MONOCYTE ACTIVATION THROUGH THE MCP1 RECEPTOR CCR2

通过 MCP1 受体 CCR2 激活单核细胞

• 批准号: 2810535
• 负责人: OSWALD QUEHENBERGER
• 金额: $ 11.12万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2810535
• 关键词: antireceptor antibody; biological signal transduction; chimeric proteins; clinical research; cytokine receptors; guanine nucleotide binding protein; guinea pigs; human subject; hypercholesterolemia; leukocyte activation /transformation; low density lipoprotein; monocyte; monocyte chemoattractant protein 1; polymerase chain reaction; protein sequence; receptor binding; receptor expression; tissue /cell culture; transfection

DESCRIPTION (Adapted from Investigator's abstract): Monocytes are stimulated by specific ligands to participate in processes which contribute to inflammation and host defense. Although the mechanisms of monocyte infiltration into tissues are not fully understood, locally generated cytokines, notably monocyte chemotactic peptide 1 (MCP-1), appear to play a crucial role in monocyte recruitment. Two distinct isoforms of the MCP-1 receptor CCR2 that differ only in their alternatively spliced intracellular carboxyl tail have been identified. A major aim of the proposed work is to determine the relative expression of CCR2A and CCR2B on the plasma membrane of freshly isolated human monocytes, and to study the distinct cellular responses they induce. The difference between both isoforms lies exclusively in the amino acid sequence of the carboxy tail which is involved in signal transduction. This difference could alter the selective coupling to GTP binding proteins, resulting in distinct cellular responses. Antibodies directed against specific receptor domains and transfection systems will be used to investigate the interaction between receptor and GTP binding protein, and the resulting cellular responses. Specific aim 2 is to identify and characterize receptor domains essential for ligand binding and signaling. These results will be the basis for the design of antagonists. In preliminary studies, antibodies against the 1st and 2nd extracellular loops prevented ligand binding and inhibited the functional response of monocytes to MCP-1 indicating that multiple domains are involved in receptor function. First, chimeric receptors will be constructed to determine more globally the ligand binding domain(s), and then the microstructures and individual amino acid residues essential for ligand binding and signaling will be determined. In specific aim 3, we will determine the effects of low density lipoproteins (LDL) on expression of CCR2A and CCR2B. In preliminary studies, LDL dramatically increased the expression of CCR2B in monocytic cells lines, resulting in augmented chemotactic response to MCP-1. Experiments will be designed to determine the mechanisms by which LDL regulates CCR2 expression and to study the pathologic effects of hyperresponsive monocytes. We believe our findings will provide fundamental insights into the mechanisms of monocyte activation and recruitment by CCR2, expand our knowledge of various inflammatory diseases processes, including atherosclerosis, and could be used to develop novel and effective therapeutic strategies.

描述（改编自研究者摘要）：单核细胞是 受特定配体的刺激，参与有助于 炎症和宿主防御 虽然单核细胞的机制 对组织的浸润还不完全了解，局部产生 细胞因子，特别是单核细胞趋化肽1（MCP-1），似乎发挥作用， 在单核细胞募集中的重要作用。 MCP-1受体CCR 2的两种不同亚型仅在其 已经鉴定了可变剪接的细胞内羧基尾。 一 建议工作的主要目的是确定的相对表达 新鲜分离的人单核细胞质膜上的CCR 2A和CCR 2B， 并研究它们诱导的不同细胞反应。 的差异 两种亚型之间的区别仅在于 参与信号转导的羧基尾。 这种差异 可以改变与GTP结合蛋白的选择性偶联， 不同的细胞反应。 针对特异性受体的抗体 结构域和转染系统将用于研究相互作用 受体和GTP结合蛋白之间的相互作用， 应答 具体目标2是鉴定和表征必需的受体结构域 用于配体结合和信号传导。 这些结果将成为 对抗者的设计 在初步研究中，针对第1代的抗体 和第二细胞外环阻止配体结合，并抑制 单核细胞对MCP-1的功能反应表明， 与受体功能有关。 首先，嵌合受体将是 构建以更全面地确定配体结合结构域，和 那么微结构和单个氨基酸残基对于 将测定配体结合和信号传导。 具体目标3： 确定低密度脂蛋白（LDL）对表达的影响， CCR 2A和CCR 2B。 在初步研究中，低密度脂蛋白显著增加了 CCR 2B在单核细胞系中的表达， 对MCP-1的趋化反应。 实验将被设计来确定 LDL调节CCR 2表达的机制，并研究LDL对CCR 2表达的影响。 高反应性单核细胞的病理作用。 我们相信，我们的发现将提供基本的见解， 单核细胞活化和招募的机制，扩大我们的研究。 了解各种炎症性疾病的过程，包括 动脉粥样硬化，并可用于开发新的和有效的 治疗策略