Antigenic analysis of H5N1 highly pathogenic avian influenza viruses circulating in Egypt (2006-2012)
Antigenic analysis of H5N1 highly pathogenic avian influenza viruses circulating in Egypt (2006-2012)
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DOI：
10.1016/j.vetmic.2013.09.022
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发表时间：
2013-12-27
影响因子：
3.3
通讯作者：
Lee, Chang-Won
中科院分区：
文献类型：
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作者：
Ibrahim, Mahmoud;Eladl, Abdel-Fattah;Lee, Chang-Won
高致病性禽流感H5 N1自2006年2月传入埃及后持续传播，造成了巨大的经济损失和频繁的人类感染。可用的HA序列的系统发育分析揭示了两个主要亚系的存在;经典2.2.1和变体2.2.1.1。经典的2.2.1病毒被细分为两个病毒簇;簇C1包含最初引入的病毒和2006年至2009年的分离株，簇C2出现在2007年并继续传播。变体2.2.1.1代表主要来自鸡的分离株，并细分为两个聚类;聚类V1包含2007年至2009年的分离株，聚类V2包含2008年至2011年的分离株。序列分析显示，在以前报道的抗原位点和高进化率，这可能是由于疫苗接种和/或自然感染的选择性压力28个氨基酸的突变。使用灭活全病毒免疫SPF鸡产生的超免疫血清，使用血凝抑制（HI）和病毒中和（VN）试验对2006年至2012年代表不同簇群的18株H5 N1分离株进行抗原性分析。祖先埃及H5 N1分离株（459-3/06）与其他分离株的抗原相关性范围为30.7%至79.1%，表明H5 N1病毒与祖先毒株的抗原性发生了显著漂移。C2和V2簇之间的抗原相关性范围为28.9%至68%，支持对来自这两个簇的疫苗种子株的需求。有趣的是，A/CK/EG/1709-6/2008 H5 N1毒株显示出对不同H5 N1簇中病毒的广泛交叉反应性（抗原相关性范围为63.9%至85.8%），证明了作为疫苗毒株的潜在候选者。抗原制图，有利于定量解释和易于可视化的血清学数据的基础上构建HI结果，并进一步证明了埃及H5 N1病毒之间的几个抗原组。总之，共同传播的H5 N1病毒株之间的交叉反应性可能不足以相互保护，建议在实验感染试验中检测含有不同抗原组分离株的疫苗，以选择疫苗种子株。此外，有必要持续监测以检测新出现的变异，然后进行详细的抗原分析以更新疫苗。(C)2013爱思唯尔有限公司版权所有。
The highly pathogenic avian influenza (HPAI) H5N1 in Egypt circulated continuously after its introduction in February 2006 with substantial economic losses and frequent human infections. Phylogenetic analysis of the available HA sequences revealed the presence of two main sublineages; the classic 2.2.1 and the variant 2.2.1.1. The classic 2.2.1 had subdivided into two clusters of viruses; cluster Cl contained the originally introduced virus and isolates from 2006 to 2009 and cluster C2 emerged in 2007 and continues to circulate. The variant 2.2.1.1 represents the isolates mainly from chickens and subdivided into two clusters; cluster V1 contains isolates from 2007 to 2009 and cluster V2 contains isolates from 2008 to 2011. Sequence analysis revealed 28 amino acid mutations in the previously reported antigenic sites and high evolution rate which may be due to selective pressure from vaccination and/or natural infection. Antigenic analysis of 18 H5N1 isolates from 2006 to 2012 that represent different clusters was conducted using hemagglutination inhibition (HI) and virus neutralization (VN) assays using hyperimmune sera produced by immunizing SPF chickens with inactivated whole-virus. Antigenic relatedness of ancestral Egyptian H5N1 isolate (459-3/06) with other isolates ranged from 30.7% to 79.1% indicating significant antigenic drift of the H5N1 viruses from the ancestral strains. The antigenic relatedness between C2 and V2 clusters ranged from 28.9% to 68% supporting the need for vaccine seed strains from both clusters. Interestingly, A/CK/EG/1709-6/2008 H5N1 strain showed a broad cross reactivity against viruses in different H5N1 clusters (antigenic relatedness ranged from 63.9% to 85.8%) demonstrating a potential candidate as a vaccine strain. Antigenic cartography which facilitates a quantitative interpretation and easy visualization of serological data was constructed based on HI results and further demonstrated the several antigenic groups among Egyptian H5N1 viruses. In conclusion, the cross reactivity between the co-circulating H5N1 strains may not be adequate for protection against each other and it is recommended to test vaccines that contain isolates from different antigenic groups in experimental infection trials for the selection of vaccine seed strain. Furthermore, the continuous monitoring for detecting the emerging variants followed by detailed antigenic analysis for updating vaccines is warranted. (C) 2013 Elsevier B.V. All rights reserved.