Autophagy Promotes Replication of Influenza A Virus In Vitro
Autophagy Promotes Replication of Influenza A Virus In Vitro
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DOI：
10.1128/jvi.01984-18
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发表时间：
2019-02-01
影响因子：
5.4
通讯作者：
Zhou，Hongbo
中科院分区：
文献类型：
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作者：
Wang，Ruifang;Zhu，Yinxing;Zhou，Hongbo
甲型流感病毒（IAV）感染可诱导自噬体积聚。然而，自噬机制对IAV感染的影响仍然存在争议。在这里，我们表明，通过饥饿或雷帕霉素处理诱导细胞自噬增加了子代病毒的产生，而使用小干扰RNA（siRNA）和药理学抑制剂破坏自噬减少了子代病毒的产生。进一步的研究表明，自噬的改变显著影响病毒生命周期或病毒RNA合成的早期阶段。重要的是，我们证明了IAV M2和NP蛋白的单独过表达导致LC 3脂质化为LC 3-II，并且LC 3从细胞质溶胶重新分布到指示真实自噬体的点状囊泡。有趣的是，在单独转染M2或NP以及感染IAV期间，M2和NP都与LC 3斑点共定位并相互作用，导致病毒核糖核蛋白（vRNP）输出和感染性病毒颗粒形成的增加，这表明IAV-宿主自噬相互作用在调节IAV复制中起关键作用。我们发现NP和M2诱导AKT-mTOR依赖性自噬途径和HSP 90 AA 1表达的增加。最后，我们的研究提供了证据表明，IAV复制需要一个自噬途径，通过PB 2和HSP 90 AA 1的相互作用，通过调节宿主细胞中HSP 90 AA 1的表达和AKT-mTOR信号通路来增强病毒RNA的合成。总之，我们的研究揭示了一种新的机制，即NP和M2介导的自噬在A型流感病毒致病性的病毒复制的不同阶段发挥作用。然而，自噬机制在IAV复制中的作用仍不清楚。因此，我们探索了IAV促进其复制的详细机制。我们证明了IAV NP和M2介导的自噬通过调节AKT-mTOR信号通路和HSP 90 AA 1表达来促进IAV复制。PB 2和HSP 90 AA 1的相互作用首先导致病毒RNA合成增加;随后NP与LC 3的结合有利于vRNP输出，随后M2和LC 3的相互作用导致感染性病毒颗粒的产生增加，从而加速病毒子代的产生。这些发现提高了我们对IAV在宿主细胞中致病性的理解。
Influenza A virus (IAV) infection could induce autophagosome accumulation. However, the impact of the autophagy machinery on IAV infection remains controversial. Here, we showed that induction of cellular autophagy by starvation or rapamycin treatment increases progeny virus production, while disruption of autophagy using a small interfering RNA (siRNA) and pharmacological inhibitor reduces progeny virus production. Further studies revealed that alteration of autophagy significantly affects the early stages of the virus life cycle or viral RNA synthesis. Importantly, we demonstrated that overexpression of both the IAV M2 and NP proteins alone leads to the lipidation of LC3 to LC3-II and a redistribution of LC3 from the cytosol to punctate vesicles indicative of authentic autophagosomes. Intriguingly, both M2 and NP colocalize and interact with LC3 puncta during M2 or NP transfection alone and IAV infection, leading to an increase in viral ribonucleoprotein (vRNP) export and infectious viral particle formation, which indicates that the IAV-host autophagy interaction plays a critical role in regulating IAV replication. We showed that NP and M2 induce the AKT-mTOR-dependent autophagy pathway and an increase in HSP90AA1 expression. Finally, our studies provided evidence that IAV replication needs an autophagy pathway to enhance viral RNA synthesis via the interaction of PB2 and HSP90AA1 by modulating HSP90AA1 expression and the AKT-mTOR signaling pathway in host cells. Collectively, our studies uncover a new mechanism that NP- and M2-mediated autophagy functions in different stages of virus replication in the pathogenicity of influenza A virus.IMPORTANCEAutophagy impacts the replication cycle of many viruses. However, the role of the autophagy machinery in IAV replication remains unclear. Therefore, we explored the detailed mechanisms utilized by IAV to promote its replication. We demonstrated that IAV NP- and M2-mediated autophagy promotes IAV replication by regulating the AKT-mTOR signaling pathway and HSP90AA1 expression. The interaction of PB2 and HSP90AA1 results in the increase of viral RNA synthesis first; subsequently the binding of NP to LC3 favors vRNP export, and later the interaction of M2 and LC3 leads to an increase in the production of infectious viral particles, thus accelerating viral progeny production. These findings improve our understanding of IAV pathogenicity in host cells.