Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany.
Steinbeis Innovation Center for Systems Biomedicine, Falkensee, Germany.
PLoS Pathog. 2019 Mar 18;15(3):e1007601. doi: 10.1371/journal.ppat.1007601. eCollection 2019 Mar.
Influenza viruses (IVs) tend to rapidly develop resistance to virus-directed vaccines and common antivirals targeting pathogen determinants, but novel host-directed approaches might preclude resistance development. To identify the most promising cellular targets for a host-directed approach against influenza, we performed a comparative small interfering RNA (siRNA) loss-of-function screen of IV replication in A549 cells. Analysis of four different IV strains including a highly pathogenic avian H5N1 strain, an influenza B virus (IBV) and two human influenza A viruses (IAVs) revealed 133 genes required by all four IV strains. According to gene enrichment analyses, these strain-independent host genes were particularly enriched for nucleocytoplasmic trafficking. In addition, 360 strain-specific genes were identified with distinct patterns of usage for IAVs versus IBV and human versus avian IVs. The strain-independent host genes served to define 43 experimental and otherwise clinically approved drugs, targeting reportedly fourteen of the encoded host factors. Amongst the approved drugs, the urea-based kinase inhibitors (UBKIs) regorafenib and sorafenib exhibited a superior therapeutic window of high IV antiviral activity and low cytotoxicity. Both UBKIs appeared to block a cell signaling pathway involved in IV replication after internalization, yet prior to vRNP uncoating. Interestingly, both compounds were active also against unrelated viruses including cowpox virus (CPXV), hantavirus (HTV), herpes simplex virus 1 (HSV1) and vesicular stomatitis virus (VSV) and showed antiviral efficacy in human primary respiratory cells. An in vitro resistance development analysis for regorafenib failed to detect IV resistance development against this drug. Taken together, the otherwise clinically approved UBKIs regorafenib and sorafenib possess high and broad-spectrum antiviral activity along with substantial robustness against resistance development and thus constitute attractive host-directed drug candidates against a range of viral infections including influenza.
流感病毒（IVs）往往会迅速对病毒定向疫苗和针对病原体决定因素的常用抗病毒药物产生耐药性，但新型宿主定向方法可能会阻止耐药性的发展。为了确定针对流感的宿主定向方法最有前途的细胞靶标，我们对 A549 细胞中的 IV 复制进行了比较小干扰 RNA（siRNA）功能丧失筛选。对包括高致病性禽流感 H5N1 株、乙型流感病毒（IBV）和两种人类流感 A 病毒（IAV）在内的四种不同 IV 株的分析显示，四种 IV 株均需要 133 个基因。根据基因富集分析，这些与株无关的宿主基因特别富含核质转运。此外，还鉴定了 360 个株特异性基因，这些基因在 IAV 与 IBV 和人源与禽源 IV 之间的使用模式存在明显差异。与株无关的宿主基因用于定义 43 种实验性和其他临床批准的药物，针对据报道的 14 种编码宿主因子。在批准的药物中，基于尿素的激酶抑制剂（UBKIs）regorafenib 和 sorafenib 表现出高 IV 抗病毒活性和低细胞毒性的优越治疗窗口。这两种 UBIK 似乎都在病毒核糖核蛋白（vRNP）脱壳之前，在内化后阻断参与 IV 复制的细胞信号通路。有趣的是，这两种化合物对包括牛痘病毒（CPXV）、汉坦病毒（HTV）、单纯疱疹病毒 1（HSV1）和水疱性口炎病毒（VSV）在内的无关病毒也具有活性，并在人原代呼吸细胞中表现出抗病毒功效。regorafenib 的体外耐药性发展分析未能检测到该药物对 IV 耐药性的发展。总之，临床批准的 UBIKs regorafenib 和 sorafenib 具有高广谱抗病毒活性，并且对耐药性发展具有很大的稳健性，因此是针对包括流感在内的一系列病毒感染的有吸引力的宿主定向药物候选物。
