摘要目的 探讨中药血必净注射液对体外脂多糖(LPS)刺激CD4+CD25+调节性T细胞(Treg)凋亡及其介导效应T细胞(Teff)增殖反应、分泌白细胞介素-2(IL-2)功能的影响.方法 40只雄性清洁级Wistar大鼠,实验前禁食12 h.免疫磁珠法分选大鼠脾脏CD4+CD25+Treg,分为对照组(n=8)、抗CD3/CD28组(n=8)、抗CXB/CD28+LPS组(/1,=8)、抗CD3/CD28+血必净组(n=8)和抗CD3/CD28+LPS+血必净组(n=8).培养3 d后流式细胞术检测CD4+CD25+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,酶联免疫吸附试验检测IL-10分泌.同时,CD4+CD25+Treg与CD4+CD25-T细胞1:1培养,刀豆素A刺激68 h后分析Treg对Teff增殖的抑制效应,并检测上清中IL-2/可溶性IL-2受体水平.结果 抗CD3/CD28诱导Treg凋亡率为(33.70±3.06%),显著高于对照组(12.84±0.84)%;抗CD3/CD28+LPS+血必净组(45.13±2.70)%凋亡率明显高于抗CD3/CD28+LPS组[(29.41±1.63)%,P＜0.01].同时,CD4+CLY25+Treg roxp3和CTLA-4表达及IL-10分泌随凋亡增加而降低.抗CD3/CD28+血必净组(31.26%)Teff增殖反应平均抑制率显著低于对照组(54.48%,P＜0.05),抗CD3/CD28+LPS+血必净组抑制率与抗CD3/CD28+LPS组比较亦明显下降(P＜0.01).此外,抗CD3/CD28+血必净组和抗CD3/CD28+LPS+血必净组IL-2分泌水平均显著高于抗CD3/CD28+LPS组(P＜0.01).结论 LPS刺激可明显上调大鼠Treg对Teff的抑制功能,血必净注射液能通过促进Treg凋亡而有效改善其对Teff的抑制效应.

abstractsObjective To investigate the effect of Xuebijing injectiong on lipopolysaccharide(LPS)-induced apoptosis of CD4+CD25+regulatory T cells(Tregs)and immune function of effector T cells(Teff)in vitro.Method CD4+CD25+Tregs isolated from rat spleens were divided into the control group,anti-CD3/CD28 group,anti-CD3/CD28+LPS group,anti-CD3/CD28+Xuebijing injection group,and anti-CD3/CD28+LPS+Xuebijing injection group.The apoptosis rate and expression of forkhead/winged helix transcription factor p3 (Foxp3)and cytotoxic T-lymphocyte-associated antigen 4(CTLA-4)of CD4+CD25+Tregs were detected by flow cytometry(FCM),and the secretion of IL-10 of Tregs was measured by ELBA on day 3.CD4+CD25-T cells were co-cultured with CD4+CD25+Tregs(1:1)for 68 hours,proliferative activity of Teff was determined by MTT,and interleukin(IL)-2/sIL-2Rα levels were measured by ELISA.Results The apoptosis rate of CD4+CD25+Tregs in anti-CD3/CD28 group was 33.70± 3.06%,which was significantly higher than that in control group(12.84±0.84%).Also,apoptosis rate of CD4 CD25+Tregs in anti-CD3/CD28+LPS+Xuebijing injection group(45.13±2.70%)was much higher than that in anti-CD3/CD28+IPS group(29.41 ± 1.63%,P＜0.01).The expression of Foxp3 as well as CTLA-4,and the secretion of IL-10 were markedly decreased along with increases in the apoptosis rates.Compared with control group(54.48%),the mean inhibitory rate of Teff proliferative activity in response to Con A was significantly decreased in anti-CD3/CD28+Xuebijing injection group(31.26%,P＜0.05),and it was markedly decreased in anti-CD3/CD28+LPS+Xuebijing injection group comaped to anti-CD3/CD28+LPS group(P＜0.01).In addition,IL-2 levels in the supernatant of anti-CD3/CD28+Xuebijing injection group and anti-CD3/CD28+LPS+Xuebijing injection group were significantly higher than those of anti-CD3/CD28+IPS group(P＜0.01).Conclusions The inhibitory activity of CD4+CD25+Tregs on Teff appears to be upregulated by IPS stimulation in vitro,and Xuebijing injection could markedly enhance apoptosis of CD4+CD25+Tregs,thereby improving suppressive immune function of Teff.