Improved Humoral Immunity and Protection against Influenza Virus Infection with a 3d Porous Biomaterial Vaccine

Area of Science:

• Biomaterials Science
• Immunology
• Vaccine Development

Background:

• Emerging pathogens necessitate novel vaccine platforms for robust humoral immunity and neutralizing antibody generation.
• Current adjuvants like aluminum hydroxide (Alum) have limitations, driving the need for improved vaccine delivery systems.

Purpose of the Study:

• To develop and evaluate antigen-loaded hydrogel microparticles as a vaccine platform to enhance humoral immunity.
• To investigate the impact of material properties on immune response and protective efficacy.

Main Methods:

• Fabrication of antigen-loaded hydrogel microparticles with varying polymer concentrations.
• Assessment of immune responses in mice, including CD4+ T follicular helper (Tfh) cell and germinal center (GC) B cell populations.
• Evaluation of antigen-specific antibody titers and protection against influenza virus challenge.

Main Results:

• Hydrogel microparticles induced robust cellular humoral immune responses, comparable to Alum.
• Increased material stiffness correlated with superior antigen-specific antibody titers.
• Vaccination with inactivated influenza virus-loaded microparticles conferred protection against high-dose viral challenge.

Conclusions:

• Tuning the physical and chemical properties of hydrogel microparticles enhances adjuvanticity for improved humoral immunity.
• This flexible platform can be adapted for various antigens, including inactivated viruses, to generate high-affinity antibodies and long-lasting immunity.