Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas del Instituto Politécnico Nacional, Distrito Federal, Mexico City, Mexico.
PLoS One. 2013 Jul 23;8(7):e70005. doi: 10.1371/journal.pone.0070005. Print 2013.
Hemagglutinin is the major surface glycoprotein of influenza viruses. It participates in the initial steps of viral infection through receptor binding and membrane fusion events. The influenza pandemic of 2009 provided a unique scenario to study virus evolution. We performed molecular dynamics simulations with four hemagglutinin variants that appeared throughout the 2009 influenza A (H1N1) pandemic. We found that variant 1 (S143G, S185T) likely arose to avoid immune recognition. Variant 2 (A134T), and variant 3 (D222E, P297S) had an increased binding affinity for the receptor. Finally, variant 4 (E374K) altered hemagglutinin stability in the vicinity of the fusion peptide. Variants 1 and 4 have become increasingly predominant, while variants 2 and 3 declined as the pandemic progressed. Our results show some of the different strategies that the influenza virus uses to adapt to the human host and provide an example of how selective pressure drives antigenic drift in viral proteins.
血凝素是流感病毒的主要表面糖蛋白。它通过受体结合和膜融合事件参与病毒感染的初始步骤。2009 年的流感大流行提供了一个独特的场景来研究病毒进化。我们对在 2009 年甲型流感（H1N1）大流行期间出现的四种血凝素变体进行了分子动力学模拟。我们发现变体 1（S143G，S185T）可能是为了避免免疫识别而出现的。变体 2（A134T）和变体 3（D222E，P297S）与受体的结合亲和力增加。最后，变体 4（E374K）改变了融合肽附近的血凝素稳定性。随着大流行的进展，变体 1 和 4 变得越来越普遍，而变体 2 和 3 则减少。我们的研究结果表明，流感病毒采用了一些不同的策略来适应人类宿主，并提供了一个例子，说明选择性压力如何驱动病毒蛋白的抗原漂移。
