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

项目1：B细胞的质量和对天然登革病毒感染的抗体应答 （加州大学伯克利分校） 总结 四种登革热病毒血清型（DENV 1 -4）引起人类最重要的蚊媒病毒性疾病， 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 目前批准用于人类，唯一注册的疫苗是有问题的。的总体方法 项目1是利用独特的巴布亚新几内亚样本集来解决有关DENV的复杂问题 抗体和B细胞免疫学在相关的临床和流行病学背景下。该项目旨在 分析抗体/B细胞免疫谱与感染结果、疾病严重程度和抗体 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 该项目的假设是，由库确定的B细胞和抗体应答的质量 以及抗体和B细胞的特性，影响随后的DENV感染的结果， 长期抗体反应。重点是表征抗体的库和动力学 在原发性和继发性感染之前和之后的反应更详细，因为新的最先进的工具变得 在我们的P01计划中。每个目标都来自当前P01的发现和试剂。 重要的是，我们整合了经典的最先进的分子遗传学和系统血清学方法 为了全面检查抗原特异性和Fc特性以及效应子功能， 以前所未有的分辨率预测保护或发病机制。这项研究之所以可行，是因为 正在进行的儿童登革热队列研究（2004年至今），一项基于社区的前瞻性队列研究， 尼加拉瓜马那瓜，跟踪约3,700名儿童，现在已经进入第15个年头， （2005年至今）在马那瓜，这两个项目一起使得能够调查感染前的样本，记录了重复的 DENV感染和长期B细胞/抗体应答。该项目与其他项目具有高度协同作用 本P01中的项目通过共享相似的样本（项目3和4）以及方法和试剂（项目2）， 整合B细胞/抗体应答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的应答（项目3）和免疫应答 在减毒活DENV疫苗接种后获得（项目2）。项目1目标1将定义完整的曲目 在亚洲和美洲登革热流行人群中的类型特异性抗体，确定了主要的足迹 抗原位点，并研究基因型对多克隆血清中表位识别的影响。目标2将 根据抗体库和Fc效应子功能确定临床结果的预测因子， 隐性感染与有症状感染以及轻度与重度登革热。目标3将检查 免疫后抗体大小和动力学的流行病学、抗原特异性和Fc效应子驱动的预测因子 原发性和继发性DENV感染，并将两者进行比较。这种发现方法将产生机械的 对免疫功能的深入了解总的来说，本项目将确定抗体/B细胞相关的保护作用， 发病机制，以及抗体反应的幅度和持久性，这应该是有用的， 开发和评估登革热疫苗。

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.