PROJECT 1: Quality of B Cell and Antibody Responses to Natural Dengue Virus Infections

项目1：自然感染登革热病毒的B细胞质量和抗体反应 (加州大学伯克利分校) 摘要 登革热病毒的四种血清型(DENV1-4)会导致人类最重要的蚊媒病毒疾病， 每年约有3.9亿人感染，全球有超过30亿人面临感染风险。然而，没有任何治疗方法是 目前已被批准用于人类，唯一注册的疫苗存在问题。总体思路是 项目1是利用尼加拉瓜独特的样本集来解决有关DENV的复杂问题 相关临床和流行病学背景下的抗体和B细胞免疫学。该项目旨在 分析抗体/B细胞免疫模式与感染结局、疾病严重程度和抗体的关系 动力学。每个目标还涉及登革热免疫学中的具体基本问题。整体而言 这个项目的假设是B细胞和抗体反应的质量，由曲目决定 抗体和B细胞的特性，影响后续DENV感染的结局以及 长期抗体反应。重点是对抗体的谱系和动力学进行表征 随着新的最先进的工具变得更加详细，在初次和二次感染之前和之后的反应 在我们的P01计划中提供。每个目标都源自当前P01的调查结果和试剂。 重要的是，我们结合了经典的最先进的分子遗传学和系统血清学方法 全面检查抗原特异性和Fc特征以及效应器功能 以前所未有的分辨率预测保护或发病机制。拟议中的研究是有可能的 正在进行的儿科登革热队列研究(2004-至今)，这是一项基于社区的前瞻性队列研究 尼加拉瓜马那瓜，追踪约3,700名儿童，现已进入第15个年头，以及登革热医院的研究 (2005年至今)在马那瓜，共同使感染前样本的调查成为可能，有记录的重复 DENV感染，以及长期的B细胞/抗体反应。这个项目与另一个项目具有很强的协同性 通过分享相似的样本(项目3和4)、方法和试剂(项目2)和 整合B细胞/抗体反应的计算生物学分析和统计模型(核心B) 在DENV自然感染期间，T细胞对DENV的反应(项目3)和免疫反应 在减毒活疫苗接种后获得(项目2)。项目1目标1将确定完整的曲目 在亚洲和美洲登革热流行人群中的类型特异性抗体，定义了主要 抗原结合位点，并研究了基因对多克隆血清表位识别的影响。目标2将 根据抗体库和Fc效应器功能确定临床结果的预测因子，与 隐性感染与症状感染以及轻微与严重的登革热疾病。Aim 3将审查 流行病学、抗原特异性和Fc效应器驱动的抗体强度和动力学预测因子 原发和继发DENV感染，并将两者进行比较。这种发现方法将产生机械论。 对免疫功能的洞察。总体而言，该项目将确定抗体/B细胞与保护和 致病机制，以及抗体反应的大小和持久性，这应该对 登革热疫苗的开发和评价。

PROJECT 1: Quality of B Cell and Antibody Responses to Natural Dengue Virus Infections (University of California, Berkeley) SUMMARY The four dengue virus serotypes (DENV1-4) cause the most important mosquito-borne viral disease of humans, with ~390 million infections annually and over 3 billion people worldwide at risk of infection. Yet, no treatment is currently approved for use in humans, and the only registered vaccine is problematic. The overall approach of Project 1 is to take advantage of unique Nicaraguan sample sets to address complex questions about DENV antibody and B cell immunology in a relevant clinical and epidemiological context. The Project is designed to analyze the antibody/B cell immune profile in relation to infection outcome, disease severity, and antibody dynamics. Each aim also addresses specific fundamental questions in dengue immunology. The overall hypothesis of this project is that the quality of B cell and antibody responses, as detemined by the repertoire and characteristics of the antibodies and B cells, impacts outcome of subsequent DENV infection as well as the long-term antibody response. The focus is on characterizing the repertoire and dynamics of the antibody response before and after primary and secondary infections in more detail as new state-of-the-art tools become available in our P01 program. Each aim derives from findings and reagents arising from the current P01. Importantly, we integrate classical state-of-the-art molecular genetics and systems serology approaches to comprehensively examine both antigen-specific and Fc characteristics and effector functions that predict protection or pathogenesis with unprecedented resolution. The proposed research is possible due to the ongoing Pediatric Dengue Cohort Study (2004-present), a community-based prospective cohort study in Managua, Nicaragua, following ~3,700 children, now in its 15th year, and the Dengue Hospital-based Study (2005-present) in Managua, which together enable investigation of pre-infection samples, documented repeat DENV infections, and long-term B cell/antibody responses. This project is highly synergistic with the other Projects in this P01 by sharing similar samples (Projects 3 & 4) and methods and reagents (Project 2) and integrating computational biological analyses and statistical models (Core B) of the B cell/antibody response during DENV natural infections with the T cell response to DENV (Project 3) and with the immune response obtained after live attenuated DENV vaccination (Project 2). Project 1 Aim 1 will define the complete repertoire of type-specific antibodies in dengue-endemic populations in Asia and the Americas, define the footprint of major antigenic sites, and investigate the effect of genotype on epitope recognition in polyclonal sera. Aim 2 will determine predictors of clinical outcome in terms of antibody repertoire and Fc effector function, in relation to inapparent vs. symptomatic infection as well as mild vs. severe dengue disease. Aim 3 will examine epidemiological, antigen-specific, and Fc effector-driven predictors of antibody magnitude and kinetics after primary and secondary DENV infection and will compare the two. This discovery approach willl yield mechanistic insights into immune function. Overall, this project will identify antibody/B cell correlates of protection and pathogenesis, as well as of magnitude and durability of the antibody response, which should be useful for development and evaluation of dengue vaccines.