CELLULAR AND MOLECULAR EVENTS IN B LYMPHOCYTE ACTIVATION

描述（改编自研究者摘要）：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 不断地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，我们对分子的理解存在重大差距， 调节质膜上组成性运输的事件。 我们 我建议使用B淋巴细胞研究这一过程，特别是高比率的 抗体分泌（浆）细胞作为模型系统。 的总目标 这些实验是为了表征血浆中的分泌室 细胞和定义的蛋白质和结构，确定特异性 从高尔基体到质膜的组成性囊泡运输。 为此，我们将实现以下具体目标： 分离并表征来自于大肠杆菌的含有IgM的高尔基体后转运囊泡 浆细胞，并研究发育表达 囊泡相关SNARE蛋白; 2）表征含有IgM的SNARE蛋白。 浆细胞中的分泌囊泡隔室，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的囊泡在质膜上的停靠位点， 并确定t-SNARE和细胞骨架在指定 这些地点的定位; 4）确定货物装载的特异性 在高尔基体后分泌囊泡中， 蛋白质，包括免疫球蛋白，被运输到质膜 在相同或不同的分泌囊泡中; 5）产生携带 编码v-和t-SNARE的基因中的淋巴细胞特异性靶向突变 浆细胞中表达的蛋白质，以确定这些蛋白质的作用。 蛋白质在抗体分泌以及T和B细胞的其它方面中的作用 生物学 这些实验的结果将不仅提供新的 关于调节高速率抗体分泌的信息，但是 还应该提供第一个分子的见解， 组成性囊泡运输淋巴细胞，并有助于 对组成性胞吐作用后期步骤的一般理解。 这些 实验还可以提供新的见解的分子基础， 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转运，以及其他感染性 剂.

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.