Tissue systems biology of immune dysregulation in aging by single cell spatial metabolomics

免疫系统随着年龄的增长而变化，并逐渐导致免疫反应不充分， 病原体免疫细胞经历衰老，不可逆的细胞周期停滞，并分泌衰老- 相关分泌表型（SASP）因子，导致空间组织的病理改变， 淋巴器官生发中心（GC）的细胞类型。老年人GC结构受损 人口，减少抗体的生产在老龄化的个人。B细胞免疫代谢对于满足 快速增殖、体细胞超突变和GC中基于亲和力的选择的能量需求。但 T滤泡辅助细胞（TFH）和GC B细胞中代谢途径的协调仍然不清楚 明白目前迫切需要在单个细胞中破译TFH依赖的B细胞免疫代谢， GC中的水平，用于识别老化相关的分子缺陷。因此，该项目将利用最近 开发了空间分辨代谢分析框架（3D-SMF），该框架映射了CD 4 + T细胞和B细胞 在天然淋巴组织中的亚群及其代谢相关物。我们的长期目标是产生单细胞 与年轻人相比，老年人GC中TFH依赖性B细胞发育的代谢见解 一个本项目的目标是在固定的细胞内逐像素定义空间分辨的B细胞免疫代谢。 人扁桃体和淋巴结组织。我们假设细胞衰老的独特代谢程序 和SASP因子多样性受脂质代谢事件调节，导致年龄依赖性独特免疫; 并且这些程序在较年轻年龄组的次级淋巴器官亚型中特别有效 相比之下，老年人。该假设的依据是3D-SMF数据显示耗竭 以及天然扁桃体组织中GC中脂肪酸的富集。中心假设将通过以下方式进行检验： 追求两个具体目标。目的1将提供对脂质相关的 人扁桃体中TFH细胞和B细胞亚群（幼稚、GC B细胞和浆细胞）的免疫代谢 组织中目标2将定义TFH和B细胞亚型以及整体细胞的代谢网络建模 与扁桃体组织相比，淋巴结中的组成不同。为了实现这些目标，3D-SMF和 多重酶谱将用于使用代谢网络分析B细胞免疫代谢 天然扁桃体和淋巴结中B细胞亚群的比较。这个项目建立了一个跨学科的团队 整合了来自单细胞生物技术、生物工程、衰老炎症、代谢建模、 和生物信息学。拟议的应用程序是创新的，因为它使用尖端技术来定义 扁桃体和淋巴结组织的空间代谢组学和蛋白质组学 从传统的专注于从其天然微环境中分离T细胞和B细胞来研究免疫 老化的缺陷。这项研究是有意义的，因为它定义了TFH依赖的B细胞免疫代谢， 淋巴组织来解读衰老中免疫失调的单细胞代谢指纹。

The immune system changes with age and gradually leads to incompetent immune responses against pathogens. Immune cells experience senescence, an irreversible cell cycle arrest, and secrete senescence- associated secretory phenotype (SASP) factors, causing pathological alterations of spatial organization and cell types in the germinal centers (GCs) of lymphoid organs. GC structures are impaired in the elderly population, reducing antibody production in aging individuals. B cell immunometabolism is crucial to meet the energy needs of rapid proliferation, somatic hypermutation, and affinity-based selection in GCs. However, the coordination of metabolic pathways in T follicular helper cells (TFH) and GC B cells is still not clearly understood. There is a critical need to decipher the TFH-dependent B cell immunometabolism at the single cell level in GCs for identifying aging-associated molecular defects. Thus, this project will leverage the recently developed spatially resolved metabolic profiling framework (3D-SMF) that maps the CD4+ T cell and B cell subsets and their metabolic correlates in native lymphoid tissues. Our long-term goal is to generate single cell metabolic insights of TFH-dependent B cell development in GCs of elderly individuals compared to young ones. The goal of this project is to define spatially resolved B cell immunometabolism pixel-by-pixel in fixed human tonsil and lymph node tissues. We hypothesize that unique metabolic programs of cellular senescence and SASP factor diversity are regulated by lipid metabolism events, causing age-dependent unique immunity; and these programs are distinctively potent in subtypes of secondary lymphoid organs in younger aged groups compared to the older ones. The rationale for this hypothesis is based on the 3D-SMF data showing depletion and enrichment of fatty acids in GCs located in native tonsil tissues. The central hypothesis will be tested by pursuing two specific Aims. Aim 1 will provide a deeper understanding of the lipid-associated immunometabolism in TFH cells and B-cell subsets (naïve, GC B cells, and plasma cells) in human tonsil tissues. Aim 2 will define how the metabolic network modeling of TFH and B cell subtypes and overall cell composition differs in lymph nodes in comparison to tonsil tissues. To accomplish these Aims, 3D-SMF and multiplexed enzyme profiling will be used to analyze B cell immunometabolism using a metabolic network comparison of B cell subsets in native tonsils and lymph nodes. This project builds an interdisciplinary team integrating experts from single cell biotechnology, bioengineering, inflammation in aging, metabolic modeling, and bioinformatics. The proposed application is innovative because it uses cutting-edge technology to define spatial metabolomics and proteomics of tonsil and lymph node tissues without dissociation protocols and shifts from the traditional focus on isolating T cell and B cells from their native microenvironment to study immune defects in aging. This research is significant because it defines TFH-dependent B cell immunometabolism in lymphoid tissues to decipher single-cell metabolic fingerprints of immune dysregulation in aging.