Influenza A virus (IAV) causes annual epidemics of respiratory disease in humans, often complicated by secondary coinfection with bacterial pathogens such as Staphylococcus aureus. Here, we report that the S. aureus secreted protein lipase 1 enhances IAV replication in vitro in primary cells, including human lung fibroblasts. The proviral activity of lipase 1 is dependent on its enzymatic function, acts late in the viral life cycle, and results in increased infectivity through positive modulation of virus budding. Furthermore, the proviral effect of lipase 1 on IAV is exhibited during in vivo infection of embryonated hen’s eggs and, importantly, increases the yield of a vaccine strain of IAV by approximately 5-fold. Thus, we have identified the first S. aureus protein to enhance IAV replication, suggesting a potential role in coinfection. Importantly, this activity may be harnessed to address global shortages of influenza vaccines.

中文翻译：

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金黄色葡萄球菌脂肪酶 1 增强甲型流感病毒的复制。

甲型流感病毒 (IAV) 会导致人类呼吸道疾病的年度流行病，通常伴有继发性合并感染细菌病原体如金黄色葡萄球菌。在这里，我们报告金黄色葡萄球菌分泌的蛋白质脂肪酶 1在体外增强 IAV在原代细胞（包括人肺成纤维细胞）中的复制。脂肪酶 1 的前病毒活性取决于其酶促功能，在病毒生命周期后期发挥作用，并通过对病毒出芽的正向调节导致感染性增加。此外，脂肪酶 1 对 IAV 的前病毒作用在体内表现出鸡胚蛋的感染，重要的是，将 IAV 疫苗株的产量提高了约 5 倍。因此，我们已经确定了第一个可增强 IAV 复制的金黄色葡萄球菌蛋白，这表明在共感染中具有潜在作用。重要的是，这项活动可用于解决全球流感疫苗短缺问题。