Expression and Evaluation of a Novel HAV-VP1 and HBS-Ag Fusion Protein for Potential Applications in Immunization and Diagnosis

Hepatitis A virus (HAV) is a causative agent of acute hepatitis in humans, infecting more than one million individuals every year, including both symptomatic and asymptomatic infections. The currently available preventive vaccines for HAV are based on either wild-type or live-attenuated virus strains, which can contribute to the costliness of the vaccination process. Therefore, it may be worthwhile to explore the potential of subunit vaccines that utilize immunogenic viral products.

This study presents the results of a novel recombinant protein production study that employed the native structures of HAV-VP1 and HBs-Ag. The fusion protein underwent comprehensive characterization to evaluate its potential applications in diagnostics and immunization. The truncated recombinant protein, HAV-VP1 (position 99-259 aa) -HBs-Ag, was successfully expressed in the Escherichia coli BL21-DE3 system.

The recombinant protein, with a molecular weight of 46 kDa, was evaluated using SDS-PAGE gel electrophoresis and confirmed by western blotting. The fusion protein was successfully detected in serum samples positive for HBV or HAV using anti-HBs and anti-VP1 antibodies. Additionally, it elicited a potent humoral response in BALB/c mice.

The novel recombinant protein described in this study has the potential to serve as a bivalent vaccine against HAV and HBV infections. The next step involves evaluating the immunogenicity and safety profile of the protein.