Plasmids encoding protein aggregation domains act as molecular adjuvants for DNA vaccines.

Background: DNA vaccines provide high tolerability and safety but commonly suffer from suboptimal immunogenicity. We previously reported that a plasmid vector (pATRex), encoding the DNA sequence for the von Willebrand I/A domain of the tumor endothelial marker-8 (TEM8) when given in combination with plasmid-encoded tumor antigens acted as a powerful molecular adjuvant enhancing immunity against breast and melanoma tumors.

Aims: In the present study we addressed two unsolved issues; would the adjuvant action of pATRex extend to a DNA vaccine against infectious disease and, if so, what is the mechanistic basis for pATRex adjuvant action?

Results: Here we show in a murine malaria vaccine model that co-administration of pATRex potentiates antibody production elicited by an intramuscular injection of plasmid encoding Plasmodium yoelii merozoite surface protein 4/5 (PyMSP4/5).