- In this study presented at ASV, held in June in Blacksburg, Virginia, it was demonstrated that Japanese encephalitis virus (JEV) particle-based platform harboring foreign epitopes on the surface of the particle may facilitate the development of a bivalent vaccine against JEV and hepatitis C viruses.
- The researchers tested insertions at 11 positions within the JEV envelope protein.
- At three of these positions, the inserted HCV E2 neutralizing epitope was recognized by HCV1 antibody and was confirmed to be displayed on the surface of the particles.
- JEV SVPs containing HCV-neutralizing epitope (SVP-E2) at one of these sites, or at all 3 sites, were produced in 293T cells, and were purified from culture supernatant by gel chromatography.
- Sera from mice immunized with SVP-E2 inhibited infection by JEV and by trans-complemented HCV particles (HCVtcp) derived from genotype-1b, -2a, and -3a viruses, whereas sera from mice immunized with synthetic E2 peptides did not show any neutralizing activity.
- Further, sera from mice immunized with SVP-E2 neutralized HCVtcp with N415K mutation in E2, which is the escape mutant from HCV1 antibody.
- In the present study, investigators from the National Institute of Infectious Diseases in Tokyo took advantage of the properties of JEV to develop antigens for use in a HCV vaccine.
- Notably, the surface-exposed JEV envelope protein is tolerant of inserted foreign epitope, permitting display of novel antigens on JEV subviral particles (SVP).
Why this matters
- Directly acting antivirals recently have become available for the treatment of hepatitis C virus (HCV) infection, but there is no prophylactic vaccine for HCV.