Mannose-based VZV-gE protein self-adjuvanted hydrogel vaccine enhances immune response.

Herpes zoster (HZ) is an infectious disease caused by the varicella zoster virus. Vaccination, especially recombinant protein vaccine, is an effective preventive method. However, the protein vaccine is easy to degrade, and its immunogenicity is weak, combined adjuvants and delivery systems can improve protein vaccines immune efficacy. In this work, a self-adjuvanted hydrogel vaccine (OHH/gE) was prepared by oxidized mannan and hydroxypropyl chitosan, which could slowly release antigen to continuously stimulate the body to improve immune level and effectively prevent and treat Hz. The results showed that this hydrogel (OHH) was injectable, able to gel in situ and slowly release antigens, protecting them from degradation. OHH, as a toll like receptor (TLR-4 agonist), causes the upregulation of costimulatory molecules (CD11c, CD80, CD86). After subcutaneous administration, OHH/gE significantly increased the antibody levels (IgG, IgG2a, IgG1) as well as the cellular immune levels (IL-2, IL-4, IL-10, IFN-γ). In addition, OHH/gE promoted lymphocyte activation and prolonged germinal centers, which was associated with high body fluid levels. Overall, this study designed a novel antigen delivery platform with adjuvant function, which showed great potential in the immunotherapy of diseases.