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以下方式破坏外来靶标： 认识他们并吸收他们。 恒定区受体 巨噬细胞表面上的IgG抗体识别结合的IgG， 并向巨噬细胞发出信号以开始吞噬作用。 提出的是一组实验，旨在研究分子 在巨噬细胞和巨噬细胞之间的初始接触区域中发生的事件 一个潜在的目标，导致目标识别和发病 吞噬作用 本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 含有半抗原缀合的磷脂的靶向膜将 沉积在固体平面衬底上。 半抗原特异性IgG的行为 在膜上（结合曲线，结合动力学速率，横向迁移率， 低聚反应）将在不同的条件下仔细表征。 条件 接下来，讨论了对蛋白质的分子要求和蛋白质的作用。 代谢活化和/或结合的巨噬细胞相关细胞系， 在存在半抗原特异性IgG的情况下， 考察 在第二个模型系统中，纯化的小鼠巨噬细胞 IgG的细胞表面受体将重组为磷脂 沉积在平面衬底上的双层。 半抗原特异性 IgG，然后是可溶性单价半抗原或多价携带半抗原的抗体。 在巨噬细胞表面的这些平面模型上的靶标将被 研究了 荧光显微镜中的几种非常新的技术将 经过改进并用于探测分子运动、相互作用和 在平面膜处或附近的分布，包括荧光 相关光谱和全内反射荧光 显微镜 拟议的研究有很好的机会提供新的和 关于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 在其他免疫细胞类型中， 抗体介导的靶标识别。 制定和完善 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 生物物理学和生物技术。