Nrf2 regulation of alveolar macrophage immune responses in vivo to Mycobacterium tuberculosis

Nrf2 调节肺泡巨噬细胞对结核分枝杆菌的体内免疫反应

• 批准号: 10555299
• 负责人: Alissa Chen Rothchild
• 金额: $ 19.43万
• 依托单位: UNIVERSITY OF MASSACHUSETTS AMHERST
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-25 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10555299
• 关键词: Acceleration; Address; Adult; Aerosols; Agonist; Alveolar Macrophages; Antibiotic Therapy; Antioxidants; Bacillus; Bacteria; Cause of Death; Cell Death; Cells; Cessation of life; Communicable Diseases; Containment; Deposition; Detection; Development; Disease Outcome; Disease Progression; Distal; Dose; Drug resistant Mycobacteria Tuberculosis; Equilibrium; Event; Failure; Flow Cytometry; Future; Gene Expression; Goals; Growth; Host Defense; Hour; Immune; Immune response; Immunity; Impairment; In Vitro; Infection; Infection Control; Infectious Agent; Inflammation; Inflammatory; Inflammatory Response; Knockout Mice; Length; Lentivirus; Lung; Lung diseases; Macrophage; Maintenance; Modeling; Mouse Strains; Mucous Membrane; Mus; Mycobacterium tuberculosis; Myelogenous; Myeloid Cells; Oropharyngeal; Outcome; Pathway interactions; Positioning Attribute; Protocols documentation; Pulmonary Inflammation; Reagent; Regulation; Reporter; Reporting; Risk; Role; Sentinel; Sorting; System; Time; Tissues; Toxic effect; Treatment Protocols; Tuberculosis; Tuberculosis Vaccines; Vaccine Design; antimicrobial; cell type; conditional knockout; draining lymph node; immunopathology; immunoregulation; improved; in vivo; inhibitor; mouse model; prevent; programs; recruit; respiratory; response; small hairpin RNA; systemic inflammatory response; tool; transcription factor; transcriptome sequencing; transmission process; vaccine strategy

PROJECT SUMMARY Mycobacterium tuberculosis (Mtb) claims nearly 1.5 million lives each year and is one of the leading causes of death by an infectious agent worldwide. The lack of a protective TB vaccine for adult pulmonary disease, the length and toxicity of current antibiotic treatment regimens, and the rise in Mtb drug resistance all strongly motivate the pursuit of new host-directed therapies and strategies for vaccine design. Alveolar macrophages are the first cells in the lung to be infected with Mtb following aerosol transmission, performing a critical role as Mtb innate sentinels in the airway. They must initiate the host response that will recruit other innate cells into the lung and transfer bacteria to cells that can carry it to the draining lymph node for efficient immune priming. As tissue- resident myeloid cells, alveolar macrophages also perform a critical homeostatic function, clearing debris from the airway without triggering pulmonary inflammation. It is unknown how alveolar macrophages balance their innate sensing and tissue maintenance duties, while any delay in the initiation of the host response to Mtb provides the bacteria with additional time to replicate unchecked. Our previous results showed that Mtb-infected alveolar macrophages up-regulate a cell-protective signature, dependent on the transcription factor Nrf2. This in vivo response is distinct from the canonical pro-inflammatory response previously reported for Mtb-infected macrophages in vitro indicating that new information that can be gained from this in vivo approach. Our results showed that in the absence of Nrf2, Mtb-infected alveolar macrophages are more activated, less viable, and demonstrate enhanced control of bacteria within the first 10 days of infection, yet it is unknown how Nrf2 regulation of alveolar macrophage function early during infection impacts the subsequent stages of disease progression. The goal of this proposal is to develop diverse tools to modulate alveolar macrophage Nrf2 expression in order to define how Nrf2 impacts the timing and quality of the immune events following bacterial deposition in the airway, which ultimately lead to either disease progression or bacterial containment. First, we will characterize Nrf2 regulation of alveolar macrophage cell death and bacterial dissemination using myeloid- specific Nrf2 conditional knock-out strains (Aim 1). Second, we will develop an ex vivo system to study how Nrf2 interferes with alveolar macrophage innate sensing pathways and an shRNA lentiviral oropharyngeal delivery system to transiently block alveolar macrophage Nrf2 expression in vivo, allowing us to avoid any confounding effects of Nrf2 during development (Aim 2). The studies are driven by the hypothesis that the induction of a cell- protective program by Nrf2 prevents alveolar macrophages from mounting a rapid and effective pro-inflammatory response to Mtb infection, leading to delays in subsequent immune events that impair the host from controlling infection. By developing new tools and reagents to study the role of alveolar macrophage-specific Nrf2 expression, we will gain a better understanding of the early events of Mtb infection in the lung and evaluate the potential of Nrf2 as a future target for host-directed therapy.

