Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, VT, United States.
Department of Medicine, University of Vermont College of Medicine, Burlington, VT, United States; Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia; Sydney Medical School, University of Sydney, Sydney, Australia; Translational Airways Group, School of Life Sciences, University of Technology, Sydney, Australia.
Redox Biol. 2019 Apr;22:101129. doi: 10.1016/j.redox.2019.101129. Epub 2019 Jan 29.
Protein disulfide isomerases (PDI) are a family of redox chaperones that catalyze formation or isomerization of disulfide bonds in proteins. Previous studies have shown that one member, PDIA3, interacts with influenza A virus (IAV) hemagglutinin (HA), and this interaction is required for efficient oxidative folding of HA in vitro. However, it is unknown whether these host-viral protein interactions occur during active infection and whether such interactions represent a putative target for the treatment of influenza infection. Here we show that PDIA3 is specifically upregulated in IAV-infected mouse or human lung epithelial cells and PDIA3 directly interacts with IAV-HA. Treatment with a PDI inhibitor, LOC14 inhibited PDIA3 activity in lung epithelial cells, decreased intramolecular disulfide bonds and subsequent oligomerization (maturation) of HA in both H1N1 (A/PR8/34) and H3N2 (X31, A/Aichi/68) infected lung epithelial cells. These reduced disulfide bond formation significantly decreased viral burden, and also pro-inflammatory responses from lung epithelial cells. Lung epithelial-specific deletion of PDIA3 in mice resulted in a significant decrease in viral burden and lung inflammatory-immune markers upon IAV infection, as well as significantly improved airway mechanics. Taken together, these results indicate that PDIA3 is required for effective influenza pathogenesis in vivo, and pharmacological inhibition of PDIs represents a promising new anti-influenza therapeutic strategy during pandemic and severe influenza seasons.
蛋白质二硫键异构酶（PDI）是一类氧化还原伴侣，可催化蛋白质中二硫键的形成或异构化。先前的研究表明，该家族的一个成员 PDIA3 与甲型流感病毒（IAV）血凝素（HA）相互作用，这种相互作用是 HA 在体外有效氧化折叠所必需的。然而，尚不清楚这些宿主-病毒蛋白相互作用是否发生在活性感染期间，以及这种相互作用是否代表流感感染治疗的潜在靶点。在这里，我们表明 PDIA3 在 IAV 感染的小鼠或人肺上皮细胞中特异性地上调，并且 PDIA3 直接与 IAV-HA 相互作用。用 PDIs 抑制剂 LOC14 处理肺上皮细胞，可抑制 PDIA3 活性，减少 H1N1（A/PR8/34）和 H3N2（X31，A/Aichi/68）感染的肺上皮细胞中 HA 的分子内二硫键和随后的寡聚化（成熟）。这些减少的二硫键形成显著降低了病毒载量，还降低了肺上皮细胞的促炎反应。在 IAV 感染时，小鼠肺上皮细胞特异性缺失 PDIA3 导致病毒载量和肺炎症免疫标志物显著减少，以及气道力学显著改善。总之，这些结果表明 PDIA3 是体内有效流感发病所必需的，而 PDIs 的药理学抑制代表了大流行和严重流感季节中一种有前途的新抗流感治疗策略。
