Exosomes mediate horizontal transmission of viral pathogens from insect vectors to plant phloem.
Exosomes mediate horizontal transmission of viral pathogens from insect vectors to plant phloem.
复制标题
外泌体介导病毒病原体从昆虫载体到植物韧皮部的水平传播
作者：
Chen Q;Liu Y;Ren J;Zhong P;Chen M;Jia D;Chen H;Wei T
许多刺吸式昆虫能将病毒病原体与唾液一起水平传播到植物韧皮部，但其机制尚不清楚。在这里，我们报告说，一个重要的水稻呼肠孤病毒劫持小泡，称为外泌体，穿越顶端质膜到唾液储存腔中的叶蝉载体的唾液腺。因此，病毒粒子与外泌体一起水平传播到水稻韧皮部中，以在载体饲养期间建立初始植物感染。从培养的叶蝉细胞分泌的纯化的外泌体富集有病毒粒子。沉默外泌体分泌相关的小GTdR ab 27 a或用外泌体生物发生抑制剂GW 4869处理强烈阻止了体内和体外的病毒外泌体释放。此外，病毒外衣壳蛋白的15 nm长结构域与Rab5的特异性相互作用诱导病毒体在外泌体中的包装，最终激活Rab27 a依赖性外泌体释放途径。因此，我们预期外泌体介导的病毒水平传播是被媒介传播病毒劫持的保守策略。
Numerous piercing-sucking insects can horizontally transmit viral pathogens together with saliva to plant phloem, but the mechanism remains elusive. Here, we report that an important rice reovirus has hijacked small vesicles, referred to as exosomes, to traverse the apical plasmalemma into saliva-stored cavities in the salivary glands of leafhopper vectors. Thus, virions were horizontally transmitted with exosomes into rice phloem to establish the initial plant infection during vector feeding. The purified exosomes secreted from cultured leafhopper cells were enriched with virions. Silencing the exosomal secretion-related small GTPase Rab27a or treatment with the exosomal biogenesis inhibitor GW4869 strongly prevented viral exosomal release in vivo and in vitro. Furthermore, the specific interaction of the 15-nm-long domain of the viral outer capsid protein with Rab5 induced the packaging of virions in exosomes, ultimately activating the Rab27a-dependent exosomal release pathway. We thus anticipate that exosome-mediated viral horizontal transmission is the conserved strategy hijacked by vector-borne viruses.