image: This is the structure of the influenza virus hemagglutinin from pandemic and seasonal strains, highlighting sites of antibody neutralization and sugar modifications that confer resistance to antibodies. Shown here are surface renderings (side and top views) of the pandemic (left) and seasonal (right) influenza hemagglutinin viral spike (gray). In red, we show the site of antibody neutralization that is shared between the 1918 and 2009 pandemic viruses, called the RBD-A region. In blue, we depict glycosylation sites that interfere with the access of antibodies to the sensitive RBD-A site. The RBD-A region of HA is completely exposed in the pandemic strains, but in the seasonal strains, the added glycosylation effectively shields the RBD-A region from neutralizing antibodies. This image relates to an article that appeared in the March 24, 2010, issue of Science Translational Medicine. The study, by Dr. C.-J. Wei of NIAID, National Institutes of Health in Bethesda, Md., and colleagues was titled, "Cross-Neutralization of 1918 and 2009 Influenza Viruses: Role of Glycans in Viral Evolution and Vaccine Design." view more
Credit: Image courtesy of Jeffrey C. Boyington and Gary J. Nabel