Chikungunya Virus Overcomes Polyamine Depletion by Mutation of nsP1 and the Opal Stop Codon To Confer Enhanced Replication and Fitness.
Chikungunya Virus Overcomes Polyamine Depletion by Mutation of nsP1 and the Opal Stop Codon To Confer Enhanced Replication and Fitness.
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DOI：
10.1128/jvi.00344-17
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发表时间：
2017-08-01
影响因子：
5.4
通讯作者：
Vignuzzi M
中科院分区：
文献类型：
--
作者：
Mounce BC;Cesaro T;Vlajnić L;Vidiņa A;Vallet T;Weger-Lucarelli J;Passoni G;Stapleford KA;Levraud JP;Vignuzzi M
多胺是存在于所有细胞中的带正电荷的小分子，在DNA和RNA病毒的复制中起重要作用。基孔肯雅病毒（CHIKV）依赖于多胺在病毒进入时翻译病毒基因组，并且多胺的药理学消耗限制了病毒复制。然而，抗病毒耐药性的潜在发展需要更好地了解多胺如何发挥作用，并可以通过改变多胺水平的化合物来靶向。我们已经分离出了CHIKV，它对多胺耗竭具有抗性，并且在非结构蛋白1（nsP1）编码区中含有两个突变，并在nsP4之前含有蛋白石终止密码子突变。这些突变，除了促进多胺耗尽的细胞中的病毒复制，赋予增强的病毒复制在体外和体内。nsP1突变增强膜结合和甲基转移酶活性，而终止密码子突变允许增加下游翻译。当这些突变结合在一起时，会增强病毒的适应性，但单个突变体在蚊子中会减弱。总之，我们的研究结果表明，CHIKV可以进化出对多胺耗尽的抗性，并且靶向多胺生物合成途径的药物可以最好地与其他已建立的抗病毒药组合使用，以减轻抗性的发展。基孔肯雅病毒是一种蚊媒病毒，已感染全球数百万人。它向美洲的扩张和对新蚊子宿主的快速适应对人类健康构成了严重威胁，我们可以通过开发抗病毒疗法以及了解这些病毒在暴露于抗病毒疗法时如何突变来对抗。靶向多胺，细胞中带正电荷的小分子，可能是对抗RNA病毒（包括基孔肯雅病毒）的潜在策略。在这里，我们已经描述了一种病毒，它对多胺耗竭具有抗性，并且在细胞和整个生物体中具有增加的适应性。病毒基因组加帽机制、膜结合活性和终止密码子的突变出现，并且它们改变的活性在多胺不存在的情况下增强复制。这些结果强调了基孔肯雅病毒可以克服多胺耗竭的策略，并强调继续研究开发改进的抗病毒疗法。
Polyamines, which are small positively charge molecules present in all cells, play important roles in the replication of DNA and RNA viruses. Chikungunya virus (CHIKV) relies on polyamines for translation of the viral genome upon viral entry, and pharmacological depletion of polyamines limits viral replication. However, the potential development of antiviral resistance necessitates a better understanding of how polyamines function and can be targeted via compounds that alter polyamine levels. We have isolated CHIKV that is resistant to polyamine depletion and contains two mutations in the nonstructural protein 1 (nsP1)-coding region in combination with a mutation to the opal stop codon preceding nsP4. These mutations, in addition to promoting viral replication in polyamine-depleted cells, confer enhanced viral replication in vitro and in vivo. The nsP1 mutations enhance membrane binding and methyltransferase activities, while the stop codon mutation allows increased downstream translation. These mutations, when combined, enhance viral fitness, but individual mutants are attenuated in mosquitoes. Together, our results suggest that CHIKV can evolve resistance to polyamine depletion and that pharmaceuticals targeting the polyamine biosynthetic pathway may be best used in combination with other established antivirals to mitigate the development of resistance. IMPORTANCE Chikungunya virus is a mosquito-borne virus that has infected millions worldwide. Its expansion into the Americas and rapid adaptation to new mosquito hosts present a serious threat to human health, which we can combat with the development of antiviral therapies as well as understanding how these viruses will mutate when exposed to antiviral therapies. Targeting polyamines, small positively charged molecules in the cell, may be a potential strategy against RNA viruses, including chikungunya virus. Here, we have described a virus that is resistant to polyamine depletion and has increased fitness in cells and in full organisms. Mutations in viral genome capping machinery, membrane binding activity, and a stop codon arise, and their altered activities enhance replication in the absence of polyamines. These results highlight strategies by which chikungunya virus can overcome polyamine depletion and emphasize continued research on developing improved antiviral therapies.