Novel gene-silencing therapeutics for multidrug-resistant gram-negative pathogens

描述(申请人提供)：对新的抗菌剂的需求日益迫切。耐多药病原体的比率继续上升，导致全世界出现严重的发病率和死亡率。此外，目前新抗菌剂的流水线仍然非常狭窄。美国传染病学会在他们的“Bad Bugs，No Druits”运动中发现了一组病原体，它们对目前的抗生素越来越耐药。这一组包括革兰氏阴性病原体鲍曼不动杆菌和大肠杆菌。最近，抗生素发现和设计中的一种新范式被证明对许多细菌有效。这一新方法是基于一种名为多肽-磷二酸酯莫霍利诺齐聚物(PPMOS)的平台技术。PPMO是一种人工合成的DNA模拟物，以序列特异性的反义方式与RNA结合，抑制细菌基本基因的表达。PPMO已经成功地用于杀死各种细菌病原体，包括革兰氏阴性杆菌、大肠杆菌、鼠伤寒沙门氏菌、洋葱伯克霍尔德氏菌复合体和鲍曼不动杆菌。PPMO在培养中具有杀菌作用，在感染动物模型中可以减少菌血症并提高存活率。PPMO比氨苄西林等许多传统抗生素更有效。该项目的目标是开发用于治疗多重耐药病原体大肠杆菌和鲍曼不动杆菌的PPMO。其具体目标是设计、生产和筛选针对多重耐药病原菌大肠杆菌和鲍曼不动杆菌中不同基因靶点的PPMO。实验方法是以已知或怀疑对有机体生长至关重要的途径中的基因为靶点，包括内毒素、肽聚糖和脂肪酸的生物合成基因。另一种方法是使用PPMO作为辅助治疗，并针对特定的抗生素耐药机制，以恢复对当前使用的抗生素的敏感性。这项技术提供了方法学上的优势，因为许多PPMO可以快速合成，并同时针对许多目标进行测试。这使得有可能针对单个生物体中的多个基因，或者开发针对多种病原体的PPMO鸡尾酒。该项目将确定大肠杆菌和鲍曼不动杆菌中可以推进到临床前和临床研究的主要靶标PPMO。 与公共卫生相关：革兰氏阴性细菌病原体之间的多重耐药性正变得越来越频繁。我们建议利用一种新的反义技术来快速开发和筛选针对多重耐药大肠杆菌和鲍曼不动杆菌的基本基因和抗生素耐药机制的治疗化合物。由于这些反义抗菌化合物的新颖性，它们应该可以有效地对抗对现有抗生素具有抗药性的细菌。

DESCRIPTION (provided by applicant): The need for new antimicrobials is increasingly urgent. The rate of multidrug resistant pathogens continues to increase leading to significant morbidity and mortality throughout the world. Furthermore, the current pipeline for new antimicrobials remains very narrow. The Infectious Diseases Society of America has identified in their "Bad Bugs, No Drugs" campaign, a group of pathogens that have become increasingly resistant to current antibiotics. This group includes the Gram-negative pathogens Acinetobacter baumannii and Escherichia coli. A new paradigm in antibiotic discovery and design has recently been shown effective against numerous bacteria. This new approach is based on a platform technology called peptide-phosphorodiamidate mopholino oligomers (PPMOs). PPMOs are synthetic DNA mimics that bind to RNA in a sequence-specific, antisense manner and inhibit expression of essential bacterial genes. PPMOs have already been used successfully to kill a variety of bacterial pathogens including the Gram-negative bacteria Escherichia coli, Salmonella typhimurium, Burkholderia cepacia complex and Acinetobacter baumannii. PPMOS are bactericidal in culture, and reduce bacteremia and improve survival in animal models of infection. PPMOs are more potent than many traditional antibiotics such as ampicillin. The goal of this project is to develop PPMOs for therapeutic use against the multidrug resistant pathogens Escherichia coli and Acinetobacter baumannii. The specific aims are to design, produce and screen PPMOS against various gene targets in the multidrug-resistant pathogens E. coli and A. baumannii. The experimental approach is to target genes in pathways that are known or suspected to be essential for the growth of the organism, including genes for biosynthesis of lipopolysaccharide, peptidoglycan, and fatty acids. Another approach will be to use PPMOs as adjunctive therapies and target specific antibiotic resistance mechanisms in order to restore susceptibility to currently used antibiotics. This technology provides a methodological advantage because many PPMOs can be rapidly synthesized and simultaneously tested against numerous targets. This allows for the possibility of targeting multiple genes in a single organism or the development of cocktails of PPMOs that target multiple pathogens. This project will identify lead target PPMOs in E. coli and A. baumannii that can be moved forward to pre-clinical and clinical studies. PUBLIC HEALTH RELEVANCE: Multidrug resistance among Gram-negative bacterial pathogens is becoming increasingly frequent. We propose to utilize a novel anti-sense technology to rapidly develop and screen therapeutic compounds targeting essential genes as well as antibiotic resistance mechanisms in the multidrug resistant pathogens Escherichia coli and Acinetobacter baumannii. Because of the novelty of these antisense antibacterial compounds, they should be effective against bacteria that are resistant to existing antibiotics.