Recombinant Proteins Containing Hepatitis C Virus Protein Epitopes Fused with One, Two, or Three Copies of a Lipopeptide Form Nanoparticles of Different Sizes and Differing in Immunological Properties

Abstract Objective: Viral hepatitis C is a widespread infectious disease that often follows a prolonged chronic course. The development of a prophylactic and therapeutic vaccine is an urgent task to reduce the incidence of chronic hepatitis C. The aim of this study was to generate recombinant proteins with enhanced immunogenicity capable of eliciting an effective immune response, which could serve as a basis for designing a therapeutic vaccine. Methods: Using genetic engineering methods, we constructed recombinant proteins containing lipopeptide sequences derived from Neisseria meningitidis, a T-helper epitope of the viral core protein, and cytotoxic epitopes of the NS4B protein. The proteins were purified by metal affinity chromatography on Ni-NTA-agarose. Dynamic light scattering and electron microscopy were used to assess nanoparticle formation. Results and Discussion: A triple repeat of the lipopeptide sequence within the recombinant protein structure leads to the formation of nanoparticles approximately 50–100 nm in size. Immunological analysis performed on splenocytes from immunized mice and activated human peripheral blood lymphocytes showed that nanoparticle formation significantly enhances the immunogenicity of the NS4B epitopes. Conclusions: The obtained data may be used in the development of a therapeutic vaccine against the hepatitis C virus.