In vitro selection and characterisation of influenza B/Beijing/1/87 isolates with altered susceptibility to zanamivir
In vitro selection and characterisation of influenza B/Beijing/1/87 isolates with altered susceptibility to zanamivir
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DOI：
10.1006/viro.1999.0058
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发表时间：
1999-12-20
期刊：
影响因子：
3.7
通讯作者：
Bethell, R
中科院分区：
文献类型：
--
作者：
Barnett, JM;Cadman, A;Bethell, R
我们描述了在扎那米韦存在下传代的来自B/Beijing/1/87的病毒的体外筛选和特征。在扎那米韦传代期间，在斑块减少试验中，病毒分离株的表型要么是药物依赖的，要么是耐药的。药物依赖分离株对神经氨酸酶的敏感性与野生型酶相同。药物依赖的分离株含有病毒血凝素的两个突变：V90A靠近拟议的唾液酸二级结合位点，L240Q靠近主要唾液酸结合位点。耐药的病毒分离株在血凝素中含有相同的突变，但在神经氨酸酶中也含有突变E116G。对于药物依赖性病毒，由于斑块数量随着药物浓度的增加而增加，因此无法测量扎那米韦的敏感性。耐药病毒对扎那米韦的体外敏感性比野生型病毒低275 ~ 502532倍。含有E116G突变的神经氨酸酶对扎那米韦的亲和力比野生型酶低33倍。在药物依赖病毒和耐药病毒中都发现了相同的血凝素突变，这一发现证实了受体结合功能的相同变化可以导致两种表型。这一观察结果证明了流感病毒血凝素和神经氨酸酶在体外逃避扎那米韦抑制中的相互作用。(C) 1999学术出版社。
We describe the in vitro selection and characterisation of virus derived from B/Beijing/1/87 passaged in the presence of zanamivir. During zanamivir passage, the phenotype of virus isolates was either drug dependent or drug resistant in plaque reduction assays. The susceptibility of the neuraminidase of the drug-dependent isolates was unchanged from that of the wild-type enzyme. The drug-dependent isolates contained two mutations in the viral haemagglutinin: V90A, close to the proposed secondary sialic acid-binding site, and L240Q, close to the primary sialic acid-binding site. Virus isolates that were drug resistant contained the same mutations in the haemagglutinin but also contained the mutation E116G in the neuraminidase. For the drug-dependent viruses, zanamivir susceptibility could not be measured because plaque numbers increased with increasing drug concentration. The in vitro zanamivir susceptibility of drug-resistant viruses was lower than that of the wild-type virus by a factor of 275- to >2532-fold. Neuraminidase containing the E116G mutation has a 33-fold lower affinity for zanamivir than the wild-type enzyme. The finding that the same haemagglutinin mutations are found in both drug-dependent and drug-resistant viruses confirms that the same changes to the receptor binding function can contribute to both phenotypes. This observation demonstrates the interplay between the influenza virus haemagglutinin and neuraminidase in escape from zanamivir inhibition in vitro. (C) 1999 Academic Press.