Xu Z, Zhou R, Jin M, Chen H
Division of Animal Infectious Disease, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR, China.
Acta Virol. 2010;54(2):113-8. doi: 10.4149/av_2010_02_113.
Influenza A (H1N1) virus is an important pathogen that can be transmitted in the enzootic cycle involved in influenza epidemics. In this study, we analyzed natural selection on the 260 sequences of subtype 1 hemagglutinin (HA1) gene of H1N1 viruses isolated from humans and swine in Asia. Nonsynonymous and synonymous substitution rates (dN, dS) were determined for each amino acid site in the HA1 coding region. Four and two positively selected sites were identified in human and swine viruses, respectively. These sites might be involved in the change of antigenic epitopes to evade the host immune system. The results indicate that more diversifying and less purifying selection controls HA1 of human viruses compared with the swine viruses. Furthermore, thirteen sites evolving differently in human and swine viruses were identified in the HA1. These sites may play a role in the cross-species transmission. The analysis of adaptive evolution of the HA1 can provide valuable information for accelerating vaccine and drug development for prevention and treatment of influenza A (H1N1) in Asia.
Influenza A virus; H1N1; hemagglutinin; positive selection; antigenic epitope.
甲型流感（H1N1）病毒是一种重要的病原体，可在流感流行所涉及的动物疫病流行周期中传播。在本研究中，我们分析了从亚洲人类和猪身上分离出的H1N1病毒的1血凝素（HA1）基因的260个序列上的自然选择情况。确定了HA1编码区每个氨基酸位点的非同义替换率和同义替换率（dN、dS）。在人类和猪病毒中分别鉴定出4个和2个正选择位点。这些位点可能参与抗原表位的变化以逃避宿主免疫系统。结果表明，与猪病毒相比，人类病毒的HA1受到更多的多样化选择和更少的纯化选择控制。此外，在HA1中鉴定出13个在人类和猪病毒中进化不同的位点。这些位点可能在跨物种传播中起作用。对HA1的适应性进化分析可为加速亚洲甲型流感（H1N1）预防和治疗的疫苗和药物开发提供有价值的信息。
甲型流感病毒；H1N1；血凝素；正选择；抗原表位。
