Cloning and prokaryotic expression of the globular head domain of hemagglutinin antigen (HA1) of influenza A (H3N2) virus in Escherichia coli and Bacillus subtilis

Background: The influenza virus hemagglutinin is the major surface protein of the influenza A virus which is composed of HA1 and HA2 subunits. HA1 has an important role in binding of virus to cells and designing neutralizing antibodies. Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) both are known as the most useful prokaryotic hosts to express recombinant proteins. The aim of this study was to clone and express recombinant HA1 protein in E. coli and B. subtilis bacteria. Materials and Methods: HA1 gene was cloned into pET-28a vector and pHT43 shuttle vector and then, both transformed to E. coli. The recombinant plasmids were extracted and then transformed into the BL21 and WB600 as expressing hosts. After induction with isopropyl-β-d-thiogalactoside (IPTG), expressed recombinant protein was analyzed by SDS-PAGE. Finally, the expressed protein was confirmed by the Western blot. Results: HA1 gene was cloned into pET-28a vector and pHT43 shuttle vector and then, both transformed to E. coli. The recombinant plasmids were extracted and then transformed into the BL21 and WB600 as expressing hosts. After induction with isopropyl-β-d-thiogalactoside (IPTG), expressed recombinant protein was analyzed by SDS-PAGE. Finally, the expressed protein was confirmed by the Western blot. Conclusion: This study demonstrated a strategy for production and purification of recombinant protein in large scale to test as vaccine candidate against influenza and it’s potentially immunogenicity be assessed in animal models.