Characterization of early steps in the poliovirus infection process: Receptor-decorated liposomes induce conversion of the virus to membrane-anchored entry-intermediate particles
Characterization of early steps in the poliovirus infection process: Receptor-decorated liposomes induce conversion of the virus to membrane-anchored entry-intermediate particles
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DOI：
10.1128/jvi.80.1.172-180.2006
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发表时间：
2006-01-01
影响因子：
5.4
通讯作者：
Hogle, JM
中科院分区：
文献类型：
--
作者：
Tuthill, TJ;Bubeck, D;Hogle, JM
脊髓灰质炎病毒感染细胞的机制已通过生物化学和结构研究的结合来确定，从而形成细胞进入的工作模型。在生理温度下受体结合后，原生病毒（160S）发生构象变化，成为一个135S粒子，VP4和VP1的N端从这个粒子外化。这些成分与膜相互作用，形成膜孔。颗粒中的另一个构象变化伴随着感染性病毒RNA基因组从颗粒中释放出来，并可能通过膜孔进入细胞质，留下一个空的80S颗粒。在本报告中，我们描述了由镍螯合硝基三乙酸（NTA）脂质体和his标记的脊髓灰质炎病毒受体组成的受体修饰脂质体系统的产生，以及它在脊髓灰质炎病毒感染早期事件表征中的应用。受体修饰的脂质体能够捕获病毒并诱导温度依赖性病毒转化为135S颗粒。转化后，135S颗粒通过膜与VP1的N端相互作用独立于受体与脂质体结合，转化后的颗粒失去VP4，与膜分离。一个简单模型膜系统的开发为研究脊髓灰质炎病毒进入提供了一种新的工具。脂质体系统弥补了以前使用可溶性受体或全细胞的研究之间的差距，并提供了一个灵活的模板，可以外推到电子显微镜实验中，分析非包膜病毒进入的结构生物学。
The mechanism by which poliovirus infects the cell has been characterized by a combination of biochemical and structural studies, leading to a working model for cell entry. Upon receptor binding at physiological temperature, native virus (160S) undergoes a conformational change to a 135S particle from which VP4 and the N terminus of VP1 are externalized. These components interact with the membrane and are proposed to form a membrane pore. An additional conformational change in the particle is accompanied by release of the infectious viral RNA genome from the particle and its delivery, presumably through the membrane pore into the cytoplasm, leaving behind an empty 80S particle. In this report, we describe the generation of a receptor-decorated liposome system, comprising nickel-chelating nitrilotriacetic acid (NTA) liposomes and His-tagged poliovirus receptor, and its use in characterizing the early events in poliovirus infection. Receptor-decorated liposomes were able to capture virus and induce a temperature-dependent virus conversion to the 135S particle. Upon conversion, 135S particles became tethered to the liposome independently of receptor by a membrane interaction with the N terminus of VP1 Converted particles had lost VP4, which partitioned with the membrane. The development of a simple model membrane system provides a novel tool for studying poliovirus entry. The liposome system bridges the gap between previous studies using either soluble receptor or whole cells and offers a flexible template which can be extrapolated to electron microscopy experiments that analyze the structural biology of nonenveloped virus entry.