TARGETING THE E COLI CHAPERONE SURA IN RECURRENT UTI

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 尿路感染(UTIs)最常见的致病原因是致尿性大肠埃希氏菌(UPEC)，其发病率和医疗费用较高。受影响的妇女和儿童经常复发，肾脏反复感染可能导致肾脏疤痕和慢性肾脏疾病。最近在小鼠膀胱炎模型中的工作揭示了关于尿路感染发病机制的新范式。长期以来，UPEC一直被认为是一种严格意义上的细胞外病原体，已被证明入侵膀胱衬里的上皮细胞，并在这些细胞内建立大量的集合，称为细胞内细菌群落(IBCs)。UPEC在膀胱组织中形成一个静止的储存库，抵抗口服抗生素治疗，对宿主免疫防御是不可见的，这一表型可能取决于其下调宿主炎症细胞因子产生的独特能力。然后，这种细菌储存库可以作为复发感染的种子，这一发现挑战了目前的教条，即复发的尿路感染代表从胃肠道大肠杆菌群体重新接种尿路。目前的抗生素方案受到细菌耐药性发展的挑战，并不能根除慢性蓄积物。我们最近的数据表明，一种名为SurA的保守的周质伴侣对于I型粘附性菌毛的产生、UPEC抗细胞因子表型的产生以及IBC成熟过程中UPEC的细胞内生长至关重要。UPEC中SurA功能的破坏也取消了静止细菌储存库的形成。我们将在一系列生化分析中使用标记的Sura蛋白来确定UPEC中这种重要的保守伴侣蛋白的外膜底物的光谱。将进行结构域互补和突变来描述SurA的结构特征和其中的残基，这些结构特征和残基对其在UPEC中的毒力支持至关重要。这一知识将导致针对SurA功能的新型抗感染化合物的开发，并中断IBC途径和反复尿路感染的循环。相关性：尿路感染是美国第二种最常见的传染病，每年有700万人次的门诊就诊和10亿美元的医疗费用。许多患者的复发不仅是破坏性的和痛苦的，还可能导致慢性肾脏疾病，而目前针对这些患者的治疗方法是不够的。这项建议确定了一个新的目标，以中断反复尿路感染的循环。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Urinary tract infections (UTIs), most commonly caused by uropathogenic Escherichia coli (UPEC), are associated with substantial morbidity and medical cost. Affected women and children are often plagued with recurrences, and repeated infections of the kidney can lead to renal scarring and chronic kidney disease. Recent work in the murine cystitis model has unveiled new paradigms regarding the pathogenesis of UTI. Long thought to be a strictly extracellular pathogen, UPEC has been shown to invade the epithelial cells lining the bladder and to establish large collections, termed intracellular bacterial communities (IBCs), within these cells. UPEC forms a quiescent reservoir within bladder tissue that resists oral antibiotic therapy and is invisible to host immune defenses, a phenotype that may depend on its unique ability to downregulate host inflammatory cytokine production. This bacterial reservoir can then serve as a seed for recurrent infection, a finding that challenges current dogma that recurrent UTI represents re-inoculation of the urinary tract from a gastrointestinal E. coli population. Current antibiotic regimens are challenged by the development of bacterial resistance and do not eradicate the chronic reservoir. Our recent data demonstrate that a conserved periplasmic chaperone called SurA is critical for the production of adhesive type 1 pili, for the UPEC anti-cytokine phenotype, and for intracellular growth of UPEC during IBC maturation. Disruption of SurA function in UPEC also abolishes formation of the quiescent bacterial reservoir. We will employ tagged SurA proteins in a set of biochemical assays to determine the spectrum of outer membrane substrates of this important conserved chaperone in UPEC. Domain complementation and mutagenesis will be performed to delineate the structural features of, and residues within, SurA that are critical for its support of virulence in UPEC. This knowledge will lead to the development of novel anti-infective compounds that target SurA function and interrupt the IBC pathway and the cycle of recurrent UTI. Relevance: Urinary tract infections represent the second most common infectious disease in the United States, with an annual burden of > 7 million outpatient visits and $1 billion in medical cost. Many patients suffer from recurrences that are not only disruptive and painful but can also lead to chronic kidney disease, and current therapies for these patients are insufficient. This proposal identifies a new target for interrupting the cycle of recurrent urinary tract infection.