Defining the Impact of Per/Polyfluoroalkyl Substance Exposure on Susceptibility to SARS-CoV-2 Infection and Disease

项目摘要 我们正处于一个前所未有的，现代流行病的结果，演变的小说严重 急性呼吸道综合征冠状病毒2（SARS-CoV-2）。SARS-CoV-2是已知的三种 冠状病毒可在下呼吸道复制，引起肺炎和急性呼吸道疾病。 痛苦综合症可能致命然而，人们并不同样容易患上严重的 SARS-CoV-2感染疾病（COVID-19）。一些风险因素是已知的，包括男性和 与代谢疾病相关的合并症。这次大流行发生在一次地方性暴露于 在美国被称为全氟烷基和多氟烷基物质（PFAS）的一类化学品。每日暴露 发生通过PFAS污染的食物，饮用水，灰尘和空气，导致几乎普遍的检测， 人们检查。我们不知道PFAS暴露如何影响对SARS-CoV-2的易感性 感染和COVID-19 SARS-CoV-2感染气道上皮细胞，触发Th 1-极化的前 炎症反应。感染的消退由CD 8 + T细胞介导的感染细胞清除驱动 和通过抗体结合灭活游离病毒。疾病严重程度与淋巴细胞减少症相关， 减少CD 4 + T细胞的IFN-γ产生。PFAS是啮齿动物模型中众所周知的免疫抑制剂， 和PFAS与人类接种疫苗后抗体滴度降低有关。我们的数据和其他数据， 表明PFAS是核受体激动剂，包括过氧化物酶体增殖物激活受体α (PPARα）、组成型雄烷受体（CAR）和雄烷X受体（PXR），以及它们各自的 转录程序在体内暴露后上调。有趣的是，激活至少PPARα 和PXR导致Th 2-偏移、IFN-γ产生减少和淋巴细胞减少。在此，我们建议 检查接触遗留物（全氟辛酸，PFOA）和替代品之间的相互作用 （全氟（2-甲基-3-氧己酸）酸，GenX）PFAS和SARS-CoV-2感染。我们将测试 PFAS暴露通过与核蛋白相互作用增强对SARS-CoV-2感染易感性的假设 受体。首先，在调节SARS易感性的蛋白质中存在着关键的、物种特异性的差异， CoV-2感染（血管紧张素转换酶2（ACE 2））和PFAS（PPARα）的生物学效应。在Aim中 1.建立了hACE 2/hPPARα转基因小鼠模型，并研究了SARS-CoV-2对hACE 2/hPPARα转基因小鼠的影响 感染小鼠与人类相关的稳态身体负荷的PFAS。二、高效的CD 4 + T细胞 功能对于最大限度地降低发生COVID-19的风险至关重要。PFAS激活多种核受体 已知调节免疫功能和T细胞功能。在目标2中，我们将使用腺相关病毒介导的 在体内转导PPARα、CAR和PXR shRNA，以测试每种受体在增强细胞增殖中的必要性。 对SARS-CoV-2的易感性以及PFOA的作用如何被改变。结果将提供重要的 关于同时暴露于环境化学品如何增加严重COVID-19风险的信息。

Project Summary We are in the midst of an unprecedented, modern pandemic as a result of the evolution of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019. SARS-CoV-2 is one of three known coronaviruses that can replicate in the lower respiratory tract and cause pneumonia and acute respiratory distress syndrome, which can be fatal. However, people are not equally susceptible to development of severe SARS-CoV-2 infection disease (COVID-19). Some risk factors are known, including male sex and comorbidities related to metabolic disease. This pandemic has occurred during an endemic exposure to a class of chemicals called per- and polyfluoroalkyl substances (PFAS) in the United States. Daily exposures occur via PFAS contaminated food, drinking water, dust and air, resulting in nearly universal detection in people examined. What we do not know is how PFAS exposure may influence susceptibility to SARS-CoV-2 infection and COVID-19. SARS-CoV-2 infects airway epithelial cells, triggering a Th1-polarizing pro- inflammatory response. Resolution of the infection is driven by CD8+ T cell-mediated clearance of infected cells and inactivation of the free virus by antibody-binding. Disease severity is associated with lymphopenia and reduced IFN-γ production by CD4+ T cells. PFAS are well-known immunosuppressive agents in rodent models, and PFAS are associated with reduced antibody titers following vaccinations in humans. Our data, and others, show that PFAS are agonists for nuclear receptors, including peroxisome proliferator activated receptor α (PPARα), constitutive androstane receptor (CAR) and pregnane X receptor (PXR) and that their respective transcriptional programs are upregulated following in vivo exposure. Intriguingly, activation of at least PPARα and PXR in T cells results in Th2-skewing, reduced IFN-γ production, and lymphopenia. Here, we propose to examine the interaction between exposure to legacy (perfluorooctanoic acid, PFOA) and replacement (perfluoro(2-methyl-3-oxahexanoic) acid, GenX) PFAS and infection with SARS-CoV-2. We will test the hypothesis that PFAS exposure enhances susceptibility to SARS-CoV-2 infection via interaction with nuclear receptors. First, there are critical, species-specific differences in proteins regulating susceptibility to SARS- CoV-2 infection (angiotensin-converting enzyme 2 (ACE2)) and the biological effects of PFAS (PPARα). In Aim 1 we will generate a novel hACE2/hPPARα transgenic mouse and examine the effects of SARS-CoV-2 infection in mice with human relevant steady-state body burdens of PFAS. Second, efficient CD4+ T cell function is essential for minimizing risk of developing COVID-19. PFAS activate multiple nuclear receptors known to regulate immune function and T cell function. In Aim 2, we will use adeno-associated virus-mediated transduction of PPARα, CAR and PXR shRNA in vivo, to test the necessity for each receptor in enhancing susceptibility to SARS-CoV-2 and how PFOA’s effects are modified. The results will provide essential information on how concurrent exposures to environmental chemicals enhance the risk of severe COVID-19.