Countermeasures for Bioterroism Targeting Cellular Host Factors

描述(由申请人提供)：生物恐怖主义的对策典型的针对病原体而不是宿主。然而，具有抗药性特征的病原体很容易产生，要么是通过自然发生的选择，要么是恐怖分子故意制造的。我们提出了一种新的对策方法，涉及设计病原体毒力所依赖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新设计的病原体同样有效，它们将成为现有生物防御设施的宝贵补充。我们建议使用炭疽病作为一个公认的A类病原体模型。炭疽杆菌是致命的，部分原因是它分泌的毒素。保护性抗原(PA)是致命炭疽毒素的基本递送成分，它需要与其他几种细菌毒力因子和病毒类似的呋喃类蛋白酶进行蛋白质分解处理，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胞浆，炭疽毒素就会刺激NALP1的激活，诱导细胞凋亡。NALP1是NLR家族的成员，NLR家族的蛋白质形成被称为“炎性小体”的复合体，激活caspase家族的蛋白酶。小鼠的遗传学研究表明，在炭疽杆菌暴露的环境中，NALP1是炭疽毒素诱导巨噬细胞凋亡和体内对致死性疾病易感性所必需的。我们建议产生小分子化学抑制剂的呋喃类蛋白水解酶和NLR家族的半胱氨酸氨基转移酶激活剂。为此，我们组建了一个多学科的协作团队，在高通量化学库筛选、药物化学和药物发现方面拥有专业知识；我们还生产了几种用于高通量筛选的原型分析，目的是针对Furin和NALP家族蛋白产生化学线索。这些先导将在效力、选择性和药理学特性方面进行优化，然后在炭疽啮齿动物模型中进行测试。由此产生的呋喃类和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.