TLR4在脓毒症中对调节性T细胞功能活性的影响

目的:探讨脓毒症中TLR4 （TLR4）对调节性T细胞功能及活性的影响,并探讨其作用机制。方法:SPF级C57/BL6雄性小鼠（wild type,WT）40只，C57BL/10ScNJNJU（TLR4-/-）小鼠40只，随机均分为4组，WTSham组，WTCLP组，TLR4-/-Sham组和TLR4-/-CLP。CLP组用盲肠结扎穿孔法制备脓毒症模型。造模后24 h，FCM检测脾脏CD4+CD25+Foxp3+Treg细胞数量、凋亡率及Foxp3和TLR4表达情况, RT-PCR检测Foxp3+mRNA和TLR4mRNA的表达,Western Blot检测Treg细胞内NF-κB、p-NF-κB蛋白表达情况。结果:（1） TLR4-/-CLP组Treg细胞凋亡率较WTCLP组明显增多,而细胞数量显著降低（P<0.05）。（2）WT CLP组Treg中Foxp3mRNA及蛋白表达、TLR4mRNA及蛋白水平显著升高（P<0.05），而在TLR4-/-CLP组中该表达较WT CLP组均显著降低（P<0.05）。（3） WT CLP组Treg细胞NF-κB、p-NF-κB的表达水平明显升高（P<0.05），而TLR4-/-CLP组较WT CLP组明显降低（P<0.05）。结论:在脓毒症中TLR4可显著影响Treg的功能及其活性，这可能通过TLR4/NF-κB信号通路介导有关。

The effects of TLR4 on regulating the function of Tregs in sepsis

Objective: To study the effects of TLR4 on regulating the function of Tregs in sepsis. Methods:Fortyhealthy male C57/BL mice（wild type,WT） and forty healthy male TLR4 knockout mice （TLR4-/-） were divided into Sham operation group （WT Sham group，n =20），WTCLP group （n=20），and TLR4-/-Sham group（n=20），TLR4-/-CLP group （n =20）by random number table method. In CLP group,the mice were given cecal ligation puncture（CLP），and in Sham group,the mice were given Sham-operation. Twenty-four hours after CLP,Tregnumber,Tregapoptsis rate, the expression of Foxp3 ,TLR4 at mRNA and protein level，the protein expression of NF-κB and p-NF-κB were determined. Results:（１） The apoptosis of Treg cells in TLR4-/-CLP group was higher than that in WTCLP group（P＜0.05）. （2） The levels of Foxp3mRNA and Foxp3 protein, TLR4mRNA and TLR4 protein in TLR4-/-CLP group were significantly lower than those in WTCLP group(P＜0.05）.（3）The expression of NF-κB and p-NF-κB in splenic Tregs was significantly increased in WT CLP mice in comparison to TLR4-/-CLP mice(P＜0.05）.Conclusion: TLR4 in experimental sepsiscloselyaligns with the function of Tregs, and this effect may be related to TLR4/NF-κB signaling.