LATERAL AND ROTATIONAL DYNAMICS IN BIOLOGICAL MEMBRANES

了解细胞膜的动力学和分布 与调节细胞功能有关的分子是长- 这个项目的长期目标。 一些工具技术将 用来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。 荧光光漂白恢复检查分子横向 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. 荧光能量转移和扫描 荧光相关光谱提供了关于 在细胞表面的特定分子的分布。 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 B细胞上的Ia能够呈递抗原肽， 抗原特异性T细胞将被研究，以确定可能的 由肽引起的Ia聚集或构象的变化 约束力 多克隆和单克隆半抗原特异性B细胞将被 用于将抗原呈递给T细胞。 抗原之间的关系 结构和浓度以及随后的列报 将检查效率以了解抗原如何与 B细胞膜启动抗原加工和表达 抗原肽。 抗原-Ia-T细胞受体复合物将 使用环境敏感的荧光肽进行检测， 和荧光能量转移方法来探测T细胞 相遇改变抗原-Ia相互作用。 第二个工作领域涉及T-非依赖性抗原， 丝裂原与B细胞的相互作用。 sIg抗原侧向扩散 克隆的DNP特异性B细胞上的聚集物作为抗原的功能 浓度和表位密度将通过 荧光光漂白恢复，并与 伴随B细胞分化反应。 大小和 抗原-免疫球蛋白聚集体的组成 导致刺激和耐受相同DNP的条件- 将测量特定的细胞系以与最近的- 完整的模型。 将使用流式细胞术技术 以及扫描荧光相关光谱法。 T-2诱导的高区带耐受过程中B细胞脂质的状态 独立抗原和脂多糖激活期间 将探索荧光光漂白恢复。

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.