Comparative proteomics of extracellular vesicles derived from wildtype or mutant EMCV-infected cells

Non-enveloped viruses, such as picornaviruses, can escape infected host cells via release in extracellular vesicles (EVs) prior to the induction of lysis. These EVs cloak the secreted virus particles in a host-derived membrane, which alters virus-host interactions that affect infection efficiency and antiviral immunity. Currently, little is known about the viral and host factors regulating the formation and release of EV-enclosed viruses. The encephalomyocarditis virus (EMCV), belonging to the family of picornaviruses, expresses a Leader protein that targets various host cell processes. In this study, LC-MS/MS proteomic analysis was performed on EVs isolated via density gradient-based separation from HeLa cells infected with wildtype or Leader-deficient EMCV. Proteomes of these EVs were compared and proteins incorporated in EVs in a Leader-dependent manner were subjected to functional enrichment analysis and protein-interaction analysis.

无包膜病毒（Non-enveloped viruses）如小RNA病毒（picornaviruses），可在诱导宿主细胞裂解前，通过细胞外囊泡（Extracellular Vesicles, EVs）释放以逃离受感染宿主细胞。这些细胞外囊泡会将分泌的病毒颗粒包裹于宿主来源的膜结构中，从而改变病毒-宿主相互作用，进而影响感染效率与抗病毒免疫。目前，对于调控被细胞外囊泡包裹的病毒的形成与释放的病毒及宿主因子，我们仍知之甚少。脑心肌炎病毒（Encephalomyocarditis Virus, EMCV）属于小RNA病毒科，其编码的前导蛋白（Leader protein）可靶向调控多种宿主细胞进程。本研究针对分别感染野生型或前导蛋白缺陷型脑心肌炎病毒的海拉细胞（HeLa cells），通过密度梯度分离法获取其细胞外囊泡，并对其开展液相色谱-串联质谱（LC-MS/MS）蛋白质组学分析。随后，对两组细胞外囊泡的蛋白质组进行比较，并将以依赖前导蛋白的方式被整合入细胞外囊泡的蛋白质进行功能富集分析与蛋白质相互作用分析。