Toll样受体2在分枝杆菌诱导巨噬细胞凋亡中的作用

发布时间：2018-10-23 18:52

【摘要】：目的建立分枝杆菌感染巨噬细胞的模型,探讨Toll样受体2(TLR2)在分枝杆菌诱导巨噬细胞凋亡中的作用。方法使用豆蔻酰佛波醇乙酯(PMA)诱导U937细胞分化使之具有吞噬能力,分别用胞内分枝杆菌(M.intracellulare)、结核分枝杆菌(MTB)、脓肿分枝杆菌(M.abscessus)感染已分化的U937细胞,于感染后0、4、8、24、48和72h提取细胞,用流式细胞仪检测u937细胞凋亡率及细胞膜TLR2的表达,Western blot检测U937细胞感染后72 h时细胞内总TLR2的含量,并观察阻断TLR2后U937细胞感染分枝杆菌后的凋亡变化。结果 M.intracellulare M.abscessus感染U937细胞后的细胞凋亡率随时间的推移逐渐升高,4h后凋亡率已显著高于正常对照组,而MTB感染后的细胞凋亡率也有升高但与正常对照组差异无统计学意义;3种分枝杆菌感染U937细胞后的细胞凋亡率差异有统计学意义(P0.05),由高到低的排列依次为M.abscessus、M.intracellulare和MTB。U937细胞的TLR2表达量在分枝杆菌感染后4 h内迅速升高,8 h后TLR2的含量稳定下来,不同分枝杆菌感染U937细胞后TLR2的表达并不相同(P0.05),由高到低的排列依次为MTB、M.intracellulare和M.abscessus。阻断U937细胞的TLR2可以明显降低感染分枝杆菌后细胞的凋亡率。结论 TLR2并不直接引起巨噬细胞的凋亡,但TLR2在分枝杆菌诱导巨噬细胞凋亡中有重要作用。
[Abstract]:Objective to establish a model of mycobacterium infection with macrophages and to investigate the role of Toll like receptor 2 (TLR2) in mycobacterium induced macrophage apoptosis. Methods U937 cells were induced to differentiate into phagocytic cells by (PMA). U937 cells were infected with Mycobacterium endocytogenes (M.intracellulare) and Mycobacterium tuberculosis (MTB), abscess (M.abscessus), respectively. The apoptosis rate of U937 cells and the expression of TLR2 in U937 cells were detected by flow cytometry. The total TLR2 content in U937 cells 72 h after infection was detected by, Western blot. The apoptosis changes of U937 cells infected with Mycobacterium after TLR2 blocking were observed. Results the apoptosis rate of U937 cells infected with M.intracellulare M.abscessus increased gradually with the passage of time, and the apoptosis rate of U937 cells was significantly higher than that of normal control group 4 hours later. The apoptosis rate of U937 cells infected with MTB was significantly higher than that of normal controls (P0.05), and the order from high to low was M. abscessus M. intracellulare and MTB.U937. The expression of TLR2 in the cells increased rapidly within 4 h after mycobacterium infection, and the content of TLR2 stabilized at 8 h after infection. The expression of TLR2 was not the same in U937 cells infected with different mycobacteria (P0.05). The order from high to low was MTB,M.intracellulare and M.abscessus. Blocking TLR2 of U937 cells could significantly reduce the apoptosis rate of mycobacterium infection. Conclusion TLR2 does not directly induce macrophage apoptosis, but TLR2 plays an important role in mycobacterium induced macrophage apoptosis.
【作者单位】：第二军医大学南京临床学院(南京军区南京总医院)呼吸内科;
【分类号】：R378.91

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