The immune response to a DNA vaccine can be modulated by co-delivery of cytokine genes using a DNA prime-protein boost strategy

Abstract

A large-scale DNA vaccination trial was performed in sheep to investigate whether co-delivery of the cytokine genes IL-4, IL-5, IL-15, GM-CSF or IFN-γ could modulate the immune response generated to an antigen, in a DNA prime-recombinant protein boost regime. Vaccination with the recombinant EG95 protein has been shown to induce protection in sheep from Echinococcus granulosus infection, the causative agent of hydatid disease. Here we demonstrate that vaccination with DNA encoding EG95 effectively primed the humoral response, as judged by high IgG anti-EG95 titres detected one-week after a boost with the recombinant protein. However, by two weeks after protein-boost the titres in the control..