Hemagglutinin specificity and neuraminidase coding capacity of neuraminidase-deficient influenza viruses
Hemagglutinin specificity and neuraminidase coding capacity of neuraminidase-deficient influenza viruses
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DOI：
10.1006/viro.1996.8421
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发表时间：
1997-03-03
期刊：
影响因子：
3.7
通讯作者：
Air, GM
中科院分区：
文献类型：
--
作者：
Yang, P;Bansal, A;Air, GM
通过在含有来自绿色小单孢菌的神经氨酸酶和针对流感NA的抗血清的培养基中传代A/NWS/33（HA）-tern/Australia/G70 c/ 75（NA）（H1 N9）流感病毒，获得神经氨酸酶（NA）缺陷型突变病毒原种。所得突变体的生长依赖于向培养基中添加细菌神经氨酸酶。核苷酸序列分析显示NA基因有较大的单缺失，NA基因片段两端保守。这些RNA片段都具有编码含有NA的N-末端“尾”和膜锚定区的肽的能力，但在病毒体或感染细胞中尚未证实该肽的存在。与从H1 N9病毒中选择NA缺陷突变体的容易性相反，没有从其他三种病毒中选择突变体。亲本H1 N9和突变体NWSc-Mvi的HA编码区段预测，与含有NWS/33 HA基因的H1 N2抵抗体的HA相比，在接近H3 HA的受体结合位点的残基227（H3编号）处Pro变为His。这种变化可能有助于改变HA特异性，从而允许选择可以在高水平NA活性存在下感染细胞的突变体。看来NA在流感感染中的作用是从HA中去除唾液酸，而不是破坏细胞上的受体。(C)1997年学术出版社。
Neuraminidase (NA)-deficient mutant virus stocks have been obtained by passaging A/NWS/33(HA)-tern/Australia/G70c/ 75(NA) (H1N9) influenza virus in medium containing neuraminidase from Micromonospora viridifaciens and antiserum against the influenza NA. Growth of the resulting mutants is dependent on addition of bacterial neuraminidase to the medium. Nucleotide sequence analysis showed large single deletions in the NA genes, with both ends of the NA gene segments conserved. These RNA fragments all have the capacity to code for a peptide that contains the N-terminal ''tail'' and membrane-anchoring region of the NA, but the presence of this peptide has not been demonstrated in virions or infected cells. In contrast to the ease of selection of NA-deficient mutants from the H1N9 virus, no mutants were selected from three other viruses. The HA-coding segments of parental H1N9 and mutant NWSc-Mvi predict a change of Pro to His at residue 227 (H3 numbering), close to the receptor-binding site of H3 HA, compared to the HA of an H1N2 reassortant that contains the NWS/33 HA gene. This change may contribute to an altered HA specificity that allows selection of mutants that can infect cells in the presence of high levels of NA activity. It appears that the role of NA in influenza infection is to remove sialic acid from the HA rather than to destroy receptors on cells. (C) 1997 Academic Press.