PDF(Pubmed)
Abstract：
Chikungunya virus (CHIKV) is an enveloped, positive-sense RNA virus that has re-emerged to cause millions of human infections worldwide. In humans, acute CHIKV infection causes fever and severe muscle and joint pain. Chronic and debilitating arthritis and joint pain can persist for months to years. To date, there are no approved antivirals against CHIKV. Recently, the ribonucleoside analog 4\'-fluorouridine (4\'-FlU) was reported as a highly potent orally available inhibitor of SARS-CoV-2, respiratory syncytial virus, and influenza virus replication. In this study, we assessed 4\'-FlU\'s potency and breadth of inhibition against a panel of alphaviruses including CHIKV, and found that it broadly suppressed alphavirus production in cell culture. 4\'-FlU acted on the viral RNA replication step, and the first 4 hours post-infection were the critical time for its antiviral effect. In vitro replication assays identified nsP4 as the target of inhibition. In vivo, treatment with 4\'-FlU reduced disease signs, inflammatory responses, and viral tissue burden in mouse models of CHIKV and Mayaro virus infection. Treatment initiated at 2 hours post-infection was most effective; however, treatment initiated as late as 24-48 hours post-infection produced measurable antiviral effects in the CHIKV mouse model. 4\'-FlU showed effective oral delivery in our mouse model and resulted in the accumulation of both 4\'-FlU and its bioactive triphosphate form in tissues relevant to arthritogenic alphavirus pathogenesis. Together, our data indicate that 4\'-FlU inhibits CHIKV infection in vitro and in vivo and is a promising oral therapeutic candidate against CHIKV infection.IMPORTANCEAlphaviruses including chikungunya virus (CHIKV) are mosquito-borne positive-strand RNA viruses that can cause various diseases in humans. Although compounds that inhibit CHIKV and other alphaviruses have been identified in vitro, there are no licensed antivirals against CHIKV. Here, we investigated a ribonucleoside analog, 4\'-fluorouridine (4\'-FlU), and demonstrated that it inhibited infectious virus production by several alphaviruses in vitro and reduced virus burden in mouse models of CHIKV and Mayaro virus infection. Our studies also indicated that 4\'-FlU treatment reduced CHIKV-induced footpad swelling and reduced the production of pro-inflammatory cytokines. Inhibition in the mouse model correlated with effective oral delivery of 4\'-FlU and accumulation of both 4\'-FlU and its bioactive form in relevant tissues. In summary, 4\'-FlU exhibits potential as a novel anti-alphavirus agent targeting the replication of viral RNA.
摘要：
基孔肯雅病毒（CHIKV）是一种被包裹的病毒，正义性RNA病毒重新出现，导致全球数百万人感染。在人类中,急性CHIKV感染引起发烧和严重的肌肉和关节痛。慢性和衰弱性关节炎和关节痛可持续数月至数年。迄今为止,没有批准的抗CHIKV的抗病毒药物。最近,据报道，核糖核苷类似物4'-氟尿苷（4'-FlU）是SARS-CoV-2，呼吸道合胞病毒的高效口服抑制剂，和流感病毒复制。在这项研究中,我们评估了4'-FlU对一组包括CHIKV在内的甲病毒的效力和抑制宽度，并发现它广泛抑制了细胞培养物中的甲病毒的产生。4\'-FlU作用于病毒RNA复制步骤，感染后的第一个4小时是其抗病毒作用的关键时期。体外复制测定将nsP4鉴定为抑制的靶标。在体内,用4'-FlU治疗减少疾病体征，炎症反应，CHIKV和Mayaro病毒感染小鼠模型中的病毒组织负荷。在感染后2小时开始的治疗是最有效的;然而，在感染后24-48小时开始的治疗在CHIKV小鼠模型中产生了可测量的抗病毒作用。4'-FlU在我们的小鼠模型中显示出有效的口服递送，并导致4'-FlU及其生物活性三磷酸盐形式在与关节炎性α病毒发病机理相关的组织中积累。一起,我们的数据表明，4'-FlU在体外和体内抑制CHIKV感染，是一种有前途的口服治疗CHIKV感染的候选药物。包括基孔肯雅病毒（CHIKV）在内的重要病毒是蚊子传播的正链RNA病毒，可以在人类中引起各种疾病。尽管已经在体外鉴定了抑制CHIKV和其他甲病毒的化合物，没有针对CHIKV的许可抗病毒药物。这里,我们研究了核糖核苷类似物，4'-氟尿苷(4'-Flu),并证明它在体外抑制了几种甲病毒的感染性病毒产生，并降低了CHIKV和Mayaro病毒感染小鼠模型中的病毒负担。我们的研究还表明4'-FlU治疗减少了CHIKV诱导的足垫肿胀并减少了促炎细胞因子的产生。小鼠模型中的抑制与4'-FlU的有效口服递送和4'-FlU及其生物活性形式在相关组织中的积累相关。总之,4'-FlU显示出作为靶向病毒RNA复制的新型抗甲病毒剂的潜力。
