CELLULAR AND MOLECULAR EVENTS IN B LYMPHOCYTE ACTIVATION

描述(改编自研究人员的摘要)：淋巴细胞发挥着 对脊椎动物的生存起着至关重要的作用。为了完成这项任务，他们 不断对环境进行采样并对其做出反应，这些事件依赖于 质膜上的囊泡运输。尽管重要的是 在这个过程中，我们对分子的理解有很大的差距 在质膜上规范结构性交易的事件。我们 建议使用B淋巴细胞，特别是高比率淋巴细胞来研究这一过程 抗体分泌(浆)细胞，作为模型系统。的总体目标 这些实验是为了表征血浆中的分泌室。 细胞，并定义决定特异性的蛋白质和结构 构成囊泡从高尔基体到质膜的运输。 为此，我们将实现以下具体目标：1) 含IgM的高尔基体转运后囊泡的分离和鉴定 并研究其在发育过程中的表达。 囊泡相关的SNARE蛋白；2)鉴定含有IgM的 浆细胞中的分泌囊泡室，并确定它是否 与其他结构，特别是细胞骨架共定位；3)定位 含有IgM的囊泡在质膜上的对接位置， 并确定t型圈套和细胞骨架在指定 这些地点的定位；4)确定货物装载的特殊性 在高尔基体后分泌囊泡中询问膜和分泌物 包括免疫球蛋白在内的蛋白质被输送到质膜。 在相同或不同的分泌囊泡中；5)产生携带 V-SNARE和T-SNARE基因的淋巴细胞特异性靶向突变 在浆细胞中表达的蛋白质，以确定这些蛋白的作用 抗体分泌及T、B细胞其他方面的蛋白质 生物学。这些实验的结果不仅将提供新的 关于调节高水平抗体分泌的信息，但 也应该提供第一个分子洞察力，以了解 构成泡在淋巴细胞中的运输，并有助于 对构造性胞吐作用后期步骤的一般理解。这些 实验也可能提供对分子基础的新见解 免疫缺陷，并提供必要的工具研究 病毒和病毒颗粒的细胞内运输，以及其他感染性 探员们。

DESCRIPTION (Adapted from the investigator's abstract): Lymphocytes play a critical role in the survival of vertebrates. To accomplish this task, they constantly sample the environment and respond to it, events which rely on vesicular trafficking at the plasma membrane. Despite the importance of this process, there are major gaps in our understanding of the molecular events that regulate constitutive trafficking at the plasma membrane. We propose to study this process using B lymphocytes, especially high-rate antibody secreting (plasma) cells, as model systems. The overall goals of these experiments are to characterize the secretory compartment in plasma cells and define the proteins and structures that determine the specificity of constitutive vesicular trafficking from the Golgi to the plasma membrane. To accomplish this, we will carry out the following specific aims: 1) Isolate and characterize IgM-containing post-Golgi transport vesicles from plasma cells, and investigate the developmental expression of vesicle-associated SNARE proteins; 2) Characterize the IgM-containing secretory vesicle compartment in plasma cells, and determine if it co-localizes with other structures especially the cytoskeleton; 3) Localize the docking sites for the IgM-containing vesicles at the plasma membrane, and determine the role of t-SNAREs and the cytoskeleton in specifying the localization of these sites; 4) Determine the specificity of cargo loading in post-Golgi secretory vesicles by asking if membrane and secretory proteins, including immunoglobulins, are transported to the plasma membrane in the same or different secretory vesicles; 5) Produce mice carrying lymphocyte-specific targeted mutations in genes encoding v- and t-SNARE proteins expressed in plasma cells, in order to define the role of these proteins in antibody secretion as well as in other aspects of T and B cell biology. The results of these experiments will not only provide new information concerning the regulation of high-rate antibody secretion, but should also provide the first molecular insights into the specificity of constitutive vesicular trafficking in lymphocytes, and contribute to a general understanding of the late steps in constitutive exocytosis. These experiments may also provide novel insights into the molecular basis for immunodeficiencies, and provide the tools necessary to study the intracellular transport of viruses and viral particles, and other infectious agents.