In vivo electroporation enhances immunogenicity and protection against influenza A virus challenge of an M2e-HSP70c DNA vaccine

There is a growing concern regarding continuous risk of emerging a new influenza pandemic. It is highlighted the need for novel vaccination techniques that quickly and effectively employed to respond to such threats. Although, DNA vaccine is a simple and effective approach to induce antigen specific immune responses, their potency requires further improvement. DNA vaccine encoding conserved antigen of influenza virus could provide protection in various animal models. Therefore, we constructed a plasmid vector encoding M2e-HSP70c sequences, pcDNA/MHc, as a candidate for universal influenza vaccine. The expression of newly constructed vectors was verified by transient transfection of mammalian cells (HEK293T cell line) and western blot analysis using commercial antibodies. Mice were injected subcutaneously (s.c.) by the help of electroporation (IEP) in the footpad area and boosted without IEP with 100 μg of constructed vector. Furthermore, the potency of this construct to provoke humoral immune responses and its protectivity against lethal dose of viral challenge were evaluated. Based on our study, the fusion construct was immunogenic in mice and was able to confer both protection against lethal challenge of H1N1 virus and reduce viral load in lung homogenates of the infected mice.