Expression of pseudorabies virus glycoproteins E and B based on vaccinia virus.

Pseudorabies virus (PRV) glycoprotein E (gE) and glycoprotein B (gB) exhibit strong immunogenicity and serve as essential antigens for differentiating infected from vaccinated animals (DIVA). However, the expression and purification of gE and gB are often very difficult due to glycosylation. To evaluate the ability of poxvirus vectors to express glycosylated proteins, this study expressed PRV gE and gB via recombination vaccinia virus (VACV) vectors and assessed their biological activity. Genes encoding gE or gB were cloned and inserted into plasmid transfer vectors and integrated into VACV via homologous recombination. Recombinant viruses were purified through sucrose density gradient ultracentrifugation, followed by target protein purification via affinity chromatography. Rabbits were immunized with purified gE or gB proteins and boosted with the corresponding recombinant viruses (rVACV-gE or rVACV-gB). Post-boost antibody responses were significantly greater in both the gE and gB groups than in the control group. Antibodies obtained six weeks post-immunization showed binding affinity for wild-type PRV gE and gB. These results demonstrated that poxvirus vectors enable efficient, high-yield expression of complex viral glycoproteins.