Intramuscular DNA immunization with in vivo electroporation induces antigen-specific cellular and humoral immune responses in both systemic and gut-mucosal compartments.

Mucosal delivery of antigens induces antigen-specific immune responses in both systemic and mucosal compartments, and is an attractive approach for preventing initial infection with mucosal pathogens. It has been shown that the intramuscular (i.m.) immunization of plasmid DNA by in vivo electroporation (DNA e.p.) induces both cellular and humoral immune responses in the airway-mucosal compartment as well as in the systemic compartment, implying there is a mechanism that bridges between the systemic and mucosal immune responses. An important question is whether the i.m. DNA e.p.-immunization alone can induce antigen-specific immune responses in the gut-mucosal compartment. Here, we investigated the induction of antigen-specific CD8(+) T cells and antibodies in both systemic and gut-mucosal compartments following i.m. DNA e.p.-immunization to mice. Surprisingly, the i.m. DNA e.p.-immunization induced the antigen-specific CD8(+) T cells and antigen-specific antibodies in the gut-mucosal as well as the systemic compartment. These results suggest that the i.m. DNA e.p.-immunization should be considered as an effective vaccine strategy for the prevention of gut-mucosal infectious diseases.