结核分枝杆菌热休克蛋白65对ApoE基因敲除小鼠Treg/Th17免疫平衡的影响

Effects of Mycobacterium tuberculosis HSP65 on Treg/Th17 immune balance in Apo E-knockout mice

研究结核分枝杆菌热休克蛋白65(HSP65)对Apo E-/-小鼠Treg/Th17免疫平衡的影响。首先,将结核分枝杆菌HSP65蛋白免疫高脂饲喂Apo E-/-小鼠,再采用ELISA检测小鼠血清中抗HSP65抗体的产生情况,流式细胞术检测血中CD4+CD25+Foxp3+调节性T细胞(Treg)和CD4+IL-17+辅助性T细胞17(Th17)的数量,ELISA检测血清中IL-10、TGF-β1、IL-17和IL-21含量,生化分析仪检测血中总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的含量,染色法计算动脉粥样硬化斑块面积。结果发现结核分枝杆菌HSP65蛋白诱导Apo E-/-小鼠产生了高水平的抗HSP65抗体,Treg细胞及其分泌的IL-10和TGF-β1细胞因子数量明显减少,Th17细胞及其分泌的IL-17和IL-21细胞因子数量明显增加,TC、TG、HDL-C及LDL-C的含量未见改变,但动脉粥样硬化斑块的面积明显增加。由此可见结核分枝杆菌HSP65蛋白能够破坏Apo E-/-小鼠Treg/Th17免疫平衡,促进动脉粥样硬化的发展。

To investigate the effects of Mycobacterium tuberculosis heat shock protein 65（HSP65）on Treg/Th17 immune balance in ApoE-knockout（ApoE^-/-）mice, ApoE^-/- mice with a high-cholesterol diet were immunized with M. tuberculosis HSP65. Sera were obtained for measurement of anti-HSP65 antibodies by ELISA; the effect of administration of different antigens was investigated, respectively, using flow cytometry analysis on the number of CD4^＋ CD25^＋ Foxp3^＋ Tregs and CD4^＋ IL-17^＋ Th17; the production of cytokines（IL-10, TGF-β1, IL-17 and IL-21）by these cells were determined by ELISA; total plasma cholesterol（TC）, triglyceride（TG）, high-density lipoprotein cholesterol（HDL-C）and low-density lipoprotein cholesterol（LDL-C）levels were detected by biochemical autoanalyzer. Atherosclerotic lesions were measured by lipid deposition stained with oil red O. The results demonstrated that the levels of anti-HSP65 IgG antibodies were increased significantly in Mycobacterium tuberculosis HSP65-treated ApoE-/- mice, revealed obvious decrease in Treg number, Treg related cytokines（IL-10, TGF-β1）levels and significant increase in Th17 number, Th17 related cytokines（IL-17 and IL-21）levels, the levels of TC, TG, HDL-C and LDL-C did not change between groups, while the atherosclerotic lesions significantly increased. Results indicate that M. tuberculosis HSP65 could interrupt the Th17/Treg immune balance in ApoE^-/- mice, suggesting a potential role in the formation and progression of atherosclerosis.