Expression of a Novel Fusion Recombinant Protein VP8-VP1 in Escherichia coli as a Rota-HAV Vaccine Candidate

Rotaviruses (RV) and hepatitis A virus (HAV) are pathogens responsible for more than 2 million hospitalizations, especially in developing countries, due to transmission through the fecal-oral route. Currently, there are several FDA-approved RV and HAV vaccines available which are based on killed or attenuated viruses. However, these vaccines often have side effects and low efficacy in eliciting specific immunity. Therefore, the design of a vaccine based on a recombinant protein, composed of RV and HAV antigens seems essential.

We used bioinformatics tools to design and analyze the properties, predict the structure and evaluate the function, immunogenicity, antigenicity, and truncated sequences of HAV VP1 and RV VP8 as a dual vaccine platform. The predicted epitopes were expressed as a recombinant protein in Escherichia coli BL21 where half of the VP1 protein was fused with the Rota protein VP8 using  pET24a expression vector,.

The expressed protein was confirmed by SDS-PAGE and Western blotting. Subsequently, high-scale expression, purification, refolding and determination of the protein concentration (~2.4 µg/µl) were obtained.

Upon completion of the future immunogenicity evaluation through injection into mice, the present fusion protein can potentially serve as a candidate for a recombinant vaccine against both RV and HAV infections.