项目概要 结核分枝杆菌 (Mtb) 每年夺去近 150 万人的生命，是导致结核病的主要原因之一 全世界范围内因传染原而死亡。由于缺乏针对成人肺部疾病的保护性结核疫苗， 当前抗生素治疗方案的持续时间和毒性，以及结核分枝杆菌耐药性的上升都强烈 激发对新的宿主导向疗法和疫苗设计策略的追求。肺泡巨噬细胞是 气溶胶传播后肺部第一个被 Mtb 感染的细胞，与 Mtb 一样发挥着关键作用 气道中的先天哨兵。它们必须启动宿主反应，将其他先天细胞招募到肺部 并将细菌转移到可以将其携带到引流淋巴结的细胞中，以实现有效的免疫启动。作为组织- 作为常驻骨髓细胞，肺泡巨噬细胞也发挥着重要的稳态功能，清除细胞内的碎片 气道而不引发肺部炎症。目前尚不清楚肺泡巨噬细胞如何平衡其 先天感知和组织维护职责，而宿主对结核分枝杆菌反应启动的任何延迟 为细菌提供额外的时间不受限制地复制。我们之前的结果表明，感染 Mtb 的 肺泡巨噬细胞依赖转录因子 Nrf2 上调细胞保护特征。这在 体内反应不同于先前报道的结核分枝杆菌感染者的典型促炎症反应 体外巨噬细胞表明可以从这种体内方法中获得新信息。我们的成果 研究表明，在缺乏 Nrf2 的情况下，感染 Mtb 的肺泡巨噬细胞更加活跃，活力较低，并且 证明 Nrf2 在感染的前 10 天内增强了对细菌的控制，但尚不清楚 Nrf2 如何 感染早期肺泡巨噬细胞功能的调节影响疾病的后续阶段 进展。该提案的目标是开发多种工具来调节肺泡巨噬细胞 Nrf2 表达，以确定 Nrf2 如何影响细菌感染后免疫事件的时间和质量 沉积在气道中，最终导致疾病进展或细菌遏制。首先，我们 将利用髓系细胞表征 Nrf2 对肺泡巨噬细胞死亡和细菌传播的调节 特定 Nrf2 条件敲除菌株（目标 1）。其次，我们将开发一个离体系统来研究Nrf2如何 干扰肺泡巨噬细胞先天传感途径和 shRNA 慢病毒口咽递送 系统瞬时阻断体内肺泡巨噬细胞 Nrf2 表达，使我们能够避免任何混淆 Nrf2 在发育过程中的影响（目标 2）。这些研究是由以下假设驱动的：细胞的诱导 Nrf2 的保护程序可防止肺泡巨噬细胞快速有效地促炎 对结核分枝杆菌感染的反应，导致后续免疫事件的延迟，从而损害宿主的控制能力 感染。通过开发新的工具和试剂来研究肺泡巨噬细胞特异性Nrf2的作用 表达，我们将更好地了解肺部 Mtb 感染的早期事件并评估 Nrf2 作为宿主定向治疗的未来靶点的潜力。