Influenza virus vectors: stability of generated recombinant virus

Evaluating the conformational changes of a modified viral protein could be the first step in generating a successful stable recombinant virus. This study demonstrates the effect of a small epitope addition into the haemagglutinin (HA) protein of theH1N1 influenza virus, which was compared with the wild-type protein. A hexahistindine (His6) tag was inserted intoa selected antigenic domain within thehaemagglutininHA1 subunit of the A/Puerto Rico/8/34 influenza virus. To investigate the stability of the recombinant HA protein, a molecular dynamics (MD) simulation was used for the His6-HA protein and for the wild-type HA protein under physiological conditions. Analysis of the MD trajectories showed no significant differencein terms of stability between both systems after 100 nanoseconds of the MD simulation. The His6 tag influenza virus was then successfully generated using the helper virus-based method. The recombinant mRNA was positively detected amongst the wild-type virus population after three passages of the polymerase chain reaction (PCR) detection method. Our findings indicate that addition of a small epitope is less likely to affect virus stability and infectivity for up to several rounds. Finally, an affinity purification trial resulted in an eluted sample with a low virus amount, which most likely represents the isolated His-tagged virus; however, more investigation is required.