Evolutionary Pathways of the Pandemic Influenza A (H1N1) 2009 in the UK

Galiano, Mónica; Agapow, Paul‐Michael; Thompson, Catherine; Underwood, Anthony; Ellis, Joanna; Green, Jonathan; Zambon, Maria

doi:10.1371/journal.pone.0023779

Cited by 37 publications

(43 citation statements)

References 45 publications

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“…The high similarity of НА and NA genes (94%) was observed for viruses isolated on the different continents already at the stage of BLAST system-assisted search and was confirmed by data obtained by other authors [8,9]. Taking into ac -8, 9].…”

Section: Resultssupporting

confidence: 73%

Phylogenetic Analysis of Neuraminidase Gene of Influenza A(h3n2) Viruses Isolated in Ukraine in 2013–2014 Season

Бабій

Лейбенко

Фесенко

et al. 2015

Microbiology&Biotechnology

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Section: Resultssupporting

confidence: 73%

Phylogenetic Analysis of Neuraminidase Gene of Influenza A(h3n2) Viruses Isolated in Ukraine in 2013–2014 Season

Бабій

Лейбенко

Фесенко

et al. 2015

Microbiology&Biotechnology

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“…A phylogenetic tree of pH1N1 HA was constructed in order to determine the evolutionary pathways along which the substitutions described above have been introduced into the virus population. Previously, phylogenetic analysis of pH1N1 detected only limited variation in the HA protein in the first 2 seasons (22). In later studies, which were mostly restricted to analysis of sets of sequences obtained from a specific country or region, segregation into specific clades was described (23)(24)(25)(26)(27)(28).…”

Section: Resultsmentioning

confidence: 99%

Evolution of the Hemagglutinin Protein of the New Pandemic H1N1 Influenza Virus: Maintaining Optimal Receptor Binding by Compensatory Substitutions

Vries

Martínez-Romero

et al. 2013

J Virol

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e Pandemic influenza A H1N1 (pH1N1) virus emerged in 2009. In the subsequent 4 years, it acquired several genetic changes in its hemagglutinin (HA). Mutations may be expected while virus is adapting to the human host or upon evasion from adaptive immune responses. However, pH1N1 has not displayed any major antigenic changes so far. We examined the effect of the amino acid substitutions found to be most frequently occurring in the pH1N1 HA protein before 1 April 2012 on the receptor-binding properties of the virus by using recombinant soluble HA trimers. Two changes (S186P and S188T) were shown to increase the receptor-binding avidity of HA, whereas two others (A137T and A200T) decreased binding avidity. Construction of an HA protein tree revealed the worldwide emergence of several HA variants during the past few influenza seasons. Strikingly, two major variants harbor combinations of substitutions (S186P/A137T and S188T/A200T, respectively) with opposite individual effects on binding. Stepwise reconstruction of the HA proteins of these variants demonstrated that the mutations that increase receptorbinding avidity are compensated for by the acquisition of subsequent mutations. The combination of these substitutions restored the receptor-binding properties (avidity and specificity) of these HA variants to those of the parental virus. The results strongly suggest that the HA of pH1N1 was already optimally adapted to the human host upon its emergence in April 2009. Moreover, these results are in agreement with a recent model for antigenic drift, in which influenza A virus mutants with high and low receptor-binding avidity alternate.T he spread of new animal influenza A viruses (IAVs) in the human population requires specific adaptations in several viral proteins. Clearly, the hemagglutinin (HA) receptor-binding and fusion protein needs to adapt to the new sialic acid (SIA) receptor repertoire present on epithelial cells in the human upper airway (1-3). However, optimal adaptation does not simply translate into the HA protein acquiring high-avidity binding to human receptors. Strong binding by HA of decoy receptors, for example, receptors present on soluble proteins in the mucus, is probably detrimental for virus replication. Also, efficient release of newly assembled viral particles requires a delicate balance between binding of HA to host cell receptors and neuraminidase (NA)-mediated cleavage of this interaction (4-6).The emergence of the new pandemic H1N1 (pH1N1) virus (7, 8) in 2009 has resulted in the accumulation of sequences of large numbers of pH1N1 virus isolates over a number of consecutive influenza seasons. Thus, for the first time in history, the evolution of a newly emerged IAV spreading in the human population can be followed in great detail. Apart from the possible selection of adaptive changes in HA that result in optimized receptor-binding properties, HA is also under selective pressure by the host immune response. IAV can escape from antibody recognition by the accumulation of amino acid substitut...

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“…Amino acid sequence and structural analyses identified a natural mutation at position 374 as a major explanatory factor for this phenotypic change. Interestingly, the Glu374Lys substitution had already been highlighted in a number of reports but was not reported to have any phenotypic or clinical relevance (6,(32)(33)(34). In addition, while this paper was under review, a report that also highlighted this substitution as important for HA stability in A(H1N1)pdm09 viruses was published (35).…”

Section: Discussionmentioning

confidence: 96%