Innovative technologies to transform antibiotic discovery. Project 4 Infection site-specific amplification of antimicrobial conjugates

摘要 由于快速演变的耐药性，临床上对革兰氏阴性菌的药物治疗是一项迫切的未得到满足的需求 菌株，常规抗生素不能穿透细胞外壁，以及体内非靶点药物毒性。 抗菌肽和其他小分子抗菌素在临床前应用前景看好 抗多药耐药革兰氏阴性病原菌的检测，但在临床上面临重大挑战 翻译是体内治疗效果不佳的结果。这项建议解决了小说的不足。 利用革兰氏阴性菌细胞表面多药耐药的治疗策略 葡聚糖和当地环境提供抗菌剂有效载荷。长期循环的亲药物结构将是 在全身给药后有选择地针对感染部位进行改造并激活以应对 受感染的组织微环境所特有的蛋白质分解活性。建议的抗菌剂，称为 抗菌结合物(AMCs)由病原体特异性靶向剂、微环境特异性靶向剂组成 可切割接头和杀菌有效载荷。这种模块化设计允许探索不同的组件 以优化偶联物的活性。建议的AMCs将在体外设计和广泛评估，并 在由Sangeeta Bhatia博士组成的麻省理工学院联合团队的毒性和抗菌活性动物模型中， 蒂莫西·卢、劳拉·基斯林和布拉德利·潘特鲁特。他们的实验室将利用对蛋白酶反应的专业知识 纳米材料、合成生物学和计算设计、蛋白质-多糖识别过程以及 分别采用生物偶联技术和多肽快速合成技术来促进AMCs的发展。 这种新的治疗方式有几个优点：对病原体靶点的高度特异性将 限制对宿主的毒性，使之能够使用选择性较低的抗菌剂，结合物将增加 药代动力学，且窄谱活性可避免一般耐药机制的扩散 在物种之间，并限制对宿主微生物群的损害。该项目的完成将产生领先地位 用于治疗耐药革兰氏阴性感染的抗菌素结合物。集体优化 先导化合物的治疗概况将确定可以推进临床前试验的最佳候选者， 有可能提供一种有效地绕过获得性革兰氏阴性抗生素的治疗策略 抵抗。

ABSTRACT Drugging Gram-negative bacteria in the clinic is an urgent unmet need due to rapidly-evolving resistant strains, the inability of conventional antibiotics to penetrate the outer cell wall, and off-target in vivo drug toxicities. Antimicrobial peptides (AMPs) and other small molecule antibacterial leads have shown promise in preclinical testing for killing multi-drug resistant Gram-negative pathogens, but have faced significant challenges in clinical translation as a result of inferior therapeutic outcomes in vivo. This proposal addresses the shortage of novel treatment strategies for multi-drug resistant Gram-negative pathogens by exploiting the pathogen's cell surface glycans and local environment to deliver antimicrobial payloads. Long-circulating, pro-drug constructs will be engineered that selectively target the site of infection after systemic administration and activate in response to proteolytic activity specific to the infected tissue microenvironment. The proposed antimicrobial agents, termed antimicrobial conjugates (AMCs) consist of a pathogen-specific targeting agent, a microenvironment-specific cleavable linker, and a bactericidal payload. This modular design allows the exploration of different components to optimize the conjugate's activity. The proposed AMCs will be designed and extensively evaluated in vitro and in animal models for toxicity and antimicrobial activity by a joint team at MIT composed of Drs. Sangeeta Bhatia, Timothy Lu, Laura Kiessling, and Bradley Pentelute. Their labs will leverage expertise with protease-responsive nanomaterials, synthetic biology and computational design, protein-glycan recognition processes, and bioconjugation and rapid peptide synthesis technologies, respectively, to advance the development of AMCs. This new therapeutic modality has several advantages: the high level of specificity for pathogen targets will limit toxicity to host, enabling the use of less selective antimicrobial agents, the conjugates will have increased pharmacokinetics, and the narrow spectrum activity will avoid the spread of general resistance mechanisms between species and limit damage to the host microbiota. Completion of the project will generate lead antimicrobial conjugates for the treatment of resistant Gram-negative infections. Collectively optimizing the therapeutic profiles of lead compounds will identify top candidates that can be advanced for pre-clinical trials, with the potential to deliver a therapeutic strategy that effectively bypasses acquired Gram-negative antibiotic resistance.