Chiral Aluminum Oxyhydroxide Supraparticles as Adjuvants

Area of Science:

• Vaccinology
• Immunology
• Materials Science

Background:

• Aluminum-based adjuvants are widely used but have limitations in stimulating cellular immunity.
• Developing novel adjuvants that enhance both humoral and cellular immune responses is crucial for effective vaccines.

Purpose of the Study:

• To synthesize and evaluate chiral aluminum oxyhydroxide supraparticles (AlOOH SPs) as novel vaccine adjuvants.
• To investigate the mechanisms underlying the adjuvant activity of these chiral AlOOH SPs.

Main Methods:

• One-pot hydrothermal synthesis of chiral AlOOH SPs using cysteine enantiomers.
• Assessment of dendritic cell (DC) maturation and antigen cross-presentation.
• In vivo studies using ovalbumin (OVA) and H9N2 influenza virus antigens.
• Mechanistic studies involving Toll-like receptor 2 (TLR2) and NLRP3 inflammasome activation.

Main Results:

• L-AlOOH SPs showed superior DC maturation and antigen cross-presentation compared to D-AlOOH SPs.
• L-SPs activate DCs via TLR2, enhancing NLRP3 inflammasome activation.
• In vivo, L-SPs significantly increased OVA-specific antibody titers (21.59-fold) and influenza virus antibody titers (15.28-fold) compared to commercial aluminum adjuvants.

Conclusions:

• Chiral AlOOH SPs are effective next-generation adjuvants that simultaneously enhance humoral and cellular immunity.
• These findings highlight the potential of chiral AlOOH SPs for cancer immunotherapy and pandemic preparedness.