FUNCTION OF THE B CELL ANTIGEN IN ANTIGEN PROCESSING

描述(改编自调查人员摘要)：处理和 B细胞向辅助性T细胞递呈抗原是人类免疫缺陷病毒的中心事件 启动T细胞依赖的抗体反应。处理涉及到 显示与主要抗原结合的蛋白质抗原的转化 表面上的组织相容性复合体II类分子(MHC II类) B细胞以供T细胞识别。特异性B细胞天然结合 细胞表面B细胞抗原受体(BCR)的抗原和 结合的抗原随后被内化并递送到适当的 用于处理的亚细胞隔间。BCR介导的抗原处理是 效率很高。BCR在抗原中至少起着两个关键作用 处理是：(1)捕获细胞表面的抗原，并 将它们送到亚细胞隔间进行处理，以及(2)在 通过抗原进行交叉连接，以启动信号转导级联 调节抗原的处理。目前，两者的分子基础 BCR的功能尚不清楚。BCR是由多个组件组成的 由抗原结合成分组成的复合体，膜 免疫球蛋白(MIG)和信号转导组件 二硫键连接的IGA/IGB杂二聚体。这项提议的目标是 在分子水平上确定BCR在抗原处理中的作用。这个 这项提议的目的是1)表征bcr介导的抗原 运输途径，2)确定BCR贩运中的离散步骤 由bcr介导的信号转导调节，3)确定 Bcr介导的抗原需要哪些bcr成分？ 处理和4)识别BCR复合体携带的结构元素 它们是抗原运输和调节这一过程所必需的 运输。这些研究的结果将帮助我们获得 控制抗原处理，并为设计 自身免疫性疾病的有效疫苗和治疗方法。

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.