TLR1/2信号促CD8^+T细胞功能及其机制

TLR1/2 signaling enhances CD8^+T cell function and its underlying mechanism

目的:探讨Toll受体1/2(Toll like receptor1/2,TLR1/2)信号对荷瘤小鼠来源的CD8^+T细胞功能的影响及其可能机制。方法:利用小鼠Lewis肺癌细胞株3LL建立小鼠肺癌荷瘤模型,MACS分选小鼠脾CD8^+T细胞;体外经PBS或TLR1/2激动剂BLP刺激后,Real-time PCR和流式细胞术分别从基因和蛋白水平检测CD8^+T细胞的TLR分子表达;用ELISA和流式细胞术检测经PBS或BLP刺激后的CD8^+T细胞分泌细胞因子和增殖的能力,并用关键信号分子抑制剂分析可能的分子机制。结果:与PBS对照组相比,TLR1/2激动剂BLP不但有效上调荷瘤机体CD8^+T细胞TLR1和TLR2分子的基因水平[TLR1:(0.353±0.015)vs(0.101±0.017),P<0.01;TLR2:(0.232±0.031)vs(0.080±0.004),P<0.05]及蛋白水平(P<0.05),而且显著促进CD8^+T细胞分泌功能性细胞因子[IFN-γ:(2 375±305)vs(850±50),P<0.05;IL-2:(1 600±200)vs(350±50),P<0.05]和增殖的能力(P<0.05),这一效应依赖于NF-KB和P38通路。结论:TLR1/2信号直接作用于荷瘤小鼠的CD8^+T细胞并促进其功能,该研究既丰富了TLR的作用范围,也为基于TLR激动剂的肿瘤生物治疗提供了实验依据。

Objective：To investigate the effect of Toll like receptor 1/2（TLR1/2） signaling on CD8＋T cells derived from 3LL tumor-bearing mice and its underlying mechanisms. Methods：3LL Lewis lung carcinoma cell line was used to establish tumor-bearing mice model, of which CD8＋T cells were purified from the spleen by MACS. CD8＋T cells were stimulated in vitro with PBS or TLR1/2 agonist, BLP, and then the gene and protein expression levels of TLRs in CD8＋T cells were measured by Real-time PCR and Flow cytometry. What’s more, cytokine secretion and proliferation of CD8＋T cells after PBS or BLP stimulation were detected by ELISA and Flow cytometry. The inhibitors of key signal molecules were used to explore the underlying mechanisms of BLP influencing CD8＋T cells derived from 3LL-bearing mice. Results： Compared with PBS group, BLP not only greatly increased the expressions of TLR1 and TLR2 genes （TLR1： ／[0.353±0.015／] vs ／[0.101±0017／], P〈0.01; TLR2： （／[0.232±0.031／] vs ／[0.080±0.004／], P〈0.05） and proteins （P〈0.05）, but also significantly enhanced the functional cytokine secretion （IFN-γ： ／[2 375±305／] vs ／[850±50／], P〈0.05;IL-2： ／[1 600±200／] vs ／[350±50／],P〈0.05）; in addition, it promoted the proliferation of CD8＋T cells （P〈0.05）. All of these were dependent on NF-κB and P38 pathways. Conclusion： TLR1/2 signaling could directly promote the functions of CD8＋T cells derived from 3LL-tumor bearing mice, which might enrich the scope of TLRs and also provide the basis for TLR agonist-based tumor immunotherapy.