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

基本信息

批准号：
10241505
负责人：
Joern Coers
金额：
$ 45.89万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-01 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10241505
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 Race Reporting Research Role Shigella Shigella flexneri Signal Transduction Site Surface Tail Testing Time Work antimicrobial arm 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

项目摘要

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. !

摘要 - 人类 GBP 作为细胞内细菌病原体免疫调节剂鸟苷酸结合蛋白 (GBP) 是宿主防御蛋白，在对细胞内细菌病原体的细胞自主免疫。这些蛋白质是主要的调节因子基本的宿主防御模块并参与炎症小体激活和执行直接杀菌活动。然而，几乎所有这些工作都是在鼠标中完成的人类 GBP (hGBP) 的模型和抗菌功能仍然知之甚少。在我们的最近的研究中，我们发现了人类 GBP 不同的宿主防御功能，并将特定的人类 GBP 具有新颖的耐药机制，可防御一类重要的细菌病原体。具体来说，我们发现人类 GBP1 (hGBP1) 支持两种新型宿主防御机制胞质革兰氏阴性细菌病原体：1) hGBP1 蛋白与胞质革兰氏阴性菌相关宿主细胞胞浆中的阴性细菌，例如福氏志贺氏菌或泰国伯克霍尔德氏菌。一旦与细菌结合，hGBP1 就会直接干扰细菌基于肌动蛋白的细胞内运动从而阻止细菌传播； 2) hGBP1 介导趋化因子产生的激活由受感染的上皮细胞引起。因此，hGBP1 激活似乎充当两个不同但协同免疫功能：细胞固有的防御程序可防止细胞间传播病原体，而旁分泌免疫信号的产生促进了病原体的激活和招募免疫细胞到达感染部位。在这项工作中，我们将定义这些背后的分子机制我们发现了 hGBP1 的两个重要作用。在 Aim1 中，我们将结合细胞培养和生化方法来定义 hGBP1 特异性检测革兰氏阴性菌的机制宿主细胞胞浆中的细菌，这是抑制基于肌动蛋白的运动的关键过程。在 Aim2 中，我们将描述 hGBP1 与细菌结合阻断基于肌动蛋白的运动的机制。在 Aim3 中我们将探索 hGBP1 作为免疫传感途径的新型调节剂的第二个独立功能利用细菌遗传学、宿主遗传学和细胞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，即 S.福氏效应蛋白 IpaH9.8 拮抗 hGBP1 功能。因此，使用IpaH9.8- 缺陷的 S. flexneri 菌株将使我们能够监测和功能解剖 hGBP1 驱动的操作主机响应。总的来说，这里提出的工作将提供对以下角色的基本理解： hGBP1 和其他人类 GBP 对细胞内细菌病原体的细胞自主免疫。！