Validating the Flavivirus Envelope Protein as an Antiviral Target

项目总结 登革病毒(DENV)和其他黄病毒是导致重大疾病的主要人类病原体。 通过广泛传播的蚊子物种传播，其中许多病毒传播迅速，并可能有 在先前不存在豁免权的情况下，对公共卫生造成毁灭性影响。因此，有很大的需要 应对当前和未来黄病毒威胁的对策。当前抗病毒药物的主要限制 开发的抗病毒靶标数量相对较少，其中大部分是病毒酶 (例如，聚合酶、蛋白酶)；当直接作用抗病毒药物用作 单一疗法；以及大多数这些药物的窄谱活性(“一种细菌，一种药物”)。新班级 可以介导广谱抗相关病毒活性的靶标，以及具有高屏障的靶标 尤其需要抵抗力来对抗新出现的病毒，因为我们通常缺乏足够的时间和 一旦这些病毒构成重大威胁，在有用的时间范围内开发新药的资源。 靶向黄病毒包膜蛋白E的小分子有可能模仿体液 在复制周期的早期，通过细胞外接触目标并阻止病毒进入而产生免疫反应。 我们已经确定了多个小分子抑制物系列，它们与DENV包膜蛋白E和 在病毒进入过程中抑制E介导膜融合，即使在颗粒上只有少数E拷贝时也是如此 是受抑制物结合的。这些化合物结合在结构域I和II之间的口袋中，抑制西尼罗河病毒、寨卡病毒、 和日本脑炎病毒，这至少是由于这个网站的部分保存。我们最近建立了一个 基于靶点的检测及其在DENV和寨卡病毒E蛋白新抑制剂鉴定中的应用 它们结合在保守的口袋里，比我们最初的抑制剂具有更多的类似药物的特性。建房 在这项工作中，我们现在提出一个全面的计划，合理地优化小分子抑制剂 DENV E蛋白作为一种潜在的抗病毒策略。为此，我们将把建模和结构结合起来- 具有有效筛选级联的指导性药物设计，使用基于互补靶点的生化 细胞和机械分析，使两个化学上不同的铅系列得到有效的优化。我们的 这项工作的主要目标是在DENV感染的小鼠模型中证明抗病毒效果，从而 一流的直接作用抗病毒药物的基础，用于治疗DENV构成的日益增长的全球威胁。

PROJECT SUMMARY Dengue virus (DENV) and other flaviviruses are major human pathogens that cause significant disease. Transmitted by widespread mosquito species, many of these viruses spread rapidly and can have a devastating impact on public health where prior immunity does not exist. There is thus a significant need for countermeasures to combat both current and future flavivirus threats. Major limitations in current antivirals development are the relatively small number of validated antiviral targets, most of which are viral enzymes (e.g., polymerases, proteases); the low barrier to resistance when direct-acting antivirals are used as monotherapies; and the narrow spectrum activity of most of these agents (“one bug, one drug”). New classes of targets that can mediate broad-spectrum activity against related viruses and that have high barriers to resistance are particularly needed to combat emerging viruses since we generally lack sufficient time and resources to develop new drugs on a useful time scale once these viruses pose significant threats. Small molecules targeting the flavivirus envelope protein, E, have the potential to mimic the humoral immune response by engaging their target extracellularly and blocking viral entry early in the replication cycle. We have identified multiple small molecule inhibitor series that bind to the DENV envelope protein, E, and inhibit E-mediated membrane fusion during viral entry even when only a minority of copies of E on the particle are inhibitor-bound. These compounds bind in a pocket between domains I and II and inhibit West Nile, Zika, and Japanese encephalitis viruses due to at least partial conservation of this site. We recently established a target-based assay and validated its use in the identification of new inhibitors of DENV and Zika E proteins that bind in the conserved pocket and that have more drug-like properties than our original inhibitors. Building on this work, we now propose a comprehensive plan to rationally optimize small molecule inhibitors of the DENV E protein as a potential anti-viral strategy. Towards this end, we will combine modeling and structure- guided drug design with an efficient screening cascade using complementary target-based biochemical, cellular and mechanistic assays to enable efficient optimization of two chemically distinct lead series. Our primary goal in this work is to demonstrate antiviral efficacy in a murine model of DENV infection, thus laying the foundation for first-in-class direct acting antivirals to treat the growing global threat that DENV poses.