Small molecule inhibitors of bacterial iron acquisition systems

细菌铁获取系统的小分子抑制剂

基本信息

批准号：
8891411
负责人：
HARRY L. MOBLEY
金额：
$ 39.48万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-15 至 2017-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8891411
关键词：
Antibiotic Resistance Antibiotics Assimilations Attention Bacteremia Bacteria Bacterial Infections Binding Biological Biological Assay Biological Factors Blood Circulation Chemicals Complement Data Development Disease Dose Enzymes Escherichia coli Ferritin Fimbrial Adhesins Funding Gastroenteritis Gene Cluster Goals Grouping Growth Health Heme Hemoglobin Human Incidence Infection Investigation Ions Iron Iron Chelation Knowledge Licensing Life Mediating Outcome Pathway interactions Prevention Production Proteins Proteomics Public Health Quinolones Recurrence Research Respiratory System Respiratory tract structure Sampling Scourge Series Services Siderophores Site Structure Structure-Activity Relationship System Testing Therapeutic Agents Toxin Trimethoprim-Sulfamethoxazole Urinary tract Urinary tract infection Uropathogenic E. coli Vaccination Vaccines Virulence Woman Work antimicrobial antimicrobial drug base burden of illness cofactor combat cost counterscreen disability experience fitness follow-up heme-binding protein high throughput screening improved inhibitor/antagonist men novel pathogen pathogenic Escherichia coli prevent receptor resistant strain response small molecule small molecule libraries transcriptomics uptake vaccine development

项目摘要

DESCRIPTION (provided by applicant): The urinary tract is among the most common sites of bacterial infection and Escherichia coli is by far the most common species infecting this site. Infections are routinely treated with antibiotics including trimethoprim- sulfamethoxazole or quinolones. While vaccine development is in the pipeline, there are no vaccines currently licensed for use in the U.S. In the face of steadily climbing rates of antibiotic resistance and dramatic reduction in development of new antibiotics, isolation of novel small molecule antimicrobials are desperately needed. Lack of such new treatments will result in urinary tract infections (UTI) with multiply antibiotic-resistant strains that are untreatable. Using a series of unbiased screens including transcriptomic, proteomic, immunoproteomic, and qPCR assays, we have identified iron acquisition systems (siderophore- and heme- mediated) as vulnerable targets for inhibition and potential therapy. Our long-term research goal is to prevent and therapeutically treat UTIs in women and men. The objective is to identify and characterize small molecule inhibitors of iron uptake in gram-negative bacterial pathogens. In a pilot high throughput culture-based screen of 6298 compounds, we had an initial hit rate of 2.3% (147 compounds) [overall Z' factor=0.81 (avg Z' per plate=0.9), S/B=6, CV=6%] with a cutoff set at 3 SD below the negative control and inhibitory activity higher than 30%. Five hits were validated by counterscreens, dose response curves, and inhibition with fresh chemical samples. For one compound, data are consistent with inihibition of the TonB system as its target. Our central hypothesis is that specific small molecule inhibitors that do not depend on iron chelation can specifically block iron acquisition in bacteria. This discovery will drive biological investigationof the diverse iron acquisition mechanisms and complement our vaccination efforts using iron receptor protein targets. We will achieve our objective by completing the following specific aims: 1) Develop and implement a high throughput screen to identify small molecule inhibitors of iron acquisition by extraintestinal pathogenic Escherichia coli (ExPEC); 2) Conduct counter screens, validate hits using fresh chemical samples, and analyze structure-activity relationships (SAR) for small molecule inhibitors of ExPEC iron acquisition; and 3) Determine common targets used by iron acquisition pathways that are inhibited by each validated small molecule inhibitor. The expected outcomes of these aims will be to identify compounds and develop derivatives that arrest bacterial growth by preventing bacterial iron assimilation. The positive impact of these studies will be substantial. We will identify novel small molecule inhibitors of bacterial iron uptake from among 150,000 chemical compounds and 27,278 natural product extracts, validate these hits with fresh samples, and improve upon these products by assessment of derivatives. This knowledge will provide us with alternate therapeutic agents beyond existing antibiotics and potential vaccines to prevent this public health scourge in women with recurrent UTI and those susceptible to their first UTI.

描述（由申请人提供）：尿路是细菌感染和大肠杆菌的最常见部位之一，是迄今为止感染该部位的最常见物种。通常用抗生素（包括甲氧苄啶 - 磺胺甲恶唑或喹诺酮类）治疗感染。虽然疫苗开发仍在管道中，但面对抗生素耐药性的稳定攀升率和新的新抗生素发展的急剧降低，目前尚无疫苗用于使用的疫苗，因此迫切需要新型的小分子抗生素的分离。缺乏这种新的治疗方法将导致尿路感染（UTI）具有不可治疗的多重抗生素菌株。使用一系列公正的筛选包括转录组，蛋白质组学，免疫蛋白质组学和QPCR分析，我们已经将铁采集系统（副体和血红素介导的）确定为抑制和潜在治疗的脆弱靶标。我们的长期研究目标是预防和治疗男女的尿路感染。目的是识别和表征革兰氏阴性细菌病原体中铁摄取的小分子抑制剂。在试点高吞吐量的基于6298种化合物的高吞吐量筛选中，我们的初始命中率为2.3％（147种化合物）[总Z'因子= 0.81（AVG z'每板= 0.9），s/b = 6，cv = 6％]，截止量为3 SD的临界值低于阴性对照和抑制活性高于30％。五个命中率通过反屏幕，剂量反应曲线和新鲜化学样品抑制验证。对于一种化合物，数据与TONB系统作为其目标的无限性一致。我们的中心假设是，不依赖铁螯合的特定小分子抑制剂可以特异性地阻止细菌中的铁采集。这一发现将推动采用各种铁的获取机制的生物学研究，并使用铁受体蛋白靶标的我们的疫苗接种工作。我们将通过完成以下特定目的来实现目标：1）开发和实施高吞吐量屏幕，以鉴定通过遗产肠外致病性大肠杆菌（Expec）识别获得铁的小分子抑制剂（EXPEC）； 2）进行计数器筛选，使用新鲜的化学样品验证命中，并分析实验铁采集的小分子抑制剂的结构活性关系（SAR）； 3）确定由铁采集途径使用的共同靶标，这些靶标被每个经过验证的小分子抑制剂抑制。这些目的的预期结果将是鉴定化合物并开发通过防止细菌铁同化来阻止细菌生长的衍生物。这些研究的积极影响将是巨大的。我们将确定150,000种化合物和27,278种天然产物提取物中的细菌铁吸收的新型小分子抑制剂，用新鲜的样品验证这些命中，并通过评估衍生物来改进这些产物。这些知识将为我们提供除现有抗生素和潜在疫苗以外的替代治疗剂，以防止反复发作的UTI妇女的这种公共卫生祸害，并且容易受到第一UTI的影响。