Construction of Novel Plasmid Vector for DNA Immunization

DNA vaccines use eukaryote expression vectors to produce immunizing proteins in the vaccinated host and it represents a novel approach to vaccine and immuno-therapeutic development. We constructed a 2.9 kb compact plasmid vector (pVAC) which contains CMV promoter, polycloning site, BGH poly A terminator, ampicillin resistance gene and PBR322 origin. Enriched unmathlyated CpG motifs have introduced into pVAC-ISS1 and pVAC-ISS2 which are derived from pVAC for enhancing Thl responses. These plasmid DNAs rapidly induced interleukin 6 secretion in vivo. It is expected that these vectors will contribute to the DNA inoculation against infectious disease and various cancers without adjuvant.