Infection of A549 human type II epithelial cells with Mycobacterium tuberculosis induces changes in mitochondria' morphology, distribution and mass that are dependent on the early secreted antigen, ESAT-6
Infection of A549 human type II epithelial cells with Mycobacterium tuberculosis induces changes in mitochondria' morphology, distribution and mass that are dependent on the early secreted antigen, ESAT-6
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DOI：
10.1016/j.micinf.2015.06.003
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发表时间：
2015-10-01
影响因子：
5.8
通讯作者：
Reaves, Barbara J.
中科院分区：
文献类型：
--
作者：
Fine-Coulson, Kari;Giguere, Steeve;Reaves, Barbara J.
结核分枝杆菌（Mtb）的肺部感染涉及肺泡上皮细胞（AECs）的侵袭。我们使用Mitotracker Red（R）通过共聚焦显微镜和流式细胞术评估Mtb感染的A549 II型AEC中感染后6至48小时（hpi）线粒体形态/分布和质量的变化。在感染早期，线粒体的形态没有影响，然而，到48 hpi线粒体出现碎片和集中在核周围。在流式细胞术实验中，中位数荧光强度（MFI）下降了44%，在48 hpi;双标记使用抗体的完整的膜蛋白COXIV显示，这些变化是由于线粒体质量的减少。这些变化没有发生与非致病菌株，牛分枝杆菌BCG。ESAT-6是Mtb Erdman中存在但M.牛卡介苗。我们使用Mtb Erdman（ESAT-6缺失突变体及其互补物）进行了类似的实验。MR下降在48 hpi的父母和补充株与未感染的对照组分别为52%和36%，没有减少检测到的缺失突变体。这些结果表明ESAT-6参与了由毒性Mtb在AEC中诱导的线粒体扰动，并表明线粒体自噬可能在感染过程中发挥作用。(C)2015巴斯德研究所。出版社：Elsevier Masson SAS All rights reserved.
Pulmonary infection by Mycobacterium tuberculosis (Mtb) involves the invasion of alveolar epithelial cells (AECs). We used Mitotracker Red (R) to assess changes in mitochondrial morphology/distribution and mass from 6 to 48 h post infection (hpi) by confocal microscopy and flow cytometry in Mtb-infected A549 type II AECs. During early infection there was no effect on mitochondria' morphology, however, by 48 hpi mitochondria appeared fragmented and concentrated around the nucleus. In flow cytometry experiments, the median fluorescence intensity (MFI) decreased by 44% at 48 hpi; double-labelling using antibodies to the integral membrane protein COXIV revealed that these changes were due to a decrease in mitochondrial mass. These changes did not occur with the apathogenic strain, Mycobacterium bovis BCG. ESAT-6 is a virulence factor present in Mtb Erdman but lacking in M. bovis BCG. We performed similar experiments using Mtb Erdman, an ESAT-6 deletion mutant and its complement. MR decreased at 48 hpi in the parent and complemented strains versus uninfected controls by 52% and 36% respectively; no decrease was detected in the deletion mutant. These results indicate an involvement of ESAT-6 in the perturbation of mitochondria induced by virulent Mtb in AECs and suggest mitophagy may play a role in the infection process. (C) 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.