Spectinomycin analogs for NTM infections

用于 NTM 感染的壮观霉素类似物

• 批准号: 10471892
• 负责人: Richard E. Lee
• 金额: $ 82.97万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-17 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10471892
• 关键词: Acute; Amikacin; Aminoglycosides; Animals; Antibiotics; Bacterial Proteins; Binding; Binding Proteins; Binding Sites; Biological Assay; Biology; Chemistry; Chronic; Chronic lung disease; Clarithromycin; Clinical; Complement; Complex; Cryoelectron Microscopy; Data; Development; Disease; Drug Design; Drug Kinetics; Drug resistance; Ensure; Enzymes; Epidemic; Ethylenes; Exhibits; Extreme drug resistant tuberculosis; Generations; Genetic Transcription; Genus Mycobacterium; Goals; Human; In Vitro; Infection; Libraries; Link; Lung; Maximum Tolerated Dose; Methods; Minimum Inhibitory Concentration measurement; Mitochondrial Proteins; Modeling; Modification; Multi-Drug Resistance; Mus; Mutagenicity Tests; Mycobacterium Infections; Mycobacterium abscessus; Mycobacterium avium; Organoids; Outcome; Pathogenicity; Pathology; Pathway interactions; Permeability; Pharmaceutical Preparations; Pharmacology; Pharmacotherapy; Predisposition; Property; Protein Synthesis Inhibition; Proteins; Refractory; Research Personnel; Resistance; Ribosomes; Safety; Side; Spectinomycin; Structure; Testing; Therapeutic; Translational Research; Translations; Treatment Efficacy; Virulence; analog; base; biological adaptation to stress; cytotoxicity; design; efficacy study; emerging pathogen; genome sequencing; in vitro activity; in vivo; lipophilicity; liver metabolism; member; mouse model; mutant; mycobacterial; non-tuberculosis mycobacteria; novel therapeutics; pathogen; resistance mechanism; response; safety study; safety testing; standard of care; transcriptome sequencing; whole genome

Non-tuberculous mycobacteria (NTM) are emerging pathogens with high intrinsic drug resistance. Mycobacterium abscessus is the most pathogenic refractory NTM member, and infections with this pathogen are associated with especially poor clinical outcomes. The standard of care therapy of amikacin and clarithromycin fails in a high proportion of cases, and thus there is a clear need for new therapeutic options. To approach this challenge, we investigated the synthetic modification of spectinomycin, an aminocyclitol antibiotic that exhibits potent bacterial protein synthesis inhibition but has limited efficacy in mycobacteria due to intrinsic resistance mechanisms. A library of semi-synthetic spectinomycin analogs was profiled for activity against M. abscessus, from which a distinct structural subclass of ethylene linked aminomethyl spectinomycins (eAmSPC) was identified. Initial leads of this subclass display potent anti-M. abscessus activity, while maintaining the desired pharmacological properties of minimal cytotoxicity and hepatic metabolism, low protein binding, and absence of mitochondrial protein synthesis inhibition. These leads have favorable activity against multi-drug resistant M. abscessus clinical isolates, are active against other NTM pathogens, minimally induce the WhiB7 ribosomal stress response pathway, are not substrates for mycobacterial aminoglycoside modifying enzymes and demonstrate robust efficacy in M. abscessus mouse infection models. The results of these preliminary studies suggest that eAmSPCs have the potential to be developed into treatments for M. abscessus and other NTM infections. The key goals of this proposal are to increase the potency and tolerability of the eAmSPCs. This will be achieved through an iterative drug cycle to include: (i) A structure-guided optimization strategy will be applied to the ethyl side chain to reduce its lipophilicity and generate extra binding interactions in the RpsE / 30S helix-34 binding side pocket. (ii) Further rounds of optimization will be guided by mycobacterial ribosomal inhibition, minimum inhibitory concentration (MIC) activity against a panel of non-tuberculous mycobacteria (NTM), and in vitro pharmacokinetic studies. Recently developed Cryo-EM methods in mycobacterial ribosomes will confirm the binding mode and assist in these structure-based drug design efforts. Accumulation studies to investigate permeability and efflux will help define which structural modifications are successful in overcoming intrinsic resistance mechanisms. Whole- genome sequencing and RNAseq studies will ensure compounds remain on target and explore drug resistance and virulence mechanisms. (iii) In vivo pharmacokinetics, safety, and efficacy studies on emerging leads will be determined, in comparison to the standard of care antibiotics, using acute and chronic mouse models of NTM infection that recapitulate the pathology of NTM infected human lung. Late leads will be profiled for in vitro pharmacology safety. Compounds developed in this proposal against M. abscessus will be prioritized to include those with activity against M. avium and other NTMs in order to generate therapeutics with a wider spectrum against this important group of pathogens.

非结核分枝杆菌（NTM）是具有高度内在耐药性的新兴病原体。脓肿分枝杆菌是致病性最强的难治性 NTM 成员，这种病原体的感染与特别不良的临床结果相关。阿米卡星和克拉霉素的标准护理治疗在大部分病例中都失败，因此显然需要新的治疗选择。为了应对这一挑战，我们研究了壮观霉素的合成修饰，这是一种氨基环醇抗生素，具有有效的细菌蛋白质合成抑制作用，但由于内在的耐药机制，对分枝杆菌的功效有限。对半合成壮观霉素类似物文库针对脓肿分枝杆菌的活性进行了分析，从中鉴定出乙烯连接的氨甲基壮观霉素 (eAmSPC) 的独特结构亚类。该亚类的最初先导显示出有效的抗 M 抗体。脓肿活性，同时保持最小的细胞毒性和肝代谢、低蛋白质结合以及不存在线粒体蛋白质合成抑制等所需的药理学特性。这些先导化合物对多重耐药脓肿分枝杆菌临床分离株具有良好的活性，对其他 NTM 病原体具有活性，最小程度地诱导 WhiB7 核糖体应激反应途径，不是分枝杆菌氨基糖苷修饰酶的底物，并且在脓肿分枝杆菌小鼠感染模型中表现出强大的功效。这些初步研究的结果表明，eAmSPC 有潜力被开发用于治疗脓肿分枝杆菌和其他 NTM 感染。该提案的主要目标是提高 eAmSPC 的效力和耐受性。这将通过迭代药物循环来实现，包括：（i）将结构引导的优化策略应用于乙基侧链，以降低其亲脂性并在 RpsE / 30S helix-34 结合侧袋中产生额外的结合相互作用。 (ii) 进一步的优化将以分枝杆菌核糖体抑制、针对一组非结核分枝杆菌 (NTM) 的最低抑菌浓度 (MIC) 活性以及体外药代动力学研究为指导。最近开发的分枝杆菌核糖体冷冻电镜方法将确认结合模式并协助这些基于结构的药物设计工作。研究渗透性和外排的积累研究将有助于确定哪些结构修饰可以成功克服内在阻力机制。全基因组测序和 RNAseq 研究将确保化合物保持在目标上，并探索耐药性和毒力机制。 (iii) 将使用 NTM 感染的急性和慢性小鼠模型来确定新兴先导药物的体内药代动力学、安全性和功效研究，与护理标准抗生素进行比较，这些模型概括了 NTM 感染的人肺的病理学。后期的先导化合物将进行体外药理学安全性分析。该提案中开发的针对脓肿分枝杆菌的化合物将优先考虑那些具有针对鸟分枝杆菌和其他 NTM 活性的化合物，以便产生针对这一重要病原体群的更广谱的治疗方法。