ESAT6通过mTOR抑制自噬并促进BCG增殖

ESAT6 inhibits autophagy and promotes BCG proliferation through mTOR

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。

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-roTOR and P-70S6K were detected using Western blotting. The roTOR inhibitor Torinl combined with ESAT6 was transfected into Raw264.7 cells. P62 and P-roTOR were detected with Western blotting, LysoTracker immunofluorescence method was used to observe the lyso- some, and BCG bacteria proliferation was conducted to count bacteria of each group. Results The levels of P-roTOR, P-70S6K and P62 in the cells were significantly higher after transfection with ESAT6. LC3I com- pleted the conversion to LC3II. The levels of P-roTOR and P62 in the Torinl combined ESAT6 group and in the Torinl 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 acti- vation of mTOR.