Baculovirus surface-displayed hemagglutinin of H5N1 influenza virus sustains its authentic cleavage, hemagglutination activity, and antigenicity.

Baculovirus-mediated transductions of viral glycoprotein genes into mice were shown to elicit protective immune response in several reports. Here we reported that, under the control of ie1 promoter from white spot syndrome virus, hemagglutinin (HA) gene of H5N1 influenza virus could be efficiently expressed in both insect and mammalian cells mediated by recombinant baculovirus vectors. The HA protein, partially cleaved as in H5N1 virus, was significantly displayed on the surface of baculovirus and conferred the viral particle hemagglutination activity. Intramuscular injection of the purified HA-displaying baculovirus into mice stimulated the production of antibodies with Hemagglutination inhibition and neutralization activities against tested influenza virus. These data suggested an alternative way to apply baculovirus as an immunizing reagent against influenza virus infection.