Development of Effective Cancer Vaccine Using Targeting System of Antigen Protein to APCs

To develop a novel cancer vaccine using the targeting system of antigen protein to antigen-presenting cells (APCs) for efficient and safe cancer therapy. The novel delivery system was constructed with antigen protein, benzalkonium chloride (BK), and gamma-polyglutamic acid (gamma-PGA), using ovalbumin (OVA) as a model antigen protein and evaluating its immune induction effects and utilities for cancer vaccine. BK and gamma-PGA enabled encapsulation of OVA and formed stable anionic particles at nanoscale, OVA/BK/gamma-PGA complex. Complex was taken up by dendritic cell line DC2.4 cells efficiently. We subcutaneously administered the complex to mice and examined induction of IgGs. The complex induced not only Th2-type immunoglobulins but also Th1-type immunoglobulins. OVA/BK/gamma-PGA complex inhibited tumor growth of E.G7 cells expressing OVA regularly; administered OVA/BK/gamma-PGA complex completely rejected tumor cells. The novel vaccine could be platform technology for a cancer vaccine.