Induction of Atypical Autophagy by Porcine Hemagglutinating Encephalomyelitis Virus Contributes to Viral Replication.
Induction of Atypical Autophagy by Porcine Hemagglutinating Encephalomyelitis Virus Contributes to Viral Replication.
复制标题
猪血凝脑脊髓炎病毒诱导非典型自噬有助于病毒复制
DOI：
10.3389/fcimb.2017.00056
复制
发表时间：
2017
影响因子：
5.7
通讯作者：
He W
中科院分区：
文献类型：
--
作者：
Ding N;Zhao K;Lan Y;Li Z;Lv X;Su J;Lu H;Gao F;He W
自噬是一种基本的生物代谢过程，涉及细胞内膜运输途径，回收细胞成分并消除溶酶体内的细胞内微生物。自噬在病毒感染和繁殖中也起着重要作用。然而，一些病原体，包括病毒，已经进化出独特的技巧来逃避或利用自噬。本研究探讨猪血凝性脑脊髓炎病毒（PHEV）诱导神经-2a细胞自噬的机制，并探讨自噬在PHEV复制中的作用。PHEV触发的神经2a细胞自噬依赖于大量双膜或单膜液泡的存在、GFP-LC3荧光点的积累和LC3脂化。此外，PHEV诱导了不完全的自噬效应，因为在PHEV感染的细胞中p62的降解水平没有改变。通过间接免疫荧光标记在phev感染细胞中使用LysoTracker和溶酶体相关膜蛋白进行进一步验证。我们还通过自噬诱导剂雷帕霉素或自噬抑制剂3-MA和溶酶体抑制剂氯喹（CQ）的药理学实验研究了病毒复制的变化。与模拟处理相比，3-MA抑制自噬增加了病毒复制，而雷帕霉素促进自噬减少了PHEV复制。CQ处理增强了PHEV感染的神经-2a细胞LC3脂化，但降低了PHEV复制。这些结果表明PHEV感染诱导非典型自噬，引起自噬体的出现，但阻断了与溶酶体的融合，而溶酶体是PHEV在神经细胞内复制所必需的。
Autophagy is a basic biological metabolic process involving in intracellular membrane transport pathways that recycle cellular components and eliminate intracellular microorganisms within the lysosome. Autophagy also plays an important part in virus infection and propagation. However, some pathogens, including viruses, have evolved unique trick to escape or exploit autophagy. This study explores the mechanism of autophagy induction by porcine hemagglutinating encephalomyelitis virus (PHEV) in Neuro-2a cells, and examines the role of autophagy in PHEV replication. PHEV triggered autophagy in Neuro-2a cells is dependent on the presence of bulk double- or single-membrane vacuoles, the accumulation of GFP-LC3 fluorescent dots, and the LC3 lipidation. In addition, PHEV induced an incomplete autophagic effect because the degradation level of p62 did not change in PHEV-infected cells. Further validation was captured using LysoTracker and lysosome-associated membrane protein by indirect immunofluorescence labeling in PHEV-infected cells. We also investigated the change in viral replication by pharmacological experiments with the autophagy inducer rapamycin or the autophagy inhibitor 3-MA, and the lysosomal inhibitor chloroquine (CQ). Suppression of autophagy by 3-MA increased viral replication, compared with the mock treatment, while promoting of autophagy by rapamycin reduced PHEV replication. CQ treatment enhanced the LC3 lipidation in PHEV-infected Neuro-2a cells but lowered PHEV replication. These results show that PHEV infection induces atypical autophagy and causes the appearance of autophagosomes but blocks the fusion with lysosomes, which is necessary for the replication of PHEV in nerve cells.