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

幽门螺杆菌在约50%的人的胃中持续定植 导致胃部炎症和发生胃部疾病的风险增加，包括 癌世界卫生组织（WHO）将胃癌列为癌症相关的第三大原因。 并将其分类为H. pylori作为I型致癌物。克拉霉素耐药发生率增加 也导致世卫组织宣布H.幽门螺杆菌是新抗菌剂开发的优先目标。细菌脂蛋白 被酰化修饰以帮助脂蛋白锚到革兰氏阴性菌的内膜或外膜。 这些蛋白质作为细菌脂蛋白的抑制剂是抗菌剂开发的新兴靶点 合成或定位。H.幽门螺杆菌脂蛋白以多种方式促进发病， 包括在将癌蛋白（CagA）递送到哺乳动物细胞中的作用。我们假设脂蛋白分选 和修饰对H. pylori免疫发病机制在以前的研究中，我们 结果表明，在H.幽门螺杆菌脂蛋白和所需的两种蛋白质 将脂蛋白定位于内膜和外膜对于生长是必需的。在目前的提案中， 我们将确定H的其他元素。pylori脂蛋白定位系统，并确定H. pylori脂蛋白在免疫发病机制中的作用。在目标1中，我们将描述脂蛋白在H.幽门 鉴定定位信号和定位系统的先前未鉴定的蛋白质。此外，本发明还 脂蛋白被宿主的先天受体识别，导致促炎或抗炎反应 这取决于脂蛋白上酰基链修饰的数量和种类。因此，在目标2中，我们 确定H.幽门螺杆菌脂蛋白通过表征脂蛋白的酰基化影响免疫细胞活化和炎症 链存在于H上。幽门螺杆菌脂蛋白，定义酰基链的数量和种类如何影响先天性 信号，并分析感染H.表达tri- vs的幽门螺杆菌菌株 二酰化脂蛋白。拟议的研究将增加我们对脂蛋白生物学及其影响的理解 从而增强我们治疗H.幽门螺杆菌感染和胃癌。结果将奠定 为进一步研究新型脂蛋白的构效关系奠定了基础 定位成分，抗菌剂的开发，以及确定脂蛋白和先天信号在 H. pylori发病机制

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.