A Novel Benzodiazepine Compound Inhibits Yellow Fever Virus Infection by Specifically Targeting NS4B Protein
A Novel Benzodiazepine Compound Inhibits Yellow Fever Virus Infection by Specifically Targeting NS4B Protein
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DOI：
10.1128/jvi.01253-16
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发表时间：
2016-12-01
影响因子：
5.4
通讯作者：
Chang, Jinhong
中科院分区：
文献类型：
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作者：
Guo, Fang;Wu, Shuo;Chang, Jinhong
尽管已有高效疫苗，但过去 20 年来黄热病病例数量不断增加，这凸显了抗病毒治疗的迫切需要。在一项高通量筛选活动中，我们鉴定出一种乙酸苯二氮卓 (BDAA) 化合物，可有效抑制黄热病病毒 (YFV)。有趣的是，虽然用 2 μM BDAA 处理 YFV 感染的培养物可将病毒颗粒产量减少 2 个对数以上，但该化合物对来自 14 个不同病毒科的 21 种其他病毒没有活性。耐药病毒的选择和遗传分析表明，用丝氨酸、苏氨酸或丙氨酸替换非结构蛋白 4B (NS4B) 的氨基酸 219 (P219) 处的脯氨酸赋予 YFV 对 BDAA 的抗性，而在培养的哺乳动物细胞中没有明显丧失复制适应性。然而，用甘氨酸替代 P219 会产生 BDAA 抗性，同时复制能力显着丧失。生物信息学分析预测，P219氨基酸位于NS4B第五个假定跨膜结构域的内质网腔侧，该突变可能导致病毒蛋白无法与BDAA相互作用。因此，我们的研究揭示了 NS4B 蛋白在支持 YFV 复制中的重要作用和结构基础。此外，在感染 YFV 的仓鼠中，口服 BDAA 可以保护 90% 的动物免于死亡，使病毒载量显着降低 2 个对数以上，并减轻病毒感染引起的肝损伤和体重减轻。因此，令人鼓舞的临床前结果保证了进一步开发 BDAA 或其衍生物作为治疗黄热病的抗病毒药物。 重要性 黄热病是一种急性病毒性出血性疾病，威胁着生活在非洲和拉丁美洲热带地区的约 10 亿人。尽管高效的黄热病疫苗已经问世七十多年，但低疫苗接种率未能阻止高危地区的疫情暴发。据估计，非洲每年发生多达 170 万例 YFV 感染，导致 29,000 至 60,000 人死亡。迄今为止，还没有针对黄热病的特异性抗病毒治疗方法。为了应对这一医学挑战，我们发现了一种苯二氮卓类化合物，它通过靶向病毒 NS4B 蛋白来选择性抑制 YFV。据我们所知，这是第一份在动物模型中证明 YFV NS4B 抑制剂体内安全性和抗病毒功效的报告。因此，我们在开发用于黄热病临床管理的特异性抗病毒疗法方面已经达到了一个重要的里程碑。
Although a highly effective vaccine is available, the number of yellow fever cases has increased over the past 2 decades, which highlights the pressing need for antiviral therapeutics. In a high-throughput screening campaign, we identified an acetic acid benzodiazepine (BDAA) compound which potently inhibits yellow fever virus (YFV). Interestingly, while treatment of YFV-infected cultures with 2 mu M BDAA reduced the virion production by greater than 2 logs, the compound was not active against 21 other viruses from 14 different viral families. Selection and genetic analysis of drug-resistant viruses revealed that replacement of the proline at amino acid 219 (P219) of the nonstructural protein 4B (NS4B) with serine, threonine, or alanine conferred YFV with resistance to BDAA without apparent loss of replication fitness in cultured mammalian cells. However, replacement of P219 with glycine conferred BDAA resistance with significant loss of replication ability. Bioinformatics analysis predicts that the P219 amino acid is localized at the endoplasmic reticulum lumen side of the fifth putative transmembrane domain of NS4B, and the mutation may render the viral protein incapable of interacting with BDAA. Our studies thus revealed an important role and the structural basis for the NS4B protein in supporting YFV replication. Moreover, in YFV-infected hamsters, oral administration of BDAA protected 90% of the animals from death, significantly reduced viral load by greater than 2 logs, and attenuated virus infection-induced liver injury and body weight loss. The encouraging preclinical results thus warrant further development of BDAA or its derivatives as antiviral agents to treat yellow fever.IMPORTANCEYellow fever is an acute viral hemorrhagic disease which threatens approximately 1 billion people living in tropical areas of Africa and Latin America. Although a highly effective yellow fever vaccine has been available for more than 7 decades, the low vaccination rate fails to prevent outbreaks in at-risk regions. It has been estimated that up to 1.7 million YFV infections occur in Africa each year, resulting in 29,000 to 60,000 deaths. Thus far, there is no specific antiviral treatment for yellow fever. To cope with this medical challenge, we identified a benzodiazepine compound that selectively inhibits YFV by targeting the viral NS4B protein. To our knowledge, this is the first report demonstrating in vivo safety and antiviral efficacy of a YFV NS4B inhibitor in an animal model. We have thus reached a critical milestone toward the development of specific antiviral therapeutics for clinical management of yellow fever.