PROJECT 3: Quality of T Cell Responses Following DENV Natural Infections and Live-Attenuated Dengue Virus Vaccination

项目3：DENV自然感染和减毒活疫苗后T细胞反应的质量 登革热病毒疫苗接种(拉霍亚过敏和免疫学研究所) 摘要 P01的总主题是研究和揭示获得性免疫在DENV感染和疫苗接种的背景下在塑造临床和病毒学终点和结果方面的作用。在项目3中，我们将具体解决T细胞反应质量和临床结果以及抗体质量和持久性之间的关系这一中心问题。除了准确测量DENV特异性T细胞的数量和数量外，我们还将彻底定义T细胞反应的质量。首先，我们将研究 DENV特异性T细胞；例如，包膜(E)特异性T细胞反应对于帮助B细胞是否更有效？ 非结构蛋白(NS)衍生的反应是否更有助于CD8T杀伤受感染的靶 细胞？其次，我们将检查反应质量的另一个重要组成部分，即DENV血清型之间的交叉反应，或与疫苗接种中使用的载体的交叉反应。这一问题与 第一个获得许可的DENV疫苗(Dengvaxia®)的性能不佳，它使用的是DENV衍生的E 在缺乏DENV NS蛋白的黄热病病毒主干中表达的蛋白质。第三，我们将确定 感染和接种引起的CD4和CD8亚群，记忆亚群驱动 应答，它们的特定转录特征是什么，效应器应答的多特异性程度， 以及DENV特异性T细胞的T细胞受体(TCR)谱有多窄或多多样化。这一全面的 分析将允许提出以下问题：是什么推动了质量？质量如何影响结果？我们的 假设T细胞反应的质量影响感染的临床结局和 疫苗接种，要么通过DENV特异性T细胞的直接效应功能，要么通过调节 B细胞应答的数量和质量。这一假设将通过描述数量和质量来检验 在有症状(DF或严重登革热)或无症状DENV之前的记忆T细胞反应 尼加拉瓜儿童登革热队列研究核心C分发的样本中的感染情况(目标1)。我们 还将调查T细胞帮助在抗体质量和持久性方面的作用(项目1)。此外，我们还将 使用在菲律宾队列(核心C)接种Dengvaxia®疫苗后12-18个月收集的样本，以及 特别关注在DENV血清阴性和血清阳性疫苗接种前观察到的差异 疫苗接种(目标2)。同时，我们将分析经历过新城疫突破的疫苗接种者的样本。 接种疫苗后的感染。被认为定义“质量”的变量包括：抗原的大小- 特异性T细胞反应，主要抗原靶标的定义，与其他血清型的交叉反应， 记忆和CD4/CD8亚群的测定，细胞因子分泌的多特异性，转录 配置文件和TCR曲目多样性。我们将测试这些“质量”措施中的哪一项，单独或在 结合其他变量，与临床结果的相关性最好。这些研究与以下方面密切相关 本P01中的其他项目，因为项目1(自然感染)和项目2(接种疫苗)将使用相同的 样本/样本集，以调查体液反应的质量。统计建模以及集成 跨项目的分析将由核心B执行。总体而言，我们的研究将建立保护的相关性 来自DENV疾病的T细胞反应的质量，这将构成对登革热的重要贡献 疫苗的开发和评估。

PROJECT 3: Quality of T-Cell Responses Following DENV Natural Infections and Live-Attenuated Dengue Virus Vaccination (La Jolla Institute for Allergy and Immunology) SUMMARY The overall theme of the P01 is to study and reveal the role of adaptive immunity in the context of DENV infection and vaccination, in terms of shaping clinical and virological endpoints and outcomes. In Project 3, we will specifically address the central issue of the relation between quality of T cell responses and clinical outcomes as well as antibody quality and durability. Beyond accurately measuring magnitude and number of DENV-specific T cells, we will thoroughly define the quality of T cell responses. First, we will study the antigens targeted by DENV-specific T cells; for example, are envelope (E)-specific T cell responses more effective for helping B cells? Are non-structural (NS) protein-derived responses better for providing help for killing infected targets by CD8 T cells? Second, we will examine another important component of response quality, namely its cross-reactivity among DENV serotypes, or with the vectors used in vaccination. This issue is of relevance in the context of the suboptimal performance of the first licensed DENV vaccine (Dengvaxia®), which utilizes DENV-derived E proteins expressed in a yellow fever virus backbone, which lacks DENV NS proteins. Third, we will determine the CD4 and CD8 subsets elicited by infection and vaccination, in terms of which memory subsets drive responses, what their specific transcriptomic profiles are, to what degree effector responses are multi-specific, and how narrow or diverse the T cell receptor (TCR) repertoire of DENV-specific T cell is. This comprehensive analysis will allow to ask the questions: What drives quality? And how does quality influence outcomes? Our hypothesis is that the quality of T cell responses influences the clinical outcomes of infection and vaccination, either by direct effector functions of DENV-specific T cells, or indirectly, through modulation of the quantity and quality of B cell responses. This hypothesis will be tested by characterizing the quantity and quality of memory T cell responses prior to either symptomatic (DF or severe dengue disease) or inapparent DENV infection in samples distributed by Core C from the Pediatric Dengue Cohort Study in Nicaragua (Aim 1). We will also investigate the role of T cell help in relation to antibody quality and durability (Project 1). Further, we will utilize samples collected 12-18 month after Dengvaxia® vaccination in the Philippine cohort (Core C), and specifically focus on differences observed in DENV-seronegative versus -seropositive vaccinees prior to vaccination (Aim 2). In parallel, we will analyze samples from vaccinees who experience breakthrough DENV infections after vaccination. The variables considered to define “quality” will include: magnitude of antigen- specific T cell response, definition of the dominant antigenic targets, cross-reactivity with other serotypes, determination of memory and CD4/CD8 subsets, multi-specificity in terms of cytokine secretion, transcriptomic profiles, and TCR repertoire diversity. We will test which of these “quality” measures, either alone or in combination with other variables, best correlates with the clinical outcomes. These studies are closely linked with other projects in this P01, as Project 1 (natural infection) and Project 2 (vaccination) will use the same samples/sample sets to investigate the quality of humoral responses. Statistical modeling as well as integrated analyses across projects will be performed by Core B. Overall, our studies will establish correlates of protection from DENV disease based on quality of T cell responses, which will constitute important contributions to dengue vaccine development and evaluation.