Unraveling Human T Follicular Helper Cell Development

揭开人类滤泡辅助 T 细胞发育的谜团

• 批准号: 10568500
• 负责人: Philip A Mudd
• 金额: $ 58.12万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-06 至 2027-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10568500
• 关键词: 2019-nCoV; Activities of Daily Living; Address; Adoptive Transfer; Affinity; Animal Model; Antibodies; Antibody Affinity; Antigens; Autologous; Axillary lymph node group; B-Cell Development; B-Lymphocytes; Biological Assay; Biological Models; Blood; CD4 Positive T Lymphocytes; COVID-19; COVID-19 pandemic; COVID-19 vaccine; Cell Maturation; Cell Separation; Cell physiology; Clinical; Collaborations; Communicable Diseases; Data; Data Set; Development; Epitopes; Event; Exhibits; Fine needle aspiration biopsy; Flow Cytometry; Genetic Transcription; Helper-Inducer T-Lymphocyte; Human; Human Volunteers; Immune response; Immunoglobulin Class Switching; Immunologist; Infection; Influenza vaccination; Intramuscular; Knowledge; Lead; Maintenance; Measures; Memory; Memory B-Lymphocyte; Methods; Modeling; Mus; Participant; Phenotype; Plasma Cells; Play; Population; Process; Production; Productivity; Proteins; RNA vaccination; RNA vaccine; Reaction; Role; SARS-CoV-2 spike protein; Sampling; Series; Signal Transduction; Site; Sorting; Specificity; Structure of germinal center of lymph node; Supporting Cell; Surface; System; T cell receptor repertoire sequencing; T-Cell Receptor; T-Lymphocyte Subsets; Techniques; Testing; Time; Tissues; Tonsillectomy; Utah; Vaccination; Vaccines; Variant; Work; antigen challenge; cohort; cytokine; deltoid muscle; draining lymph node; gene function; high dimensionality; human model; in vivo; lipid nanoparticle; lymph nodes; mouse model; neutralizing antibody; novel; plasma cell development; recruit; response; seasonal influenza; secondary lymphoid organ; single-cell RNA sequencing; time interval; ultrasound; vaccine distribution; vaccine platform

ABSTRACT Neutralizing antibodies are critical for protection from infectious diseases. The lymph node (LN) germinal center (GC) is the site where B cells undergo antibody affinity maturation and develop into long-lived plasma cells – key events that are required for the development of highly effective neutralizing antibodies following infection or vaccination. T follicular helper cells (TFH) are the CD4+ T cell subset responsible for providing B cell help during an ongoing GC. TFH are absolutely required for GC formation and maintenance. By extension, TFH are necessary to produce effective neutralizing antibodies following antigen exposure. While many aspects of the TFH response and TFH function have been examined in animal models, human TFH responses in the draining LN have only recently been explored with the novel application of an established technique: serial ultrasound-guided fine needle aspiration of draining LN following vaccination. With this technique, we recently demonstrated that the antigen-specific TFH response to SARS-CoV-2 spike (S) protein mRNA vaccination persists in the GC for more than 4 months following vaccination and correlates with the presence of S-specific GC B cells. Furthermore, we have noted substantial LN TFH transcriptional phenotypic changes suggestive of functional maturation over this prolonged GC time interval using single cell RNA-seq in a small preliminary cohort. In this proposal, we will expand upon these findings to address our primary hypothesis: human TFH phenotypic maturation occurs over time in the draining LN following vaccination and these phenotypic changes are associated with changes in TFH function. To explore this hypothesis, we propose three specific aims: 1) We will first establish that TFH phenotypic maturation occurs over time in multiple antigen-specific TFH populations that we will define and characterize from a cohort of fourteen COVID-19 mRNA vaccine recipients using single cell RNA-seq and ex vivo epitope identification methods. 2) We will determine how these antigen-specific TFH populations change in a tertiary immune response following COVID-19 mRNA vaccine “boost” and continued serial LN sampling of the same cohort participants. We will also ascertain if new antigen-specific TFH populations are recruited to the GC during a recall response. 3) Finally, we will verify that the profound phenotypic changes we observe lead to changes in the functional capacity of antigen-specific TFH to provide help to B cells using an ex vivo system of sorted human LN TFH and an in vivo murine adoptive transfer model. By addressing these aims, we will significantly enhance our understanding of the role that human TFH play in directing GC B cell responses to vaccination.

摘要 中和抗体对于预防传染病至关重要。淋巴结（LN）生发中心 (GC)是B细胞经历抗体亲和力成熟并发育成长寿浆细胞的位点--关键是 感染后产生高效中和抗体所需的事件或 预防针T滤泡辅助细胞（TFH）是负责在免疫过程中提供B细胞帮助的CD 4 + T细胞亚群。 正在进行的GC。TFH是GC形成和维持所必需的。通过扩展，TFH是必要的 以在抗原暴露后产生有效的中和抗体。虽然过渡联邦政府的反应的许多方面 和TFH功能已经在动物模型中进行了检查，在引流LN中的人TFH反应仅 最近被探索与新的应用程序的一个既定的技术：系列超声引导精细 接种疫苗后引流LN的针吸。通过这项技术，我们最近证明， 抗原特异性TFH对SARS-CoV-2刺突蛋白（S）mRNA疫苗的反应在GC中持续更长时间。 接种后4个月内，与S-特异性GC B细胞的存在相关。而且我们 已经注意到LN TFH转录表型的实质性变化，表明在此期间功能成熟 在小的初步队列中使用单细胞RNA-seq延长GC时间间隔。在本提案中，我们将 扩展这些发现，以解决我们的主要假设：人TFH表型成熟发生在 这些表型变化与TFH的变化相关 功能为了探索这一假说，我们提出了三个具体的目标：1）我们将首先建立TFH表型， 随着时间的推移，成熟发生在多种抗原特异性TFH群体中，我们将从 使用单细胞RNA-seq和离体表位的14名COVID-19 mRNA疫苗接受者队列 鉴定方法2)我们将确定这些抗原特异性TFH群体如何在第三代细胞中发生变化。 COVID-19 mRNA疫苗“加强”后的免疫应答，并继续对其进行连续LN采样 队列参与者。我们还将确定新的抗原特异性TFH群体是否被招募到GC中。 一个召回响应。3)最后，我们将证实我们观察到的深刻的表型变化导致了 抗原特异性TFH使用分选的人T细胞的离体系统为B细胞提供帮助的功能能力 LN TFH和体内鼠过继转移模型。通过实现这些目标，我们将大大提高 我们对人TFH在指导GC B细胞对疫苗接种的应答中所起作用的理解。