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

免疫系统会随着年龄的增长而改变，并逐渐导致对 病原体。免疫细胞经历衰老，不可逆转的细胞周期停滞，并分泌衰老- 相关分泌表型(SASP)因子，导致空间组织和组织的病理改变 淋巴器官生发中心(GC)的细胞类型。老年人的GC结构受损 人口，减少老年人的抗体产生。B细胞免疫代谢是满足 GC快速增殖、体细胞超突变和亲和力选择所需的能量。然而， T滤泡辅助细胞(TFH)和GC B细胞代谢途径的协调尚不清楚 明白了。迫切需要在单个细胞上破译依赖TFH的B细胞免疫代谢 GC中用于识别与衰老相关的分子缺陷的水平。因此，这个项目将利用最近的 开发了空间分辨代谢谱框架(3D-SMF)，该框架映射了CD4+T细胞和B细胞 天然淋巴组织中的亚群及其代谢相关性。我们的长期目标是产生单个细胞 老年人与年轻人GC中依赖TFH的B细胞发育的代谢研究 一个。这个项目的目标是定义空间分辨的B细胞免疫代谢逐个像素在固定 人扁桃体和淋巴组织。我们假设细胞衰老的独特代谢程序 SASP因子的多样性受脂代谢事件的调节，引起年龄依赖性的独特免疫； 这些方案在年轻人群的次级淋巴器官亚型中具有明显的效力 与较老的相比。这一假设的理论基础是基于3D-SMF数据显示的耗尽 以及天然扁桃体组织中GC中脂肪酸的丰富。核心假设将通过以下方式进行检验 追求两个具体目标。目标1将提供对与脂质相关的 人扁桃体TFH细胞和B细胞亚群(幼稚细胞、GC B细胞和浆细胞)的免疫代谢 纸巾。目标2将定义TFH和B细胞亚型以及整个细胞的代谢网络模型 与扁桃体组织相比，淋巴结中的成分不同。为了实现这些目标，3D-SMF和 多重酶图谱将用于分析使用代谢网络的B细胞免疫代谢 自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、衰老中的炎症、代谢建模、 和生物信息学。拟议的应用程序具有创新性，因为它使用了尖端技术来定义 扁桃体和淋巴结组织的空间代谢组学和蛋白质组学无解离方案和转移 从传统的从天然微环境中分离T细胞和B细胞来研究免疫 老化中的缺陷。这项研究具有重要意义，因为它定义了TFH依赖的B细胞免疫代谢 淋巴组织破译衰老过程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.