Protein-based nanoparticles in cancer vaccine development

Peptide and protein-based cancer vaccines usually fail to elicit efficient immune responses against tumors. However, delivery of these peptides and proteins as components within caged protein nanoparticles has shown promising improvements in vaccine efficacy. Advantages of protein nanoparticles over other vaccine platforms include their highly organized structures and symmetry, biodegradability, ability to specifically functionalize at three different interfaces (inside, outside, and between subunits in macromolecular assembly), and ideal size for vaccine delivery. In this review, we discuss different classes of virus-like particles and caged protein nanoparticles that have been used as vehicles to deliver and increase the interaction of cancer vaccine components with the immune system. We review the effectiveness of these protein nanoparticles towards inducing and elevating specific immune responses, which are needed to overcome the low immunogenicity of the tumor microenvironment. TEXT FOR GRAPHICAL ABSTRACT: In this review, we discuss several different protein-based nanoparticles as delivery vehicles to increase the interaction of cancer vaccine components (e.g., adjuvants, tumor-associated antigens) with the immune system. These important components can be efficiently internalized and processed by dendritic cells, which then present the antigen to the T cells for specific T cell responses that lead to specific tumor lysis and elimination. The elevated immune responses that are elicited by these nanoparticle vaccines are advantageous to overcome the low immunogenicity of the tumor microenvironment.