Establishing the Molecular Mechanisms of BCR Endocytosis

建立 BCR 内吞作用的分子机制

基本信息

批准号：
8072067
负责人：
James R Drake
金额：
$ 37.74万
依托单位：
ALBANY MEDICAL COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-06-01 至 2014-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8072067
关键词：
Address Affect Affinity Antibody Formation Antigen Presentation Pathway Antigens Autoimmunity B-Cell Activation B-Lymphocytes Biological Models Cell Communication Cell membrane Cell surface Cells Cellular biology Clathrin Clear Cell Complex Cytoplasmic Tail Development Endocytosis Event Generations Goals ITAM Immunobiology Immunologic Memory Laboratories Lead Ligands Ligation Mediating Membrane Membrane Lipids Membrane Microdomains Molecular Mus Pathway interactions Peptides Phosphorylation Population Positioning Attribute Process Publishing Receptor Signaling Receptors, Antigen, B-Cell Relative (related person)Reporting Research Personnel Research Proposals Role Signal Transduction Surface Antigens System T-Lymphocyte TFAP2A gene Testing Ubiquitination Vaccines Work antigen processing base coated pit crosslink improved novel receptor internalization receptor mediated endocytosis receptor-mediated signaling tool trafficking ubiquitin ligase

项目摘要

DESCRIPTION (provided by applicant): B cell receptor (BCR)-mediated antigen internalization is the first step in the pathway of antigen processing and presentation, a phenomenon which is essential for cognate B cell-T cell interactions, B cell activation and establishment of immunological memory. However, the cellular and molecular mechanisms underlying the internalization of antigen-BCR (Ag-BCR) complexes remain ill defined, so much so that even the identity of the endocytosis motifs within the cytoplasmic domains of the BCR remain essentially uncharacterized. Therefore, the overall goals of this proposal are to establish the mechanisms of Ag-BCR internalization under different conditions of BCR ligation and cross-linking, and determine how modulation of the pathway of Ag-BCR endocytosis impacts important events such BCR-mediated antigen processing and presentation. Based on published work from this and other laboratories, we hypothesize that Ag-BCR internalization occurs via two distinct endocytic gateways, clathrin coated pits and plasma membrane lipid rafts, and that the level of engagement of these two distinct gateways depends upon the level of BCR cross-linking and BCR signaling-induced changes in the activity of BCR endocytosis motifs. Moreover, we propose that modulation of the relative roles of each of these gateways in Ag-BCR internalization will affect the mechanism of antigen processing and presentation. To test this hypothesis we will perform EM analysis of native membranes to determine the level of Ag-BCR internalization via plasma membrane clathrin coated pits and lipid rafts under different conditions of BCR ligation (Aim 1), identify and characterize the endocytosis motif(s) within the cytoplasmic tail of the BCR and determine the impact of signaling-induced BCR phosphorylation on endocytosis motif activity (Aim 2), and establish the impact of the mechanism of internalization on Ag-BCR ubiquitination (a novel phenomenon recently reported by our laboratory) as well as the intracellular trafficking, processing and presentation of internalized Ag-BCR complexes (Aim 3). Successful completion of these studies will result in a better understanding of the cellular and molecular mechanisms of BCR-mediated antigen internalization, processing and presentation. Moreover, application of these findings will allow for the development of improved vaccines and approaches to control autoimmunity.

描述（由申请人提供）：B细胞受体（BCR）介导的抗原内在化是抗原加工和表现途径的第一步，这是一种对同源B细胞-T细胞相互作用，B细胞激活和免疫学记忆的建立至关重要的现象。然而，抗原-BCR（AG-BCR）配合物内部化的基础化的细胞和分子机制仍然不明显，以至于即使是BCR细胞质结构域内的内吞作用基序的身份，也基本上仍未被过度化。因此，该提案的总体目标是在BCR连接和交联的不同条件下建立AG-BCR内在化的机制，并确定AG-BCR内吞作用途径的调节如何影响BCR介导的抗原处理和表现等重要事件。 Based on published work from this and other laboratories, we hypothesize that Ag-BCR internalization occurs via two distinct endocytic gateways, clathrin coated pits and plasma membrane lipid rafts, and that the level of engagement of these two distinct gateways depends upon the level of BCR cross-linking and BCR signaling-induced changes in the activity of BCR endocytosis motifs.此外，我们建议调节这些网关在AG-BCR内部化中的相对作用将影响抗原加工和表现的机理。为了检验该假设，我们将对天然膜进行EM分析，以确定在BCR连接不同条件下通过质膜膜层层层覆盖的凹坑和脂质筏来确定AG-BCR内在化的水平（AIM 1），识别并表征内吞作用基序中的内吞作用基序，并确定BCR的细胞质量范围内的bcr范围内的bcr范围内的bcr量。 2），并确定内部化机制对AG-BCR泛素化的影响（我们实验室最近报道的一种新现象）以及内部化AG-BCR复合物的细胞内贩运，加工和表现（AIM 3）。这些研究的成功完成将使人们更好地了解BCR介导的抗原内在化，加工和表现的细胞和分子机制。此外，这些发现的应用将允许开发改进的疫苗和方法以控制自身免疫性。