Impact of Potential Permissive Neuraminidase Mutations on Viral Fitness of the H275Y Oseltamivir-Resistant Influenza A(H1N1)pdm09 Virus In Vitro, in Mice and in Ferrets
Impact of Potential Permissive Neuraminidase Mutations on Viral Fitness of the H275Y Oseltamivir-Resistant Influenza A(H1N1)pdm09 Virus In Vitro, in Mice and in Ferrets
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DOI：
10.1128/jvi.02681-13
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发表时间：
2014-02-01
影响因子：
5.4
通讯作者：
Boivin, Guy
中科院分区：
文献类型：
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作者：
Abed, Yacine;Pizzorno, Andres;Boivin, Guy
神经氨酸酶 (NA) 突变赋予对 NA 抑制剂 (NAI) 的抗性，通常会损害流感病毒的适应性。 A/Brisbane/59/2007 (H1N1) 毒株是唯一在人群中广泛传播的 NAI 抗性病毒，它含有允许突变，可恢复 H275Y 变化引起的有害影响。计算分析预测了 A(H1N1)pdm09 病毒的其他允许 NA 突变。在这里，我们研究了 T289M 和 N369K 突变对 A(H1N1)pdm09 H275Y 变种的病毒适应性的影响。通过反向遗传学产生重组野生型 (WT) A(H1N1)pdm09 和 H275Y、H275Y/T289M、H275Y/N369K 和 H275Y/V241I/N369K（天然变体）NA 突变体。使用 ST6GalI-MDCK 细胞进行复制动力学。在 C57BL/6 小鼠中评估毒力，并在雪貂中评估接触传播。 H275Y 突变在体外感染后 (p. i.) 的前 12 至 36 小时内显着降低病毒滴度。然而，WT 和 H275Y 病毒在小鼠中引起的死亡率、体重减轻和肺滴度相当。 T289M突变消除了体外H275Y变化引起的有害影响，同时导致小鼠体重减轻和死亡率更大，注射后第3天和第6天肺部病毒滴度显着升高。与 H275Y 突变体相比。在指数雪貂中，WT、H275Y、H275Y/T289M 和 H275Y/V241I/N369K 重组体诱导了相当的发烧、体重减轻和鼻洗病毒滴度。所有测试的病毒在接触雪貂中的传播率相当，其中 H275Y/V241I/N369K 重组体表现出比 H275Y 突变体更高的鼻洗病毒滴度。允许突变可能会增强 A(H1N1)pdm09 H275Y 病毒在体外和体内的适应性。应仔细监测此类变体的出现。
Neuraminidase (NA) mutations conferring resistance to NA inhibitors (NAIs) generally compromise the fitness of influenza viruses. The only NAI- resistant virus that widely spread in the population, the A/Brisbane/59/2007 (H1N1) strain, contained permissive mutations that restored the detrimental effect caused by the H275Y change. Computational analysis predicted other permissive NA mutations for A(H1N1)pdm09 viruses. Here, we investigated the effect of T289M and N369K mutations on the viral fitness of the A(H1N1)pdm09 H275Y variant. Recombinant wild- type (WT) A(H1N1)pdm09 and the H275Y, H275Y/T289M, H275Y/N369K, and H275Y/V241I/N369K (a natural variant) NA mutants were generated by reverse genetics. Replication kinetics were performed by using ST6GalI- MDCK cells. Virulence was assessed in C57BL/6 mice, and contact transmission was evaluated in ferrets. The H275Y mutation significantly reduced viral titers during the first 12 to 36 h postinfection (p. i.) in vitro. Nevertheless, the WT and H275Y viruses induced comparable mortality rates, weight loss, and lung titers in mice. The T289M mutation eliminated the detrimental effect caused by the H275Y change in vitro while causing greater weight loss and mortality in mice, with significantly higher lung viral titers on days 3 and 6 p.i. than with the H275Y mutant. In index ferrets, the WT, H275Y, H275Y/T289M, and H275Y/V241I/N369K recombinants induced comparable fever, weight loss, and nasal wash viral titers. All tested viruses were transmitted at comparable rates in contact ferrets, with the H275Y/V241I/N369K recombinant demonstrating higher nasal wash viral titers than the H275Y mutant. Permissive mutations may enhance the fitness of A(H1N1)pdm09 H275Y viruses in vitro and in vivo. The emergence of such variants should be carefully monitored.