Muscle specific versus ubiquitous expression of Gag based HIV-1 DNA vaccines: a comparative analysis.

Most studies on DNA-based immunization have used viral promoters to drive antigen expression. In this study, we analyzed the properties of the commonly used CMV promoter, the tissue specific murine muscle creatine kinase (MCK) promoter as well as a hybrid MCK/CMV promoter regarding promoter activity and tissue specificity in vitro. Furthermore, the efficiency of inducing HIV-1 Gag specific immune responses in vivo following intramuscular immunization of naked DNA containing a codon optimized synthetic gene was compared. Although antibody titers and cellular immune responses using the MCK construct were slightly reduced as compared to conventional CMV based vector modules, the utilization of nonviral promoters may add significantly to the safety of future DNA vaccines.