GBPs as new inflammsome regulators during mammalian host defense

GBP 作为哺乳动物宿主防御过程中新的炎症调节剂

• 批准号: 8929155
• 负责人: John David MacMicking
• 金额: $ 41.63万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-19 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8929155
• 关键词: Acute; Adjuvant; Bacteria; Bacterial Infections; Binding Proteins; Biochemical; Bioinformatics; Biological; Biology; Blood; Caspase; Caspase-1; Cell Death; Cells; Cleaved cell; Complement; Complex; Data; Detection; Disease; Engineering; Excision; Exhibits; Family; Family member; Gastroenteritis; Genes; Genetic; Genetic study; Gram-Negative Bacteria; Guanosine Triphosphate Phosphohydrolases; Health; Host Defense; Human; Immune; Immune system; Immunity; Infection; Inflammation; Inflammatory; Integration Host Factors; Intensive Care Units; Interleukin-1; Interleukin-18; Knockout Mice; Lesion; Ligands; Lytic; Macromolecular Complexes; Mediating; Molecular; Mus; Parasites; Pathway interactions; Property; Protein Family; Proteins; Research; Resistance to infection; Salmonella; Salmonella typhimurium; Sensory; Sepsis; Side; Signal Transduction; Site; Sterility; Stimulus; Testing; Therapeutic; Tissues; Variant; Virus; Work; antimicrobial; base; cytokine; foodborne; fungus; gain of function; genetic approach; genome-wide; guanylate; human disease; in vitro activity; in vivo; loss of function; macrophage; man; microbial; mutant; pathogen; pathogenic bacteria; protein function; receptor; reconstitution; research study; response; sensor; therapy design

 DESCRIPTION (provided by applicant): Inflammasomes alert the mammalian immune system to the presence of infection and tissue damage. These sensory complexes activate caspase-1 in the "canonical" pathway to cleave IL-1 family cytokines for secretion and eliminate infected host cells via a form of lytic cell death termed pyroptosis. In addition, a new "non- canonical" inflammasome has emerged that enlists caspase-11 specifically in response to Gram-negative bacteria. How each pathway discriminates microbial from danger signals and the host proteins responsible for this functional dichotomy remain unknown. Both questions are central to understanding the biology of inflammasome-mediated host defense. Here, we tackle this issue by focusing on a new family of 65-73kDa immune GTPases termed the Guanylate binding Proteins (GBPs) that uncouple these two activities. GBP5 specifically promotes canonical NLRP3 inflammasome activation to microbial but not danger signals, the first such protein to exhibit this profile. Subsequent work has found GBP1 and GBP2 confer the same selectivity. Thus the GBPs offer a unique opportunity to understand how one side of this bimodal response operates. In Aim 1 we will test whether GBP1, GBP2 and GBP5 promotes not only the canonical inflammasome pathway but also the non-canonical inflammasome triggered by Gram-negative bacterial stimuli. This will be examined using genetically-deficient human and mouse macrophages as well as newly-created Gbp1-/-, Gbp2-/- and Gbp5-/- mice infected with Salmonella typhimurium (Stm) variants that stimulate either inflammasome pathway. Our powerful genetic approach will reveal which GBP governs what inflammasome activities in vitro and in vivo. Thereafter, we will dissect the molecular mechanisms used by the inflammasome-related GBPs to confer their intracellular functions as part of Aim 2. Here gene-deficient macrophages complemented with GBP mutants with distinct biochemical lesions will test whether they are involved in cytosolic ligand detection or spatial assembly of the inflammasome complex during infection. "Reconstitution" studies will also reveal if the core inflammasome machinery is physically assembled by the GBPs as part of this macromolecular complex. Collectively, our proposal examines a new set of host factors that partition the inflammasome response with important implications for human therapies designed to promote antimicrobial activities while avoiding tissue damage.

 描述（由申请方提供）：炎性小体提醒哺乳动物免疫系统存在感染和组织损伤。这些感觉复合物在“经典”途径中激活半胱天冬酶-1，以切割IL-1家族细胞因子用于分泌，并通过称为焦亡的裂解性细胞死亡形式消除感染的宿主细胞。此外，已经出现了一种新的“非典型”炎性小体，其特异性地应答革兰氏阴性细菌而使用胱天蛋白酶-11。每种途径如何区分微生物和危险信号，以及负责这种功能二分法的宿主蛋白质仍然未知。这两个问题是理解炎性小体介导的宿主防御生物学的核心。在这里，我们通过关注一个新的65- 73 kDa免疫GTP酶家族来解决这个问题，该家族被称为鸟苷酸结合蛋白（GBP），它将这两种活性分开。GBP 5特异性地促进典型的NLRP 3炎性体对微生物的激活，但不是危险信号，这是第一个表现出这种特征的蛋白质。随后的工作发现GBP 1和GBP 2具有相同的选择性。因此，GBP提供了一个独特的机会来了解这种双峰响应的一侧如何运作。在目的1中，我们将测试GBP 1、GBP 2和GBP 5是否不仅促进经典炎性体途径，而且促进由革兰氏阴性细菌刺激物触发的非经典炎性体。这将使用遗传缺陷的人和小鼠巨噬细胞以及新创建的感染鼠伤寒沙门氏菌（Stm）变体（刺激任一炎性体途径）的Gbp 1-/-、Gbp 2-/-和Gbp 5-/-小鼠进行检查。我们强大的遗传学方法将揭示哪些GBP在体外和体内控制哪些炎性小体活动。此后，我们将剖析炎性小体相关GBP赋予其细胞内功能的分子机制，作为目标2的一部分。在这里，基因缺陷的巨噬细胞补充GBP突变体与不同的生化病变将测试它们是否参与胞质配体检测或空间组装的炎性复合体在感染过程中。“重建”研究还将揭示核心炎性小体机制是否由GBP物理组装为该大分子复合物的一部分。总的来说，我们的提案研究了一组新的宿主因子，这些因子划分了炎症反应，对旨在促进抗微生物活性同时避免组织损伤的人类疗法具有重要意义。