Small Molecule Inhibitors of P. aeruginosa Quinolone (Pqs) Quorum Sensing

项目摘要 铜绿假单胞菌Quinolone（Pqs）群体感应小分子抑制剂 RFA-AI-11-009：选定革兰氏阴性病原体的靶向耐药性（R21/R33） 铜绿假单胞菌是一种机会性革兰氏阴性病原菌， 医院感染的威胁，特别是对于免疫功能低下的患者，如烧伤 受害者、癌症患者和患有囊性纤维化或艾滋病的个体。铜绿假单胞菌也倾向于抗生素 抵抗力，通过内在和后天机制。因此，非常需要开发 新的抗假单胞菌药物，解决未开发的目标，这是一个具体的重点，这是RFA。 为了解决这个问题，我们在此提出开发新的小分子抗菌剂， P.铜绿假单胞菌喹诺酮（Pqs）群体感应系统。这是一个经过验证的目标， 小鼠感染模型，并不同于酰基高丝氨酸内酯（Las，Rhl）群体感应系统。 喹诺酮是由细菌生物合成的小分子，用于细胞-细胞信号传导。他们 控制与致病性相关的多种细菌毒力因子基因的表达， 对细菌的生存力或生长来说不是必需的。因此，靶向这些毒力因子的新型抗菌剂是 与传统的细菌毒性和抑菌抗生素相比，被认为不太可能引起耐药性。 在三个参与实验室（Tan，Rahme，Pesci）的大量先前工作的基础上，我们将 使用基于机理和结构的合理药物设计来开发PqsA的小分子抑制剂， 邻氨基苯甲酰辅酶A合成酶，其催化铜绿假单胞菌喹诺酮生物合成中的重要步骤。PqsA 已被验证为使用简单底物类似物的小鼠模型中的有效抗菌靶标，但 需要更有效和特异的抑制剂来充分利用该靶点的治疗潜力。在 R21阶段，我们将使用已应用的合理设计策略合成第一代抑制剂 在Tan实验室中成功地与相关靶标结合，然后在生化和细胞测定中评估其活性 PqsA活性和喹诺酮生产之前建立在Pesci和Rahme实验室。在R33 阶段，我们将优化抑制剂的生物化学，细胞和药理学特性，以开发 先导化合物将在已建立的铜绿假单胞菌小鼠模型中进行体内评价 在拉姆实验室感染这种多学科合作包括以下方面的必要综合专门知识： 合成有机化学、药物化学、生物化学、药理学和微生物学。我们长久以来- 长期目标是开发一种或多种先进的候选药物，用于进一步的临床前和临床评价， 新的抗生素，以打击铜绿假单胞菌和潜在的其他致病性革兰氏阴性细菌。

PROJECT SUMMARY Small Molecule Inhibitors of Pseudomonas aeruginosa Quinolone (Pqs) Quorum Sensing Submitted for RFA-AI-11-009: Targeting Resistance in Select Gram-Negative Pathogens (R21/R33) Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen that poses a significant public health threat in the context of nosocomial infections, particularly for immunocompromised patients such as burn victims, cancer patients, and individuals having cystic fibrosis or AIDS. P. aeruginosa is also prone to antibiotic resistance, through both intrinsic and acquired mechanisms. Thus, there is a great need for the development of novel anti-Pseudomonas drugs that address unexploited targets, and this is a specific focus of this RFA. To address this problem, we propose herein to develop novel small molecule antibacterials that target the P. aeruginosa quinolone (Pqs) quorum sensing system. This is a pharmacologically validated target in a mouse model of infection and is distinct from acyl homoserine lactone (Las, Rhl) quorum sensing systems. Quinolones are small molecules that are biosynthesized by the bacteria and used in cell-cell signaling. They control expression of a variety of bacterial virulence factor genes that are associated with pathogenicity but are not required for bacterial viability or growth. As such, novel antibacterials that target such virulence factors are thought less likely to elicit drug resistance compared to traditional bacteriotoxic and bacteriostatic antibiotics. Building upon extensive previous work from the three participating laboratories (Tan, Rahme, Pesci), we will use mechanism- and structure-based rational drug design to develop small molecule inhibitors of PqsA, an anthraniloyl-CoA synthetase that catalyzes an essential step in P. aeruginosa quinolone biosynthesis. PqsA has been validated as an effective antibacterial target in a mouse model using simple substrate analogues, but more potent and specific inhibitors are required to exploit fully the therapeutic potential of this target. In the R21 phase, we will synthesize first-generation inhibitors using a rational design strategy that has been applied successfully to related targets in the Tan lab, then evaluate their activities in biochemical and cellular assays for PqsA activity and quinolone production established previously in the Pesci and Rahme labs. In the R33 phase, we will optimize the biochemical, cellular, and pharmacological properties of the inhibitors to develop lead compounds that will then be advanced to in vivo evaluation in established mouse models of P. aeruginosa infection in the Rahme lab. This multidisciplinary collaboration comprises the necessary combined expertise in synthetic organic chemistry, medicinal chemistry, biochemistry, pharmacology, and microbiology. Our long- term goals are to develop one or more advanced candidates for further preclinical and clinical evaluation as novel antibiotics to combat P. aeruginosa and potentially other pathogenic Gram-negative bacteria.