DNA vaccines

Background and Objectives: Humoral and cellular immune responses to protein antigens can be efficiently primed by nucleic acid or DNA vaccination. In DNA-based vaccination, immunogenic proteins are expressed with correct post translational modification, conformation or oligomerization; this ensures t he integrity of epitopes that stimulate neutralizing antibody (B cell) resp onses. DNA (or RNA) immunization is exceptionally potent in stimulating T c ell responses because antigenic peptides are efficiently generated in (endo genous or exogenous) processing pathways (without interference by viral pro teins) from intracellular or extracellular protein antigens expressed after transient in vivo transfection. Both features are difficult to achieve wit h recombinant subunit vaccines produced in eukaryotic or prokaryotic expres sion systems. The current state of vector designs, strategies for delivery of DNA vaccines, priming humoral and cellular immune responses by DNA vacci nes, experimental strategies facilitated by DNA vaccines, unique advantages of DNA vaccination, experience of DNA vaccination in preclincal animal mod els and clinical trials, and potential risks of DNA vaccination are discuss ed. Excellent reviews on DNA-based vaccination have been published recently [1-3].