Self-assembled nanovaccine based on apoferritin: Development and vaccine regimen evaluation

Apoferritin-based systems have been explored last decade for their potential as vaccine delivery for viral diseases. The nanosized properties of an apoferritin-based system could increase immunogenicity, contribute to antigen stability, and reduce the vaccines' adverse effects. The mutated extracellular portion of the epidermal growth factor receptor (EGFRvIII peptide, PEPvIII) can be applied as a specific tumoral antigen due to rare expression in normal cells. In this context, the present study proposed the development and the immunogenicity evaluation of an apoferritin-based system (AFt) to deliver a peptide vaccine for an antitumoral purpose. We developed a formulation with different PEPvIII:AFt ratios and during the association efficiency analysis, identified the dependence between the AFt concentration and the PEPvIII association percentage in the formulation. Besides, differences in the immune responses against EGFRvIII were observed depending on the PEPvIII concentration due to the different association efficiencies. Finally, the humoral immune response results showed a high antibody production against AFt, which might affect the immunological tolerance. Collectively, this study establishes the PEPvIII:AFt formulation process and highlights the determinant factors for guaranteeing vaccine safety and efficacy.