CONSTRUCTION OF MOSAIC HBC PARTICLES PRESENTING CONSERVATIVE FRAGMENTS OF M2 PROTEIN AND HEMAGGLUTININ OF INFLUENZA A...

Virus-like HBc particles formed as a result of the self-assembly of the nuclear antigen of the hepatitis B virus can be used as a highly immunogenic carrier for the presentation of foreign epitopes when creating recombinant vaccines. We use this vehicle to create influenza vaccines based on the conservative antigens of the influenza virus, the extracellular domain of the transmembrane protein M2 (M2e) and the fragment of the second subunit of hemagglutinin (HA2). Presentation on the surface of HBc particles should improve the immunogenicity of these peptides. Using genetic engineering techniques, we obtained a fusion protein in which the HA2 sequence is attached to the N-terminus of the HBc antigen, and the M2e peptide is included in the immunodominant loop region exposed on the surface of HBc particle. The hybrid protein expressed in Escherichia coli and purified under denaturing conditions formed virus-like HBc particles after refolding in vitro. Refolding of this protein in the presence of a previously denatured HBc antigen carrying no inserts resulted in formation of mosaic virus-like particles. The developed method will allow construction of mosaic HBc particles carrying different target epitopes of the influenza virus by combining the corresponding modified HBc proteins, which opens the possibility of creating vaccines with a wider spectrum of protection.