FUNCTION OF THE B CELL ANTIGEN IN ANTIGEN PROCESSING

描述（改编自研究者摘要）： 由B细胞向辅助性T细胞呈递抗原是免疫应答的中心事件。 T细胞依赖性抗体反应的启动。 处理涉及 展示的结合至主要抗原的蛋白质抗原的转化 表面上的组织相容性复合物II类分子（MHC II类） T细胞识别B细胞。 特异性B细胞结合天然 细胞表面上的B细胞抗原受体（BCR）的抗原， 结合的抗原随后被内化并被递送至合适的免疫原。 用于加工的亚细胞区室。 BCR介导的抗原加工是 高效。 BCR至少在抗原中起两个关键作用 （1）捕获细胞表面上的抗原， 将它们递送到亚细胞区室进行处理，以及（2）在 通过抗原交联，以启动信号转导级联， 调节抗原加工。 目前，两者的分子基础 BCR的功能不清楚。 BCR是一个多组件 由抗原结合成分组成的复合物，膜 免疫球蛋白（mIg）和信号转导组分， 二硫键连接的伊加/Igb异二聚体。 本提案的目的是 在分子水平上定义BCR在抗原加工中的功能。 的 该建议的目的是1）表征BCR介导的抗原 运输途径，2）确定BCR运输中的离散步骤 由BCR介导的信号转导调节，3）以确定 BCR的哪些成分是BCR介导的抗原所必需的 处理和4）鉴定BCR复合物所携带的结构元件 抗原转运和调节 运输 这些研究的结果将帮助我们获得能力， 控制抗原加工，并为设计 自身免疫性疾病的有效疫苗和疗法。

DESCRIPTION (Adapted from Investigator's abstract): The processing and presentation of antigen by B cells to helper T cells is a central event in the initiation of T-cell dependent antibody responses. Processing involves the conversion of protein antigens that are displayed bound to the Major Histocompatibility Complex class II molecules (MHC class II) on the surfaces of B cells for the recognition by T cells. Specific B cells bind native antigen to the B cell antigen receptor (BCR) on the cell surface and the bound antigen is subsequently internalized and delivered to an appropriate subcellular compartment for processing. BCR-mediated antigen processing is highly efficient. The BCR plays at least two crucial roles in antigen processing which are: (1) to capture antigens on the cell surface and deliver them to the subcellular compartments for processing, and (2) upon cross-linking by antigen, to initiate a signal transduction cascade that regulates antigen processing. At present, the molecular basis of both functions of the BCR is not understood. The BCR is a multi-component complex consisting of an antigen binding component, the membrane immunoglobulin (mIg), and a signal transducing component, the disulfide-linked Iga/Igb heterodimer. The goal of this proposal is to define the function of BCR in antigen processing at a molecular level. The aims of this proposal are 1) to characterize the BCR-mediated antigen transport pathway, 2) to identify the discrete steps in the BCR trafficking that are regulated by BCR-mediated signal transduction, 3) to determine which components of BCR are necessary for the BCR-mediated antigen processing and 4) to identify the structural elements carried by BCR complex that are required for antigen transport and for the regulation of this transport. The results of these studies will help us to gain the ability to control antigen processing and provide the strategies for the design of effective vaccines and therapies for autoimmune diseases.