HIV-induced redox stress and the alveolar macrophage as a resistant reservoir

描述（由申请人提供）：项目概要/摘要这一题为“肺泡巨噬细胞池是HIV的储存库”的新提案解决了一个基本问题;具体地说，即使通过抗逆转录病毒疗法（ART）实现外周病毒抑制，肺泡巨噬细胞池是否充当HIV的储存库，如果是，这个储库如何改变肺泡腔内的环境并损害肺泡巨噬细胞的免疫功能？这是一个关键的问题，以解决肺部感染仍然是艾滋病毒感染者死亡的主要原因，即使他们坚持ART。我们有令人信服的实验证据表明，艾滋病毒感染抑制肺泡腔内的抗氧化防御，并导致严重的氧化还原应激。基于该提案中提出的初步数据，我们假设HIV抑制Nrf 2的表达和作用，Nrf 2是激活抗氧化反应元件（ARE）的主转录因子，部分原因是通过在这个脆弱的微环境中诱导锌缺乏，从而阻止肺泡上皮和肺泡巨噬细胞产生谷胱甘肽和其他抗-氧化剂是维持肺泡空间内健康的氧化还原电位所必需的。我们进一步假设，由于Nrf 2-ARE信号通路的这种靶向抑制， HIV促进其自身感染肺泡巨噬细胞的能力，并积累大量的细胞内前病毒，从而在肺泡腔内产生大量的HIV储库。同时， HIV诱导的氧化应激使肺泡巨噬细胞向交替激活（所谓的“M2表型”）转变。因此，肺泡巨噬细胞的先天免疫能力受损，这不仅赋予清除病毒储库的进一步抗性，而且使受感染个体易受严重肺部感染。我们的基础和临床研究人员的合作团队将利用我们正在进行的艾滋病毒感染者的合作临床研究。因此，我们不仅可以从HIV感染者的明确亚群中持续获得肺泡上皮细胞衬里液和巨噬细胞，我们还拥有专业知识，可以应用HIV发病机制，代谢组学和氧化还原信号传导方面的最先进的基本技术来测试我们的假设。同时，我们已经在进行一项饮食锌和S-腺苷甲硫氨酸的前瞻性临床试验，（一种巯基抗氧化剂，在其许多作用中增加了肺泡空间中的谷胱甘肽池），这个独特的队列将为一个大大扩展的临床试验奠定基础，这将使我们能够测试的必然假设，即设计的治疗策略，提高锌的生物利用度和肺泡内的氧化还原电位可以增强肺泡巨噬细胞的先天免疫功能，并显著减少肺中的HIV储库。这个项目将产生新的见解，我们如何能够针对肺泡巨噬细胞池，以减少艾滋病毒的负担，以及改善肺部健康，在这些脆弱的个人。

DESCRIPTION (provided by applicant): PROJECT SUMMARY/ABSTRACT This new proposal entitled "The alveolar macrophage pool is a reservoir of HIV" addresses a fundamental question; specifically, does the alveolar macrophage pool serve as a reservoir of HIV even when peripheral viral suppression is achieved by anti-retroviral therapy (ART) and if so, how does this reservoir alter the environment within the alveolar space and impair alveolar macrophage immune function? This is a critical question to address as lung infections remain the leading cause of death in persons living with HIV even when they are adherent to ART. We have compelling experimental evidence that HIV infection inhibits anti-oxidant defenses within the alveolar space and causes severe redox stress. Based on preliminary data presented in this proposal, we hypothesize that HIV inhibits the expression and actions of Nrf2, the master transcription factor that activates the anti-oxidant response element (ARE), in part by inducing zinc deficiency in this vulnerable microenvironment, and thereby prevents the alveolar epithelium and the alveolar macrophage from generating glutathione and other anti-oxidants that are critically required to maintain a healthy redox potential within the alveolar space. We further hypothesize that as a result of this targeted inhibition of the Nrf2-ARE signaling pathway, HIV promotes its own ability to infect alveolar macrophages and accumulate a large pool of intracellular pro-virus that produces a large HIV reservoir within the alveolar space. In parallel, HIV-induced oxidative stress shifts the alveolar macrophage toward alternative activation (so called 'M2 phenotype'). As a consequence, the innate immune capacity of the alveolar macrophage is impaired and this not only confers further resistance to clearing the viral reservoir but also renders the infected individual susceptible to serious lung infections. Our collaborative team of basic and clinical investigators will leverage our ongoing collaborative clinical studies in HIV-infected individuals. As a result, we not only have ongoing access to alveolar epithelial lining fluid and macrophages from well-defined subsets of HIV-infected individuals, we also have the expertise to apply state-of-the-art basic techniques in HIV pathogenesis, metabolomics, and redox signaling to test our hypotheses. In parallel, we are already conducting a prospective clinical trial of dietary zinc and S-adenosylmethionine (a thiol anti-oxidant that among its many actions increases the glutathione pool in the alveolar space) in HIV-infected individuals with inadequate immunological responses to ART. This unique cohort will form the foundation for a greatly expanded clinical trial that will enable us to test the corollary hypothesis that therapeutic strategies designed to improve zinc bioavailability and the redox potential within the alveolar space can enhance alveolar macrophage innate immune function and significantly decrease the HIV reservoir in the lung. This project will produce novel insights into how we can target the alveolar macrophage pool to decrease HIV burden as well as improve lung health in these vulnerable individuals.