Intranasal vaccines can induce protective immune responses at the mucosa surface entrance, preventing the invasion of respiratory pathogens. However, the nasal barrier remains a major challenge in the development of intranasal vaccines. Herein, a transmucosal nanovaccine based on cationic fluorocarbon modified chitosan (FCS) is developed to induce mucosal immunity. In our system, FCS can self-assemble with the model antigen ovalbumin and TLR9 agonist CpG, effectively promoting the maturation and cross-presentation of dendritic cells. More importantly, it can enhance the production of secretory immunoglobin A (sIgA) at mucosal surfaces for those intranasally vaccinated mice, which in the meantime showed effective production of immunoglobulin G (IgG) systemically. As a proof-of-concept study, such a mucosal vaccine inhibits ovalbumin-expressing B16-OVA melanoma, especially its lung metastases. Our work presents a unique intranasal delivery system to deliver antigen across mucosal epithelia and promote mucosal and systemic immunity.
Keywords: chitosan nanocomplexes; intranasal vaccine; mucosal immunity; mucosal penetration; sIgA.