SSA Dissecting the pro-viral functions of Jmjd6 in influenza A virus infection

甲型流感病毒（IAV）每年都会引起流行病，对公共卫生、粮食安全和全球经济构成重大威胁。为了复制，病毒依靠宿主细胞机制来促进病毒基因的表达。许多研究已经确定了支持病毒复制的单个宿主蛋白，但对于这些多重因素如何促成成功的病毒生命周期的理解仍然有限。该项目旨在将尖端的有条件体内基因敲除技术与转基因病毒相结合，以检查去除受感染细胞中病毒复制的关键细胞基因的效果。我们最近发现，含蛋白6 （Jmjd6）的细胞质结构域是IAV生长所必需的细胞宿主因子。Jmjd6是含有2-氧葡萄糖酸酯和Fe2+依赖性双加氧酶的jmjc结构域家族的成员。它是一种核羟化酶，已被证明可以羟化或去甲基化转录起始因子、组蛋白、剪接体成分和热休克因子，从而在多个水平上调节宿主基因表达（查阅PMID 28360925）。使用siRNA方法，我们已经生成了jmjd6消融的人肺癌A549细胞。当感染IAV时，这些细胞显示出病毒复制急剧减少，病毒mRNA和蛋白表达减少。在jmjd6敲低的细胞中，IAV的结合和内化是正常的，但病毒核糖核蛋白（vRNP）复合物的核输入严重受损。基于这些体外实验结果，我们假设Jmjd6在IAV感染的早期阶段具有特异性和必要的功能。jmjd6敲低对IAV复制异常严重的表型效应（几乎完全消除感染）使其成为进一步开发新型抗病毒策略的有吸引力的候选者。

Influenza A viruses (IAV) cause annual epidemics and are a major threat for public health, food security and the global economy. To replicate, the virus relies on host cell machinery to promote viral gene expression. Many studies have identified individual host proteins that support virus replication but there is still a limited understanding of how these multiple factors contribute to a successful virus life cycle. This project aims to combine cutting edge conditional in vivo gene knock-out technology with genetically modified viruses to examine the effects of removing a crucial cellular gene for virus replication in infected cells.We have recently identified that the jumonji domain containing protein 6 (Jmjd6) is a cellular host factor essential for IAV growth. Jmjd6 is a member of the JmjC-domain containing family of 2-oxoglutarate and Fe2+-dependent dioxygenases. It is a nuclear hydroxylase that has been demonstrated to hydroxylate or demethylate transcription initiation factors, histone proteins, spliceosomal components, and heat shock factors thereby regulating host gene expression at multiple levels (for review see PMID 28360925). Using siRNA approaches we have generated JMJD6-ablated human lung carcinoma A549 cells. When infected with IAV, these cells showed drastically reduced viral replication, and reduced viral mRNA and protein expression. Binding and internalisation of IAV was found to be normal in JMJD6-knockdown cells, but nuclear import of viral ribonucleoprotein (vRNP) complexes was severely impaired. Based on these in vitro results, we thus hypothesise that Jmjd6 has a specific and essential function in an early step of IAV infection. The unusually severe phenotypic effect of JMJD6-knockdown on IAV replication (almost complete ablation of infection) makes it an attractive candidate for further development of novel antiviral strategies.