Principal Project

COVID 19大流行说明了迫切需要了解人类B细胞对紧急情况的反应。 病原体及其在群体免疫评估中的应用。我们的实验室已经描述了， 人B细胞应答的不同分支的免疫学和分子特征，特别是， 人滤泡外效应B细胞活化途径的表征及其对不同免疫应答的贡献 记忆和浆细胞反应。在此基础上，我们提出询问B细胞的不同臂 对SARS-CoV-2病毒的反应;确定参与早期、持续和 晚期感染后反应;并确定它们对建立群体免疫的贡献，至少 部分是通过产生保护性B细胞记忆。后者是一个基本特征， 与血清抗体的持久性脱钩;因此，除非正式确认，否则将无法识别 测试.我们假设细胞B细胞记忆的建立和评估其大小的能力 和质量将是至关重要的，以跟踪人口的风险，短期再感染和季节性暴露; 设计能够触发这种保护功能的疫苗;并开发基于SARS-CoV-2 B细胞的诊断方法 试验.这些目标将使用SARS-CoV-2感染者和康复者的血液样本来实现 通过以下具体目标：目标1。SARS-CoV-2特异性B细胞的鉴定 通过多维B细胞流式细胞术的反应细胞起源的精确判定， 抗SARS-CoV-2 B细胞应答的强度和持久性将通过抗原特异性的 流式细胞术，并通过B细胞群的多重抗原测定和单细胞分析验证。目的 2. SARS-CoV-2特异性B细胞记忆和群体免疫的测量。表型特征和 在aim 1中建立的抗原特异性流式细胞术检测将应用于感染后中期和晚期 a）SARS-CoV-2特异性B细胞记忆的细胞区室 栖息地; B）其质量、数量和在种群中的分布; c）其起源（是否来自 晚期细胞前体）;和d）其一致性或相反，与血清学反应和免疫反应的解偶联。 长寿命浆细胞（LLPC）的产生。

The COVID19 pandemic illustrates the urgent need for understanding human B cell responses to emergent pathogens and its application to assessing herd immunity. Our laboratories have described the phenotypic, immunological and molecular features of different arms of human B cell responses and in particular, the original characterization of the human extrafollicular effector B cell activation pathway and its contribution to different memory and plasma cells responses. On that basis, we we propose to interrogate the different arms of the B cell response to the SARS-CoV-2 virus; to identify the B cell compartments that participate in the early, ongoing and late post-infection responses; and to determine their contribution to the establishment of herd immunity, at least in part through the generation of protective B cell memory. The latter is an essential feature that could be uncoupled from the persistence of serum antibodies; and therefore, would go unrecognized unless formally tested. We postulate that the establishment of cellular B cell memory and the ability to evaluate its magnitude and quality will be critical to track the risk of the population to short-term re-infection and seasonal exposure; to design vaccines capable to trigger this protective feature; and to develop SARS-CoV-2 B cell-based diagnostic tests. These goals will be accomplished using blood samples from SARS-CoV-2-infected and convalescent individuals through the following specific aims: Aim 1. Characterization of SARS-CoV-2-specific B cell responses through multidimensional B cell flow cytometry A precise adjudication of the cellular origin, magnitude, and persistence of the anti-SARS-CoV-2 B cell response will be accomplished by antigen-specific flow cytometry and validated by multiplex antigen assays and single cell analysis of the B cell populations. Aim 2. Measurement of SARS-CoV-2-specific B cell memory and herd immunity. Phenotypic features and antigen-specific flow cytometry assays established in aim 1, will be applied to intermediate and late post-infection time points in order to understand: a) the cellular compartments in which SARS-CoV-2-specific B cell memory resides; b) its quality, magnitude and distribution within the population; c) its provenance (whether from early of late cellular precursors); and d) its concordance or conversely, uncoupling from serological responses and the generation of long-lived plasma cells (LLPC).