MOLECULAR DYNAMICS IN RECEPTOR-MEDIATED PHAGOCYTOSIS

受体介导的吞噬作用的分子动力学

• 批准号: 3292236
• 负责人: NANCY L. THOMPSON
• 金额: $ 17.14万
• 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 1994-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3292236
• 关键词: affinity chromatography; cell membrane; fluorescence microscopy; fluorescence spectrometry; immunoglobulin A; lipid bilayer membrane; macrophage; membrane activity; membrane lipids; membrane reconstitution /synthesis; molecular dynamics; phagocytosis; phospholipids; protein reconstitution; receptor; receptor binding; receptor mediated endocytosis; tissue /cell culture

One mechanism of immunological defense is phagocytosis, in which macrophage cells ingest and destroy pathogenic microorganisms. In receptor-mediated phagocytosis, antibody receptors on a macrophage cell surface recognize antibodies bound to a foreign target and signal the macrophage to begin ingestion. Proposed is an investigation of the molecular events that occur in the initial region of contact between a macrophage and a potential target that lead to the onset of ingestion. In the research, the surfaces of pathogenic targets will be modeled by substrate-supported planar membranes containing hapten- conjugated phospholipids, and the interactions of hapten-specific antibodies with the films will be characterized for different film and antibody properties. The molecular requirements for and effects of the antibody-mediated interaction of macrophage cells with the planar membranes will then be examined. In a complementary approach, macrophage cell surfaces will be modeled by substrate-supported planar membranes constructed either from isolated natural membrane fragments or from purified and reconstituted macrophage antibody receptors and the interaction of antibodies with these model membranes will be characterized. The requirements for and effects of the antibody-mediated interaction of haptenated targets with the planar membranes containing antibody receptors will then be determined. Molecular transport and interaction will be measured with techniques in fluorescence microscopy. High order fluorescence correlation spectroscopy is a new technique that will monitor the formation of molecular clusters. Total internal reflection fluorescence microscopy, which was recently developed specifically for surface phenomena, will measure the equilibrium and kinetic parameters of molecule-membrane adhesion and will monitor molecular orientation. Fluorescence photobleaching recovery will measure lateral and rotational mobility. This research will contribute to the present understanding of (1) molecular events in the macrophage-target contact region during the onset of receptor-mediated phagocytosis, (2) factors that affect protein lateral and rotational mobility in or on membranes, and (3) the physicochemical basis of cell-surface receptor clustering. Development and refinement of techniques in protein reconstitution and surface fluorescence microscopy will be applicable to membrane biophysics in general.

免疫防御的一种机制是吞噬作用，其中 巨噬细胞摄取并消灭病原微生物。 在 受体介导的吞噬作用，巨噬细胞上的抗体受体 细胞表面识别与外源靶结合抗体， 发出信号让巨噬细胞开始摄取。 建议是一个 对发生在初始阶段的分子事件的研究 巨噬细胞和潜在目标之间的接触区域， 导致摄入 在研究中，致病目标的表面将被建模 通过含有半抗原的基底支撑平面膜- 结合磷脂，以及半抗原特异性 将针对不同的膜表征具有膜的抗体 和抗体特性。 分子的要求， 抗体介导的巨噬细胞相互作用的影响 然后检查平面膜。 中 补充方法，巨噬细胞表面将被建模 通过基底支撑的平面膜， 分离的天然膜片段或来自纯化的和 重组巨噬细胞抗体受体和 将表征具有这些模型膜的抗体。 的 抗体介导的相互作用的要求和作用 用含有抗体的平面膜半抗原化的目标 然后将确定受体。 分子运输和相互作用将用 荧光显微镜技术。 高阶荧光 相关光谱学是一种新技术， 形成分子簇。 全内反射 荧光显微镜，这是最近专门开发的 对于表面现象，将测量平衡和动力学 分子-膜粘附的参数，并将监测分子 导向 荧光光漂白恢复将测量 横向和轮换流动性。 本研究将有助于目前对（1）的理解 巨噬细胞-靶接触区的分子事件， 受体介导的吞噬作用的发生，（2）影响 膜内或膜上的蛋白质横向和旋转迁移率，以及（3） 细胞表面受体聚集的物理化学基础。 蛋白质重组技术的发展与完善 和表面荧光显微镜将适用于膜 生物物理学