MOLECULAR DYNAMICS IN RECEPTOR-MEDIATED PHAGOCYTOSIS

受体介导的吞噬作用的分子动力学

• 批准号: 3292232
• 负责人: NANCY L. THOMPSON
• 金额: $ 8.19万
• 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/3292232
• 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 识别它们并摄取它们。 恒定区域的受体 巨噬细胞表面上的IgG抗体识别IgG结合 向外国靶标并发出巨噬细胞的信号以开始吞噬作用。 提出的是一组旨在研究分子的实验 发生在巨噬细胞和 一个潜在的目标，导致目标识别和开始 吞噬作用。 提出的研究涉及对两个互补模型的研究 系统。 首先，物理和化学明确的磷脂 含有结合磷脂的靶膜将是 沉积在固体平面基板上。 触觉特异性IgG的行为 在膜上（结合曲线，结合动力学速率，横向迁移率， 低聚）将在不同的下进行仔细表征 状况。 接下来，对 巨噬细胞相关细胞系的代谢激活和/或结合在 在特异性IgG存在下的平面靶膜将是 检查。 在第二个模型系统中，纯化的小鼠巨噬细胞 IgG的细胞表面受体将被重构为磷脂 将双层存放在平面底物上。 触觉特异性的行为 IgG，然后是可溶性单价抗抗蛋白或多价承重 巨噬细胞表面的这些平面模型的目标将是 调查。 荧光显微镜中的几种非常新的技术将 被完善并用于探测分子运动，相互作用和 在平面膜上或附近的分布，包括荧光 相关光谱和总内反射荧光 显微镜。 拟议的研究是提供新的和 有关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。 很可能类似 机制以其他参与的免疫细胞类型运行 抗体介导的靶识别。 发展和完善 蛋白质重构和表面荧光显微镜中的技术 将在膜上具有广泛的细胞表面生物学适用性 生物物理学和生物技术。