Xiong Junyao, Yang Ling'en, Nan Xiaowei, Zhu Shuo, Yan Mengxue, Xiang Shengxian, Zhang Luping, Li Qi, Yang Chengjie, Wang Xugang, Wei Ning, Chen Huanchun, Si Youhui, Cao Shengbo, Ye Jing
National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China.
Frontiers Science Center for Animal Breeding and Sustainable Production, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China.
J Extracell Vesicles. 2025 Jan;14(1):e70033. doi: 10.1002/jev2.70033.
Japanese encephalitis virus (JEV) is a neurotropic zoonotic pathogen that poses a serious threat to public health. Currently, there is no specific therapeutic agent available for JEV infection, primarily due to the complexity of its infection mechanism and pathogenesis. Extracellular vesicles (EVs) have been known to play an important role in viral infection, but their specific functions in JEV infection remain unknown. Here, ultracentrifugation in combination with density gradient centrifugation was conducted to purify EVs from JEV-infected cells. The purified EVs were found to be infectious, with virions observed inside the EVs. Furthermore, our study showed the formation process of virion-containing EVs both in vitro and in vivo, which involved the fusion of multivesicular bodies with the cell membrane, leading to the release of virion-containing intraluminal vesicles into the extracellular space. Further studies revealed that EVs played a crucial role in JEV propagation by facilitating viral entry and assembly-release. Furthermore, EVs assisted JEV in evading the neutralizing antibodies and promoted viral capability to cross the blood-brain and placental barriers. Moreover, in vivo experiments demonstrated that EVs were beneficial for JEV infection and pathogenicity. Taken together, our findings highlight the significant contribution of EVs in JEV infection and provide valuable insights into JEV pathogenesis.
日本脑炎病毒（JEV）是一种嗜神经性人畜共患病原体，对公共卫生构成严重威胁。目前，尚无针对JEV感染的特异性治疗药物，主要原因是其感染机制和发病机制复杂。已知细胞外囊泡（EVs）在病毒感染中起重要作用，但其在JEV感染中的具体功能尚不清楚。在此，采用超速离心结合密度梯度离心从JEV感染的细胞中纯化EVs。发现纯化的EVs具有传染性，在EVs内部观察到病毒粒子。此外，我们的研究展示了含病毒粒子的EVs在体外和体内的形成过程，这涉及多泡体与细胞膜的融合，导致含病毒粒子的腔内囊泡释放到细胞外空间。进一步研究表明，EVs通过促进病毒进入和组装释放，在JEV传播中起关键作用。此外，EVs帮助JEV逃避中和抗体，并促进病毒穿越血脑屏障和胎盘屏障的能力。此外，体内实验表明，EVs有利于JEV感染和致病性。综上所述，我们的研究结果突出了EVs在JEV感染中的重要贡献，并为JEV发病机制提供了有价值的见解。
