Characterization of cross-clade monoclonal antibodies against H5N1 highly pathogenic avian influenza virus and their application to the antigenic analysis of diverse H5 subtype viruses
Characterization of cross-clade monoclonal antibodies against H5N1 highly pathogenic avian influenza virus and their application to the antigenic analysis of diverse H5 subtype viruses
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DOI：
10.1007/s00705-017-3350-0
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发表时间：
2017-08-01
影响因子：
2.7
通讯作者：
Imai，Kunitoshi
中科院分区：
文献类型：
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作者：
Gronsang，Dulyatad;Bui，Anh N.;Imai，Kunitoshi
H5N1高致病性禽流感病毒(HPAIV)对动物和公共卫生都是一种威胁，需要进行专门和快速的检测，以便及时控制疾病。我们用日本分离的H5N1 HPAIV的两个分支(2.2和2.5)制备了三种中和抗血凝素(HA)的单抗。阻断免疫荧光试验表明，各单抗识别不同的表位，抗2.5分支病毒的3B5.1和3B5.2单抗与分支1、2.2、2.3.2.1、2.3.2.1a、b、c和2.3.4的26株毒株均有交叉反应，提示识别的表位(S)是保守的。相反，抗分支2.2病毒的1G5单抗仅对分支1、2.3.4和2.5株有反应性。对逃逸突变体和3B5.1和3B5.2单抗识别的H5N1病毒的一些分支的分析表明，单抗与一个表位结合，包括HA1蛋白(R162和K162)中162位的氨基酸残基。然而，出乎意料的是，当检测5株欧亚起源的H5低致病性禽流感病毒(LPAIV)R162株(EA-non GsGD分支)和两株美国起源的毒株(Am-non GsGD分支)时，mAb仅识别EA-non GsGD分支株。HA1蛋白中的R162和K162残基在已报道的43个H5N1分支中的36个中高度保守，包括目前在亚洲、非洲和欧洲流行的2.3.2.1a和2.3.2.1c分支。考虑到其他地方报道的表位，HA1蛋白中的氨基酸残基(158-PTIKRSYNNTNQE-170)可能是mAbs跨分支反应的表位。3B5.1和3B5.2单抗可用于现场H5N1高致病性禽流感病毒的特异性检测。
H5N1 highly pathogenic avian influenza viruses (HPAIVs) are a threat to both animal and public health and require specific and rapid detection for prompt disease control. We produced three neutralizing anti-hemagglutinin (HA) monoclonal antibodies (mAbs) using two clades (2.2 and 2.5) of the H5N1 HPAIV isolated in Japan. Blocking immunofluorescence tests showed that each mAb recognized different epitopes; 3B5.1 and 3B5.2 mAbs against the clade 2.5 virus showed cross-clade reactivity to all 26 strains from clades 1, 2.2, 2.3.2.1, 2.3.2.1a, b, c and 2.3.4, suggesting that the epitope(s) recognized are conserved. Conversely, the 1G5 mAb against the clade 2.2 virus showed reactivity to only clades 1, 2.3.4 and 2.5 strains. An analysis of escape mutants, and some clades of the H5N1 viruses recognized by 3B5.1 and 3B5.2 mAbs, suggested that the mAbs bind to an epitope, including amino acid residues at position 162 in the HA1 protein (R162 and K162). Unexpectedly, however, when five Eurasian-origin H5 low-pathogenic AIV (LPAIV) strains with R162 were examined (EA-nonGsGD clade) as well as two American-origin strains (Am-nonGsGD clade), the mAb recognized only EA-nonGsGD clade strains. The R162 and K162 residues in the HA1 protein were highly conserved among 36 of the 43 H5N1 clades reported, including clades 2.3.2.1a and 2.3.2.1c that are currently circulating in Asia, Africa and Europe. The amino acid residues (158-PTIKRSYNNTNQE-170) in the HA1 protein are probably an epitope responsible for the cross-clade reactivity of the mAbs, considering the epitopes reported elsewhere. The 3B5.1 and 3B5.2 mAbs may be useful for the specific detection of H5N1 HPAIVs circulating in the field.