NLRP11 in non-canonical inflammasome activation in response to Shigella flexneri and cytosolic LPS.

NLRP11 在响应福氏志贺氏菌和胞质 LPS 的非典型炎症小体激活中。

• 批准号: 9910652
• 负责人: Amanda Soohoo Zajac
• 金额: $ 6.98万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2021-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9910652
• 关键词: Acute; Adaptor Signaling Protein; Apoptosis; Bacteria; Binding; CASP1 gene; Caspase; Cell Death; Cell membrane; Cells; Colon; Complex; Data; Detection; Environment; Epithelial; Epithelium; Family; General Hospitals; Genetic Screening; Goals; Human; Immune; Immune response; Immunology; Infection; Infection prevention; Inflammasome; Inflammatory; Inflammatory Response; Innate Immune System; Interleukin-1 beta; Interleukin-18; Invaded; Laboratories; Lipopolysaccharides; Maps; Massachusetts; Mediating; Microbiology; Molecular; Mus; Neutrophil Infiltration; Pathway interactions; Phagocytes; Positioning Attribute; Precipitation; Primates; Process; Proteins; Research; Research Personnel; Resources; Role; Scaffolding Protein; Shigella; Shigella Infections; Shigella flexneri; Stimulus; System; Tertiary Protein Structure; Testing; Therapeutic; Tissues; Training; Vacuole; Virulence; Work; base; career; career development; course development; cytokine; human disease; human pathogen; insight; loss of function; macrophage; medical schools; meetings; member; novel; pathogen; pathogenic bacteria; protein aggregation; receptor; reconstitution; recruit; research and development; response; sensor

Shigella flexneri are intracytosolic bacterial pathogens that cause bacillary dysentery in humans. Determining how intracytosolic bacteria are detected by the host cell is critical for advancing our understanding of the innate immune system. Infection of the colon by S. flexneri leads to an immune response that triggers recruitment of neutrophils and macrophages into the tissue. When S. flexneri enters macrophages, it activates inflammasomes, leading to pyroptosis, a type of pro-inflammatory cell death. The best studied inflammasome pathway is the canonical NLRP3 inflammasome, which consists of (1) the NOD-like receptor (NLR) NLRP3, (2) the adaptor protein ASC, and (3) the inflammatory caspase-1. A non-canonical inflammasome that consists of caspase-4/5 (caspase-11, in mice) has been described; as yet, no NLR protein has been identified. Activated inflammatory caspases from either pathway activate gasdermin D. Our preliminary data show that during S. flexneri infection NLRP11 is required for efficient cell death as well as caspase-4 and gasdermin D activation in human-derived macrophages, Our data also show that cytosolic LPS (cLPS) is sufficient to trigger NLRP11 dependent cell death in these cells. In addition, my preliminary data show that NLRP11 binds LPS and that NLRP11 and pro-caspase-4 interact independent of LPS. Based on our data, we propose a novel role for NLRP11 in the detection of cLPS in the non-canonical inflammasome pathway. My overall hypothesis is that NLRP11 (1) functions to detect cLPS with caspase-4, (2) binds and activates caspase-4, and (3) is a critical component of the non-canonical inflammasome. I propose to test this hypothesis with the following aims: 1. Define the molecular function of NLRP11 in non-canonical inflammasome activation 2. Define the requirements for the interaction of NLRP11 with caspase-4 3. Determine whether LPS, NLRP11, and caspase-4 form a ternary complex. This proposal will generate mechanistic insights into how NLRP11 acts in the non-canonical inflammasome. It is highly likely to uncover novel functional interactions in the non-canonical inflammasome and deepen our understanding of the innate immune system in general. The proposed studies will be conducted in Dr. Marcia Goldberg's laboratory at Massachusetts General Hospital (MGH) and Harvard Medical School (HMS), with the guidance of my co-sponsor, Dr. Judy Lieberman. Both MGH and HMS are rigorous academic environments with ample resources support my research and career development. I will have many opportunities to formally present my research, attend scientific meetings, and attend career development courses. The proposed studies will provide me with new expertise in microbiology and innate immunology and place me in an ideal position of reaching my career goals of being an independent researcher.

Shigella flexneri是在人类中引起细菌痢疾的遗内细菌病原体。确定 宿主细胞如何检测到室内细菌是如何促进我们对先天性的理解至关重要的 免疫系统。 S. flexneri对结肠的感染导致免疫反应，从而触发招募 中性粒细胞和巨噬细胞进入组织。当S. flexneri进入巨噬细胞时，它会激活 炎症，导致凋亡，一种促炎细胞死亡。研究最佳的炎症小组 途径是典型的NLRP3炎性体，由（1）点头样受体（NLR）NLRP3，（2）组成 衔接蛋白ASC和（3）炎症caspase-1。一个非典型炎症体，包括 已经描述了Caspase-4/5（在小鼠中caspase-11）；到目前为止，尚未鉴定NLR蛋白。活性 两种途径的炎症胱天蛋白酶激活了GasderminD。我们的初步数据表明，在S. 有效的细胞死亡以及caspase-4和Gasdermin d激活flexneri感染NLRP11是必需的 人类衍生的巨噬细胞，我们的数据还表明，胞质LP（CLP）足以触发NLRP11 这些细胞中的依赖细胞死亡。此外，我的初步数据表明NLRP11绑定了LP，并且 NLRP11和Pro-Caspase-4与LPS无关。根据我们的数据，我们提出了一个新的作用 NLRP11在非典型炎性途径中检测CLP的检测。我的总体假设是 NLRP11（1）用caspase-4，（2）检测CLP的函数结合并激活caspase-4，（3）是关键 非典型炎症体的组成部分。我建议以以下目的检验这一假设： 1。定义非典型炎症体激活中NLRP11的分子功能 2。定义NLRP11与caspase-4相互作用的要求 3。确定LPS，NLRP11和caspase-4是否形成三元复合物。 该提案将产生机械洞察力，了解NLRP11在非典型炎症体中的作用。它 很可能会发现非典型炎症体中的新功能相互作用并加深我们 总体上了解先天免疫系统。拟议的研究将在Marcia博士中进行。 马萨诸塞州总医院（MGH）和哈佛医学院（HMS）的戈德堡实验室， 我的共同赞助商Judy Lieberman博士的指导。 MGH和HM都是严格的学术环境 有足够的资源支持我的研究和职业发展。我将有很多机会正式 介绍我的研究，参加科学会议并参加职业发展课程。提议 研究将为我提供微生物学和先天免疫学方面的新专业知识，并将我置于理想状态 达到我成为独立研究人员的职业目标的立场。