N-terminal acylation and sorting of Helicobacter pylori lipoproteins and their role in host response to infection

项目摘要(摘要)幽门螺杆菌在大约50%的人的胃中持续定植 导致胃炎症和胃病风险增加的人群，包括 癌症。世界卫生组织(WHO)将胃癌列为与癌症相关的第三大原因 并将幽门螺杆菌列为I型致癌物质。克拉霉素耐药发生率上升 这也导致世卫组织宣布幽门螺杆菌为新的抗菌剂开发的优先目标。细菌脂蛋白 通过酰化修饰，帮助革兰氏阴性细菌的脂蛋白锚定在内膜或外膜上。 这些蛋白质是作为细菌脂蛋白抑制物的抗菌药物开发的新靶点。 已经确定了合成或定位。幽门螺杆菌脂蛋白在许多方面参与了致病过程， 包括向哺乳动物细胞运送癌蛋白(CagA)的作用。我们假设脂蛋白分选 修饰对于幽门螺杆菌的免疫致病作用至关重要。在之前的研究中，我们 显示负责幽门螺杆菌脂蛋白酰化的三种酶中的两种和两种蛋白质需要 脂蛋白定位于内膜和外膜是生长所必需的。在目前的提案中， 我们将确定幽门螺杆菌脂蛋白定位系统的其他元件，并确定H. 幽门螺杆菌脂蛋白在免疫发病机制中的作用在目标1中，我们将通过以下方法表征Hp中的脂蛋白定位 识别定位系统的定位信号和先前未识别的蛋白质。此外， 脂蛋白被宿主的固有受体识别，导致促炎或抗炎反应。 这取决于脂蛋白上的酰链修饰的数量和种类。因此，在目标2中，我们将 确定幽门螺杆菌脂蛋白如何影响免疫细胞的激活和炎症 幽门螺杆菌脂蛋白上存在的链，定义了酰基链的数量和种类如何影响先天 表达tri-vs的幽门螺杆菌菌株感染小鼠的信号转导和炎症及疾病分析 二酰化的脂蛋白。建议的研究将增加我们对脂蛋白生物学及其影响的了解。 治疗胃病，从而增强我们治疗幽门螺杆菌感染和胃癌的能力。结果将会揭晓 为未来旨在确定新型脂蛋白构效关系的研究奠定基础 本地化成分，抗菌药物的开发，以及确定脂蛋白和先天信号在 幽门螺杆菌致病机制中的免疫耐受。

Project Summary (Abstract) Helicobacter pylori persistently colonizes the stomach in about 50% of the human population resulting in gastric inflammation and an increased risk of developing gastric diseases including cancer. The World Health Organization (WHO) lists gastric cancer as the third leading cause of cancer-related death worldwide and classifies H. pylori as a type I carcinogen. Increasing incidence of clarithromycin resistance also has led WHO to declare H. pylori a priority target for new antimicrobial development. Bacterial lipoproteins are modified by acylation to help anchor lipoproteins to the inner or outer membrane in Gram-negative bacteria. These proteins are an emerging target of antimicrobial development as inhibitors of bacterial lipoprotein synthesis or localization have been identified. H. pylori lipoproteins contribute to pathogenesis in numerous ways, including a role in delivering an oncoprotein (CagA) to mammalian cells. We hypothesize that lipoprotein sorting and modifications are fundamentally important for H. pylori immunopathogenesis. In previous studies, we showed that two of the three enzymes responsible for acylation of H. pylori lipoproteins and two proteins required for localization of lipoproteins to the inner vs outer membrane are essential for growth. In the current proposal, we will identify additional elements of the H. pylori lipoprotein localization system and determine the impact of H. pylori lipoproteins on immunopathogenesis. In Aim 1, we will characterize lipoprotein localization in H. pylori by identifying localization signals and previously unidentified proteins of the localization system. Further, lipoproteins are recognized by innate receptors of the host, leading to pro- or anti-inflammatory responses depending on the number and variety of acyl chain modifications on lipoproteins. Therefore, in Aim 2, we will determine how H. pylori lipoproteins influence immune cell activation and inflammation by characterizing the acyl chains present on H. pylori lipoproteins, defining how the number and variety of acyl chains affect innate signaling, and analyzing inflammation and disease in mice infected with H. pylori strains expressing tri- vs diacylated lipoproteins. The proposed studies will increase our understanding of lipoprotein biology and its impact on gastric disease thereby potentiating our ability to treat H. pylori infection and gastric cancer. Results will lay the foundation for future studies aimed at determining structure-activity relationships of novel lipoprotein localization components, antimicrobial development, and defining the role of lipoproteins and innate signaling in immune tolerance in H. pylori pathogenesis.