Intranasal DNA Vaccine for Protection against Respiratory Infectious Diseases: The Delivery Perspectives

Xu, Yingying; Yuen, Pak-Wai; Lam, Jenny Ka-Wing

In a recent study, Raghwanshi et al. investigated a sophisticated DC targeted chitosan nanoparticle system for nasal DNA immunization against SARS-CoV [122] . The chitosan nanoparticles were surface functionalized with ligands to achieve DC selective targeted delivery. DEC-205 receptor is C-type lectin receptor found in DCs for recognition and uptake of pathogens. The authors developed a bifunctional fusion protein (bfFp) vector which consists of truncated core-streptavidin fused with anti-DEC-205 single chain antibody. The core-streptavidin arm of the fusion protein binds with biotinylated chitosan nanoparticles while anti-DEC-205 scFv imparts targeting specificity to DC DEC205 receptor. Plasmid DNA encoding nucleocapsid protein of SARS-coV was loaded into the chitosan nanoparticles. Following intranasal administration of the DC targeted nanoparticles in mice, the levels of mucosal IgA and systemic IgG against nucleocapsid proteins were significantly enhanced, whereas no mucosal and systemic immune responses were detected when the naked plasmid DNA was intranasally administered. The results showed that such DC targeting delivery system could be a promising strategy for low-dose nasal DNA vaccines.