Wada Yuji, Orba Yasuko, Sasaki Michihito, Kobayashi Shintaro, Carr Michael J, Nobori Haruaki, Sato Akihiko, Hall William W, Sawa Hirofumi
Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Hokkaido, Japan.
Global Institution for Collaborative Research and Education (GI-CoRE), Hokkaido University, Sapporo, Hokkaido, Japan; National Virus Reference Laboratory, University College Dublin, Belfield, Ireland.
Virology. 2017 May;505:102-112. doi: 10.1016/j.virol.2017.02.014. Epub 2017 Feb 23.
Chikungunya fever (CHIKF) is caused by chikungunya virus (CHIKV) infection which is a re-emerging mosquito-borne zoonosis. At present, there are no approved therapeutics for CHIKF. Herein, we have investigated candidate compounds which can inhibit CHIKV infection. Screening of chemical compound libraries were performed and one candidate, a benzimidazole-related compound designated Compound-A was found to inhibit infection by several CHIKV strains and a Sindbis virus strain at nanomolar concentrations. To investigate the inhibitory mechanism of action, a Compound-A resistant CHIKV (res-CHIKV) was isolated and a key mutation associated with resistance was identified by reverse-genetic recombinant CHIKVs containing amino acid substitutions present in res-CHIKV. These results demonstrated that the target site of Compound-A was the M2295 residue in the nonstructural protein 4 (nsP4), which is located in one of the functional domains of RNA-dependent RNA-polymerase (RdRp). We also confirmed that Compound-A inhibits RdRp function of CHIKV by using CHIKV replicons.
基孔肯雅热（CHIKF）由基孔肯雅病毒（CHIKV）感染引起，CHIKV是一种再度出现的蚊媒人畜共患病原体。目前，尚无获批用于治疗基孔肯雅热的药物。在此，我们研究了可抑制CHIKV感染的候选化合物。我们进行了化合物库筛选，发现一种名为化合物A的苯并咪唑相关化合物能够在纳摩尔浓度下抑制多种CHIKV毒株和一种辛德毕斯病毒毒株的感染。为研究其抑制作用机制，我们分离出一株对化合物A耐药的CHIKV（res-CHIKV），并通过含有res-CHIKV中存在的氨基酸替代的反向遗传重组CHIKV鉴定出一个与耐药相关的关键突变。这些结果表明，化合物A的作用靶点是非结构蛋白4（nsP4）中的M2295残基，该残基位于RNA依赖性RNA聚合酶（RdRp）的一个功能域中。我们还通过使用CHIKV复制子证实了化合物A抑制CHIKV的RdRp功能。
