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多糖（LPS）被两者识别。 细胞表面TLR 4复合物和胞质传感器。细胞质中细菌LPS的识别诱导了 半胱天冬酶-4/半胱天冬酶-5（CASP 4/5，人）或CASP 11（小鼠）炎性体的活化，信号传导 引发细胞凋亡的平台。细菌LPS识别的教条，基于最简单的 对显示CASP 4/11在体外结合细菌LPS的非生理数据的解释是， 细菌LPS直接被CASP 4/11而不是模式识别受体感知。我们最近发现 NLRP 11是一种模式识别受体家族中特征不明显的灵长类特异性成员， 胞质细菌LPS的模式识别受体。 我们发现人巨噬细胞中胞质细菌LPS诱导的有效细胞死亡取决于 NLRP 11在CASP 4炎性体通路中的功能。我们最初在一个全基因组中发现了NLRP 11， 筛选人骨髓来源的细胞，寻找在革兰氏阴性杆菌感染期间促进细胞死亡的因子， 阴性细菌病原体福氏志贺菌。我们建议利用我们的发现来揭示 NLRP 11在细胞溶质细菌LPS触发的人CASP 4炎性体激活中的功能，包括 S.福氏LPS在此过程中。 1.定义NLRP 11与细菌LPS和半胱天冬酶的宿主-病原体相互作用的决定因素 和NLRP 11对半胱天冬酶的特异性。我们将定义分子结构域和序列， 介导细菌LPS与NLRP 11和NLRP 11与CASP 4的相互作用。 2.确定宿主NLRP 11介导的CASP 4活化响应细胞溶质的机制 细菌病原体和胞质细菌LPS。我们将测试我们的假设，即静息态NLRP 11是 自抑制和激活的NLRP 11通过邻近诱导的二聚化触发CASP 4激活，并将测试 NLRP 11激活对细菌LPS的要求。 3.测试宿主NLRP 11识别是否受特定LPS修饰或 革兰氏阴性细菌病原体的LPS递送。我们将确定选定的修改的作用， LPS来自S. flexneri对NLRP 11识别和NLRP 11依赖性CASP 4激活的影响，并将测试 我们假设NLRP 11对CASP 4反应最关键，当S.福氏LPS在胶束还原中 条件 我们的重点是确定胞质细菌LPS触发的NLRP 11介导的激活的机制， 人CASP 4炎性小体。我们处于实现这些目标的独特地位。我们的见解是 可能对革兰氏阴性致病机制有广泛的影响，因此对研究人员有很大的兴趣。 发病机理共同体