Glycyrrhiza uralensis Polysaccharide Gold Nanoparticles as Antigen Carriers and Potential Adjuvant to DC Vaccines.

Background

Cervical cancer is the fourth leading cause of death among women worldwide, with human papillomavirus (HPV) identified as a major contributing factor. This study investigates the immunostimulatory activity and antigen delivery efficiency of Glycyrrhiza uralensis polysaccharide gold nanoparticles (GUPS-AuNPs) and assesses the antitumor efficacy of an HPV dendritic cell (DC) vaccine using GUPS-AuNPs as a delivery system.

Methods

GUPS-AuNPs were synthesized via a green reduction method and characterized using advanced techniques, including SEM, EDS, TEM, UV, and FT-IR spectroscopy. DCs served as the primary experimental model, with flow cytometry employed to evaluate the immunostimulatory activity and antigen delivery effectiveness of GUPS-AuNPs. Additionally, a TC-1 tumor-bearing mouse model was established to assess the immunostimulatory and antitumor effects of the HPV-DC vaccine facilitated by GUPS-AuNPs.

Results

The synthesized GUPS-AuNPs exhibited a particle size of 120.77 ± 3.13 nm, a surface charge of -11.9 ± 2.1 mV, and excellent stability. Flow cytometry analysis demonstrated that GUPS-AuNPs significantly enhanced DC maturation and promoted T cell proliferation. Furthermore, antigen delivery experiments revealed that GUPS-AuNPs improved the antigen capture capabilities of DCs. Confocal imaging confirmed that GUPS-AuNPs extended the intracellular retention time of antigens. In vivo studies showed that the HPV-DC vaccine formulated with GUPS-AuNPs as carriers effectively suppressed tumor growth, elevated the populations of CD4+ T and CD8+ T cells in the spleen, and induced a robust antigen-specific immune response.

Conclusions

GUPS-AuNPs effectively enhance DC maturation and antigen delivery, significantly boosting the adaptive immune response triggered by HPV vaccines and leading to the inhibition of tumor progression. This research introduces GUPS-AuNPs as a novel, safe, and efficient antigen delivery platform with promising potential for vaccine development.