Strength of TCR:self-pMHC interactions in the periphery instructs CD4+ T help cell responses

TCR 的强度：外周的自身 pMHC 相互作用指导 CD4 T 帮助细胞反应

• 批准号: 10540690
• 负责人: Sharon Celeste Morley
• 金额: $ 47.08万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-15 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10540690
• 关键词: Affinity; Alleles; Animals; Antibody Affinity; Antibody Response; Antigens; Attenuated; Autoimmunity; B-Lymphocytes; Basal metabolic rate; CD4 Positive T Lymphocytes; Cell physiology; Cells; Cellular Metabolic Process; Chromatin; Collection; Complex; Data; Development; Disease; Enzymes; Epitopes; Future; Glycerol; Helper-Inducer T-Lymphocyte; Humoral Immunities; Immune response; Immune system; Infectious Agent; Knock-in Mouse; Knockout Mice; Link; Listeria; Longevity; Measures; Mediating; Memory B-Lymphocyte; Metabolic Pathway; Metabolism; Mitochondria; Modeling; Mus; Outcome; Pathway interactions; Peptide/MHC Complex; Peripheral; Play; Primary Infection; Process; Production; Publishing; Reagent; Research Personnel; Role; Signal Transduction; Sodium Channel; T cell response; T-Lymphocyte; T-Lymphocyte Subsets; Testing; Thymus Gland; Transgenic Organisms; Vaccination; Vaccine Design; Vaccines; adaptive immunity; combat; conditional knockout; cytokine; epigenome; in vivo; in vivo evaluation; inorganic phosphate; memory CD4 T lymphocyte; neutralizing antibody; novel; novel strategies; response; success; terminally differentiated effector memory (TEM) T cells; therapeutic target; transcriptome; voltage

PROJECT SUMMARY Effective vaccines remain elusive for many deadly diseases; therefore, it is critical that we better understand how the immune system generates a robust, neutralizing antibody response to vaccination so that we may enhance this type of response in future vaccine design. B cells are the producers of high-affinity antibodies, however, it is the CD4+ T cells that provide the cytokines and co-stimulatory molecules necessary to drive this B cell fate and establish long-term humoral immunity. This is why it is critical that we better understand the development and function of specific CD4+ T cell subsets involved in generating this type of response. After a primary infection or vaccination, some activated CD4+ T cells become a specialized subset specifically known to provide direct B cell help: T follicular helper (Tfh) cells. What commits T cells to the Tfh cell fate is still unknown. Our novel approach leverages the CD4+ T cell response against the immunodominant LLO epitope from Listeria in B6 mice, using two defined CD4+ TCR transgenic lines and polyclonal T cells. The two naive T cells differ in their tonic signaling mediated through the TCR recognition of self-pMHC. Naive CD4+ T cells with low tonic signaling have a high basal metabolism, respond robustly in a primary in vivo response, and develop into Tfh and TEM cells. Conversely, naive CD4+ T cells with high tonic signaling have a low basal metabolism, and poorly form Tfh cells. The premise of this proposal is that the strength of TCR:self-pMHC reactivity (tonic signaling) is deterministic for establishing the basal metabolism and the subsequent Tfh response. In Aim 1, we will establish whether a direct relationship exists between tonic signaling and the development of Tfh following antigen exposure. To this end, we will use our novel knock-in mouse line, Scn5a+. Expression of th Scn5a voltage gated sodium channel allows us to increase tonic signaling in CD4+ T cells independent of TCR signaling. We will decrease tonic signaling using a newly developed conditional knockout allele of H-2DM. Tfh helper function will be tested using an NP-LLO model. In Aim 2 we will examine how T cell metabolism influences Tfh cell responses. We have identified the glycerol phosphate shuttle as a key player in the increased metabolism of the LLO-118 T cells. We have now generated a mouse with a conditional knockout allele of mGPD2 which will be a powerful reagent to explore the role of this metabolic pathway in LLO-118 and polyclonal CD4+ T cell responses. These findings will deepen our understanding of Tfh development and may reveal therapeutic targets for vaccine design and autoimmunity.

项目摘要 对于许多致命疾病，有效的疫苗仍然难以捉摸；因此，至关重要的是，我们更好地了解 免疫系统会产生强大的中和抗体对疫苗接种的反应，以便我们可以增强 这种类型的反应在未来的疫苗设计中。 B细胞是高亲和力抗体的生产国，但是，它是 CD4+ T细胞提供了驱动该B细胞命运所必需的细胞因子和共刺激分子和 建立长期的体液免疫。这就是为什么我们更好地了解发展和 特定CD4+ T细胞子集的功能涉及生成此类响应。初次感染或 疫苗接种，一些活化的CD4+ T细胞成为专门的专门子集，该子集已知可提供直接B细胞 帮助：T卵泡辅助器（TFH）细胞。将T细胞命名为TFH细胞命运的原因仍然未知。我们的新方法 利用B6小鼠中李斯特菌的免疫主导LLO表位的CD4+ T细胞反应，使用 两个定义的CD4+ TCR转基因系和多克隆T细胞。两个天真的T细胞在其滋补信号传导上有所不同 通过TCR识别自PMHC进行介导。幼稚的CD4+ T细胞具有低强调信号传导的 基础代谢，在主要的体内反应中反应牢固，并发展为TFH和TEM细胞。反过来， 具有高强调信号传导的幼稚CD4+ T细胞的基础代谢低，并且TFH细胞形成较差。前提 该建议的是TCR的强度：自PMHC反应性（补品信号传导）是确定性的 基础代谢和随后的TFH反应。在AIM 1中，我们将确定是否直接关系 在抗原暴露后的滋补信号传导与TFH的发展之间存在。为此，我们将使用 我们的新颖型鼠标线SCN5A+。 SCN5A电压封型钠通道的表达使我们能够 增加与TCR信号传导无关的CD4+ T细胞中的补品信号传导。我们将使用 新开发的H-2DM条件淘汰等位基因。 TFH辅助功能将使用NP-LLO模型进行测试。 在AIM 2中，我们将研究T细胞代谢如何影响TFH细胞反应。我们已经确定了甘油 磷酸盐穿梭是LLO-118 T细胞代谢增加的关键参与者。我们现在已经生成了 MGPD2有条件敲除等位基因的鼠标将是一种探索此作用的强大试剂 LLO-118和多克隆CD4+ T细胞反应中的代谢途径。这些发现将加深我们 了解TFH开发，并可能揭示疫苗设计和自身免疫性的治疗靶标。