Human NLRP11 function in non-canonical inflammasome activation by bacterial pathogen LPS

人类NLRP11在细菌病原体LPS非典型炎症小体激活中的作用

• 批准号: 10563477
• 负责人: Marcia B Goldberg
• 金额: $ 53.09万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-06 至 2028-02-29
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10563477
• 关键词: Adaptor Signaling Protein; Bacteria; Binding; CASP1 gene; CASP4 gene; CASP5 gene; Caspase; Cell Death; Cell Death Induction; Cell surface; Cells; Communities; Complex; Cytosol; Data; Dependence; Dimerization; Family; Glycolipids; Goals; Human; Immune system; In Vitro; Infection; Infection Control; Inflammasome; Innate Immune System; Ligands; Lipopolysaccharides; Listeria monocytogenes; Macrophage; Mediating; Membrane; Micelles; Modification; Molecular; Mus; Mutation; Myelogenous; Pathogenesis; Pathway interactions; Pattern recognition receptor; Physiological; Positioning Attribute; Primates; Process; Proteins; Rest; Role; Shigella flexneri; Signal Transduction; Specificity; TLR4 gene; Testing; Transfection; Variant; cytosolic receptor; genome wide screen; insight; interest; member; microbial; molecular domain; mutant; pathogen; pathogenic bacteria; response; sensor

The gram-negative bacterial outer membrane glycolipid lipopolysaccharide (LPS) is recognized by both the cell surface TLR4 complex and cytosolic sensors. Recognition of bacterial LPS in the cytosol induces the activation of the caspase-4/caspase-5 (CASP4/5, human) or CASP11 (mouse) inflammasome, signaling platforms that trigger pyroptotic cell death. The dogma for recognition of bacterial LPS, based on the simplest interpretation of non-physiological data showing that CASP4/11 bind bacterial LPS in vitro, is that cytosolic bacterial LPS is directly sensed by CASP4/11 rather than by a pattern recognition receptor. We recently found that NLRP11, a poorly characterized primate-specific member of a family of pattern recognition receptors, is a pattern recognition receptor for cytosolic bacterial LPS. We found that efficient cell death induced by cytosolic bacterial LPS in human macrophages depends on NLRP11 function in the CASP4 inflammasome pathway. We initially identified NLRP11 in a genome-wide screen of human myeloid-derived cells for factors that promote cell death during infection with the gram- negative bacterial pathogen Shigella flexneri. We propose to leverage our findings to uncover mechanisms of NLRP11 function in cytosolic bacterial LPS-triggered activation of the human CASP4 inflammasome, including the role of variants of S. flexneri LPS in this process. 1. Define determinants of host-pathogen interaction of NLRP11 with bacterial LPS and caspase(s) and of NLRP11 specificity for caspase(s). We will define the molecular domains and sequences that mediate bacterial LPS interaction with NLRP11 and NLRP11 with CASP4. 2. Determine mechanisms of host NLRP11-mediated activation of CASP4 in response to cytosolic bacterial pathogens and cytosolic bacterial LPS. We will test our hypothesis that resting state NLRP11 is autoinhibited and activated NLRP11 triggers CASP4 activation by proximity-induced dimerization and will test the requirements for bacterial LPS in NLRP11 activation. 3. Test whether host NLRP11 recognition is modulated by specific LPS modifications or modes of LPS delivery by gram-negative bacterial pathogens. We will determine the role of selected modifications of LPS from S. flexneri on its recognition by NLRP11 and on NLRP11-dependent CASP4 activation and will test our hypothesis that NLRP11 is most critical to CASP4 responses when S. flexneri LPS is in micelle-reducing conditions. Our focus is to determine mechanisms of cytosolic bacterial LPS-triggered NLRP11-mediated activation of the human CASP4 inflammasome. We are uniquely positioned to accomplish these goals. Our insights are likely to have broad implications for gram-negative pathogenesis and thus be of great interest to the pathogenesis community.

革兰氏阴性细菌外膜糖脂脂糖酸（LPS）均被两者认识 细胞表面TLR4复合物和胞质传感器。识别细菌LPS中的细菌LPS诱导 caspase-4/caspase-5（CASP4/5，人）或CASP11（小鼠）炎症的激活，信号传导 触发凋亡细胞死亡的平台。基于最简单的细菌LP的识别的教条 非生理数据的解释表明CASP4/11在体外结合细菌LPS是胞质的 细菌LPS由CASP4/11直接检测到模式识别受体。我们最近发现 NLRP11是一个模式识别受体家族的灵长类动物特异性成员，是一个 胞质细菌LPS的模式识别受体。 我们发现，人类巨噬细胞中胞质细菌LPS引起的有效细胞死亡取决于 casp4炎症途径中的NLRP11功能。我们最初在全基因组中确定了NLRP11 人类髓样细胞的筛查，以促进革兰氏阴性症感染过程中细胞死亡的因素 阴性细菌病原体志贺氏菌屈肌。我们建议利用我们的发现来揭示 NLRP11在胞质细菌LPS触发的人casp4炎症体激活中的功能，包括 S. flexneri LPS在此过程中的作用。 1。定义NLRP11与细菌LPS和caspase的宿主 - 病原体相互作用的决定因素 和caspase的NLRP11特异性。我们将定义分子域和序列 介导细菌LPS与NLRP11和NLRP11与CASP4的相互作用。 2。确定宿主NLRP11介导的CASP4激活的机理 细菌病原体和胞质细菌LPS。我们将测试我们的假设，即静止状态NLRP11是 自身抑制和激活的NLRP11通过接近诱导的二聚化触发CASP4激活，并将测试 NLRP11激活中细菌LPS的要求。 3。测试主机NLRP11识别是通过特定的LPS修改或模式调节的 通过革兰氏阴性细菌病原体递送LPS。我们将确定选定修改的作用 来自S. flexneri的LPS对NLRP11和NLRP11依赖性CASP4激活的识别，将测试 我们认为NLRP11在S. flexneri LPS中呈胶束还原时对CASP4响应最重要的假设 状况。 我们的重点是确定胞质细菌LPS触发的NLRP11介导的激活的机制 人CASP4发炎。我们在实现这些目标方面处于独特状态。我们的见解是 可能对革兰氏阴性发病机理具有广泛的影响，因此对 发病机理社区。