Expression and immunogenic characterization of recombinant gp350 for developing a subunit vaccine against Epstein-Barr virus

Abstract

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that is linked to the development of various malignancies. There is an urgent need for effective vaccines against EBV. EBV envelope glycoprotein gp350 is an attractive candidate for a prophylactic vaccine. This study was undertaken to produce the truncated (codons 1-443) gp350 protein (gp3501-443) in Pichia pastoris and evaluate its immunogenicity. The gp3501-443 protein was expressed as a secretory protein with an N-terminal His-tag in P. pastoris and purified through Ni-NTA chromatography. Immunization with the recombinant gp3501-443 could elicit high levels of gp3501-443-specific antibodies in mice. Moreover, gp3501-443-immunized mice developed strong lymphoproliferative and Th1/Th2 cytokine responses. Furthermore, the recombinant gp3501-443 could stimulate CD4+ and CD8+ T cell responses in vaccinated mice. Collectively, these findings demonstrated that the yeast-expressed gp3501-443 retained strong immunogenicity. This study will provide a useful source for developing EBV subunit vaccine candidates.