调节性T细胞对严重烧伤大鼠肠道T细胞免疫和内毒素移位的影响

Effect of Treg on intestinal T-cell immunity and endotoxin translocation in rats after severe burns

目的观察调节性T细胞(Treg)在严重烧伤大鼠肠道淋巴结中的表达变化,探讨其变化对肠道淋巴结其他T淋巴细胞的影响及其与肠道内毒素移位的关系。方法取雄性SD大鼠50只,分成正常对照组和烧伤后0.5、1、2、4h组(各10只),对各烫伤组大鼠背部造成30%全身体表面积Ⅲ度烧伤;分离肠道淋巴结,采用流式细胞仪技术检测肠道淋巴结Treg、CD3+CD4+/CD3+CD8+淋巴细胞的表达变化;采用鲎试剂(动态浊度法)检测门静脉血浆内毒素水平。结果烧伤后大鼠肠道Treg表达与CD3+CD4+/CD3+CD8+淋巴细胞比值呈负相关(r=-0.827,P<0.01);而Treg水平与门静脉血浆ET水平呈正相关(r=0.782,P<0.01)。结论严重烧伤大鼠肠道淋巴结Treg表达的增加,对肠道其他T淋巴细胞有免疫抑制作用,与肠道内毒素移位有着密切的关系。Treg在严重烧伤后肠道免疫屏障中可能起重要的作用。

Objective To observe the change of regulatory T cells expression in severely burned rats gut ,To investigate the effects of regulatory T cells on CD3＋CD4＋ /CD3＋CD8＋lymphocytes and its relation with gut-origin endotoxin translocation .Meth-ods Fifty SD male rats were randomly divided into normal control group（n=10）and burn model groups（n=40） .Rats were burned to achieve Ⅲ degree scalding ,and a 30% total body surface area（TBSA） burn model was made .Rats were sacrificed before（normal control group） and after 0 .5 ,1 ,2 ,4 burn hour（PBH groups） .Flow cytometry techniques were used for the detection of the expres-sions of regulatory T cells and CD3＋CD4＋ /CD3＋CD8＋ lymphocyte in intestinal lymph nodes which were separated .The dynamic turbidity method was used for detection of endotoxin levels in portal vein blood .Results The expression of regulatory T cells was negativelycorrelatedwithCD3＋CD4＋ /CD3＋CD8＋ lymphocyteratio（r= -0.827,P〈0.01）inintestinallymphnodeofrats,while the regulatory T cells was positively correlated with ET levels in portal vein blood plasma .（r=0 .782 ,P〈0 .01） .Conclusion The expression of the regulatory T cells in intestinal lymph node in severely burned rats was increased compared to that in normal con-trol group .Regulatory T cells suppressed the expression of intestinal T lymphocytes ,leading to gut immune inhibition .The translo-cation of intestinal endotoxin has a close relationship with regulatory T cells in severely burned rats .Regulatory T cells could have portal effects on intestinal immunity barrier .