Project 2 - B cell antigen receptor structure and antigen-BCR interaction dynamics

项目2-B细胞抗原受体结构和抗原-BCR相互作用动力学

• 批准号: 10643921
• 负责人: S. Munir ALAM
• 金额: $ 40.03万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-14 至 2027-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10643921
• 关键词: Adopted; Antibodies; Antibody Response; Antigen Receptors; Antigens; Autologous; B-Cell Activation; B-Cell Antigen Receptor; B-Lymphocytes; Binding; Binding Proteins; Biochemical; Biophysics; CD4 Positive T Lymphocytes; Categories; Cell Communication; Cell Line; Cell Separation; Cell membrane; Cell surface; Cells; Cellular Structures; Complex; Cryoelectron Microscopy; Development; Dimerization; Dissociation; Distal; Goals; HIV; HIV vaccine; HIV-1; IgE; Immunobiology; Immunoglobulin D; Immunoglobulin M; Immunologics; Ligands; MHC Class II Genes; Major Histocompatibility Complex; Mass Spectrum Analysis; Mediating; Methods; Modeling; Molecular Conformation; Nature; Peptides; Polysaccharides; Proliferating; Property; Proteins; Resolution; Rest; Shapes; Signal Transduction; Specificity; Structure; Vaccine Design; Vaccines; Virus; antigen binding; design; env Gene Products; expectation; molecular dynamics; monomer; neutralizing antibody; response; structural biology; vaccine efficacy

Project Summary/Abstract – Project 2 Structural analysis of how HIV-1 Envelope (Env) interacts with antigen receptor on B cells (BCR) to initiate B cell signaling and activation is key to understanding antibody responses against HIV protein immunogens. Recent studies of the organization of the BCR complex on the cell membrane supports a model in which BCRs exist in different signaling states that require definition in structural terms. We hypothesize the following distinct states of the BCR complex – 1) “signaling-inhibited’, 2) signaling-competent and 3) ‘signaling-disrupted’. Advances in HIV-1 Env design including those that target germline precursors have led to the development of Env immunogens as potential candidates for HIV vaccines. How BCRs of distinct specificities and signaling-states interact with Env protein immunogens that trigger signaling and activate these cells are not clearly understood. The overall goal of the project is to define BCR-antigen structures with specificity of broadly neutralizing antibodies (bnAb), non-canonical glycan-binding bnAbs and to-be isolated autologous neutralizing antibodies (anAb). In this project, we will perform biophysical/biochemical, structural and immunological analyses to define properties of HIV Env-BCR interactions for activation of B cells expressing bnAb or germline precursor BCRs. In Aim 1, we will perform Cryo-EM and molecular dynamic simulation analyses to define structures of antigen- liganded BCR complex with specificities of autologous or broadly neutralizing HIV-1 antibodies. In addition, we will define the structures of BCRs with specificities of glycan-binding bnAbs that present non-canonical Fab configurations (I-shaped versus Y-shaped). In Aim 2, we will study specificity of bnAb precursors with disrupted proximal signaling and determine whether such BCRs show distinct cell surface interaction dynamics with Env proteins. Studies in Aim 3 will define antigen-BCR interaction parameters that enhance B cell signaling, antigen internalization and MHC class II-peptide presentation of Env protein eptiopes. The proposed studies will bridge high-resolution structures and antigen-BCR interaction dynamics to B cell signaling and activation. The long- range goals of these studies are to provide the mechanistic basis for understanding the humoral response to HIV-1 vaccines and guide development of strategies to enhance vaccine efficacy.

项目摘要/摘要 - 项目2 HIV-1 Invelope（Env）如何与B细胞上的抗原受体相互作用以启动B细胞的结构分析 信号传导和激活是理解针对HIV蛋白免疫原子的抗体反应的关键。最近的 BCR复合物在细胞膜上的组织支持BCR中存在的模型 不同的信号传导状态需要以结构术语进行定义。我们假设以下不同的状态 BCR复合物 - 1）“抑制信号的信号”，2）竞争力和3）“信号破坏”。 HIV-1 ENV设计，包括针对种系前体的设计，导致Env的发展 免疫原子作为HIV疫苗的潜在候选。不同规格和信号周期的BCR如何 与触发信号传导和激活这些细胞的Env蛋白免疫原子相互作用。 该项目的总体目标是定义具有广泛中和的特异性的BCR抗原结构 抗体（BNAB），非典型的聚糖结合BNAB和孤立的自体中和抗体 （Anab）。在这个项目中，我们将执行生物物理/生化，结构和免疫学分析以定义 HIV Env-BCR相互作用的特性，用于激活表达BNAB或生殖线前体BCR的B细胞。在 AIM 1，我们将执行冷冻EM和分子动态模拟分析，以定义抗原的结构 配体BCR复合物具有自体或广泛中和HIV-1抗体的特异性。另外，我们 将用呈现非典型fab的聚糖结合BNAB的特异性定义BCR的结构 配置（I形与Y形）。在AIM 2中，我们将研究BNAB前体的特异性 近端信号传导并确定此类BCR是否与Env显示不同的细胞表面相互作用动力学 蛋白质。 AIM 3中的研究将定义抗原BCR相互作用参数，从而增强B细胞信号传导，抗原 Env蛋白EPTIPOPES的内在化和MHC II类肽表现。拟议的研究将桥接 高分辨率结构和B细胞信号传导和激活的抗原BCR相互作用动力学。长期 这些研究的范围目标是为理解对体液反应的机械基础 HIV-1疫苗和指导策略的制定以提高疫苗效率。