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.

项目摘要 结核分枝杆菌（Mtb）每年夺去近150万人的生命，并且是结核病的主要原因之一。 全球范围内的传染源死亡。由于缺乏针对成人肺病的保护性结核病疫苗， 目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， 促进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 肺中的第一个细胞在气溶胶传播后被Mtb感染，作为Mtb发挥关键作用 呼吸道中的天然哨兵。它们必须启动宿主反应，将其他先天细胞招募到肺中 并将细菌转移到可以将其携带到引流淋巴结的细胞中，以进行有效的免疫引发。作为组织- 肺泡巨噬细胞也具有重要的体内平衡功能，清除体内的碎片， 而不会引发肺部炎症。目前尚不清楚肺泡巨噬细胞如何平衡它们的 先天感觉和组织维护职责，而宿主对结核分枝杆菌应答启动的任何延迟 为细菌提供了额外的时间来进行不受控制的复制。我们之前的研究结果表明， 肺泡巨噬细胞依赖于转录因子Nrf 2上调细胞保护信号。这 体内反应不同于先前报道的结核杆菌感染的典型促炎反应。 巨噬细胞的体外研究表明，可以从这种体内方法中获得新的信息。我们的结果 表明在Nrf 2缺失的情况下，结核杆菌感染的肺泡巨噬细胞更活跃，存活率更低， 在感染的前10天内表现出对细菌的增强控制，但目前尚不清楚Nrf 2 感染早期肺泡巨噬细胞功能的调节影响疾病的后续阶段 进展本提案的目标是开发不同的工具来调节肺泡巨噬细胞Nrf 2 表达，以定义Nrf 2如何影响细菌感染后免疫事件的时间和质量。 在气道中沉积，这最终导致疾病进展或细菌遏制。一是 将表征Nrf 2对肺泡巨噬细胞死亡和细菌传播的调节， 特异性Nrf 2条件性敲除菌株（Aim 1）。其次，我们将开发一个离体系统来研究Nrf 2如何 干扰肺泡巨噬细胞先天性感知通路和shRNA慢病毒口咽递送 系统在体内瞬时阻断肺泡巨噬细胞Nrf 2表达，使我们能够避免任何混淆 Nrf 2在发育过程中的作用（目的2）。这些研究是由一个假设驱动的，即细胞的诱导- Nrf 2的保护程序阻止肺泡巨噬细胞快速有效地进行促炎性反应， 对Mtb感染的反应，导致随后的免疫事件延迟，损害宿主对Mtb感染的控制。 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Nrf 2的作用， 表达，我们将更好地了解肺结核感染的早期事件， Nrf 2作为宿主导向治疗的未来靶点的潜力。