Sharma Biswa Nath, Marschall Manfred, Rinaldo Christine Hanssen
Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway Department of Medical Biology, UiT The Arctic University of Norway, Tromsø, Norway.
Institute for Clinical and Molecular Virology, University of Erlangen-Nuremberg, Erlangen, Germany.
Antimicrob Agents Chemother. 2014 Nov;58(11):6724-34. doi: 10.1128/AAC.03714-14. Epub 2014 Aug 25.
The human JC polyomavirus (JCPyV) causes the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). A growing number of patients with induced or acquired immunosuppression are at risk for infection, and no effective antiviral therapy is presently available. The widely used antimalarial drug artesunate has shown broad antiviral activity in vitro but limited clinical success. The aim of this study was to investigate the effect of artesunate on JCPyV replication in vitro. The permissivity for JCPyV MAD-4 was first compared in four cell lines, and the monkey kidney cell line COS-7 was selected. Artesunate caused a concentration-dependent decrease in the extracellular JCPyV DNA load 96 h postinfection, with a 50% effective concentration (EC50) of 2.9 μM. This effect correlated with a decreased expression of capsid protein VP1 and a reduced release of infectious viral progeny. For concentrations of <20 μM, transient reductions in cellular DNA replication and proliferation were seen, while for higher concentrations, some cytotoxicity was detected. A selective index of 16.6 was found when cytotoxicity was calculated based on cellular DNA replication in the mock-infected cells, but interestingly, cellular DNA replication in the JCPyV-infected cells was more strongly affected. In conclusion, artesunate is efficacious in inhibiting JCPyV replication at micromolar concentrations, which are achievable in plasma. The inhibition at EC50 probably reflects an effect on cellular proteins and involves transient cytostatic effects. Our results, together with the favorable distribution of the active metabolite dihydroartemisinin to the central nervous system, suggest a potential use for artesunate in patients with PML.
人类 JC 多瘤病毒（JCPyV）可引发致命的脱髓鞘疾病——进行性多灶性白质脑病（PML）。越来越多的诱导性或获得性免疫抑制患者面临感染风险，且目前尚无有效的抗病毒治疗方法。广泛使用的抗疟药物青蒿琥酯在体外显示出广泛的抗病毒活性，但临床疗效有限。本研究旨在探讨青蒿琥酯对 JCPyV 体外复制的影响。首先在四种细胞系中比较了 JCPyV MAD-4 的易感性，选择了猴肾细胞系 COS-7。青蒿琥酯在感染后 96 小时导致细胞外 JCPyV DNA 载量呈浓度依赖性下降，半数有效浓度（EC50）为 2.9 μM。这种效应与衣壳蛋白 VP1 的表达降低以及感染性病毒子代的释放减少相关。对于浓度<20 μM 的情况，细胞 DNA 复制和增殖出现短暂减少，而对于更高浓度，则检测到一些细胞毒性。基于 mock 感染细胞中的细胞 DNA 复制计算细胞毒性时，发现选择性指数为 16.6，但有趣的是，JCPyV 感染细胞中的细胞 DNA 复制受到的影响更强。总之，青蒿琥酯在微摩尔浓度下可有效抑制 JCPyV 复制，这种浓度在血浆中是可以达到的。EC50 时的抑制作用可能反映了对细胞蛋白的影响，并涉及短暂的细胞生长抑制作用。我们的结果，连同活性代谢物双氢青蒿素向中枢神经系统的良好分布，提示青蒿琥酯在 PML 患者中具有潜在应用价值。
