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

项目摘要 我们正处于一场史无前例的现代大流行之中，这是新的严重流感病毒演变的结果 2019年的SARS冠状病毒(SARS-CoV-2)。SARS-CoV-2是已知的三种 可在下呼吸道复制并导致肺炎和急性呼吸道的冠状病毒 窘迫综合症，可能是致命的。然而，人们并不同样容易患上严重的 非典冠状病毒2型感染性疾病(新冠肺炎)。一些风险因素是已知的，包括男性和 与代谢性疾病相关的并存。这场大流行发生在一次地方性接触一种 在美国称为全氟烷基和多氟烷基物质(PFAS)的一类化学品。每日曝露 通过全氟辛烷磺酸污染的食物、饮用水、粉尘和空气发生，导致在 人们进行了检查。我们不知道的是，PFAS暴露如何影响对SARS-CoV-2的易感性 感染和新冠肺炎。SARS-CoV-2感染呼吸道上皮细胞，触发Th1极化亲 炎症反应。感染的解决是由CD8+T细胞介导的对感染细胞的清除推动的 以及通过抗体结合使游离病毒失活。疾病的严重程度与淋巴细胞减少和 减少γ+T细胞产生干扰素。在啮齿动物模型中，全氟辛烷磺酸是众所周知的免疫抑制剂， 而全氟辛烷磺酸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PfA是核受体的激动剂，包括过氧化物酶体增殖物激活受体α (PPARα)、组成性雄烷受体(CAR)和孕烷X受体(PXR)及其各自 体内暴露后，转录程序上调。有趣的是，至少激活了PPARα 而T细胞中的PXR会导致Th2型细胞倾斜，减少干扰素-γ的产生，并导致淋巴细胞减少。在此，我们建议 检查暴露于遗留物质(全氟辛酸，PFOA)和替换之间的相互作用 (全氟(2-甲基-3-氧杂己酸)酸，GenX)PFAS和SARS-CoV-2感染。我们将测试 PFAS暴露通过与核相互作用增加SARS-CoV-2感染易感性的假说 感受器。首先，调控SARS易感性的蛋白质存在关键的、特定于物种的差异-- 冠状病毒2型感染(血管紧张素转换酶2)和PPARα的生物学效应。在AIM 1我们将建立一种新型的hACE2/hPPARα转基因小鼠，并检测其对SARS-CoV-2的影响。 感染小鼠与人类相关的稳态体力负荷全氟辛烷磺酸。第二，高效的CD4+T细胞 功能对于将发展新冠肺炎的风险降至最低至关重要。PfA激活多个核受体 已知可调节免疫功能和T细胞功能。在目标2中，我们将使用腺相关病毒介导的 体内转导PPARα、CAR和PXR shRNA，以验证各受体在促进 对SARS-CoV-2的易感性以及如何改变全氟辛烷磺酸的影响。结果将提供至关重要的 关于同时接触环境化学品如何增加严重新冠肺炎风险的信息。

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.