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（由申请人提供）：γ干扰素诱导的溶酶体硫醇还原酶（GILT）是内吞途径中唯一已知的可以还原蛋白质中二硫键的酶，它在抗原呈递细胞（APC）中组成型高表达并发挥关键作用。在含有二硫键的抗原加工过程中，由 MHC II 类分子呈递给 CD4+ T 细胞，并且在树突状细胞中，交叉呈递大多数细胞类型中，GILT 的同源物都存在于许多缺乏适应性免疫系统的物种中，这表明 GILT 也可以被 MHC I 类分子抗原诱导为 CD8+ T 细胞。除了其在抗原加工中的作用之外，该提议还可能具有其他功能：GILT 是暴露于细菌的巨噬细胞最佳产生呼吸爆发所必需的。缺乏酶活性 GILT 的巨噬细胞产生的活性氧 (ROS) 较少，并且杀死吞噬细菌（包括鼠伤寒沙门氏菌、大肠杆菌和金黄色葡萄球菌）的能力受到损害。 GILT 基因被删除的患者清除腹膜沙门氏菌感染的能力受到损害我们将确定 GILT 是否影响巨噬细胞胞质的整体氧化还原电位。我们将确定 GILT 表达是否影响负责 ROS 的主要系统的稳态细胞内分布。巨噬细胞和中性粒细胞中NADPH氧化酶-2（Nox2）的生成，以及它是否影响LPS刺激和观察到的这些成分分布的变化我们还将确定巨噬细胞溶酶体和吞噬体中作为 GILT 活性靶标的分子，特别关注发光暴露的 Nox2 成分。其他细胞类型产生 ROS，包括使用 Nox2 的原型细胞类型、中性粒细胞以及可以使用 Nox2 同源物产生 ROS 的其他细胞类型。 Nox2。其中一些同源物与 Nox2 具有相同的调控成分，但其他的则不然。这些研究将使我们能够确定 GILT 是否在 ROS 生成中发挥一般作用，并确定其作用的分子机制。