MOLECULAR DYNAMICS IN RECEPTOR-MEDIATED PHAGOCYTOSIS

受体介导的吞噬作用的分子动力学

• 批准号: 3292230
• 负责人: NANCY L. THOMPSON
• 金额: $ 11.83万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-07-01 至 1989-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3292230
• 关键词: affinity chromatography; cell membrane; chemical binding; fluorescence microscopy; fluorescence spectrometry; immunoglobulin A; intermolecular interaction; macrophage; membrane activity; membrane lipids; membrane reconstitution /synthesis; phagocytosis; phospholipids; tissue /cell culture

Macrophage cells in the immune system destroy foreign targets by recognizing them and ingesting them. Receptors for the constant region of IgG antibodies that are on the surfaces of macrophages recognize IgG bound to a foreign target and signal the macrophage to begin phagocytosis. Proposed is a set of experiments designed to investigate the molecular events that occur in the region of initial contact between a macrophage and a potential target, leading both to target recognition and the onset of phagocytosis. The proposed research involves the investigation of two complementary model systems. In the first, physically and chemically well-defined phospholipid target membranes containing hapten-conjugated phospholipids will be deposited on solid planar substrates. The behavior of hapten-specific IgG at the membranes (binding curves, binding kinetic rates, lateral mobility, oligomerization) will be carefully characterized under different conditions. Next, the molecular requirements for and effects of the metabolic activation and/or binding of macrophage-related cell lines at the planar target membranes in the presence of hapten-specific IgG will be examined. In the second model system, purified mouse macrophage cell-surface receptors for IgG will be reconstituted into phospholipid bilayers deposited on planar substrates. The behavior of hapten-specific IgG, followed by soluble monovalent haptyens or multivalent hapten-bearing targets at these planar models of the macrophage cell-surface will be investigated. Several very new techniques in fluorescence microscopy will be refined and employed to probe molecular motion, interaction, and distribution at or near planar membranes, including fluorescence correlation spectroscopy and total internal reflection fluorescence microscopy. The proposed research stands an excellent chance of providing new and important information about the cell-surface molecular mechanisms of macrophage receptor-mediated phagocytosis. It is likely that similar mechanisms operate in other immunological cell types that participate in antibody-mediated target recognition. Development and refinement of techniques in protein reconstitution and in surface fluorescence microscopy will have wide applicability in cell-surface biology, in membrane biophysics, and in biotechnology.

免疫系统中的巨噬细胞通过 认出它们并吞下它们。恒定区的受体 巨噬细胞表面的免疫球蛋白抗体识别免疫球蛋白结合 并向巨噬细胞发出开始吞噬的信号。 提出了一系列旨在研究分子的实验 发生在巨噬细胞和巨噬细胞之间初始接触区域的事件 一个潜在的目标，导致目标识别和 吞噬作用。 所提出的研究涉及两个互补模型的研究 系统。首先，物理和化学上定义明确的磷脂 含有半抗原结合磷脂的靶膜将是 沉积在固体平面衬底上。半抗原特异性免疫球蛋白的行为 在膜上(结合曲线、结合动力学速率、侧向迁移率、 齐聚)将在不同的 条件。接下来，对分子的要求和影响 巨噬细胞相关细胞系的代谢激活和/或结合 在半抗原特异性免疫球蛋白存在下的平面靶膜 检查过了。在第二个模型系统中，纯化的小鼠巨噬细胞 细胞表面的免疫球蛋白受体将被重组为磷脂 沉积在平面衬底上的双层膜。半抗原特异性的行为 免疫球蛋白，紧随其后的是可溶性单价半抗原或多价半抗原 巨噬细胞表面的这些平面模型的靶点将是 调查过了。荧光显微镜中的几项非常新的技术将 被改进并用于探测分子运动、相互作用和 平面膜上或其附近的分布，包括荧光 相关光谱与全内反射荧光 显微镜。 拟议的研究很有可能提供新的和 细胞表面分子机制的重要信息 巨噬细胞受体介导的吞噬作用。很可能是相似的 机制在其他免疫细胞类型中发挥作用，这些细胞参与 抗体介导的目标识别。开发和完善 蛋白质重组和表面荧光显微镜技术 将在细胞表面生物学、膜生物学中具有广泛的适用性 生物物理学，以及生物技术。