Influenza virus hemagglutinin: a model for protein N-glycosylation in recombinant Escherichia coli.

Background: The hemagglutinin molecule of influenza virus is considered as an ideal model to study biological processes as well as the effect of glycosylation on the function of glycoproteins. Objectives: The large subunit of the influenza virus A/New Caledonia/20/99 (H1N1) hemagglutinin (HA1) was expressed in recombinant Escherichia coli containing the glycosylation system of Campylobacter jejuni. This viral glycoprotein contains glycosylation motifs recognized by prokaryotic and eukaryotic oligosaccharyltransferases. Methods: In order to express the hemagglutinin large subunit gene, the gene was amplified using reverse transcription polymerase chain reaction (RT-PCR), and it was cloned in pET22b for periplasmic expression. Results: Western blotting and lectin blotting bands confirmed glycosylation of the HA1 in recombinant E. coli. Conclusion: Such a successful accomplishment of hemagglutinin expression in recombinant E. coli can be used to construct carbohydrates in hemagglutinin molecules of different strains in order to produce effective antigens for vaccine and rapid diagnostic kits against new emerging viruses.