Dynamic Metabolic Reprogramming in Macrophages during Immune Response

项目摘要/摘要 这个项目的主要目标是了解细胞新陈代谢是如何动态重新编程的 免疫反应中的巨噬细胞，以及这种代谢重新编程如何影响免疫功能。 新出现的研究表明，新陈代谢在支持和协调免疫方面起着至关重要的作用。 然而，我们对巨噬细胞代谢的了解才刚刚开始，而且在很大程度上仅限于静态。 与不同激活状态相关的代谢偏好的比较。了解与时间相关的 新陈代谢的重新连接具有重要意义，因为免疫反应是一个高度动态的过程，通过 哪些巨噬细胞经历了一系列的功能转变，介导了 发炎。巨噬细胞反应的适当调节至关重要，因为无法激活或控制巨噬细胞。 功能在适当的时候会导致多种疾病。我们采取的综合方法 从多组学特征开始研究免疫应答过程中的动态代谢重组 这揭示了代谢过程，其变化在时间上与功能转换相耦合。接下来的是 通过有针对性的扰动来确定这些代谢变化对免疫功能的影响。那我们 进行同位素示踪研究，以定量表征通过这些途径的通量在 免疫反应，并确定重要的调节点。最后，深入的分子研究被用来 阐明驱动这些关键代谢变化的机制以及这些代谢的机制 改变协调免疫功能。我们在动态代谢重组方面的初步工作 巨噬细胞对内毒素和干扰素-γ的刺激显示三氯乙酸循环和核苷酸的变化 新陈代谢对这种免疫反应至关重要。我们发现TCA循环中的代谢流 经历两个阶段的重塑，丙酮酸脱氢酶复合体(PDHC)的抑制推动 从早期炎症阶段过渡到晚期抑制阶段。在此基础上，Aim 1将调查 PDHC抑制的分子机制，并验证PDHC抑制驱动转变的假说 进入更受抑制的状态，通过限制组蛋白乙酰化的乙酰辅酶A来调节免疫耐受。 目标2将侧重于核苷酸代谢，以定量研究核苷酸的合成、降解和 在脂多糖和干扰素-γ刺激下打捞通量的变化，并阐明其机制 改变。目标3将通过描述动态代谢重新编程来扩大该提案的范围 使用多组学方法对各种其他刺激作出反应。它将确定关键的代谢转变在 每一种反应，并创建了一个路线图，朝着代谢-免疫耦合的机械性理解。 总体而言，这一建议将阐明巨噬细胞免疫反应的代谢基础，巨噬细胞 在基础科学中非常重要，与巨噬细胞在疾病中发挥关键作用的疾病有广泛的相关性。

Project Summary / Abstract The overarching goal of this project is to understand how cellular metabolism is dynamically reprogrammed in macrophages during immune responses, and how such metabolic reprogramming impacts immune functions. Emerging research indicates that metabolism plays a crucial role in supporting and orchestrating immunity. However, our understanding of macrophage metabolism is just beginning, and is largely limited to static comparisons of metabolic preferences associated with different activation states. Understanding time-dependent metabolic rewiring is of great significance because an immune response is a highly dynamic process, through which macrophages undergo a sequence of functional transitions that mediate the onset and resolution of inflammation. Proper regulation of macrophage responses is critical, as failure to activate or control macrophage functions at the appropriate times can lead to a variety of diseases. The integrative approach that we take to investigate dynamic metabolic rewiring during an immune response starts with a multi-omics characterization that reveals metabolic processes whose alteration is temporally coupled to functional transitions. This is followed by targeted perturbations to determine the impact of these metabolic alterations on immune functions. Then we perform isotopic tracing studies to quantitatively characterize how fluxes through these pathways change during immune responses and identify important regulatory points. Finally, in-depth molecular studies are used to elucidate the mechanisms driving these key metabolic alterations and the mechanisms by which such metabolic alterations orchestrate immune functions. Our preliminary work on the dynamic metabolic rewiring in macrophages upon LPS and interferon-γ stimulation revealed that alterations in TCA cycle and nucleotide metabolism are critical for this immune response. We discovered that metabolic fluxes through the TCA cycle undergo a two-stage remodeling and that inhibition of the pyruvate dehydrogenase complex (PDHC) drives the transition from early inflammatory stage to late suppressive stage. Building on this, aim 1 will investigate the molecular mechanism causing PDHC inhibition, and test the hypothesis that PDHC inhibition drives the transition into a more suppressive state and mediates immune tolerance by restricting acetyl-coA for histone acetylation. Aim 2 will focus on nucleotide metabolism to quantitatively study how nucleotide synthesis, degradation, and salvage fluxes change upon LPS and interferon-γ stimulation, and elucidate the mechanism driving such changes. Aim 3 will expand the scope of this proposal by characterizing the dynamic metabolic reprograming in response to a variety of other stimuli using multi-omics approaches. It will identify key metabolic transitions in each response and create a roadmap towards mechanistic understanding of the metabolism-immunity coupling. Overall, this proposal will elucidate the metabolic underpinnings of immune responses in macrophages, which has great importance in basic science and broad relevance to diseases where macrophages play a key role.