A common solution to group 2 influenza virus neutralization.
Friesen, R.H., Lee, P.S., Stoop, E.J., Hoffman, R.M., Ekiert, D.C., Bhabha, G., Yu, W., Juraszek, J., Koudstaal, W., Jongeneelen, M., Korse, H.J., Ophorst, C., Brinkman-van der Linden, E.C., Throsby, M., Kwakkenbos, M.J., Bakker, A.Q., Beaumont, T., Spits, H., Kwaks, T., Vogels, R., Ward, A.B., Goudsmit, J., Wilson, I.A.(2014) Proc Natl Acad Sci U S A 111: 445-450
- PubMed: 24335589 
- DOI: https://doi.org/10.1073/pnas.1319058110
- Primary Citation of Related Structures:  
4NM4, 4NM8 - PubMed Abstract: 
The discovery and characterization of broadly neutralizing antibodies (bnAbs) against influenza viruses have raised hopes for the development of monoclonal antibody (mAb)-based immunotherapy and the design of universal influenza vaccines. Only one human bnAb (CR8020) specifically recognizing group 2 influenza A viruses has been previously characterized that binds to a highly conserved epitope at the base of the hemagglutinin (HA) stem and has neutralizing activity against H3, H7, and H10 viruses. Here, we report a second group 2 bnAb, CR8043, which was derived from a different germ-line gene encoding a highly divergent amino acid sequence. CR8043 has in vitro neutralizing activity against H3 and H10 viruses and protects mice against challenge with a lethal dose of H3N2 and H7N7 viruses. The crystal structure and EM reconstructions of the CR8043-H3 HA complex revealed that CR8043 binds to a site similar to the CR8020 epitope but uses an alternative angle of approach and a distinct set of interactions. The identification of another antibody against the group 2 stem epitope suggests that this conserved site of vulnerability has great potential for design of therapeutics and vaccines.
Organizational Affiliation: 
Crucell Vaccine Institute, Janssen Center of Excellence for Immunoprophylaxis, 2333 CN, Leiden, The Netherlands.