Restoration of virulence of escape mutants of H5 and H9 influenza viruses by their readaptation to mice

• DOI: 10.1099/vir.0.81185-0
• Publication Date: 2005-09-26T17:52:32Z
• Authors: Irina A. Rudneva; Natalia A. Ilyushina; Tatiana A. Timofeeva; Robert G. Webster; Nikolai V. Kaverin
• Keywords: Wild type

Antigenic mapping of the haemagglutinin (HA) molecule H5 and H9 influenza viruses by selecting escape mutants with monoclonal anti-HA antibodies subjecting selected to immunological analysis sequencing has previously been performed. The used as wild-type strains were mouse-adapted variants original isolates. Phenotypic characterization revealed that amino acid change in HA conferred resistance a antibody was sometimes associated additional effects, including decreased virulence for mice. In present study, low-virulence readapted Analysis reacquisition not necessarily achieved gene sequence, but also either removal glycosylation site (the one acquired mutant) without exact restoration initial or, an mutant had no newly sites, remote part molecule. data suggest such ‘compensating’ mutations, removing damaging effects antibody-selected changes, may be important course virus evolution.