Macrophage Metabolism After Target Cell Ingestion Regulates Anti-Inflammatory Reprogramming

摘要 炎症是肺部疾病的普遍存在的组成部分，其涉及白细胞在肺组织中的积聚。 空域为了解决炎症，死亡和垂死的白细胞必须被清除，并产生白细胞。 必须关闭炎性细胞因子。宏程序（Macrology，简称M程序）是这些过程的关键组成部分， 然而，重新编程炎性M β以执行这些角色的触发因素仍然不完全清楚。 死亡细胞的清除已被证明提供了一个重要的重编程信号，但我们有限， 死亡细胞摄取促进M β功能重定向的精确机制的知识。 最近的工作已经证明了细胞代谢在决定M β功能中的关键作用。摄入目标 细胞提供了必须被支原体消化的各种大分子的明确来源。然而，很少有研究 已经做了评估细胞内代谢产物产生的这一过程或考虑随后的 免疫后果。 我们提出了第一个全面的研究M β代谢后，靶细胞摄入， 降解，并假设细胞内代谢物水平的变化控制摄入驱动的M 重新编程我们的初步研究已经确定了一个有前途的分子靶点，多胺，这是 在摄取凋亡靶细胞后，M β显著增加。多胺具有已知的抗- 炎症功能，包括抑制多种促炎细胞因子。我们建议测试 假设在靶细胞摄取后，由M β引起多胺合成的上调对于抑制 一种关键的巨噬细胞因子IL-1β，对体内肺部炎症的消退很重要。 在K99指导阶段，我将根据我的经验，学习生物学和靶细胞 通过学习与细胞代谢相关的技术清除，包括无偏代谢组学和使用 同位素代谢物来测量代谢通量。在这个阶段，我将：1）完成一个全面的， 对摄入靶细胞后产生的代谢物进行综合评估，重点是多胺， 并评估这些代谢物是否来源于消化的靶细胞材料，以及2）具体评估 炎症性巨噬细胞多胺合成的调节作用与此同时，我将丰富我的 通过参加期刊俱乐部、研讨会、全国会议、课程作业和 由实习生咨询委员会进行半年一次的评估。R 00独立阶段将允许我 建立我的实验室，我继续研究：3）M-多胺如何影响细胞因子的产生后， 靶细胞摄取，和4）M-多胺对炎症消退和肺修复的作用。 总的来说，这个建议将增强我目前的专业知识，解决目标领域的一个关键未知问题， 细胞清除，并提供必要的基础，建立自己作为一个独立的研究科学家。

ABSTRACT Inflammation is a ubiquitous component of lung disease involving accumulation of leukocytes in the airspaces. In order for inflammation to resolve, dead and dying leukocytes must be removed and production of inflammatory cytokines must be turned off. Macrophages (Mϕ) are key orchestrators of these processes, however the triggers that reprogram inflammatory Mϕ to perform these roles remain incompletely understood. Clearance of dead cells has been shown to provide an important reprogramming signal, but we have limited knowledge of the precise mechanisms by which dead cell ingestion facilitates redirection of Mϕ function. Recent work has demonstrated a key role for cellular metabolism in determining Mϕ function. Ingested target cells provide a clear source of varied macromolecules that must be digested by Mϕ. However, little research has been done to assess intracellular metabolites produced by this process or to consider the subsequent immune consequence. We propose the first comprehensive study of Mϕ metabolism following target cell ingestion and degradation, and hypothesize that changes in the levels of intracellular metabolites control ingestion-driven Mϕ reprogramming. Our preliminary studies have identified a promising molecular target, polyamines, which are dramatically increased in Mϕ following the ingestion of apoptotic target cells. Polyamines have a known anti- inflammatory function including suppression of numerous pro-inflammatory cytokines. We propose to test the hypothesis that upregulation of polyamine synthesis by Mϕ following target cell ingestion is critical to suppress a key Mϕ cytokine IL-1β, and important for the resolution of lung inflammation in vivo. During the K99 mentored phase, I will build upon my experience studying Mϕ biology and target cell clearance by learning techniques related to cellular metabolism including unbiased metabolomics and the use of isotope metabolites to measure metabolic flux. During this phase, I will: 1) complete a comprehensive, integrated assessment of the metabolites produced following ingestion of target cells, focusing on polyamines, and assess whether these metabolites derive from digested target cell material, and 2) specifically assess the role of arginase-1 in regulating polyamine synthesis by inflammatory Mϕ. Simultaneously, I will enrich my professional development by participating in journal clubs, seminars, national conferences, coursework, and having semi-annual evaluations by a trainee advisory committee. The R00 independent phase will allow me to establish my laboratory as I continue investigation into: 3) how Mϕ polyamines affect cytokine production after target cell ingestion, and 4) the effects of Mϕ polyamines on resolution of inflammation and lung repair. Collectively, this proposal will enhance my current expertise, address a critical unknown in the field of target cell clearance, and provide the necessary foundation to establish myself as an independent research scientist.