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.

福氏志贺菌是引起人类细菌性痢疾的胞内细菌病原体。确定 胞质内细菌如何被宿主细胞检测到对于我们进一步理解先天性 免疫系统大肠杆菌感染。弗氏杆菌引起免疫反应， 中性粒细胞和巨噬细胞进入组织。当S.弗氏杆菌进入巨噬细胞， 炎性小体，导致焦亡，一种促炎细胞死亡。研究最多的炎性小体 NLRP 3是典型的NLRP 3炎症体，其由（1）NOD样受体（NLR）NLRP 3，（2） 衔接蛋白ASC，和（3）炎性半胱天冬酶-1。一种非典型炎性小体，包括 半胱天冬酶-4/5（在小鼠中的半胱天冬酶-11）已经被描述;到目前为止，还没有鉴定出NLR蛋白。激活 来自任一途径炎性半胱天冬酶激活gasdermin D。我们的初步数据表明，在S。 福氏杆菌感染NLRP 11是有效细胞死亡以及caspase-4和gasdermin D激活所必需的。 我们的数据还表明，胞质LPS（cLPS）足以触发NLRP 11 这些细胞中的细胞死亡。此外，我的初步数据显示，NLRP 11结合LPS， NLRP 11和caspase-4不依赖于LPS相互作用。根据我们的数据，我们提出了一个新的作用， NLRP 11在非典型炎性体途径中检测cLPS。我的总体假设是， NLRP 11（1）用于检测具有半胱天冬酶-4的cLPS，（2）结合并激活半胱天冬酶-4，以及（3）是一个关键的 非典型炎性小体的组成部分。我打算用以下目标来检验这一假设： 1.定义NLRP 11在非典型炎性小体激活中的分子功能 2.定义NLRP 11与caspase-4相互作用的要求 3.确定LPS、NLRP 11和caspase-4是否形成三元复合物。 该提案将产生对NLRP 11如何在非典型炎性小体中起作用的机制见解。它 很有可能揭示非典型炎性小体中的新功能相互作用，并加深我们的研究。 对先天免疫系统的总体了解。拟定研究将在Dr. Marcia Goldberg在马萨诸塞州总医院（MGH）和哈佛医学院（HMS）的实验室， 我的共同赞助人朱迪·利伯曼博士的指导MGH和HMS都是严格的学术环境 有充足的资源支持我的研究和职业发展。我会有很多机会正式 展示我的研究成果，参加科学会议，参加职业发展课程。拟议 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，并使我处于理想的状态。 我的职业目标是成为一名独立的研究人员。