Chemokines and Immune Cells in Hind Limb Ischemia

后肢缺血中的趋化因子和免疫细胞

• 批准号: 6935939
• 负责人: PAULA K SHIREMAN
• 金额: $ 29.2万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6935939
• 关键词: T lymphocyte; angiogenesis; cellular immunity; chemokine; enzyme linked immunosorbent assay; flow cytometry; gene targeting; genetically modified animals; histochemistry /cytochemistry; ischemia; laboratory mouse; leukocyte activation /transformation; limbs; monocyte chemoattractant protein 1; necrosis; tissues

DESCRIPTION (provided by applicant): New treatments are needed to decrease the complications of atherosclerosis, which include death, disability, heart attack, and amputation. Notably, collateral artery formation that "naturally" bypasses arterial obstructions occurs in all patients, but to a variable degree. Understanding the mechanisms of collateral artery formation and ischemic tissue necrosis could lead to new primary and adjuvant therapies for atherosclerosis. My long term research goal is to understand the basic mechanisms underlying collateral artery formation and tissue necrosis and specifically, in this application, ! will determine the influence of the immune system in collateral artery formation and tissue necrosis secondary to ischemia. Central to my hypothesis is that the recruitment and activation of inflammatory cells and the concomitant immune response influences collateral artery formation and susceptibility to tissue necrosis. I hypothesize that 1) immune differences account for their differential susceptibility to tissue necrosis in two inbred mouse strains, 2) T-cell recruitment and activation is an important determinant of susceptibility to tissue necrosis and 3) the MCP-1/CCR2 axis is an important determinant of susceptibility to tissue necrosis. Monocyte Chemoattractant Protein-1 (MCP-1) and its receptor CCR2 are important regulators of immune cell recruitment and differentiation. To test these hypotheses, I have in preliminary studies a) developed a mouse hind limb model of ischemia and have demonstrated that inbred strains of mice have differential susceptibilities to tissue necrosis; b) demonstrated that nude mice lacking T-cells and mice lacking MCP-1 or CCR2 have an increased incidence and severity of tissue necrosis as compared to wild type controls and c) shown that there is an increased recruitment of inflammatory cells to the ischemic hind limb. To test my hypothesis, I have proposed three specific aims. In aim #1, I will identify the mechanisms underlying the differential susceptibility to tissue necrosis in two inbred strains of mice. In aim #2, I will determine the role of T-cells and the Thl/Th2 immune response in tissue necrosis and in aim #3 I will determine the role of the MCP-1tCCR2 axis in tissue necrosis by using mice that are genetically inactivated for CCR2 and its ligand, MCP-1. The experiments outlined in this proposal are innovative because they utilize the power of genetic knockout mice in a hind limb ischemia model. I have assembled an experienced team of researchers in the diverse areas of vascular biology, immunology and physiology to test these hypotheses. The significance of this research is that a better understanding of the mechanisms of collateral artery formation and susceptibility to tissue necrosis could lead to the design of novel primary or adjuvant treatments for atherosclerotic occlusive disease and thereby decrease death and disability rates from myocardial infarction and amputations.

描述（由申请人提供）： 需要新的治疗方法来减少动脉粥样硬化的并发症，包括死亡、残疾、心脏病和截肢。值得注意的是，“自然”绕过动脉阻塞的侧支动脉形成发生在所有患者中，但程度不同。了解侧支动脉形成和缺血性组织坏死的机制可能会导致动脉粥样硬化的新的主要和辅助疗法。我的长期研究目标是了解侧支动脉形成和组织坏死的基本机制，特别是在本应用中！将确定免疫系统对侧支动脉形成和继发于缺血的组织坏死的影响。我的假设的核心是炎症细胞的募集和激活以及伴随的免疫反应影响侧支动脉的形成和组织坏死的易感性。我假设 1) 免疫差异导致了两种近交小鼠品系对组织坏死的不同易感性，2) T 细胞募集和激活是组织坏死易感性的重要决定因素，3) MCP-1/CCR2 轴是组织坏死易感性的重要决定因素。组织坏死易感性的重要决定因素。单核细胞趋化蛋白-1 (MCP-1) 及其受体 CCR2 是免疫细胞招募和分化的重要调节因子。为了检验这些假设，我在初步研究中a）开发了小鼠后肢缺血模型，并证明近交系小鼠对组织坏死具有不同的敏感性； b) 证明，与野生型对照相比，缺乏 T 细胞的裸鼠和缺乏 MCP-1 或 CCR2 的小鼠组织坏死的发生率和严重程度增加；c) 表明，缺血后肢的炎症细胞募集增加肢。为了检验我的假设，我提出了三个具体目标。在目标#1中，我将确定两种近交系小鼠对组织坏死的不同易感性的潜在机制。在目标 #2 中，我将确定 T 细胞和 Thl/Th2 免疫反应在组织坏死中的作用，在目标 #3 中，我将通过使用基因失活的小鼠确定 MCP-1tCCR2 轴在组织坏死中的作用对于 CCR2 及其配体 MCP-1。该提案中概述的实验具有创新性，因为它们在后肢缺血模型中利用了基因敲除小鼠的力量。我组建了一支血管生物学、免疫学和生理学不同领域经验丰富的研究人员团队来测试这些假设。这项研究的意义在于，更好地了解侧支动脉形成和组织坏死易感性的机制，可以设计出针对动脉粥样硬化闭塞性疾病的新型主要或辅助治疗方法，从而降低心肌梗塞和截肢造成的死亡和残疾率。