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Mechanisms of Leukocyte Integrin Signaling

白细胞整合素信号传导机制

基本信息

批准号：
7196544
负责人：
Clifford A Lowell
金额：
$ 35.91万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-07-01 至 2010-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7196544
关键词：
76-kDa SH2 domain-containing leukocyte protein Acute Adhesions Adhesives Anti-Inflammatory Agents Anti-inflammatory Back Biochemical Biochemical Genetics Bone Marrow CD18 Antigens Cell membrane Cells Class Complex Data Defect Disease Disease model Disruption Enzymes Family Fc Receptor Fetal Liver Fluorescence Resonance Energy Transfer Hematopoietic stem cells ITAM Infection Inflammation Inflammatory Inflammatory Response Injury Integrin Signaling Pathway Integrins Invaded Knock-out LCP2 gene Laboratories Leukocytes Link Lipids Localized Lung Lymphocyte antigen Macrophage Activation Mediating Methods Microscopy Mitogen-Activated Protein Kinases Modeling Molecular Mus Mutant Strains Mice Mutation Myeloid Cells Pathogenesis Pathway interactions Patients Peptides Pharmaceutical Preparations Process Proteins Reaction Research Personnel Rheumatoid Arthritis Sensitivity and Specificity Series Signal Pathway Signal Transduction Signal Transduction Pathway Signaling Molecule Structure T-Cell Receptor T-Lymphocyte TYROBP gene Techniques Testing Therapeutic Tissues Vascular Endothelium Vasculitis Work adapter protein base cellular transduction diaminopyrimidine human SYK protein in vivo leukocyte activation macrophage mutant neutrophil novel novel strategies programs receptor reconstitution research study response retroviral transduction retroviral-mediated src Homology Region 2 Domain src-Family Kinases syk Family Tyrosine Kinase therapeutic target

项目摘要

DESCRIPTION (provided by applicant): Uncontrolled neutrophil adhesion and activation contributes to significantly to tissue damage in inflammatory diseases such as rheumatoid arthritis and vasculitis. Integrins are the major adhesive receptors on neutrophils that regulate cellular activation. Investigating the basic mechanisms of neutrophil integrin signaling is therefore critical to our understanding of the pathogenesis of inflammatory disease. This application is focused on the "outside-in" integrin signaling pathway that induces neutrophil and macrophage activation. In previous work, we have demonstrated that outside-in integrin signaling is mediated by Src-family and Syk tyrosine kinases. In turn, these enzymes signal to SLP-76 leading to downstream activation of MAP kinases. The sequential involvement of Src-family kinases, Syk and SLP-76 is reminiscent of classical immunoreceptor signaling, such as B or T-cell receptor pathways, which depends on ITAM-containing adapter proteins. In preliminary data, we have found that neutrophils derived from DAP-12-/- FcRgamma-/- mice, which lack the two major ITAM adapters present in myeloid cells, are also completely defective in neutrophil integrin signaling. Based on these observations we hypothesize that leukocyte outside-in integrin signaling mimics classical immunoreceptor signaling pathways. We will test this hypothesis is a series of genetic and biochemical experiments. Using retroviral-mediated fetal liver hematopoietic stem cell transduction, we will introduce a series of mutant versions of Syk and DAP-12 into syk-/- or DAP-12-/- FcRgamma-/- mice that will test whether ITAM-Syk interactions are required for integrin signaling in primary neutrophils and macrophages. We will also test whether beta2 integrins form a complex with ITAM-containing DAP-12 and Syk, using biochemical methods and FRET-based microscopy techniques. If Syk and DAP12/FcRgamma are critical in outside-in integrin signaling, then deficiency of these molecules should result in equivalent defects in inflammatory processes in vivo. We will test this using two disease models that are known to be integrin dependent. If our hypothesis that integrin outside-in signaling mimics immunoreceptor pathways by use of ITAM molecules is validated, this will significantly change the view of integrin function in neutrophil-dependent inflammation. Therapeutic targeting of the integrin outside-in signaling pathway may provide novel classes of anti-inflammatory drugs.

描述（由申请人提供）：不受控制的中性粒细胞粘附和激活对炎症性疾病（如类风湿关节炎和血管炎）的组织损伤有重要作用。整合素是中性粒细胞上调节细胞活化的主要粘附受体。因此，研究中性粒细胞整合素信号传导的基本机制对我们理解炎症性疾病的发病机制至关重要。该应用集中于诱导中性粒细胞和巨噬细胞活化的“由外而内”整合素信号通路。在之前的工作中，我们已经证明了src家族和Syk酪氨酸激酶介导了外向内整合素信号传导。反过来，这些酶向SLP-76发出信号，导致下游MAP激酶的激活。src家族激酶、Syk和SLP-76的顺序参与让人想起经典的免疫受体信号传导，如B或t细胞受体途径，这依赖于含有itam的适配蛋白。在初步数据中，我们发现来自DAP-12-/- FcRgamma-/-小鼠的中性粒细胞，缺乏髓细胞中存在的两种主要ITAM适配器，在中性粒细胞整合素信号传导方面也完全缺陷。基于这些观察，我们假设白细胞外-内整合素信号通路模拟经典的免疫受体信号通路。我们将通过一系列的基因和生化实验来检验这一假设。利用逆转录病毒介导的胎肝造血干细胞转导，我们将引入一系列Syk和ap -12的突变版本到Syk -/-或ap -12-/- FcRgamma-/-小鼠中，以测试ITAM-Syk相互作用是否需要在原代中性粒细胞和巨噬细胞中进行整合素信号传导。我们还将使用生化方法和基于fret的显微镜技术测试β 2整合素是否与含有DAP-12和Syk的itam形成复合物。如果Syk和DAP12/FcRgamma在外向内整合素信号传导中起关键作用，那么这些分子的缺乏应该会导致体内炎症过程中相应的缺陷。我们将使用两种已知的依赖于整合素的疾病模型来测试这一点。如果我们关于整合素外向内信号通过ITAM分子模拟免疫受体途径的假设得到验证，这将显著改变整合素在中性粒细胞依赖性炎症中的功能。整合素外-内信号通路的治疗靶点可能提供新型抗炎药物。