LATERAL AND ROTATIONAL DYNAMICS IN BIOLOGICAL MEMBRANES

了解膜的动力学和分布 与细胞功能调节有关的分子是长- 本项目的学期目标。几种乐器技术将被 用于研究分子的横向和旋转运动 参与抗原和有丝分裂原对淋巴细胞的刺激。 荧光光漂白回收检测分子侧向 运动，而时间分辨磷光各向异性和 偏振荧光耗竭测量蛋白质旋转 放松一下。荧光能量传递和扫描 荧光相关光谱学提供了有关 特定分子在细胞表面的分布。 一个研究目标是关于B细胞 将抗原呈递给T辅助细胞。横向和旋转运动 能将抗原肽呈递给B细胞上的Ia 将对抗原特异性T细胞进行研究，以确定可能的 多肽引起的Ia聚集或构象变化 有约束力的。多克隆和单克隆半抗原特异性B细胞将 用来将抗原呈递给T细胞。抗原与抗原性的关系 结构和集中度以及随后的陈述 将检查效率以了解抗原如何与 B细胞膜启动抗原处理和表达 抗原肽。抗原-Ia-T细胞受体复合体 使用环境敏感的荧光肽进行检测 以及荧光能量转移方法来探测T细胞如何 相遇改变了抗原-Ia的相互作用。 第二个工作领域涉及T非依赖性抗原和 丝裂原与B细胞的相互作用。SIG抗原的侧向扩散 作为抗原功能的克隆的DNP特异性B细胞上的聚集 浓度和表位密度将通过以下方式测量 荧光光漂白的回收率及与 伴随B细胞分化反应。大小和 形成的抗原-免疫球蛋白聚集体的组成 导致刺激和耐受相同的DNP的条件- 将对特定的细胞系进行测量，以与最近- 完成的模型。将使用流式细胞仪技术 结合扫描荧光相关光谱分析。 T-T诱导高区域耐受时B细胞脂状态的变化 独立抗原和脂多糖激活过程中 将探索通过荧光光漂白回收。

Understanding how the dynamics and distributions of membrane molecules relate to the regulation of cellular function is the long- term goal of this project. Several instrumental techniques will be used to study the lateral and rotational motions of molecules involved in lymphocyte stimulation by antigens and mitogens. Fluorescence photobleaching recovery examines molecular lateral motions, while time-resolved phosphorescence anisotropy and polarized fluorescence depletion measure protein rotational relaxation. Both fluorescence energy transfer and scanning fluorescence correlation spectroscopy provide information on the distributions of specific molecules on cell surfaces. One research goal concerns the mechanisms by which B cells present antigens to T helper cells. Lateral and rotational motions of Ia on B cells capable of presenting antigenic peptides to antigen-specific T cells will be studied to identify possible changes in Ia aggregation or conformation caused by peptide binding. Polyclonal and monoclonal hapten-specific B cells will be used to present antigen to T cells. The relation between antigen structure and concentration and subsequent presentation efficiency will be examined to learn how antigen encounter with the B cell membrane initiates antigen processing and expression of antigenic peptides. Antigen-Ia-T cell receptor complexes will be examined using environmentally-sensitive fluorescent peptides and fluorescence energy transfer methods to probe how T cell encounter modifies antigen-Ia interactions. The second area of work deals with T-independent antigen and mitogen interaction with B cells. Lateral diffusion of sIg-antigen aggregates on cloned DNP-specific B cells as functions of antigen concentration and epitope density will be measured by fluorescence photobleaching recovery and compared with accompanying B cell differentiative responses. The size and composition of antigen-immunoglobulin aggregates formed under conditions leading to stimulation and tolerance of the same DNP- specific cell lines will be measured for comparison with recently- completed models. Flow cytometric techniques will be used together with scanning fluorescence correlation spectroscopy. The state of B cell lipids during high zone tolerance induced by T- independent antigens and during activation by lipopolysaccharide will be explored by fluorescence photobleaching recovery.