A novel tetrameric gp3501–470 as a potential Epstein–Barr virus vaccine

Abstract

Infectious mononucleosis and B-cell transformation in response to infection with Epstein-Barr virus (EBV) is dependent upon binding of the EBV envelope glycoprotein gp350 to CD21 on B-cells. Gp350-specific antibody comprises most of the EBV neutralizing activity in the serum of infected patients, making this protein a promising target antigen for a prophylactic EBV vaccine. We describe a novel, tetrameric gp350-based vaccine that exhibits markedly enhanced immunogenicity relative to its monomeric counterpart. Plasmid DNA was constructed for synthesis, within transfected CHO cells, of a tetrameric, truncated (a.a. 1-470) gp350 protein (gp3501-470). Tetrameric gp3501-470 induced ~20-fold higher serum titers of gp3501-470-specific IgG and >19-fold enhancements in neutralizing titers at the highest dose, and was >25-fold more immunogenic on a per-weight basis than monomeric gp3501-470. Further, epidermal immunization with plasmid DNA encoding gp3501-470 tetramer induced 8-fold higher serum titers of gp3501-470-specific IgG relative to monomer. Tetrameric gp3501-470 binding to human CD21 was >24-fold more efficient on a per-weight basis than monomer, but neither tetramer nor monomer mediated polyclonal human B-cell activation. Finally, the introduction of strong, universal tetanus toxoid (TT)-specific CD4+ T-cell epitopes into the tetrameric gp3501-470 had no effect on the gp3501-470-specific IgG response in naïve mice, and resulted in suppressed gp3501-470-specific IgG responses in TT-primed mice. Collectively, these data suggest that tetrameric gp3501-470 is a potentially promising candidate for testing as a prophylactic EBV vaccine, and that protein multimerization, using the approach described herein, is likely to be clinically relevant for enhancing the immunogenicity of other proteins of vaccine interest.

Targeting Epstein-Barr virus infection as an intervention against multiple sclerosis

“…Vaccination using this glycoprotein suppressed IM, but not latent EBV infection . A tetramer of the gp350 is under development as a future vaccine; it has increased specific immunogenicity without inducing production of polyvalent antibodies .…”

High Epstein-Barr Virus Load and Genomic Diversity Are Associated with Generation of gp350-Specific Neutralizing Antibodies following Acute Infectious Mononucleosis

“…Cellular entry is initiated by EBV gp350 glycoprotein binding to the virus host cell receptors (CR2/CD21 [6] or CR1/CD35 [7]). gp350 is thought to be a major target of neutralizing antibodies (8)(9)(10), and vaccine development efforts are focused on generating gp350-specific neutralizing antibodies (11)(12)(13)(14)(15). Most immunogens are based on sequences from lab-adapted strains, as are assays used to measure neutralizing antibodies.…”

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

“…A soluble N-terminal gp350 fragment (aa 1-470) has been shown to prevent EBV attachment to cells by blocking receptor binding (Nemerow et al 1990). A previous study supported the feasibility of using truncated gp350 protein (residues 1-470) as a promising candidate for prophylactic EBV vaccines (Cui et al 2013).…”

“…Therefore, the recombinant gp350 1-443 induced stronger lymphoproliferative responses than RVVgp150. Recombinant gp350 expressed in CHO cells (Cui et al 2013) and measles virus (Mok et al 2012) have been shown to induce significantly high-level production of IL-4 and IFN-γ. The splenocytes from gp350 1-443 -immunized mice also displayed increased production of IFN-γ, TNF-α, IL-4, and IL-10.…”

“…Until recently, various expression systems, including mammalian cells (Cui et al 2013;Young et al 2008), recombinant viruses Ragot et al 1993), Escherichia coli, and insect cells (Nuebling et al 1992), have been used to produce recombinant gp350. Recombinant gp350 proteins expressed in these systems exhibited strong immunogenicity and were promising EBV vaccine candidates.…”