Synthetic Multicomponent Nanovaccines Based on the Molecular Co-assembly of β-Peptides Protect against Influenza A Virus

Peptides with the ability to self-assemble into nanoparticles have emerged as an attractive strategy to design antigen delivery platforms for subunit vaccines. While toll-like receptor (TLR) agonists are promising immunostimulants, their use as soluble agents is limited by their rapid clearance and off-target inflammation. Herein, we harnessed molecular co-assembly to prepare multicomponent cross-β-sheet peptide nanofilaments exposing an antigenic epitope derived from the influenza A virus and a TLR agonist. The TLR7 agonist imiquimod and the TLR9 agonist CpG were respectively functionalized on the assemblies by means of an orthogonal pre- or post-assembly conjugation strategy. The nanofilaments were readily uptaken by dendritic cells, and the TLR agonists retained their activity. Multicomponent nanovaccines induced a robust epitope-specific immune response and completely protected immunized mice from a lethal influenza A virus inoculation. This versatile bottom-up approach is promising for the preparation of synthetic vaccines with customized magnitude and polarization of the immune responses.