Human GBPs in cell-autonomous immunity to intracellular bacterial pathogens

人类 GBP 对细胞内细菌病原体的细胞自主免疫

• 批准号: 10468317
• 负责人: Joern Coers
• 金额: $ 45.89万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-01-21
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10468317
• 关键词: Actins; Amino Acid Motifs; Bacteria; Binding; Binding Proteins; Biochemical; Biochemical Genetics; Biological; Biological Assay; Biological Response Modifiers; Burkholderia; C-terminal; Cell Culture Techniques; Cell Line; Cells; Chemicals; Chimeric Proteins; Cytosol; Data; Dynamin; Epithelial Cells; GBP1 gene; Genetic; Gram-Negative Bacteria; Host Defense; Host Defense Mechanism; Human; Immune; Immune response; Immune signaling; Immunity; In Vitro; Infection; Infection Control; Inflammasome; Interferons; Intervention; Lead; Link; Lipopolysaccharides; Maps; Mediating; Modeling; Modification; Molecular; Monitor; Mus; Nature; Nucleic Acids; O Antigens; Pathway Analysis; Pathway interactions; Pattern; Play; Primates; Process; Production; Proteins; Publishing; Reporting; Research; Role; Shigella; Shigella flexneri; Signal Transduction; Site; Surface; Tail; Testing; Time; Work; antagonist; antimicrobial; arms race; bacterial genetics; bactericide; base; cell motility; chemokine; genetic approach; guanylate; human disease; immune function; in vivo; mouse model; mutant; novel; novel strategies; paracrine; paralogous gene; pathogen; pathogenic bacteria; polymerization; prevent; programs; recruit; resistance mechanism; response; tissue culture; transcriptome sequencing

SUMMARY - Human GBPs as regulators of immunity to intracellular bacterial pathogens Guanylate binding proteins (GBPs) are host defense proteins that play diverse and critical roles in cell-autonomous immunity to intracellular bacterial pathogens. These proteins are major regulators of fundamental host defense modules and involved in processes such as inflammasome activation and the execution of direct bactericidal activities. However, almost all of this work has been performed in mouse models and antimicrobial functions of human GBPs (hGBPs) are still poorly characterized. In our recent studies we identified divergent host defense functions of the human GBPs and linked specific human GBPs to novel resistance mechanisms that protect against an important class of bacterial pathogens. Specifically, we found that human GBP1 (hGBP1) underpins two novel host defense mechanisms against cytosolic Gram-negative bacterial pathogens: 1) hGBP1 protein associates with cytosolic Gram- negative bacteria such as Shigella flexneri or Burkholderia thailandensis in the host cell cytosol. Once bound to bacteria, hGBP1 directly interferes with the actin-based intracellular motility of bacteria and thereby blocks bacterial dissemination; and 2) hGBP1 mediates activation of chemokine production by infected epithelial cells. Thus, hGBP1 activation appears to serve as a central node for two distinct but synergistic immune functions: a cell-intrinsic defense program prevents cell-to-cell spread of the pathogen while the production of paracrine immune signals promotes the activation and recruitment of immune cells to the site of infection. In this work, we will define the molecular mechanisms underlying these two important roles for hGBP1 that we have uncovered. In Aim1 we will combine cell culture and biochemical approaches to define the mechanism by which hGBP1 specifically detects Gram-negative bacteria in the host cell cytosol, a process critical for the inhibition of actin-based motility. In Aim2 we will characterize the mechanism by which hGBP1 bound to bacteria blocks actin-based motility. In Aim3 we will explore a second, independent function of hGBP1 as a novel regulator of an immune sensing pathway leading to the production of immune-modulatory chemokines using bacterial genetics, host genetics and cell biological approaches. In all of these studies we will take advantage of our recent discovery that the S. flexneri effector protein IpaH9.8 antagonizes hGBP1 function. Therefore, the use of IpaH9.8- deficient S. flexneri strains will enable us to monitor and functionally dissect an operational hGBP1-driven host response. Overall, the work proposed here will provide a fundamental understanding of the role of hGBP1 and other human GBPs in cell-autonomous immunity to intracellular bacterial pathogens. !

概述-人GBP作为细胞内细菌病原体免疫的调节剂 鸟苷酸结合蛋白（GBP）是宿主防御蛋白，其在植物体内发挥多种关键作用。 对细胞内细菌病原体的细胞自主免疫。这些蛋白质是 基本的宿主防御模块并参与炎性小体激活和炎症反应等过程 执行直接杀菌活动。然而，几乎所有这些工作都是在小鼠中进行的。 人GBP（hGBP）的模型和抗微生物功能仍然缺乏表征。在我们 最近的研究，我们确定了不同的宿主防御功能的人GBP和连接特定的人类 GBP是针对一类重要的细菌病原体的新型耐药机制。 具体来说，我们发现人GBP 1（hGBP 1）支持两种新的宿主防御机制， 胞质革兰氏阴性细菌病原体：1）hGBP 1蛋白与胞质革兰氏阴性细菌病原体结合。 阴性细菌如福氏志贺氏菌或泰国伯克霍尔德氏菌。 一旦与细菌结合，hGBP 1直接干扰细菌基于肌动蛋白的细胞内运动 从而阻断细菌传播;和2）hGBP 1介导趋化因子产生的活化 感染的上皮细胞。因此，hGBP 1的激活似乎是两个不同但 协同免疫功能：细胞内在防御程序可防止免疫缺陷病毒的细胞间传播。 而旁分泌免疫信号的产生促进病原体的激活和募集， 免疫细胞到感染部位。在这项工作中，我们将定义这些分子机制 hGBP 1的两个重要作用在Aim 1中，我们将联合收割机细胞培养和 生物化学方法来定义hGBP 1特异性检测革兰氏阴性菌的机制 细菌在宿主细胞胞质溶胶，一个过程的肌动蛋白为基础的运动抑制的关键。在AIM 2中，我们将 描述hGBP 1与细菌结合阻止肌动蛋白运动的机制。在AIM 3中，我们将 探索hGBP 1作为免疫感应途径的新调节剂的第二个独立功能 导致使用细菌遗传学、宿主遗传学和细胞遗传学产生免疫调节趋化因子， 生物学方法。在所有这些研究中，我们将利用我们最近的发现， S.弗氏效应蛋白IpaH9.8拮抗hGBP 1功能。因此，使用IpaH9.8- 缺陷型S.福氏菌株将使我们能够监测和功能解剖一个操作性的hGBP 1驱动的 主机响应。总的来说，这里提出的工作将提供一个基本的理解的作用， hGBP 1和其他人GBP在对细胞内细菌病原体的细胞自主免疫中的作用 !