Respiratory Virology Group, Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra, Australia.
Respiratory Virology Group, Health Research Institute, Faculty of Education, Science, Technology and Mathematics, University of Canberra, Canberra, Australia
mBio. 2017 Sep 19;8(5):e01009-17. doi: 10.1128/mBio.01009-17.
Infected cells can undergo apoptosis as a protective response to viral infection, thereby limiting viral infection. As viruses require a viable cell for replication, the death of the cell limits cellular functions that are required for virus replication and propagation. Picornaviruses are single-stranded RNA viruses that modify the host cell apoptotic response, probably in order to promote viral replication, largely as a function of the viral proteases 2A, 3C, and 3CD. These proteases are essential for viral polyprotein processing and also cleave cellular proteins. proteases cleave proapoptotic adaptor proteins, resulting in downregulation of apoptosis. proteases also cleave nucleoporins, disrupting the orchestrated manner in which signaling pathways use active nucleocytoplasmic trafficking, including those involved in apoptosis. In addition to viral proteases, the transmembrane 2B protein alters intracellular ion signaling, which may also modulate apoptosis. Overall, picornaviruses, via the action of virally encoded proteins, exercise intricate control over and subvert cell death pathways, specifically apoptosis, thereby allowing viral replication to continue.
受感染的细胞可以通过凋亡作为对病毒感染的一种保护反应，从而限制病毒感染。由于病毒需要一个存活的细胞进行复制，因此细胞的死亡限制了病毒复制和传播所需的细胞功能。小核糖核酸病毒是单链 RNA 病毒，它们改变宿主细胞的凋亡反应，可能是为了促进病毒复制，这主要是病毒蛋白酶 2A、3C 和 3CD 的功能。这些蛋白酶对于病毒多蛋白的加工至关重要，并且还能切割细胞蛋白。蛋白酶切割促凋亡衔接蛋白，导致凋亡下调。蛋白酶还切割核孔蛋白，破坏信号通路使用主动核质运输的协调方式，包括涉及凋亡的信号通路。除了病毒蛋白酶外，跨膜 2B 蛋白还改变细胞内离子信号，这也可能调节细胞凋亡。总之，小核糖核酸病毒通过病毒编码蛋白的作用，对细胞死亡途径（特别是细胞凋亡）进行精细的控制和颠覆，从而允许病毒复制继续进行。
