Role of ISG15 in Inhibition of Ebola Virus Budding

描述(申请人提供)：埃博拉病毒是一种A类病毒，是一种新出现的人类病原体，可导致毁灭性的出血热暴发。组装和萌芽是埃博拉病毒复制周期中的重要后期事件。虽然关于病毒复制的这些动态和多方面阶段已经了解了很多，但组装和萌芽的分子机制仍然不清楚。这项提案重点关注埃博拉病毒的VP40基质蛋白。埃博拉VP40蛋白含有晚期萌芽结构域(L结构域)，通过介导与宿主蛋白的相互作用，在病毒输出过程中发挥关键作用，如Tsg101。我们假设宿主的先天免疫反应通过靶向VP40 L结构域的活性来抑制埃博拉病毒的萌发。初步数据表明，干扰素刺激基因15(ISG15)可以抑制埃博拉VP40 VLP的萌发。为了验证我们的假设，我们提出了三个特定的目标：1)确定ISG15的表达是否以一种L结构域依赖的方式抑制埃博拉VP40VLP的释放；2)确定ISG15的表达是否抑制埃博拉病毒或表达埃博拉病毒L结构域的VSV重组体的释放；以及3)确定ISG15的表达是否抑制埃博拉VP40/宿主TSG101的相互作用。这些研究的结果将提供有关先天免疫反应的特定成分如何抑制埃博拉病毒萌芽的基础知识，并为未来进一步阐明这些先天免疫反应对埃博拉病毒感染的机制和生物学意义提供基础。

DESCRIPTION (provided by applicant): Ebola virus is a Category A virus and an emerging human pathogen that causes devastating outbreaks of hemorrhagic fever. Assembly and budding are important late events in the replication cycle of Ebola virus. While much has been learned regarding these dynamic and multifaceted stages of virus replication, the molecular mechanisms of assembly and budding remain unclear. This proposal focuses on the VP40 matrix protein of Ebola virus. Ebola VP40 protein contains late budding domains (L-domain) that play a key role in virus egress by mediating interactions with host proteins, such as tsg101. We hypothesize that host innate immune responses inhibit Ebola virus budding by targeting VP40 L-domain activity. Preliminary data implicate interferon stimulated gene 15 (ISG15) in inhibiting Ebola VP40 VLP budding. To test our hypothesis, we propose 3 Specific Aims: 1) To determine whether expression of ISG15 inhibits release of Ebola VP40 VLPs in an L-domain dependent manner, 2) To determine whether expression of ISG15 inhibits release of Ebola virus or VSV recombinants expressing Ebola virus L-domains, and 3) To determine whether expression of ISG15 inhibits Ebola VP40/host tsg101 interactions. Results from these studies should provide fundamental knowledge of how specific components of the innate immune response may inhibit Ebola virus budding, and provide the foundation for future studies to elucidate further the mechanisms and biological significance of these innate immune responses to Ebola virus infection.