Zika virus dumbbell-1 structure is critical for sfRNA presence and cytopathic effect during infection.
Zika virus dumbbell-1 structure is critical for sfRNA presence and cytopathic effect during infection.
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所有黄病毒在3′非翻译区（3′ UTR）都含有保守的RNA结构，这些结构对黄病毒RNA的复制、翻译和致病都很重要。黄病毒如寨卡病毒（ZIKV）在病毒3′ UTR中含有多个保守的RNA结构，包括称为哑铃-1（DB-1）的结构。以前的研究表明，DB-1结构是重要的黄病毒正链基因组复制，但黄病毒DB-1结构的功能作用和机制，它有助于病毒的发病机制是未知的。利用最近解决的黄病毒DB RNA结构数据，我们设计了两个DB-1突变体ZIKV感染性克隆，称为ZIKV-TL.PK和ZIKV-p.2.5′，其破坏DB-1三级折叠。我们发现两种ZIKV DB-1突变体克隆的病毒正链基因组复制与野生型（WT）ZIKV相似，但ZIKV DB-1突变体由于减少的半胱天冬酶-3活化而表现出显著降低的细胞病变效应。我们接下来显示，与ZIKV-WT相比，ZIKV DB-1突变体在感染期间表现出降低的sfRNA种类水平。然而，ZIKV DB-1突变体3′ UTR在体外XRN 1降解后表现出不变的sfRNA生物合成。我们还发现，ZIKV DB-1突变体病毒（ZIKV-p.2.5′）表现出对I型干扰素治疗的增强的敏感性，并且两种ZIKV-DB-1突变体由于在干扰素I/II型受体敲除小鼠的脑组织中的组织特异性减毒病毒复制而表现出降低的发病率和死亡率。我们提出黄病毒DB-1 RNA结构在感染期间维持sfRNA水平，尽管维持了sfRNA生物发生，并且这些结果表明sfRNA水平的ZIKV DB依赖性维持支持哺乳动物细胞和ZIKV鼠疾病模型中的半胱天冬酶-3依赖性、细胞病变效应、I型干扰素抗性和病毒发病机制。被称为黄病毒的病毒组在全世界引起重要疾病，包括登革热病毒、寨卡病毒、日本脑炎病毒等等。所有这些黄病毒在病毒基因组的非翻译区具有高度保守的RNA结构。其中一个共享的RNA结构，称为哑铃区，尚未得到充分研究，但该区域的突变对疫苗开发很重要。在这项研究中，我们在寨卡病毒哑铃区进行了结构信息靶向突变，并研究了对病毒的影响。我们发现，寨卡病毒哑铃型突变体由于产生支持感染、支持病毒诱导的细胞死亡和支持逃离宿主免疫系统所需的非编码RNA的能力降低而显著减弱或减毒。这些数据表明，黄病毒哑铃RNA结构中的靶向突变可能是开发未来候选疫苗的重要方法。
All flaviviruses contain conserved RNA structures in the 3′ untranslated region (3′ UTR) that are important for flavivirus RNA replication, translation, and pathogenesis. Flaviviruses like Zika virus (ZIKV) contain multiple conserved RNA structures in the viral 3′ UTR, including the structure known as dumbbell-1 (DB-1). Previous research has shown that the DB-1 structure is important for flavivirus positive-strand genome replication, but the functional role of the flavivirus DB-1 structure and the mechanism by which it contributes to viral pathogenesis are not known. Using the recently solved flavivirus DB RNA structural data, we designed two DB-1 mutant ZIKV infectious clones, termed ZIKV-TL.PK and ZIKV-p.2.5′, which disrupt DB-1 tertiary folding. We found that viral positive-strand genome replication of both ZIKV DB-1 mutant clones is similar to wild-type (WT) ZIKV, but ZIKV DB-1 mutants exhibit significantly decreased cytopathic effect due to reduced caspase-3 activation. We next show that ZIKV DB-1 mutants exhibit decreased levels of sfRNA species compared to ZIKV-WT during infection. However, ZIKV DB-1 mutant 3′ UTRs exhibit unchanged sfRNA biogenesis following XRN1 degradation in vitro. We also found that ZIKV DB-1 mutant virus (ZIKV-p.2.5′) exhibited enhanced sensitivity to type I interferon treatment, and both ZIKV-DB-1 mutants exhibit reduced morbidity and mortality due to tissue-specific attenuated viral replication in brain tissue of interferon type I/II receptor knockout mice. We propose that the flavivirus DB-1 RNA structure maintains sfRNA levels during infection despite maintained sfRNA biogenesis, and these results indicate that ZIKV DB-dependent maintenance of sfRNA levels support caspase-3-dependent, cytopathic effect, type I interferon resistance, and viral pathogenesis in mammalian cells and in a ZIKV murine model of disease. The group of viruses termed flaviviruses cause important disease throughout the world and include dengue virus, Zika virus, Japanese encephalitis virus, and many more. All of these flaviviruses have highly conserved RNA structures in the untranslated regions of the virus genome. One of the shared RNA structures, termed the dumbbell region, is not well studied, but mutations in this region are important for vaccine development. In this study, we made structure-informed targeted mutations in the Zika virus dumbbell region and studied the effect on the virus. We found that Zika virus dumbbell mutants are significantly weakened or attenuated due to a decreased ability to produce non-coding RNA that is needed to support infection, support virus-induced cell death, and support escape from the host immune system. These data show that targeted mutations in the flavivirus dumbbell RNA structure may be an important approach to develop future vaccine candidates.
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影响因子：
5.5
作者：
Durbin, Anna P.;Kirkpatrick, Beth D.;Pierce, Kristen K.;Schmidt, Alexander C.;Whitehead, Stephen S.
通讯作者：
Whitehead, Stephen S.
影响因子：
5.2
作者：
Fernández-Sanlés A;Ríos-Marco P;Romero-López C;Berzal-Herranz A
通讯作者：
Berzal-Herranz A
影响因子：
5
作者：
Brinton MA;Basu M
通讯作者：
Basu M
影响因子：
3.4
作者：
Cumberworth SL;Clark JJ;Kohl A;Donald CL
通讯作者：
Donald CL
影响因子：
5.4
作者：
Huang, CYH;Butrapet, S;Kinney, RM
通讯作者：
Kinney, RM