Nitazoxanide Inhibits Human Norovirus Replication and Synergizes with Ribavirin by Activation of Cellular Antiviral Response
Nitazoxanide Inhibits Human Norovirus Replication and Synergizes with Ribavirin by Activation of Cellular Antiviral Response
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DOI：
10.1128/aac.00707-18
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发表时间：
2018-11-01
影响因子：
4.9
通讯作者：
Pan, Qiuwei
中科院分区：
文献类型：
--
作者：
Dang, Wen;Xu, Lei;Pan, Qiuwei
诺如病毒是全世界病毒性肠胃炎的主要病因。虽然诺如病毒胃肠炎在免疫功能正常的个体中是自限性的，但在免疫功能低下的患者中发生慢性感染，导致衰弱和危及生命的并发症。Nitazoxanide （NTZ）已在临床经验中使用，并已证明对诺如病毒胃肠炎有效。在这项研究中，我们旨在利用人类诺如病毒（HuNV）复制子揭示NTZ及其活性代谢物tizoxanide （TIZ）的抗病毒潜力和作用机制。NTZ和TIZ，统称为噻唑烷类（TZD），能有效抑制HuNV和诺如病毒替代物猫杯状病毒的复制。机制研究表明，TZD激活细胞抗病毒反应并刺激干扰素刺激基因（ISGs）亚群的表达，特别是干扰素调节因子1 (IRF-1)，不仅在Huh7细胞为基础的HuNV复制子中，而且在初始Huh7和Caco-2细胞以及新型人类肠道类器官中。外源IRF-1的过表达抑制了HuNV的复制，而IRF-1的敲低在很大程度上减弱了TZD的抗病毒活性，这表明IRF-1介导了TZD对HuNV的抑制。通过使用Janus激酶（JAK）抑制剂CP-690550和STAT1敲除方法，我们发现TZD诱导的抗病毒反应独立于经典的JAK-信号转导和转录激活因子（JAK- stat）途径。此外，TZD和利巴韦林协同抑制HuNV复制，并在长期治疗后完全耗尽宿主细胞的复制子。总之，我们的研究结果表明，TZD通过激活细胞抗病毒反应，特别是通过诱导一种突出的抗病毒效应物IRF-1，来对抗HuNV的复制。NTZ单药治疗或联合利巴韦林是治疗诺如病毒胃肠炎的有希望的选择，特别是在免疫功能低下的患者中。
Norovirus is the main cause of viral gastroenteritis worldwide. Although norovirus gastroenteritis is self-limiting in immunocompetent individuals, chronic infections with debilitating and life-threatening complications occur in immunocompromised patients. Nitazoxanide (NTZ) has been used empirically in the clinic and has demonstrated effectiveness against norovirus gastroenteritis. In this study, we aimed at uncovering the antiviral potential and mechanisms of action of NTZ and its active metabolite, tizoxanide (TIZ), using a human norovirus (HuNV) replicon. NTZ and TIZ, collectively referred to as thiazolides (TZD), potently inhibited replication of HuNV and a norovirus surrogate, feline calicivirus. Mechanistic studies revealed that TZD activated cellular antiviral response and stimulated the expression of a subset of interferon-stimulated genes (ISGs), particularly interferon regulatory factor 1 (IRF-1), not only in a Huh7 cell-based HuNV replicon, but also in naive Huh7 and Caco-2 cells and novel human intestinal organoids. Overexpression of exogenous IRF-1 inhibited HuNV replication, whereas knockdown of IRF-1 largely attenuated the antiviral activity of TZD, suggesting that IRF-1 mediated TZD inhibition of HuNV. By using a Janus kinase (JAK) inhibitor, CP-690550, and a STAT1 knockout approach, we found that TZD induced antiviral response independently of the classical JAK-signal transducers and activators of transcription (JAK-STAT) pathway. Furthermore, TZD and ribavirin synergized to inhibit HuNV replication and completely depleted the replicons from host cells after long-term treatment. In summary, our results demonstrated that TZD combated HuNV replication through activation of cellular antiviral response, in particular by inducing a prominent antiviral effector, IRF-1. NTZ monotherapy or combination with ribavirin represent promising options for treating norovirus gastroenteritis, especially in immunocompromised patients.