Induction of tumor-specific immunity by multi-epitope rat HER2/neu-derived peptides encapsulated in LPD Nanoparticles

The goal of study was first to design multi-epitope peptides from the rat HER2/neu (rHER2/neu) oncogene and then to evaluate the effectiveness of these peptides encapsulated in liposome-polycation-DNA(LPD) nanoparticles (NPs) for the induction of immune response in BALB/c mice. Four multi-epitope peptides derived from the rHER2/neu were designed and different groups of mice were vaccinated with free peptides or peptides encapsulated in NPs. Two of the four tested peptides (p5 and p435), as well as their combinations with the LPD NPs induced a significantly higher IFN-gamma and CTLresponses in comparison with the control groups. Consequently, these responses led to lower tumor sizes and longer survival time in TUBO tumor mice model. Our results demonstrate that rHER2/neu-peptides (p5 and p435) and their encapsulation can induce an antigen-specific immunity. This study also presents the first attempt to evaluate the effectiveness of natural rHER2/neu-peptides containing CTL multi-epitope and encapsulated in LPD NPs.