tetano
Editor, Senior Moderator
Influenza Other Respi Viruses. 2012 Jan 12. doi: 10.1111/j.1750-2659.2011.00328.x. [Epub ahead of print]
Epitope specificity of anti-HA2 antibodies induced in humans during influenza infection.
Stanekov? Z, Mucha V, Sl?dkov? T, Bla?kovičov? H, Kostolansk? F, Varečkov? E.
Source
Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovak Republic Public Health Authority of the Slovak Republic, National Influenza Centre, Bratislava, Slovak Republic.
Abstract
Please cite this paper as: Stanekov?et al. (2012) Epitope specificity of anti-HA2 antibodies induced in humans during influenza infection. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2011.00328.x Background The conserved, fusion-active HA2 glycopolypeptide (HA2) subunit of influenza A hemagglutinin comprises four distinct antigenic sites. Monoclonal antibodies (MAbs) recognizing three of these sites are broadly cross-reactive and protective. Objectives This study aimed to establish whether antibodies specific to these three antigenic sites were elicited during a natural influenza infection or by vaccination of humans. Methods Forty-five paired acute and convalescent sera from individuals with a confirmed influenza A (subtype H3) infection were examined for the presence of HA2-specific antibodies. The fraction of antibodies specific to three particular antigenic sites (designated IIF4, FC12, and CF2 here) was investigated using competitive enzyme immunoassay. Results Increased levels of antibodies specific to an ectodomain of HA2 (EHA2: N-terminal residues 23-185 of HA2) were detected in 73% of tested convalescent sera (33/45), while an increased level of antibodies specific to the HA2 fusion peptide (N-terminal residues 1-38) was induced in just 15/45 individuals (33%). Competitive assays confirmed that antibodies specific to the IIF4 epitope (within HA2 residues 125-175) prevailed in 86% (13/15) over those specific to the other two epitopes during infection. However, only a negligible increase in HA2-specific antibodies was detectable following vaccination with a current subunit vaccine. Conclusions We observed that the antigenic site localized within N-terminal HA2 residues 125-175 was more immunogenic than that within residues 1-38 (HA2 fusion protein), although both are weak natural immunogens. We suggest that new anti-influenza vaccines should include HA2 (or specific epitopes localized within this glycopolypeptide) to enhance their cross-protective efficacy.
? 2012 Blackwell Publishing Ltd.
PMID:
22236105
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22236105
Epitope specificity of anti-HA2 antibodies induced in humans during influenza infection.
Stanekov? Z, Mucha V, Sl?dkov? T, Bla?kovičov? H, Kostolansk? F, Varečkov? E.
Source
Institute of Virology, Slovak Academy of Sciences, Bratislava, Slovak Republic Public Health Authority of the Slovak Republic, National Influenza Centre, Bratislava, Slovak Republic.
Abstract
Please cite this paper as: Stanekov?et al. (2012) Epitope specificity of anti-HA2 antibodies induced in humans during influenza infection. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2011.00328.x Background The conserved, fusion-active HA2 glycopolypeptide (HA2) subunit of influenza A hemagglutinin comprises four distinct antigenic sites. Monoclonal antibodies (MAbs) recognizing three of these sites are broadly cross-reactive and protective. Objectives This study aimed to establish whether antibodies specific to these three antigenic sites were elicited during a natural influenza infection or by vaccination of humans. Methods Forty-five paired acute and convalescent sera from individuals with a confirmed influenza A (subtype H3) infection were examined for the presence of HA2-specific antibodies. The fraction of antibodies specific to three particular antigenic sites (designated IIF4, FC12, and CF2 here) was investigated using competitive enzyme immunoassay. Results Increased levels of antibodies specific to an ectodomain of HA2 (EHA2: N-terminal residues 23-185 of HA2) were detected in 73% of tested convalescent sera (33/45), while an increased level of antibodies specific to the HA2 fusion peptide (N-terminal residues 1-38) was induced in just 15/45 individuals (33%). Competitive assays confirmed that antibodies specific to the IIF4 epitope (within HA2 residues 125-175) prevailed in 86% (13/15) over those specific to the other two epitopes during infection. However, only a negligible increase in HA2-specific antibodies was detectable following vaccination with a current subunit vaccine. Conclusions We observed that the antigenic site localized within N-terminal HA2 residues 125-175 was more immunogenic than that within residues 1-38 (HA2 fusion protein), although both are weak natural immunogens. We suggest that new anti-influenza vaccines should include HA2 (or specific epitopes localized within this glycopolypeptide) to enhance their cross-protective efficacy.
? 2012 Blackwell Publishing Ltd.
PMID:
22236105
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/22236105