中文摘要：

目的探讨血必净注射液对内毒素诱导CD41^＋CD25^＋调节性T细胞（Treg）凋亡影响的剂量-效应关系。方法体外培养免疫磁珠法分选大鼠脾脏CD4^＋CD25^＋Treg，分为对照组、抗CD3／CD28组、抗CD3／CD28＋脂多糖（LPS）组、抗CD3／CD28＋血必净组（1、5、25mg／ml）和抗CD3／CD28＋LPS＋血必净组（1、5、25mg／ml）。以刺激第3日为观察时间点，采用流式细胞术分析Treg凋亡率、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）表达水平，酶联免疫吸附法（ELISA）检测白细胞介素-10（IL-10）分泌情况。结果抗CD3／CD28＋血必净各组CD4^＋CD25^＋Treg凋亡率高于对照组和抗CD3／CD28组，抗CD3／CD28＋LPS＋血必净各组凋亡率较对照组和抗CD3／CD28＋LPS组明显升高（P〈0．05或P〈0．01）；且凋亡率随血必净刺激剂量增加而升高，其中5mg／ml血必净组凋亡率接近50％。Foxp3和CTLA-4的表达及IL-10分泌随凋亡率增加而逐渐降低，不同剂量血必净组间比较差异有统计学意义（P〈0．05或P〈0．01）。结论血必净注射液能显著促进内毒素介导Treg的凋亡，并呈一定程度的剂量-效应关系。

英文摘要：

Objective To evaluate the effect of various doses of Xuebijing injection （血必净注射液） on lipopolysaccharide （LPS）-mediated apoptosis of CD4^＋ CD25^＋ regulatory T cells （Treg） in rats in vitro. Methods CD4^＋CD25^＋ Treg, separated by the immunomagnetic beads isolate system from spleens in rats, were divided into the control group, anti-CD3/CD28 group, anti-CD3/CD28＋LPS group, anti-CD3/CD28＋ Xuebijing treated group （1, 5 and 25 mg/ml Xuebijing, respectively）, and anti-CD3/CD28＋LPS＋Xuebijing treated group （1, 5 and 25 mg/ml, respectively）. The apoptotic rates, the expression of transcription factor orkhead/winged helix transcription factor （Foxp3） and membrane molecule cytotoxic T lymphocyte-associated antigen 4 （CTLA-4） of Treg were analyzed by flow cytometry （FCM）, and secretion levels of interleukin-10 （IL-10） were measured by enzyme-labeled immunosorbent assay （ELISA） on day 3. Results The apoptotic rate of CD4^＋ CD25^＋ Treg in anti-CD3/CD28＋Xubijing treated groups was markedly higher than that in control group and anti-CD3/CD28 group （P〈0.05 or P〈0.01）. Meanwhile, the apoptotic rates of CD4^＋ CD25^＋Treg in anti-CD3/CD28＋LPS＋Xubijing group were significantly elevated in comparison to the control and anti-CD3/CD28 ＋LPS groups （P 〈 0. 05 or P 〈 0. 01）. Along with the increased doses of Xuebijing injection, the apoptotic rates of CD4^＋CD25^＋ Tregs were also enhanced, and among them, the rates of 5 mg/ml Xuebijing injection treated group approached to 50%. In addition, the mean fluorescence intensity of Foxp3 as well as CTLA-4, and the secretion levels of IL-10 were negatively correlated with the apoptotic rates of CD4^＋ CD25^＋ Tregs. There were statistical significances of above three indexes in the various doses of Xuebijing groups （P〈0. 05 or P〈0.01）. Conclusion Treatment with Xuebijing injection could markedly enhance the apoptosis of CD4^＋CD25^＋ Tregs, showing a dose-dependent response pattern.