Structural and mechanistic elucidation of non-canonical inflammasome signaling

非典型炎症小体信号传导的结构和机制阐明

• 批准号: 10374131
• 负责人: Jianbin Ruan
• 金额: $ 41万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-17 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10374131
• 关键词: Adult; Bacterial Infections; Binding; Biochemical; Biological Process; C-terminal; CASP1 gene; Caspase; Catalytic Domain; Cause of Death; Cell Death; Cell membrane; Child; Communicable Diseases; Complex; Cryoelectron Microscopy; Disease; Electron Microscopy; Elements; Endotoxins; Filament; Future; Goals; Gram-Negative Bacteria; Human; Immunologic Surveillance; In Vitro; Infection; Inflammasome; Inflammatory; Intervention; Knowledge; Ligand Binding; Ligands; Lipids; Lipopolysaccharides; Mass Spectrum Analysis; Membrane; Modeling; Molecular; Multiprotein Complexes; Mus; Mutagenesis; N-terminal; Newborn Infant; Oxides; Patients; Phase; Phospholipids; Play; Process; Research; Resolution; Role; Sepsis; Sequence Alignment; Signal Pathway; Signal Transduction; Site; Structure; Testing; Therapeutic; VDAC1 gene; Variant; X-Ray Crystallography; base; biophysical properties; design; drug development; experience; experimental study; improved; in vivo; inflammatory marker; insight; microbial; novel strategies; novel therapeutic intervention; programs; receptor; reconstitution; recruit; sensor; septic patients; trial design

Project Summary/Abstract Caspase-4/-5/-11 non-canonical inflammasomes have been known to play pivotal roles in various inflammatory and infectious diseases, such as sepsis. Current studies demonstrate that caspase-4/-5/-11 are activated by directly sensing intracellular microbial infections, such as lipopolysaccharide (LPS, also known as endotoxin), or endogenous products, such as oxidized phospholipids (e.g., OxPAPC), through their N-terminal caspase activation and recruitment domains (CARDs) and C-terminal catalytic domains, respectively. However, the molecular mechanisms of how caspase-4/-5/-11 recognize their ligands and how caspase-4/-5/-11 are activated upon binding ligands remain unknown. In this proposal, we aim to elucidate the structural basis of non-canonical inflammasome signaling by characterizing the interactions between caspase-4/-5/-11 and ligands - LPS and OxPAPC, and determining the high-resolution structures of caspase/-4/-5/-11 in complex with ligands. Our structural findings will provide new therapeutic strategies for sepsis and other non-canonical inflammasome- associated diseases. We propose three specific aims to achieve our goal: 1) Biochemical characterization of the interactions between caspase-4/-5/-11 and LPS-including the identification of the essential structural elements in the LPS molecule and key residues on caspase-4/-5/-11 CARDs that are required for caspase-4/-5/-11 activation; 2) Determine high-resolution structures of caspase-4/-5/-11 CARDs both in their inactive form and in complex with LPS; 3) Characterize the interactions between caspase-4/-11 and OxPAPC, and determine the high resolution structures of caspase-4/-11 catalytic domains in complex with OxPAPC. We will pursue these aims using cutting-edge experimental approaches including biochemical and biophysical characterization, X-ray crystallography, mass spectrometry, electron microscopy, and cellular experiments. The proposed studies will significantly expand our current knowledge on the mechanisms of non-canonical inflammasome signaling, and provide rationale and a structural basis for designing novel strategies to control the activation of the non- canonical inflammasome for better treatment of related diseases.

项目总结/文摘