A Novel Therapeutic Peptide to Treat P. aeruginosa Infection in Cystic Fibrosis Patients

项目摘要 我们的目标是开发6K-F17作为一种可以与妥布霉素配合使用的抗菌剂 囊性纤维化患者慢性耐药铜绿假单胞菌感染的治疗。CF 影响到全球超过70,000人1。即使使用目前的一系列抗生素，80%-95%的CF患者也会 最终死于慢性细菌感染引起的呼吸衰竭3。因此，有一个 尚未满足的重大需求是开发新的抗菌剂，用于治疗慢性阻塞性肺疾病患者的慢性耐药感染。 Cf是一种遗传性疾病，由囊性纤维化跨膜传导调节因子突变引起。 (Cftr)编码氯离子转运蛋白的基因。跨上皮氯离子转运受损导致 呼吸道分泌物脱水和呼吸道粘液缺乏清晰度5、6。因此，患有CF的人 容易发生以生物膜为基础的慢性细菌感染、支气管扩张症和呼吸衰竭。 慢性感染铜绿假单胞菌已被证明会导致更快的肺功能下降，质量较低 生命，和过早死亡8-11。治疗慢性铜绿假单胞菌感染尤其具有挑战性。 菌株不断适应环境挑战，包括形成粘液样生物膜。这些 生物膜保护细菌免受自然宿主防御机制的影响，使它们对小分子更具抵抗力 分子抗生素5，12-18。 通过使用阳离子，在开发生物被膜感染治疗方面取得了进展 抗菌肽(CAPS)。帽子天然存在于各种各样的生物体中，从植物到 并构成先天免疫系统19-21的主要组成部分。重要的是，这些天然的帽子 通过破坏细菌的细胞膜来杀死细菌--实际上是通过倒伏并积累在细菌体内来“炸毁”细菌。 而不是针对特定的细菌蛋白质或生化途径。这 机制阻碍了细菌对CAPS的耐药性的出现。最近，我们团队开发了一种小说 一种名为6K-F17的多肽，可以破坏铜绿假单胞菌产生的生物膜，并使用一种新的 膜缔合机制。由于其独特的作用机制，6K-F17与 抗生素，如妥布霉素，以杀死抗药性铜绿假单胞菌菌株。 在这项工作的基础上，这项建议的目标是产生最佳剂量、药代动力学和 6K-F17在小鼠体内的毒理学研究具体目标是：1)生产足够数量的6K-F17和 规范分析和效价分析；2)确定6K-F17的最佳有效清除剂量。 3)初步建立了6K-F17在正常小鼠的急性毒理学模型。 这些研究的成功完成将推动一种令人兴奋的抗菌剂的治疗 CF患者中的耐药铜绿假单胞菌，以及潜在的其他耐药肺部感染。

Project Summary Our objective is to develop 6K-F17 as an antimicrobial agent that can be prescribed with tobramycin for the treatment of chronic, antibiotic-resistant Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients. CF affects over 70,000 people worldwide1. Even with the current array of antibiotics, 80-95% of CF patients will ultimately succumb to respiratory failure brought on by chronic bacterial infections3. As a result, there is a significant unmet need to develop new antimicrobials for chronic, antibiotic-resistant infections in CF patients. CF is a genetic disease arising from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene that encodes a chloride ion transporter4. Impaired trans-epithelial chloride transport leads to dehydrated airway secretions and a lack of airway mucus clearance5, 6. As a result, individuals with CF are prone to chronic, biofilm-based bacterial infections, bronchiectasis and respiratory failure6, 7In particular, chronic infection with P. aeruginosa has been shown to lead to more rapid lung function decline, a lower quality of life, and premature death8-11. Chronic infection with P. aeruginosa is particularly challenging to treat as this strain continually adapts to environmental challenges, including the formation of a mucus-like biofilms. These biofilms protect bacteria from natural host defense mechanisms and make them more resistant to small molecule antibiotics 5, 12-18. Progress toward developing treatments for biofilm infections has been made through the use of cationic antimicrobial peptides (CAPs). CAPs are found naturally in a wide variety of organisms ranging from plants to humans and constitute a major component of the innate immune system19-21. Importantly, these natural CAPs kill bacteria by destroying their membranes – in effect ‘blowing up’ the bacteria by lodging and accumulating in their membranes - rather than by targeting a specific bacterial protein or biochemical pathway. This mechanism impedes the advent of bacterial resistance to CAPs. Recently, our team developed a novel peptide, called 6K-F17, that can disrupt biofilms created by P. aeruginosa and kill the bacteria using a novel mechanism of membrane association. Due to its unique mechanism of action, 6K-F17 synergizes with antibiotics, such as tobramycin, to kill antibiotic-resistant strains of P. aeruginosa. Building from this work, the objective of this proposal is to generate the optimal dose, pharmacokinetics and toxicology profiles for 6K-F17 in mice. The specific aims are to: 1) produce sufficient amounts of 6K-F17 and standardize analytical and potency assays; 2) determine the optimal effective dose of 6K-F17 to eliminate P. aeruginosa infection in mice; and 3) establish a preliminary acute toxicology profile for 6K-F17 in normal mice. Successful completion of these studies will advance an exciting antimicrobial agent for the treatment of antibiotic-resistant P. aeruginosa, and potentially other antibiotic-resistant lung infections, in CF patients.