Countermeasures for Bioterroism Targeting Cellular Host Factors

描述（由申请人提供）：生物恐怖主义的对策通常针对病原体而不是宿主。然而，具有耐药特性的病原体很容易产生，要么是自然发生的选择，要么是恐怖分子蓄意制造的。我们提出了一种新的对策方法，包括设计病原体依赖于其毒力的细胞宿主因子的多用途抑制剂。由于这些抑制剂对天然病原体和重组病原体同样有效，它们将成为现有生物防御装备的宝贵补充。我们建议使用炭疽作为a类病原体的成熟模型。炭疽芽孢杆菌是致命的，部分原因是它分泌的毒素。保护性抗原（PA）是致死性炭疽毒素的重要递送成分，为了变得活跃，它需要furin家族蛋白酶进行蛋白水解处理，类似于其他几种细菌毒力因子和病毒，包括出血热黄病毒和禽流感H5N1（禽流感）。一旦进入宿主细胞的细胞质，炭疽毒素刺激NALP1的激活，诱导细胞凋亡。NALP1是NLR家族的一员，NLR家族的蛋白质形成被称为“炎性小体”的复合物，可以激活半胱天冬酶家族蛋白酶。小鼠的遗传学研究表明，在炭疽杆菌暴露的环境下，NALP1是炭疽毒素诱导的巨噬细胞凋亡和对致命疾病的体内易感性所必需的。我们建议制备呋喃家族蛋白酶的小分子化学抑制剂和nlr家族半胱天冬酶激活剂。为此，我们组建了一支多学科合作团队，在高通量化学文库筛选、药物化学和药物发现方面具有专业知识；我们还生产了几种用于高通量筛选的原型试验，目的是产生针对furin和nalp家族蛋白的化学导联。这些线索将优化效力，选择性和药理学性质，然后在炭疽啮齿动物模型中进行测试。由此产生的furin-和nalp1家族宿主蛋白的化学抑制剂将为潜在的临床开发提供先导化合物。

DESCRIPTION (provided by applicant): Countermeasures for bioterrorism typical target the pathogen as opposed to the host. However, pathogens with drug-resistant characteristics are readily produced, either by naturally occurring selection or deliberate engineering by terrorists. We propose a novel countermeasure approach involving design of multi-purpose inhibitors of cellular host factors that pathogens depend on for their virulence. Because these inhibitors are equally effective against both the natural and the re-engineered pathogens, they will be a valuable addition to the existing biodefense armamentarium. We propose to use Anthrax as a well-established model of a Class A pathogen. Bacillus anthracis is deadly in part because of the toxin it secretes. To become active, Protective Antigen (PA), an essential delivery component of lethal Anthrax Toxin, requires furin-family proteases for proteolytic processing, similar to several additional bacterial virulence factors and viruses, including hemorrhagic fever flaviviruses and avian influenza H5N1 (bird flu). Once inside the cytosol of host cells, the Anthrax Toxin stimulates activation of NALP1, inducing apoptosis. NALP1 is a member of the NLR family, proteins that form complexes known as "inflammasomes," which activate caspase-family proteases. Genetic studies of mice indicate that NALP1 is required for Anthrax Toxin-induced macrophage apoptosis and in vivo susceptibility to lethal disease in the setting of Bacillus anthracis exposure. We propose to generate small-molecule chemical inhibitors of furin-family proteases and NLR-family caspase activators. To this end, we have assembled a multi-disciplinary, collaborative team with expertise in high-throughput chemical library screening, medicinal chemistry, and drug discovery; we have also produced several prototype assays for high throughput screening, with the aim of generating chemical leads against furin- and NALP-family proteins. These leads will be optimized for potency, selectivity, and pharmacological properties, and then tested in rodent models of Anthrax. The resulting chemical inhibitors of furin- and NALP1-family host proteins will provide lead compounds for potential clinical development.