Intradermal DNA immunization of mice against influenza A virus using the novel PowderJect ® system

The PowderJect ® system, a device that uses compressed helium gas to accelerate microscopic particles into the skin, was used as a delivery system for DNA vaccines to elicit a virus-specific cytotoxic T cell response (CTL) in mice. Transient expression of β-galactosidase (β-Gal) was observed in the epidermis when gold particles coated with β-Gal expression plasmid were delivered to mouse skin with the device. When DNA encoding the nucleoprotein gene (NP) of influenza A virus was used to coat gold particles, a strong and specific anti-NP CTL response was elicited by immunizations with nanogram amounts of the NP DNA vector. This study shows the potential for application of the PowderJect ® system to intradermal delivery of DNA in order to elicit an immune response.