The role of ArsS in gastric infection by Helicobacter pylori

 描述（由申请人提供）：幽门螺杆菌定植在世界上约50%人口的正常胃酸分泌胃中。定植与胃部疾病有关，包括胃炎、消化性溃疡和十二指肠溃疡、胃癌和MALT淋巴瘤。虽然三联疗法的初始根除率是成功的（~95%），但抗生素耐药性使成功治疗感染越来越困难。因此，迫切需要一种无抗生素的替代根除单药治疗。幽门特异性的、保留胃肠道植物群或改善抗生素治疗以减少治疗的持续时间和复杂性。 本研究的长期目标是了解H。幽门螺杆菌对胃酸有反应并存活下来，并利用这一知识来开发新的治疗方案和/或改善目前的根除疗法。本文的目的是确定酸敏感双组分系统（TCS）ArsRS如何调节酸诱导的尿素酶及其辅助蛋白向内膜的运输，以与胃感染和酸存活所需的UreI形成膜结合复合物。这项研究的基本原理是，了解ArsS使用的机制将允许药理学干扰，导致新的H。幽门特异性无激素单药治疗和/或改善目前的根除方案。 具体目标是：1.阐明传感激酶ArsS介导的酸诱导信号传导机制。由于ArsS是胃定植和酸生存所必需的，了解蛋白质转运至UreI的机制和UreI/尿素酶膜复合物的形成将提供新的根除靶点。2.鉴定酸依赖性膜蛋白质组和ArsS对所鉴定蛋白质的细菌内运输的贡献。这个细菌内蛋白质运输的显著例子为开发抗感染药物提供了独特的机会。3.识别高 通过高通量筛选（HTS）获得亲和性ArsS抑制剂。由于ArsS的酸敏感结构域位于周质中，并且ArsS对于胃感染是必需的，因此它是一个有吸引力的根除靶标。我们设计了一种HTS，可以检测ArsS和UreI之间选择的抑制剂。 目标1和2的工作将利用生物化学和分子生物学技术来鉴定负责维持H.幽门。目标3中提出的工作将提供抑制胃感染所需的ArsRS信号级联的先导化合物。这三个目标的结果将通过提供新的靶点和改进目前的根除疗法产生重要的积极影响。

 DESCRIPTION (provided by applicant): Helicobacter pylori colonizes the normal acid-secreting stomach of about 50% of the world's population. Colonization is associated with gastric disease, including gastritis, peptic and duodenal ulcers, gastric carcinoma, and MALT lymphoma. Although initial eradication rates with triple therapy were successful (~95%), antibiotic resistance has made successful treatment of infection progressively more difficult. Thus, there is a critical need for an antibiotic-free alternative eradication mono-therapy that is . pylori-specific, sparing commensal gut flora or improvement to antibiotic therapy that decreases the duration and complexity of treatment. The long-term goal of this study is to understand how H. pylori responds to and survives gastric acidity and exploit this knowledge to develop novel treatment regimens and/or improve current eradication therapies. The objective here is to determine how the acid-sensitive Two-Component System (TCS), ArsRS, regulates the acid-induced trafficking of urease and its accessory proteins to the inner membrane to form a membrane- bound complex with UreI that is required for gastric infection and acid survival. The rationale for the study is that understanding the mechanisms used by ArsS will allow pharmacological interference resulting in new H. pylori-specific antibiotic-free monotherapy and/or improvement in current eradication regimens. The specific aims are: 1. Elucidate the acid-induced signaling mechanism mediated by the sensor kinase ArsS. Because ArsS is essential for gastric colonization and acid survival, knowing the mechanism of protein trafficking to UreI and the formation of the UreI/urease membrane complex will provide novel eradication targets. 2. Identify the acid-dependent membrane proteome and the contribution of ArsS to intrabacterial trafficking of the identified proteins. This remarkable example of intra-bacterial protein trafficking provides a unique opportunity to develop anti-infective drugs. 3. Identify high affinity ArsS inhibitors by High- Throughput Screening (HTS). Because the acid-sensing domain of ArsS is in the periplasm and ArsS is essential for gastric infection, it is an attractive eradication target. We have designed an HTS that will allow detection of inhibitors that select between ArsS and UreI. The work of aims 1 and 2 will use biochemical and molecular biological techniques to identify proteins and regulatory pathways responsible for maintenance of gastric colonization by H. pylori. The work proposed in aim 3 will provide lead compounds that inactivate the ArsRS signaling cascade required for gastric infection. The results of these three aims will have an important positive impact by providing novel targets and improving current therapies for eradication.