The Extent of the Uptake of Plasmid Into the Skin Determines the Immune Responses Induced by a DNA Vaccine Applied Topically Onto the Skin

This study explored the enhancement of immune responses from a DNA vaccine applied topically to the skin by inducing hair follicles into the anagen stage. Three methods were tested: hair plucking, retinoic acid (RA), and O-tetradecanoylphorbol-13-acetate (TPA). Hair plucking was found to be the most effective method for enhancing antibody responses, as it facilitated better uptake or retention of the DNA in the application area. In contrast, RA and TPA treatments caused more skin damage and severe local inflammation. The study concluded that the extent of plasmid DNA uptake in the skin correlated with the strength of the antibody responses.