Defining functional neuraminidase inhibitor drug resistance motifs in avian influenza viruses and the consequential impact on virus fitness in chicken cells
Defining functional neuraminidase inhibitor drug resistance motifs in avian influenza viruses and the consequential impact on virus fitness in chicken cells
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DOI：
10.1101/663872
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发表时间：
2019-06
期刊：
影响因子：
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通讯作者：
D. Bialy;Holly Shelton
中科院分区：
文献类型：
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作者：
D. Bialy;Holly Shelton
神经氨酸酶抑制剂（NAIs）是全球推荐用于治疗或预防人类流感病毒感染的抗病毒药。对目前许可的NAI的功能性耐药性的定位仅限于人流感病毒，只有零星的报告调查了禽流感病毒（AIV）。然而，过去的大流行以及越来越多的人感染AIV已经表明了获得关于可能跨越物种障碍的禽类NA的信息的重要性。在这项研究中，我们将先前在人类毒株中发现的四种NAI耐药相关突变引入六种流行的AIV亚型的NA中，这些亚型威胁家禽业和人类健康：H7N9，H6N1，H4N6和高致病性H5N8，H5N6和H5N2。使用已建立的MUNANA测定，我们表明，R292K取代显着损害NA活性在所有菌株，而E119 V，H274 Y和N294 S有更多的变量对NA活性的影响。这些突变对NAI敏感性的影响是药物和菌株特异性的。我们已经表明，尽管NA活性受损，但与野生型相比，耐药H5N6和H6N1病毒在原代鸡细胞中复制到相当或显著更高的滴度。NAI抗性H5N6的复制适应性也在卵中得到证实。两种耐药H5N6病毒在其血凝素（HA）中具有单个氨基酸取代，这降低了受体结合特性。我们的研究结果表明，有没有通用的NAI耐药决定因素的所有菌株，虽然有些是明显有害的病毒，其他人可以迅速补偿收购其他基因片段的同时变化。重要性禽流感病毒（AIV）引起的人类感染数量不断增加。这与过去观察到的对神经氨酸酶抑制剂药物（NAI）耐药的流感病毒株的迅速出现一起引起了对公共卫生的重大关注。我们研究了在AIV背景下，先前报道的人流感病毒神经氨酸酶（NA）中NAI耐药相关的分子变化。我们发现，单个氨基酸取代可以赋予多药耐药性，或导致多个病毒亚型的单药耐药性。我们还发现，与相应的野生型相比，耐药病毒保留或显示出增强的适应性特性，这可以通过快速获得血凝素中的并发突变来实现。我们的研究强调了持续监测AIV的NAI耐药性和了解抗病毒耐药性的分子基础的必要性，因为这些信息对于大流行的准备是非常宝贵的，并可能促进新疗法的开发。
Neuraminidase inhibitors (NAIs) are antiviral agents recommended worldwide to treat or prevent influenza virus infections in humans. Mapping of functional resistance to currently licensed NAIs has been limited to human influenza viruses with only sporadic reports investigating avian influenza viruses (AIV). However past pandemics as well as the increasing number of humans infected with AIV have shown the importance of having information about avian NAs that could cross the species barrier. In this study we introduced four NAI resistance-associated mutations previously found in human strains into the NA of six prevalent AIV subtypes that threaten the poultry industry and human health: H7N9, H6N1, H4N6 and highly pathogenic H5N8, H5N6 and H5N2. Using the established MUNANA assay we show that R292K substitution significantly impaired NA activity in all strains, whereas E119V, H274Y and N294S have more variable effects on NA activity. The impact of these mutations on NAI susceptibility was drug- and strain-specific. We have shown that despite compromised NA activity drug-resistant H5N6 and H6N1 viruses replicated to comparable or significantly higher titres in primary chicken cells as compared to wild type. The replicative fitness of NAI-resistant H5N6 was also confirmed in ovo. Two drug resistant H5N6 viruses had single amino acid substitutions in their haemagglutinin (HA) which reduced receptor binding properties. Our results demonstrate that there are no universal NAI resistance determinants for all strains and although some are clearly deleterious for the virus, others can be rapidly compensated by acquiring concurrent changes in other gene segments. IMPORTANCE The number of human infections caused by avian influenza viruses (AIV) keeps increasing. This together with the rapid emergence of influenza strains resistant to neuraminidase inhibitor drugs (NAIs) observed in the past raises a significant concern to public health. We studied the NAI resistance-associated molecular changes, previously reported in neuraminidase (NA) of human influenza, in AIV background. We found that single amino acid substitution can confer a multidrug resistance, or lead to a single-drug resistance across multiple virus subtypes. We also found that the drug-resistant viruses retained or showed enhanced fitness properties as compared to the corresponding wild-type, and this could be achieved by quick acquisition of concurrent mutations in haemagglutinin. Our study highlights the need for constant monitoring of NAI-resistance in AIV and understanding the molecular basis of antiviral resistance, as such information would be invaluable for pandemic preparedness and may facilitate the development of novel therapeutics.