Development of Multifunctional Aminated Gelatin Nanoparticles as an Adjuvant Antigen-Carrier for Mucosal Immunization

The mucosal immune system is the first line of defense against invasion by foreign pathogens. Mucosal vaccine is considered an ideal vaccination strategy capable of inducing both mucosal (secretory IgA) and systemic immune responses. It is a critical challenge for developing effective mucosal antigen delivery system to elicit effective immune responses. Gelatin is a biodegradable and biocompatible macromolecule. Cationic gelatin nanoparticles can readily be prepared by simply introducing amine residues to the carboxyl groups of gelatin as ideal carriers for more efficient protein delivery. Oligodeoxynucleotide that contain CpG motif (CpG-ODN) can trigger an immunomodulatory cascade that involves both cell-mediated and humoral immune responses. In this project, we will develop of multifunctional aminated gelatin nanoparticles as an adjuvant antigen-carrier for mucosal immunization. We will investigate preparation of multifunctional aminated gelatin nanoparticles, protein/antigen loading efficiency, in vitro and in vivo mechanisms, and the application in cancer immunotherapy. During the first year, CpG-ODN will be incorporated into the gelatin nanoparticles with surface modification of cationic molecules. By modifying the particle size and surface charge, the optimal component of the nanoparticle will be performed. The characteristics, stabilities, loading ratio of protein/antigen will be analyzed. The antigen delivery efficiency, maturation and cytokine production of dendritic cells will also be investigated after cultured with multifunctional aminated gelatin nanoparticles in vitro. During the second year, mice will be immunized with multifunctional aminated gelatin nanoparticles via intranasal routes. The cellular uptake by antigen-presenting cells in nasopharynx-associated lymphoid tissue (NALT) will be analyzed. The antigen-specific antibodies and subtype antibodies of serum and nasal wash fluid will be analyzed. Further, mice will be immunized and the activities of cytotoxic T cells will be illustrated and the therapeutic efficacy of multifunctional aminated gelatin nanoparticles against tumor will also be investigated.