RATIONAL DESIGN OF MANNOSIDES FOR INHIBITION OF FIMH AND TREATMENT OF UTI

描述(申请人提供)：尿路(UT)是人类常见的感染部位，在美国估计有800万门诊就诊，估计每年的费用超过25亿美元。最常见的患者是女性，一生中有50%的机会患上急性尿路感染(UTI)，大部分是由尿路致病性大肠杆菌(UPEC)引起的。复发是一个常见的问题。出现急性尿路感染首次发作的女性有25%-44%的机会发展为第二次，有3%的机会在6个月内经历三次发作。由于这种感染引起的相当大的发病率，高复发率和细菌耐药性的上升，新的治疗策略是必要的。UPEC产生含有甘露糖结合的FimH尖端粘附素的1型菌毛。在膀胱中，FimH介导细菌侵入表面的小关节细胞。在这些细胞内，UPEC迅速复制形成生物膜样的细胞内细菌群落(IBCs)。在IBC扩散后，UPEC传播到邻近的细胞并重复这个循环，从而解释了单个细菌如何能够迅速扩张并在UT站稳脚跟并在UT引起疾病。急性IBC级联的一个结果是形成静止的细胞内储存库(QIR)，这些储存库不能被抗生素治疗清除，可以持续几个月，并可能滋生新一轮感染。我们已经确定了FimH-甘露糖相互作用的结构基础和菌毛组装的机制。这些知识形成了合理设计化合物的基础，这些化合物通过干扰关键的宿主-病原体相互作用来阻止细菌的定植、IBC的形成和感染。为这项提议提供资金以应对挑战赠款15-DK-103将极大地加强我们寻找治疗尿路感染的替代战略的努力，这在面对不断增加的抗生素耐药性和复发的情况下至关重要。利用基于合理结构的药物设计和合成，我们建议开发高亲和力的甘露糖衍生物(甘露糖苷)，其功能是通过防止IBC级联中的细菌扩张来阻止疾病。我们还设计和生产了阻止菌毛组装的杀菌剂。将评估最好的抑制剂的药代动力学、生物利用度和潜在毒性等类药物性质，并将在大量体外测试和我们的体内小鼠模型中评估它们在阻断毒力方面的有效性。 公共卫生相关性：这笔拨款旨在合理设计、合成和测试1型毛孔FimH粘附素抑制剂的疗效，这将极大地加强我们寻找治疗尿路感染的替代策略的努力，尿路感染是人类最常见的感染之一。这一点尤其重要，因为在其他健康的女性中，抗生素耐药性的上升和尿路感染的高复发率。

DESCRIPTION (provided by applicant): The urinary tract (UT) is a common site of infection in humans, with an estimated 8 million outpatient visits in the U.S. and an estimated cost exceeding $2.5 billion annually. The most frequent sufferers are women, with a 50% lifetime chance of developing an acute UT infection (UTI), the majority caused by uropathogenic Escherichia coli (UPEC). Recurrence is a common problem. Women who present with an initial episode of acute UTI have a 25-44% chance of developing a second and a 3% chance of experiencing three episodes within six months. Due to considerable morbidity caused by this infection, the high recurrence rate and the rising incidence of bacterial antibiotic resistance, new strategies for treatment are necessary. UPEC produce type 1 pili that contain the mannose binding FimH tip adhesin. In the bladder, FimH mediates bacterial invasion into superficial facet cells. Inside these cells, UPEC rapidly replicate forming biofilm-like intracellular bacterial communities (IBCs). Upon dispersal of the IBC, UPEC spread to neighboring cells and repeat the cycle thus explaining how single bacteria are able to rapidly expand and gain a foothold and cause disease in the UT. One outcome of the acute IBC cascade is the formation of quiescent intracellular reservoirs (QIRs) that are not cleared by antibiotic treatments, can persist for months, and can seed new rounds of infection. We have determined the structural basis of the FimH-mannose interaction and the mechanism of pilus assembly. This knowledge forms the basis for rational design of compounds that block bacterial colonization, IBC formation and infection, by interfering with critical host-pathogen interactions. Funding of this proposal in response to challenge grant 15-DK-103 will greatly enhance our efforts to find alternative strategies for treatment of UTI which is critical in the face of rising antibiotic resistance and recurrence. Using rational structure-based drug design and synthesis, we propose to develop high affinity mannose derivatives (mannosides) that function to block disease by preventing bacterial expansion in the IBC cascade. We also have designed and produced pilicides that block pilus assembly. The drug-like properties including pharmokinetics, bioavailability and potential toxicity of the best inhibitors will be evaluated and their efficacy in blocking virulence will be assessed in a multitude of in vitro assays and in our in vivo murine model. PUBLIC HEALTH RELEVANCE: This grant to rationally design, synthesize and test the efficacy of type 1 pilus FimH adhesin inhibitors will greatly enhance our efforts to find alternative strategies for treatment of urinary tract infections, one of the most common infections in humans. This is particularly important due to rising antibiotic resistance and high UTI recurrence rates in otherwise healthy females.