高于其他各组（P均〈0．01）。Foxp3、CTLA-4表达和IL-10分泌量随Treg凋亡率增加而减少，相关系数（τ）分别为-0．878（P-0．042）、-0．877（P-0．042）、-0．743（P-0．010）。与正常组比较，模型组IFN-γ、IL-4水平和IFN—γ／IL-4比值均明显升高（IFN-γ：（254．70±44．88）ng／L比（0．68±0．78）ng／L，IL-4：（8．82±0．61）ng／L比（3．48±0．98）ng／L，IFN—γ／IL-4比值：30．28±4．87比0．23±0．30，P均〈0．013；而血必净组IFN-γ[（491．54±84．28）ng／L3和IFN-γ／IL-4比值（45．31±8．01）均显著高于模型组（P〈0．01和P〈0．05）；各组间IL-17水平无明显差异（P均〉0．05）。结论脓毒症时Treg凋亡率增加可减轻对效应T细胞的抑制功能，血必净注射液能有效促进脓毒症Treg凋亡，介导Th2向Th1漂移。

英文摘要：

Objective To evaluate the influence of apoptosis of CD4^＋CD25^＋ regulatory T lymphocyte （Treg） on polarization of helper T lymphocyte （Th） and effect of Xuebijing injection （血必净注射液） in septic rats. Methods A sepsis model was reproduced by cecal ligation and puncture （CLP）. Wistar rats were randomly divided into the normal group （n=8）, sham operation group （n= 8）, model group （n=8） and Xuebijing injection treatment group （n=8）. CD4^＋CD25^＋Tregs in each group were separated by immunomagnetie beads isolation system on day 3, the apoptotic rates, expression of forkhead/winged helix transcription factor p3 （Foxp3） as well as cytotoxic T lymphocyte-associated antigen 4 （CTLA-4） of Treg were analyzed by flow cytometry, and the secretion level of interleukin-10 （IL-10） of Tregs was determined by enzyme linked immunosorbent assay （ELISA） after culturing Tregs for 12 hours. Interferon-γ （IFN-γ）, IL-4, and IL-17 levels, which were respectively secreted by Th1, Th2 and Th17, were measured by ELISA in the supernatant after CD4^＋ CD25^＋ Tregs were co-cultured with CD4^＋ CD25^- T lymphoeytes for 68 hours. Results The apoptosis rate of the normal group was （12.03±0. 89） %, which was not significantly different compared with the sham operation group [（9.48 ±2.17）%]. The apoptosis rate of model group [（5. 87±0. 44）%] was much lower than that of the normal and sham operation groups, while the Xuebijing injection treatment group [（27.29± 2.48）%] had the highest apoptosis rate compared to others （all P〈0. 01）. The expression of Foxp3, CTLA-4, and the secretion of IL-10 of Treg were negatively correlated with the apoptosis rates, correlation coefficients （r） respectively were -0. 878 （P=0. 042）, - 0. 877 （P = 0. 042）, and - 0. 743 （P=0. 010）. The secretion of IFN-γ, IL-4 and ratio of IFN-γ/IL-4 in model group were significantly elevated compared with the normal group [IFN-γ： （254. 70±44. 88） ng/L vs. （0