Novel antimicrobial agents to overcome antibiotic resistant Pseudomonas and MRSA respiratory infection

根据疾病控制和预防中心的说法， 美国每年有23,000人死亡，200万人患病。许多死亡病例是 与危及生命的并发症有关，尤其是败血症。对经济影响的估计各不相同，但 高达200亿美元的直接医疗保健成本，以及高达350亿美元的损失， 生产力从住院和病假。不幸的是，由于令人担忧的 近年来，耐药细菌的增加以及新药物开发和发现的空白 在过去的三十年里，制药公司生产的抗生素。因此，小说的发展 有效对抗耐药细菌的疗法不仅具有科学和医学重要性， 国家优先。我们开发了一系列合理设计的阳离子抗菌肽（eCAPs） 使用不同的氨基酸计算排列，以实现不同药物的体外失活， 耐药菌株。先导化合物之一WLBU 2（仅由Arg、瓦尔和Trp组成）具有 证明了对多种难治性耐药病原体的有效杀菌活性， 对其他膜活性化合物产生了耐药性，如天然抗菌肽（AMP） LL 37和粘菌素，最后的抗生素。此外，我们已经证明， 与标准抗生素剂和天然AMP相比，细菌对WLBU 2产生抗性。重要的是， WLBU 2在铜绿假单胞菌脓毒症的鼠模型中显示出体内功效， 系统管理。由于最初的治疗指数较窄（TI ≤ 5），我们持续 使用系统迭代设计方法优化eCAP结构，以降低宿主毒性并增强 效力和稳定性。初步数据表明，其中一些基于Trp的eCAP（统称为 W2 eCAP）已经证明了更高的TI。基于这些探索性研究的令人兴奋的结果， 使用W2 eCAP来克服细菌抗性是一个吸引人的概念。因此，我们假设， W2 eCAP将显示出增强的针对DR细菌的杀菌活性以及可忽略的宿主毒性， 因此，可作为治疗肺炎引起的脓毒症的有效疗法。由于独特的肺 微环境，许多问题仍然需要回答之前，使用W2 eCAP的临床理想可以是 实现了因此，本提案的主要目的是了解：1）W2 eCAP如何发挥其抗菌作用 在与肺部相关的疾病中对抗主要呼吸道耐药病原体的活动 微环境; 2）W2 eCAPs杀死细菌的分子机制;（3）最佳处理 方案（全身与气道递送相比），以选择具有最高TI的W2 eCAP;以及（4） 所选W2 eCAP的药代动力学性质。

According to the Centers for Disease Control and Prevention, antibiotic-resistant infections are already linked to 23,000 deaths and 2 million illnesses in the United States each year. Many of the mortality cases are associated with life-threatening complications, especially sepsis. Estimates of the economic impact vary, but have ranged as high as $20 billion in excess direct healthcare costs, and as much as $35 billion in lost productivity from hospitalizations and sick days. Unfortunately, the problem is worsening because of an alarming increase in antibiotic-resistant bacteria in recent years and the void in the development and discovery of new antibiotics by pharmaceutical companies over the last three decades. As a consequence, development of novel therapies to effectively combat drug-resistant bacteria is not only of scientific and medical importance, but a national priority. We have developed a series of rationally engineered cationic antimicrobial peptides (eCAPs) using different amino acids computationally arranged to achieve in vitro inactivation of diverse drug- resistant bacterial strains. One of the lead compounds, WLBU2 (made only of Arg, Val, and Trp), has demonstrated potent bactericidal activity against diverse difficult-to-treat drug resistant pathogens that have developed resistance to other membrane-active compounds, such as the natural antimicrobial peptide (AMP) LL37 and colistin, an antibiotic of last resort. In addition, we have demonstrated a substantially lower tendency for bacteria to develop resistance to WLBU2 compared to standard antibiotic agents and natural AMPs. Importantly, WLBU2 demonstrates in vivo efficacy in a murine model of P. aeruginosa sepsis when the bacteria were systemically administered. Because of an initially narrow therapeutic index (TI ≤ 5), we are continuously optimizing eCAP structure using a systematic iterative design approach to lower host toxicity and enhance potency and stability. Preliminary data indicate that some of these Trp-based eCAPs (collectively referred to as W2eCAPs) have already demonstrated a higher TI. Based on the exciting results from these exploratory studies, the use of W2eCAPs to overcome bacterial resistance is an appealing concept. Hence, we hypothesize that W2eCAPs will display enhanced bactericidal activities against DR bacteria as well as negligible host toxicity and, therefore, can be used as an effective therapy to treat pneumonia-induced sepsis. Due to the unique lung microenvironment, many questions remain to be answered before the clinical ideal of using W2eCAPs can be realized. Thus, the primary purpose of this proposal is to understand: 1) how W2eCAPs exert their antimicrobial activities against major respiratory drug resistant pathogens in conditions associated with the lung microenvironment; 2) the molecular mechanisms used by W2eCAPs to kill bacteria; (3) the optimal treatment regimens (systemic compared to airway delivery) to select the W2eCAP with the highest TI; and (4) the pharmacokinetic properties of the selected W2eCAPs.