Expression of hemagglutinin protein from the avian influenza virus H5N1 in a baculovirus/insect cell system significantly enhanced by suspension culture

Background: Prevention of a possible avian influenza pandemic necessitates the development of rapid diagnostic tests and the eventual production of a vaccine. Results: For vaccine production, hemagglutinin ( HA1) from avian influenza H5N1 was expressed from a recombinant baculovirus. Recombinant HA1 was expressed in monolayer or suspension culture insect cells by infection with the recombinant baculovirus. The yield of rHA1 from the suspension culture was 68 mg/ l, compared to 6 mg/ l from the monolayer culture. Immunization of guinea pigs with 50 mu g of rHA1 yielded hemagglutinin inhibition and virus neutralization titers of 1: 160 after two times vaccination with rHA1 protein. Conclusion: Thus, the production of rHA1 using an insect suspension cell system provides a promising basis for economical production of a H5 antigen.