Enhancement of antigen specific humoral immune responses after delivery of a DNA plasmid based vaccine through a contact-independent helium plasma

Non-viral in vivo delivery of DNA, encoding for specific proteins, has traditionally relied on chemical or physical forces applied directly to tissues. Physical methods typically involve contact between an applicator/electrode and tissue and often results in transient subject discomfort. To overcome these limitations of contact-dependent delivery, a helium plasma source was utilized to deposit ionized gasses to treatment/vaccination sites without direct contact between the applicator and the tissues. The study reported here evaluated the efficacy of this strategy as an effective method to administer DNA vaccines. Balb/C mice were vaccinated with a DNA plasmid expressing an HIVgp120 envelope glycoprotein either with or without co-administration of helium plasma or electroporation. The results indicated, for the first time, the potential efficacy of helium plasma delivery for the induction and enhancement of antigen specific immune responses following DNA vaccination.