Electroporation of RNA stimulates immunity to an encoded reporter gene in mice

Electroporation is the application of high-voltage short-duration pulses to transiently permeabilize cells, permitting the cellular uptake of macromolecules, including nucleic acid. Although much attention has been focused on DNA vaccines, antigen-encoding RNA molecules may also stimulate immunity. Several methods are being examined in an effort to enhance the efficacy of nucleic acid delivery. One such method is the application of electroporation. The present study was designed to develop electroporation for use as a method of RNA delivery in conjunction with the Semliki Forest virus (SFV) RNA vector system for stimulation of immunity. Expression of SFV-based β-galactosidase and luciferase vectors was observed in the muscle after electroporation. Although some tissue damage was induced following intramuscular injection and electroporation with SFV vector RNA encoding LacZ at optimum pulse conditions, immunity to LacZ was efficiently induced. Following two immunizations, there was a higher IgG2a antibody response with the viral vector delivery and a higher IgG1 response in electroporated rSFV-LacZ RNA immunized mice.