A DNA vaccine coding for glycoprotein B of pseudorabies virus induces cell-mediated immunity in pigs and reduces virus excretion early after infection

Glycoproteins B (gB), gC and go of pseudorabies virus (PRV) have been impli cated as important antigens in protective immunity against PRV infection. A s cell-mediated immunity plays a major role in this protective immunity, we determined the significance of these glycoproteins in the actual induction of cell-mediated immunity. We vaccinated pigs with plasmid DNA constructs coding for gB, gC or go and challenged them with the virulent NIA-3 strain of pseudorabies virus. Vaccination with plasmid DNA coding for gB induced t he strongest cell-mediated immune responses including cytotoxic T cell resp onses, whereas plasmid DNA coding for go induced the strongest virus neutra lising antibody responses. Interestingly, vaccination with gB-DNA reduced v irus excretion early after challenge infection while vaccination with gC-DN A or gD-DNA did not. This is the first study to demonstrate that DNA vaccination induces cytotox ic T cell responses in pigs and that cell-mediated immunity induced by vacc ination with gB-DNA is important for the reduction of virus excretion early after challenge infection. (C) 2000 Elsevier Science B.V. All rights reser ved.