Dendritic Cell Targeted Nanovaccine Delivery System Prepared with an Immune-Active Polymer.

Targeting dendritic cells (DCs), either ex vivo (Ex. Sipuleucel-T) or in vivo, for stimulating cellular immunity has been a leading approach for cancer vaccines. We have rationally engineered a nanoparticle (NP)-based delivery system for vaccines (InAc-NPs) using inulin acetate (InAc) as the polymer to target DCs. The material and the antigen-encapsulated InAc-NPs (∼190 nm in diameter) were characterized for their physicochemical properties. As a potent vaccine adjuvant, InAc-NPs activated TLR4 on multiple immune cells, including DCs and primary swine and human cells, to secrete various cytokines as detected by enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. In addition, InAc-NPs promoted the maturation of DCs as observed by a decreased phagocytic ability and enhanced capability to activate various maturation markers (MHC-I, MHC-II, CD40, and CD80) quantified using flow cytometry. In mice, the InAc-NPs produced strong serum antibody titers (total IgG, IgG1, and IgG2a) against...