"The major goal of this research has been to find and attack relatively unvarying and functionally important structures on flu viruses," said Damian Ekiert, a graduate student in the Scripps Research Kellogg School of Science and Technology who is working in the Wilson laboratory. Ekiert and Crucell's Vice President for Antibody Discovery Robert H. E. Friesen are co-first authors of the Science Express report.
By sifting through the blood of people who had been immunized with flu vaccines, Goudsmit and his colleagues several years ago discovered an antibody that bound to one such vulnerable structure. In mice, an injection of the antibody, CR6261, could prevent or cure an otherwise-lethal infection by about half of flu viruses, including H1 viruses such as H1N1, strains of which caused deadly global pandemics in 1918 and 2009.
The Crucell researchers approached Wilson, whose structural biology lab has world-class expertise at characterizing antibodies and their viral targets. Ekiert, Wilson, and their colleagues soon determined the three-dimensional molecular structure of CR6261 and its binding site on HA, as they reported in Science in 2009. That binding site, or "epitope," turned out to be on HA's lower, less-accessible stalk portion. The binding of CR6261 to that region apparently interferes with flu viruses' ability to deliver their genetic material into host cells and start a new infection. That antibody is about to begin tests in human volunteers.
The Missing Piece
Crucell researchers subsequently searched for an antibody that could neutralize some or all of the remaining flu viruses unaffected by CR6261, and recently found one, CR8020, that fits this description. As the team now reports in the Science Express paper, CR8020 powerfully neutralizes a range of human-affecting flu vir
|Contact: Mika Ono|
Scripps Research Institute