Project 2: B Cells

项目2：总结 产生血清和粘膜抗体的B细胞和浆细胞群体最终将决定 个体对SARS-CoV-2感染的体液免疫反应的有效性和持续时间。我们会 在博伊德实验室使用几种相互支持的策略来分析这些细胞：单个B细胞表型，B细胞表型 细胞受体(BCR)深度测序及DNA条码抗原的抗原特异性测定 四聚体；大宗B细胞免疫球蛋白基因谱系测序；以及从 抗原特异性B细胞。在互补策略中，贾德茨基实验室将利用酵母展示文库 患者来源的单链抗体可变片段(ScFv)富含天然重链-轻链配对 确定每个患者数百到数千个抗原特异性克隆的抗原特异性。纵向的 外周血样本和鼻活检样本我们将彻底鉴定抗原特异的B细胞 SARS-CoV-2患者应答中的克隆。我们假设，有了这些数据，我们将能够确定 B细胞对SARS-CoV-2的克隆反应的哪些特征与新冠肺炎病的差异有关 按年龄、性别、种族和先前存在的人口分组之间的严重性和差异 在检查站封锁治疗的情况下，或免疫失调。我们进一步假设 对记忆B细胞群体的分析与血清学反应一起可以预测哪些个体 将有更持久的体液保护，防止再次接触SARS-CoV-2。最后，我们将评估B 与接种疫苗相比，自然感染刺激的细胞反应，从Covaxx多肽开始- 以疫苗为基础的队列，但预计更多的疫苗将在 本项目资金的期限。除了研究B细胞反应的不同方面外， 临床场景中，我们将搜索高度相似的特征，如“收敛”的病毒特异性BCR 不同个体之间共享的可能具有预后价值的序列，例如通过揭示 个人对SARS-CoV-2有很强的中和抗体反应。我们的目标是： 具体目的1：分析急性新冠肺炎病患者的B细胞反应。 特异性目的2：评价对SARS-CoV-2 B细胞记忆形成的影响。 具体目标3：分析粘膜B细胞和浆细胞对SARS-CoV-2的反应与 血液中的B细胞。

PROJECT 2: SUMMARY The B cell and plasma cell populations that give rise to serum and mucosal antibodies will ultimately determine the effectiveness and duration of an individual’s humoral immune response to SARS-CoV-2 infection. We will use several mutually-supporting strategies to analyze these cells in the Boyd lab: single B cell phenotyping, B cell receptor (BCR) deep sequencing and determination of antigen specificity with DNA-barcoded antigen tetramers; bulk B cell immunoglobulin gene repertoire sequencing; and monoclonal antibody production from antigen-specific B cells. In complementary strategy, the Jardetzky lab will make use of yeast display libraries of patient-derived single-chain antibody variable fragments (ScFv) enriched for native heavy-light chain pairing to determine the antigen specificity of hundreds to thousands of antigen-specific clones per patient. In longitudinal peripheral blood samples and nasal biopsy samples we will thoroughly characterize antigen-specific B cell clones in patient responses to SARS-CoV-2. We hypothesize that with these data we will be able to determine which features of B cell clonal responses to SARS-CoV-2 are associated with differences in COVID-19 disease severity and differences between populations groups stratified by age, sex, ethnicity and pre-existing conditions, or dysregulated immunity in the context of checkpoint blockade treatment. We further hypothesize that analysis of memory B cell populations together with serological responses may predict which individuals will have longer-lasting humoral protection against reexposure to SARS-CoV-2. Finally, we will evaluate the B cell responses stimulated by natural infection compared to vaccination, beginning with the Covaxx peptide- based vaccine cohort, but with the expectation that additional vaccines will be approved for use during the period of this project funding. In addition to studying aspects of the B cell responses that differ among these clinical scenarios, we will search for features such as “convergent” virus-specific BCRs of highly similar sequences shared between different individuals that may have prognostic value, for example by revealing that an individual has a potent neutralizing antibody response to SARS-CoV-2. Our Aims are the following: Specific Aim 1: Analyze B cell responses in acute COVID-19 disease. Specific Aim 2: Evaluate the formation of B cell memory to SARS-CoV-2. Specific Aim 3: Analyze mucosal B cell and plasma cell responses to SARS-CoV-2 compared to responses of B cells in the blood.