ESAT6通过mTOR抑制自噬并促进BCG增殖

目的研究mTOR在结核杆菌毒力因子ESAT6诱导的自噬抑制以及促进BCG增殖中的作用。方法 PCMV-HA-ESAT6质粒转染Raw264.7细胞,用蛋白免疫印迹检测LC3、P62、P-mTOR和P-70S6K表达水平;用mTOR阻断剂Torin1联合ESAT6转染以及分别作用于Raw264.7细胞后,免疫印迹检测P62和P-mTOR表达水平,LysoTracker Red染色观察溶酶体变化,BCG增殖实验计数各组菌落数。结果 ESAT6转染细胞后,细胞P62、P-mTOR和P-70S6K表达水平显著增高,LC3I完成向LC3II的转化;联合Torin1的ESAT6转染组和Torin1处理组的P-mTOR和P62无显著变化,溶酶体无变化,BCG菌落数减少。结论 ESAT6诱导的自噬抑制和BCG的增殖依赖于mTOR的活化。

ESAT6 inhibits autophagy and promotes BCG proliferation through mTOR

Abstract: Objective To investigate the role of mTOR during the ESAT6-induced autophagy inhibition of murine macrophages and the proliferation of BCG. Methods ESAT6 plasmid was transfected into Raw264.7 cells. The levels of LC3, P62, P-mTOR and P-70S6K were detected using Western blotting. The mTOR inhibitor Torin1 combined with ESAT6 was transfected into Raw264.7 cells. P62 and P-mTOR were detected with Western blotting, LysoTracker immunofluorescence method was used to observe the lysosome, and BCG bacteria proliferation was conducted to count bacteria of each group. Results The levels of P-mTOR, P-70S6K and P62 in the cells were significantly higher after transfection with ESAT6. LC3I completed the conversion to LC3II. The levels of P-mTOR and P62 in the Torin1 combined ESAT6 group and in the Torin1 group showed no significant changes, neither did the numbers of BCG colony and lysosomes. Conclusion The ESAT6-induced inhibitions of autophagy and BCG proliferation are dependent on the activation of mTOR.