外泌体模拟通过内体融合的 HAVCR1-NPC1 途径介导甲型肝炎病毒感染。

Exosome mimicry by a HAVCR1-NPC1 pathway of endosomal fusion mediates hepatitis A virus infection.

机构信息

Food and Drug Administration, Center for Biologics Evaluation and Research, Office of Blood Research and Review, Silver Spring, MD, USA.

出版信息

Nat Microbiol. 2020 Sep;5(9):1096-1106. doi: 10.1038/s41564-020-0740-y. Epub 2020 Jun 15.

Abstract

Cell-to-cell communication by exosomes controls normal and pathogenic processes. Viruses can spread in exosomes and thereby avoid immune recognition. While biogenesis, binding and uptake of exosomes are well characterized, delivery of exosome cargo into the cytoplasm is poorly understood. We report that the phosphatidylserine receptor HAVCR1 (refs. ) and the cholesterol transporter NPC1 (ref. ) participate in cargo delivery from exosomes of hepatitis A virus (HAV)-infected cells (exo-HAV) by clathrin-mediated endocytosis. Using CRISPR-Cas9 knockout technology, we show that these two lipid receptors, which interact in the late endosome, are necessary for the membrane fusion and delivery of RNA from exo-HAV into the cytoplasm. The HAVCR1-NPC1 pathway, which Ebola virus exploits to infect cells, mediates HAV infection by exo-HAV, which indicates that viral infection via this exosome mimicry mechanism does not require an envelope glycoprotein. The capsid-free viral RNA in the exosome lumen, but not the endosomal uncoating of HAV particles contained in the exosomes, is mainly responsible for exo-HAV infectivity as assessed by methylene blue inactivation of non-encapsidated RNA. In contrast to exo-HAV, infectivity of HAV particles is pH-independent and requires HAVCR1 or another as yet unidentified receptor(s) but not NPC1. Our findings show that envelope-glycoprotein-independent fusion mechanisms are shared by exosomes and viruses, and call for a reassessment of the role of envelope glycoproteins in infection.

摘要

细胞外囊泡通过细胞间通讯控制正常和病理过程。病毒可以在细胞外囊泡中传播,从而逃避免疫识别。虽然细胞外囊泡的生物发生、结合和摄取已经得到很好的描述,但细胞外囊泡货物进入细胞质的传递过程仍知之甚少。我们报告称,磷脂酰丝氨酸受体 HAVCR1(参考文献)和胆固醇转运蛋白 NPC1(参考文献)参与了甲型肝炎病毒(HAV)感染细胞来源的细胞外囊泡(exo-HAV)中货物的传递,这一过程通过网格蛋白介导的内吞作用完成。利用 CRISPR-Cas9 基因敲除技术,我们发现这两种脂质受体在晚期内体中相互作用,对于 exo-HAV 的膜融合和将 RNA 从 exo-HAV 递送到细胞质是必需的。Ebola 病毒利用 HAVCR1-NPC1 途径感染细胞,介导 HAV 通过 exo-HAV 感染,这表明通过这种外体模拟机制的病毒感染不需要包膜糖蛋白。外体腔中的无衣壳病毒 RNA 而不是 exo-HAV 中包含的 HAV 颗粒的内体脱壳,是评估甲肝病毒 RNA 非衣壳部分在 exo-HAV 感染性中的主要因素,这可以通过亚甲蓝失活非衣壳 RNA 来证明。与 exo-HAV 相反,HAV 颗粒的感染性与 pH 无关,并且需要 HAVCR1 或另一个尚未确定的受体(多个)但不需要 NPC1。我们的研究结果表明,包膜糖蛋白非依赖性融合机制在细胞外囊泡和病毒之间是共享的,这需要重新评估包膜糖蛋白在感染中的作用。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b5dd/7483988/9e63cc0dc614/nihms-1593998-f0005.jpg

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索