Polycationic HA/CpG Nanoparticles Induce Cross-Protective Influenza Immunity in Mice

Area of Science:

• Immunology
• Nanotechnology
• Vaccinology

Background:

• The intranasal (i.n.) route is optimal for respiratory disease vaccines.
• Polycationic polyethylenimine (PEI) can form nanoparticles with viral glycoproteins.

Purpose of the Study:

• To fabricate and evaluate PEI-HA and PEI-HA/CpG nanoparticles for i.n. influenza vaccination.
• To investigate their immunogenicity, protective efficacy, and immune response profiles.

Main Methods:

• Fabrication of PEI-hemagglutinin (HA) and PEI-HA/CpG nanoparticles.
• Intranasal vaccination regimen in mice.
• Assessment of immune responses, including antibody production and cellular immunity.
• Evaluation of heterologous cross-protection.

Main Results:

• Nanoparticles significantly enhanced HA immunogenicity and provided cross-protection.
• PEI-HA/CpG nanoparticles induced robust, balanced IgG1/IgG2a responses with enhanced neutralization and ADCC.
• Both local and systemic cellular immunity were augmented and sustained for six months.
• PEI and CpG demonstrated synergistic effects on immune responses.

Conclusions:

• PEI-HA/CpG nanoparticles represent a potential cross-protective influenza vaccine candidate.
• Polycationic PEI nanoplatforms are promising for mucosal vaccine development.