Respiratory Syncytial Virus Replication Is Promoted by Autophagy-Mediated Inhibition of Apoptosis
Respiratory Syncytial Virus Replication Is Promoted by Autophagy-Mediated Inhibition of Apoptosis
复制标题
自噬介导的细胞凋亡抑制促进呼吸道合胞病毒复制
DOI：
10.1128/jvi.02193-17
复制
发表时间：
2018-04-01
影响因子：
5.4
通讯作者：
Wei, Lin
中科院分区：
文献类型：
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作者：
Li, Miao;Li, Jian;Wei, Lin
摘要呼吸道合胞病毒（RSV）是全球儿童急性下呼吸道感染（ALRI）的主要病原。病毒-宿主相互作用影响感染的进展和预后。自噬在病毒与宿主相互作用中起重要作用。呼吸道上皮细胞在RSV感染过程中是宿主防御的最前线，但它们与RSV的相互作用机制尚不清楚。在这项研究中，我们发现RSV诱导的自噬有利于RSV复制，并加剧了体内肺部病理学。从机制上讲，RSV通过活性氧（ROS）的产生和AMP活化蛋白激酶/哺乳动物雷帕霉素靶蛋白（AMPK-MTOR）信号通路的激活诱导HEp-2细胞中的完全自噬通量。此外，我们评估了自噬在RSV复制中的功能，发现在用雷帕霉素处理的HEp-2细胞中RSV复制增加，而在用3-甲基胺（3-MA）或渥曼青霉素处理的细胞中RSV复制显著降低。用针对自噬相关基因5（ATG 5）、自噬相关基因7（ATG 7）或BECN 1/Beclin 1的短发夹RNA（shRNA）敲低自噬途径中的关键分子或用ROS清除剂N-乙酰基-L-半胱氨酸（NAC）和AMPK抑制剂（化合物C）处理抑制RSV复制。3-MA或shATG 5/BECN 1在感染后48小时（hpi）显著降低细胞活力并增加细胞凋亡。用Z-VAD-FMK阻断细胞凋亡在48 hpi部分恢复了病毒复制。这些结果提供了强有力的证据表明，在RSV感染期间，自噬可能以细胞内在方式作为前病毒机制发挥作用。重要性了解呼吸道合胞病毒与呼吸道上皮细胞相互作用的机制对于开发新的抗病毒策略至关重要。在这项研究中，我们发现RSV通过ROS-AMPK信号轴诱导自噬，这反过来又促进病毒感染。自噬通过在48 hpi阻断细胞凋亡而有利于RSV复制。在机制上，RSV诱导线粒体自噬，其维持线粒体稳态并因此减少细胞色素c释放和细胞凋亡诱导。这项研究为这种病毒-宿主相互作用提供了新的见解，这可能有助于开发针对自噬过程的新的抗病毒治疗方法。
ABSTRACT Respiratory syncytial virus (RSV) is the main cause of acute lower respiratory tract infection (ALRI) in children worldwide. Virus-host interactions affect the progression and prognosis of the infection. Autophagy plays important roles in virus-host interactions. Respiratory epithelial cells serve as the front line of host defense during RSV infection, However, it is still unclear how they interact with RSV. In this study, we found that RSV induced autophagy that favored RSV replication and exacerbated lung pathology in vivo. Mechanistically, RSV induced complete autophagy flux through reactive oxygen species (ROS) generation and activation of the AMP-activated protein kinase/mammalian target of rapamycin (AMPK-MTOR) signaling pathway in HEp-2 cells. Furthermore, we evaluated the functions of autophagy in RSV replication and found that RSV replication was increased in HEp-2 cells treated with rapamycin but decreased remarkably in cells treated with 3-methylademine (3-MA) or wortmannin. Knockdown key molecules in the autophagy pathway with short hairpinp RNA (shRNA) against autophagy-related gene 5 (ATG5), autophagy-related gene 7 (ATG7), or BECN1/Beclin 1 or treatment with ROS scavenger N-acetyl-l-cysteine (NAC) and AMPK inhibitor (compound C) suppressed RSV replication. 3-MA or shATG5/BECN1 significantly decreased cell viability and increased cell apoptosis at 48 hours postinfection (hpi). Blocking apoptosis with Z-VAD-FMK partially restored virus replication at 48 hpi. Those results provide strong evidence that autophagy may function as a proviral mechanism in a cell-intrinsic manner during RSV infection. IMPORTANCE An understanding of the mechanisms that respiratory syncytial virus utilizes to interact with respiratory epithelial cells is critical to the development of novel antiviral strategies. In this study, we found that RSV induces autophagy through a ROS-AMPK signaling axis, which in turn promotes viral infection. Autophagy favors RSV replication through blocking cell apoptosis at 48 hpi. Mechanistically, RSV induces mitophagy, which maintains mitochondrial homeostasis and therefore decreases cytochrome c release and apoptosis induction. This study provides a novel insight into this virus-host interaction, which may help to exploit new antiviral treatments targeting autophagy processes.