The role of GILT in the generation of reactive oxygen species

GILT 在活性氧生成中的作用

基本信息

批准号：
9091406
负责人：
PETER CRESSWELL
金额：
$ 24.98万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-07-01 至 2017-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9091406
关键词：
Address Affect Antigen-Presenting Cells Antigens B-Lymphocytes Bacteria Biochemical Biological CD4 Positive T Lymphocytes CD8B1 gene Cells Complex Cross Presentation Cytosol Data Defect Dendritic Cells Disulfides Electron Transport Electrons Endocytosis Endothelial Cells Enzymes Escherichia coli Event Fibroblasts GTP Binding Generations Genes Goals Health Histocompatibility Antigens Class I Histocompatibility Antigens Class II Homologous Gene Hydrogen Peroxide Immune system In Vitro Incubated Infection Inflammatory Interferon Type II Interferons Knock-out Knockout Mice Ligands Lipopolysaccharides Lysosomes MHC Class I Genes MHC Class II Genes Membrane Mitochondria Molecular Monomeric GTP-Binding Proteins Mouse-ear Cress Mus NADP NADPH Oxidase Oxidants Oxidation-Reduction Oxygen Pathway interactions Pattern Peritoneal Phagocytes Phagocytosis Phagosomes Plants Play Process Production Proteins Reactive Oxygen Species Respiratory Burst Role Salmonella typhimurium Series Signal Transduction Staphylococcus aureus Superoxide Dismutase Superoxides System T-Lymphocyte Tissues Vascular Smooth Muscle antigen processing base cell type cytokine disulfide bond disulfide bond reduction improved killings macrophage mutant neutrophil neutrophil cytosol factor 40K neutrophil cytosol factor 67K pathogen

项目摘要

DESCRIPTION (provided by applicant): Gamma Interferon-inducible Lysosomal Thiolreductase (GILT) is the only known enzyme in the endocytic pathway that can reduce disulfide bonds in proteins. It is constitutively highly expressed in antigen presenting cells (APCs) and plays a key role in the processing of antigens containing disulfide bonds for presentation by MHC class II molecules to CD4+ T cells and, in dendritic cells, cross-presentation of antigens by MHC class I molecules to CD8+ T cells. GILT is also inducible by gamma interferon (IFN-) and other inflammatory cytokines in most cell types. Homologues of GILT are present in many species that lack an adaptive immune system, suggesting that it may have functions in addition to its role on antigen processing. This proposal is based on our discovery of one such function: GILT is required for the optimal generation of the respiratory burst by macrophages exposed to bacterial lipopolysaccharide (LPS) or other pathogen-associated molecular patterns (PAMPs). Macrophages lacking enzymatically active GILT produce less reactive oxygen species (ROS) and are impaired in their ability to kill phagocytosed bacteria, including Salmonella typhimurium, Escherichia coli and Staphylococcus aureus. Mice in which the GILT gene is deleted are impaired in their ability to clear a peritoneal infection by Salmonella typhimurium. We propose to determine the mechanistic underpinnings of these phenomena. We will determine whether GILT influences the overall redox potential of the macrophage cytosol. We will determine if GILT expression influences the steady state intracellular distribution of the components of the dominant system responsible for ROS generation in macrophages and neutrophils, NADPH oxidase- 2 (Nox2), and whether it affects the changes in distribution of these components observed upon LPS stimulation and phagocytosis, with and without IFN- stimulation. We will also determine the molecules in macrophage lysosomes and phagosomes that are targets for GILT activity, with a particular focus on Nox2 components that are luminally exposed. We will also determine the potential role of GILT in ROS generation by other cell types. These include the prototypical cell type that uses Nox2, the neutrophil, and other cell types that can generate ROS using homologues of Nox2. Some of these homologues share regulatory components with Nox2 but others do not. These studies will allow us to determine if GILT plays a general role in ROS generation, and to determine the molecular mechanism by which it acts.

描述（由适用提供）：伽马干扰素诱导的溶酶体硫糖酶（GILT）是内吞途径中唯一已知的酶，可以减少蛋白质中的二硫键。它一致地在抗原呈递细胞（APC）中高度表达，并且在含有二硫键的抗原加工中起关键作用，以通过MHC II类分子向CD4+ T细胞以及树突状细胞以及MHC类I类分子的CD8+ T细胞交叉抗原。在大多数细胞类型中，伽马干扰素（IFN-）和其他炎症细胞因子也诱导了镀金。镀金的同源物存在于许多缺乏适应性免疫系统的物种中，这表明它除了其在抗原加工中的作用外，还具有功能。该建议基于我们发现了一个这样的功能：镀金是由暴露于细菌脂多糖（LPS）或其他病原体相关的分子模式（PAMPS）的巨噬细胞最佳产生呼吸道爆发所必需的。缺乏酶活性镀金的巨噬细胞产生的活性氧（ROS）较少，并因其杀死吞噬细胞的能力受损，包括鼠伤寒沙门氏菌，大肠杆菌和金黄色葡萄球菌。镀金基因被删除的小鼠因其清除伤寒沙门氏菌感染的能力而受损。我们建议确定这些现象的机械基础。我们将确定镀金是否影响巨噬细胞胞质溶胶的总体氧化还原电位。我们将确定镀金表达是否影响负责巨噬细胞和中性粒细胞中ROS产生的主要系统的稳态内分布，NADPH氧化物2（NOX2），以及它是否会影响LPS刺激和吞噬细胞的分布的变化，并与IFN-IFN-ifn-ifn-ifn-ifn-im刺激有关。我们还将确定巨噬细胞溶酶体和吞噬体的分子，这些分子是镀金活性的靶标的，特别关注透明暴露的NOX2成分。我们还将通过其他细胞类型来确定GILT在ROS生成中的潜在作用。其中包括使用NOX2，中性粒细胞和其他可以使用NOX2同源物产生ROS的典型细胞类型。这些同源物中的一些与NOX2共享监管组件，而其他一些则没有。这些研究将使我们能够确定镀金在ROS的产生中是否起着一般作用，并确定其作用的分子机制。