Synergistic effect of gene-electro transfer and adjuvant cytokines in increasing the potency of hepatitis C virus genetic vaccination

Background: Gene electro-transfer (GET) increases DNA uptake and expression by muscle cells following intramuscular plasmid injection. This technology has been used to increase the production of therapeutic proteins, such as cytokines and growth factors, and to improve immunization efficiency following the injection of antigen-encoding plasmids. Methods: Hepatitis C virus (HCV) E2 and cytokine encoding plasmids were co-injected in the mouse quadriceps with or without GET and vaccination outcome was monitored by analysis of antigen-specific cellular-mediated or antibody-mediated immunity. Results: GET co-injection of cytokine-encoding and HCV E2-encoding plasmids strongly enhanced T- or B-cell responses to various levels, depending on the particular combination used. Conclusions: We propose that a cocktail of plasmids followed by GET can be the most efficient and fine-tunable approach for genetic immunization.