Scientific Publications by FDA Staff

Arch Virol 2016 Sep 1 [Epub ahead of print]

Effects of hemagglutinin amino acid substitutions in H9 influenza A virus escape mutants.

Rudneva IA, Timofeeva TA, Ignatieva AV, Shilov AA, Ilyushina NA

We assessed the pH optimum of fusion, HA thermostability, and in vitro replication kinetics of previously obtained influenza H9 escape mutants. The N198S mutation significantly increased the optimum pH of fusion. Four HA changes, S133N, T189A, N198D, and L226Q, were associated with a significant increase in HA thermostability compared to the wild-type virus. HA amino acid changes at positions 116, 133, 135, 157, 162, and 193 significantly decreased the replicative ability of H9 escape mutants in vitro. Monitoring of pleiotropic effects of the HA mutations found in H9 escape mutants is essential for accurate prediction of all possible outcomes of immune selection of H9 influenza A viruses.