PHYSIOCOCHEMICAL FEATURES OF LYMPHOCYTE PLASMA MEMBRANES

本项目的长期目标是探索 B淋巴细胞浆的物理化学结构 膜，并了解如何在这个组织的变化， 反映和/或介导细胞活化中的主要事件。 的 本项目的第一部分涉及组织和分配 膜结构域上的脂质。 尺寸、脂质成分和 将使用荧光检测脂质结构域的流动性 光漂白恢复和扫描荧光相关 谱 制备的大单层囊泡的研究 B细胞膜脂质有助于评估细胞脂质 组织依赖于细胞表面蛋白的存在。 通过特异性脂质富集的膜脂质改变， 通过糖皮质激素治疗降低胆固醇，以及 通过温度扰动将被检查。 第二 工作领域涉及的分布和相互作用 膜蛋白 扫描荧光相关 光谱实验将探索蛋白质是否 定位于一种或多种类型的富含蛋白质的区域， 特定的脂质类是否优先与 特殊蛋白质 特定关联发生在 已知的B细胞膜蛋白和其它已知的或迄今为止 将使用荧光能量评估未识别的物质 转移和新的免疫化学靶向光邻近性 标记方法 特定膜的聚集状态 将使用时间分辨磷光法评价蛋白质 各向异性 最后，B淋巴细胞 膜结构由三个激活产生 机制，抗IgM治疗，胸腺非依赖性 与人工修饰的细胞相互作用的抗原样配体 与特定的受体，脂多糖将 考察

The long-range goal of this project is to explore the physicochemical organization of the B lymphocyte plasma membrane and to learn how changes in this organization may reflect and/or mediate primary events in cellular activation. The first part of this project concern the organization and distribution of lipids on membrane domains. Sizes, lipid composition, and fluidities of lipid domains will be examined using fluorescence photobleaching recovery and scanning fluorescence correlation spectroscopy. Studies of large unilamellar vesicles prepared from B cell membrane lipid will help assess whether cellular lipid organization is dependent on the presence of cell surface protein. Membrane lipid alteration via specific lipid enrichment, via cholesterol depletion through glucocorticoid treatment, and through temperature perturbation will be examined. The second area of work concerns the distribution and interaction of membrane proteins. Scanning fluorescence correlation spectroscopy experiments will explore whether proteins are localized into one or more types of protein-rich regions and whether specific lipid classes preferentially associate with particular proteins. Specific associations occurring between known B cell membrane proteins and other known or as-yet unidentified species will be assessed using fluorescence energy transfer and new immunochemically-targeted photoproximity labeling methods. The aggregation state of specific membrane proteins will be evaluated using time-resolved phosphorescence anisotropy. Finally, immediate changes in B lymphocyte membrane structure resulting from activation by three mechanisms, by anti-IgM treatment, by thymus-independent antigen-like ligands interacting with cells artificially decorated with specific receptors, and by lipopolysaccharide will be examined.