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CHEMOKINE INDUCTION BY RECEPTOR MEDIATED PHAGOCYTOSIS

受体介导的吞噬作用诱导趋化因子

基本信息

批准号：
2910598
负责人：
Joseph D Paulauskis
金额：
$ 11.36万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-05-01 至 2001-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2910598
关键词：
DNA footprinting alveolar macrophages biological signal transduction chemokine free radical oxygen gel mobility shift assay genetic regulatory element genetic transcription inflammation laboratory rat macrophage inflammatory proteins molecular cloning nuclear runoff assay nucleic acid hybridization protein biosynthesis receptor mediated endocytosis respiratory system tissue /cell culture

项目摘要

This is a revised application of a proposal to study the intracellular signal transduction pathway which leads to expression of pro-inflammatory chemokines when macrophages encounter particles in the lung. Alveolar regions of the lung are continuously exposed to inhaled particles, including both inert particulates and aerosolized pathogens. Alveolar macrophages (AMs) are primarily responsible for clearance of these particles from the lung, and for initiating and propagating a "proper" inflammatory response. Responses to particle binding and/or phagocytosis of AMs is dependent upon characteristics of the particles encountered. Binding of opsonized particles by cell surface receptors of macrophages results in a substantial respiratory burst and subsequently increases in mRNA transcripts for pro-inflammatory cytokines including the Platelet Factor-4 family chemokines, macrophage inflammatory protein-2 (MIP-2) and KC. We hypothesize that pulmonary inflammation is induced when inhaled particles are opsonized and taken up by alveolar macrophages using specific surface receptors which transduce intracellular signals to activate transcription of the MIP-2 and KC genes. The nature of the intracellular signal(s) that mediate the induction of MIP-2/KC gene expression is unknown, however, we present substantial preliminary data implicating reactive oxygen species (ROS) as the primary stimulus for induction of these mRNAs. We propose to use molecular and biochemical techniques to define this transduction pathway in a bi-directional fashion starting from both the stimulus at the macrophage cell membrane and the response, MIP-2/KC mRNA synthesis. The specific aims of the studies we propose are: (l) To determine the regulatory mechanisms operative when macrophage binding of opsonized particles increases MIP-2 and KC mRNA levels; (2) To clone and characterize the 5'-flanking regions of the MIP-2 and KC genes; (3) To identify putative cis elements and establish their role in controlling transcription of the MIP-2 and KC genes; and (4) To establish that reactive oxygen species are a key component of the signal transduction pathway inducing MIP-2 and KC gene expression. Elucidation of the pathway by which opsonized particles induce chemokine synthesis will add significantly to our understanding of pulmonary inflammation and associated diseases.

这是一项研究细胞内的建议的修订应用导致促炎因子表达的信号转导途径当巨噬细胞遇到肺中的颗粒时，趋化因子。牙槽骨肺部的部分区域持续暴露在吸入颗粒物中，包括惰性颗粒物和气雾化病原体。牙槽骨巨噬细胞(AM)主要负责清除这些物质。来自肺的颗粒，并用于启动和传播一种“适当的” 炎症反应。对颗粒结合和/或吞噬的反应 AMS的大小取决于遇到的颗粒的特性。巨噬细胞表面受体与调理颗粒的结合导致大量的呼吸爆发，随后增加了包括血小板在内的促炎细胞因子的mRNA转录本因子-4家族趋化因子、巨噬细胞炎性蛋白-2和 KC。我们假设吸入时会引起肺部炎症。颗粒被调理并被肺泡巨噬细胞利用特异性表面受体，将细胞内信号传导至激活MIP-2和KC基因的转录。这个世界的本质介导MIP-2/KC基因诱导的细胞内信号(S) 表达是未知的，然而，我们提供了大量的初步数据将活性氧簇(ROS)作为主要刺激因素诱导这些mRNAs。我们建议使用分子和生化以双向方式定义该转导途径的技术从巨噬细胞膜的刺激和巨噬细胞的应答，MIP-2/KC mRNA合成。我们研究的具体目标是建议有：(L)确定运行时的监管机制巨噬细胞与调理颗粒的结合增加MIP-2和KC基因的表达水平；(2)克隆和鉴定MIP-2的5‘侧翼区和KC基因；(3)鉴定可能的顺式元件并建立它们的在控制MIP-2和KC基因转录中的作用；以及(4) 确定活性氧物种是信号的关键成分诱导MIP-2和KC基因表达的信号转导途径。澄清：调理颗粒诱导趋化因子合成的途径将大大增加了我们对肺部炎症和相关疾病。