Viral neutralizing activity of βA42 preparations for various IAV strains.

<p>Experiments were carried out as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0101364#pone-0101364-g001" target="_blank">figure 1</a> except that MDCK cells were used instead of HTBE cells. Panel A shows inhibition of two H3N2 strains as indicated. Panel B shows inhibition of three H1N1 strains. Panel C shows effects of a different commercially available preparation of βA42 (called βA42 HFIP) against Phil82 and Cal09 strains. Panel D shows the effect of βA42 on infection of A549 cells by Aichi68 IAV and compares the effects of pre-incubating the virus with βA42 as in panel A (“pre-incubate with IAV”) with pre-incubating the cells with βA42. In the latter case, the βA42 was either left in the cell media when virus was added (“no wash”) or washed off prior to adding the virus (“wash”). Although in the “no wash” setting infectivity was significantly reduced this effect was significantly less than when the virus was pre-incubated with βA42 (p<0.01). Finally panel D also shows the effect of pre-incubating cells with IAV at 4°C to allow binding, followed by adding βA42, and increasing the temperature to 37°C (“βA42 at 4°C”). * indicates significant reduction in viral infectivity compared with control (virus alone) (p<0.01). ** indicates where the Aichi68 strain was inhibited significantly more than the Phil82 strain (panel A). Results shown are mean±SEM of 4 or more experiments.