Analysis of Influenza Virus Hemagglutinin Receptor Binding Mutants with Limited Receptor Recognition Properties and Conditional Replication Characteristics
Analysis of Influenza Virus Hemagglutinin Receptor Binding Mutants with Limited Receptor Recognition Properties and Conditional Replication Characteristics
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DOI：
10.1128/jvi.05570-11
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发表时间：
2011-12-01
影响因子：
5.4
通讯作者：
Steinhauer, David A.
中科院分区：
文献类型：
--
作者：
Bradley, Konrad C.;Galloway, Summer E.;Steinhauer, David A.
为了检测当结合不良的流感病毒适应于在替代环境中更有效地复制时可能操作的选择过程的范围，我们在小鼠中传代了一种在血凝素(HA)受体结合位点上含有衰减性突变的病毒，并就所选突变的结构位置、病毒的复制表型及其在糖链微阵列上的结合特性对所产生的突变进行了表征。最初减毒的病毒在HA1位(Y98F)有酪氨酸到苯丙氨酸的突变，位于受体结合口袋中，但选择的病毒在不同结构位置存在第二位点假逆转突变，揭示了一系列调节受体结合的分子机制，超出了通常使用受体特异性突变体绘制的范围。对培养的小鼠呼吸道和MDCK细胞中病毒滴度的比较表明，突变体根据系统的不同表现出独特的复制特性，但在小鼠中都没有Y98F病毒那么弱。受体结合特性分析证实，最初的Y98F病毒与几种不同种类的红细胞结合能力很差，而所有突变体都重新获得了不同程度的血凝活性。有趣的是，Y98F病毒和假回复突变体都被证明与标准的葡聚糖微阵列结合效率非常低，该芯片包含迄今已鉴定的大多数流感病毒的丰富结合底物，该结合底物由功能糖链联盟提供。这些病毒还在最近开发的含有以唾液酸衍生物为终止物的糖链的微阵列上进行了检测，并揭示了与潜在的有趣的糖链亚群的有限结合。结果讨论了HA介导的受体结合的机制，以及可能作为宿主细胞表面流感病毒受体的分子种类。
To examine the range of selective processes that potentially operate when poorly binding influenza viruses adapt to replicate more efficiently in alternative environments, we passaged a virus containing an attenuating mutation in the hemagglutinin (HA) receptor binding site in mice and characterized the resulting mutants with respect to the structural locations of mutations selected, the replication phenotypes of the viruses, and their binding properties on glycan microarrays. The initial attenuated virus had a tyrosine-to-phenylalanine mutation at HA1 position 98 (Y98F), located in the receptor binding pocket, but viruses that were selected contained second-site pseudoreversion mutations in various structural locations that revealed a range of molecular mechanisms for modulating receptor binding that go beyond the scope that is generally mapped using receptor specificity mutants. A comparison of virus titers in the mouse respiratory tract versus MDCK cells in culture showed that the mutants displayed distinctive replication properties depending on the system, but all were less attenuated in mice than the Y98F virus. An analysis of receptor binding properties confirmed that the initial Y98F virus bound poorly to several different species of erythrocytes, while all mutants reacquired various degrees of hemagglutination activity. Interestingly, both the Y98F virus and pseudoreversion mutants were shown to bind very inefficiently to standard glycan microarrays containing an abundance of binding substrates for most influenza viruses that have been characterized to date, provided by the Consortium for Functional Glycomics. The viruses were also examined on a recently developed microarray containing glycans terminating in sialic acid derivatives, and limited binding to a potentially interesting subset of glycans was revealed. The results are discussed with respect to mechanisms for HA-mediated receptor binding, as well as regarding the species of molecules that may act as receptors for influenza virus on host cell surfaces.