TARGETING THE E COLI CHAPERONE SURA IN RECURRENT UTI

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 泌尿道感染（UTIs），最常见的致病性大肠杆菌（UPEC）引起的，与大量的发病率和医疗费用。受影响的妇女和儿童经常受到复发的困扰，肾脏的反复感染可导致肾瘢痕和慢性肾脏疾病。最近在鼠膀胱炎模型中的工作揭示了关于UTI发病机制的新范例。长期以来，UPEC被认为是一种严格的细胞外病原体，已被证明可以侵入膀胱内衬的上皮细胞，并在这些细胞内建立大量的集合，称为细胞内细菌群落（IBC）。UPEC在膀胱组织内形成静态储库，其抵抗口服抗生素治疗并且对宿主免疫防御是不可见的，这是一种可能依赖于其下调宿主炎性细胞因子产生的独特能力的表型。这种细菌储存库可以作为复发性感染的种子，这一发现挑战了目前的教条，即复发性UTI代表着从胃肠道E.大肠杆菌群。目前的抗生素治疗方案受到细菌耐药性发展的挑战，并且不能根除慢性储库。我们最近的数据表明，一个保守的周质分子伴侣SurA是至关重要的生产粘附1型皮利，为UPEC抗细胞因子表型，并为细胞内生长的UPEC在IBC成熟。UPEC中SurA功能的破坏也废除了静止细菌储库的形成。我们将采用标记的SurA蛋白在一组生化测定，以确定光谱的外膜基板的这一重要的保守分子伴侣在UPEC。将进行结构域互补和诱变，以描述SurA的结构特征和内部残基，这些结构特征和残基对于SurA在UPEC中的毒力支持至关重要。这些知识将导致开发新的抗感染化合物，靶向SurA功能并中断IBC途径和复发性UTI的周期。相关性：尿路感染是美国第二大常见的传染病，每年的门诊量超过700万人次，医疗费用高达10亿美元。许多患者患有复发性疾病，不仅破坏性和痛苦，而且还可能导致慢性肾脏疾病，目前对这些患者的治疗是不够的。这一建议确定了一个新的目标，中断复发性尿路感染的周期。

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.