A chikungunya Viral Replicon as a Platform for Antiviral Therapeutics

I型干扰素通过诱导大量的抗病毒效应蛋白，在感染的多个点抑制不同的病毒，从而提供对病毒感染和复制的先天免疫抵抗的初始成分。这种反应的有效性所固有的是细胞信号通路，它首先在感染时触发干扰素基因的诱导，然后在对分泌型干扰素的反应中触发干扰素刺激基因(ISG)的表达。干扰素基因的诱导通过两条不同的途径进行，一条是在大多数感染细胞中由病毒核酸触发的胞浆信号系统，另一条是依赖于Toll样受体(TLR)蛋白的跨膜途径，这在树突状细胞中是至关重要的。基因和生化数据已经证明了干扰素系统在抗病毒免疫中的本质，但它的最终有效性受到通过削弱干扰素作用的病毒毒力因子的作用来逃避病毒的限制。我们提出的研究的基本假设是，通过更好地了解干扰素的诱导和作用及其通过病毒逃避造成的损害的分子机制，我们将能够设计出基于增强先天免疫和抑制病毒逃避的新疗法。该项目专注于三种不同的病毒，每种病毒都破坏了干扰素途径，即甲型流感病毒、牛痘病毒和基孔肯雅病毒；将在一组独特的转基因树突状细胞系中分析病毒与干扰素信号之间的相互作用；并将开发一个平台来筛选病毒毒力的小分子抑制剂。这项工作将与先天免疫团队的其他成员，Easer博士、Garcia-Sastre博士和Wu密切合作进行。 该项目很好地融入了区域经济委员会的使命。先天免疫已成为RCE关键重点领域的重要组成部分，对适应性免疫产生影响，对疫苗的佐剂作用至关重要；提供感染的重要诊断指标；并通过针对先天免疫系统和毒力因子之间的相互作用，揭示一种新的治疗方法。在这些研究中获得的知识也将适用于依赖类似机制的微生物先天免疫。

Type I interferon (IFN) provides an initial component of innate immune resistance to viral infection and replication by inducing a large set of antiviral effector proteins capable of inhibiting diverse viruses at multiple points in the infection. Inherent to the effectiveness of this response are cellular signaling pathways that first trigger IFN gene induction in response to infection and subsequently trigger IFN-stimulated gene (ISG) expression in response to secreted IFN. IFN gene induction proceeds through two distinct pathways, a cytosolic signaling system triggered by viral nucleic acid in the cytoplasm that operates in most infected cells and a transmembrane pathway dependent on Toll-like receptor (TLR) proteins that is critical in dendritic cells. The essential nature of the IFN system in antiviral immunity has been demonstrated by genetic and biochemical data, but its ultimate effectiveness is limited by viral evasion through the action of viral virulence factors that impaire IFN action. The underlying hypothesis of our proposed research is that through better understaning the molecular mechanisms of IFN induction and action and their impairment by viral evasion, we will be able to devise novel therapeutics based on augmenting innate immunity and inhibiting viral evasion. This project focuses on three distinct viruses that each impair the IFN pathway, influenza A virus, vaccinia virus, and chikungunya virus; will analyze the interaction between viruses and IFN signaling in a unique set of genetically modified dendritic cells lines; and will develop a platform to screen for small molecule inhibitors of viral virulence. This work will be performed in close collaboration with other members of the innate immunity team, Drs. Easier, Garcia-Sastre, and Wu. This project is well integrated into the mission of the RCE. Innate immunity has emerged as an essential component of the key focus areas of the RCE, impacting on adaptive immunity and being critical for athe adjuvant effects of vaccines; providing an important diagnostic indication of infection; and uncovering a novel approach to therapeutics by targeting the interaction between the innate immune system and virulence factors. Knowledge gained in these studies will also be applicable to microbial innate immunity that relies on similar mechanisms.