Immunization against PR8 influenza virus with chitosan-coated ISCOMATRIX nanoparticles.

Chitosan-coated ISCOMATRIX nanoparticles co-administrated with PR8 influenza virus were successfully developed via a lipid film hydration method to evaluate their in vivo immuniadjuvant potential in immunization against influenza. The prepared ISCOMATRIX (ISC) and chitosan-coated ISCOMATRIX (ISC-CIT) showed a particle size of 171 and 233 nm with a zeta potential of -9.47 and +5.65, respectively. Furthermore, ISC-CIT formulations were co-administered with PR8 antigen (PR8-ISC-CIT) and their immunogenicity was investigated after intranasal and intramuscular immunization of BALBc/mice. The PR8-ISC formulation elicited more IFN-γ after intranasal or intramuscular administration compared with PR8-ISC-CIT formulation. In contrast, although PR8-ISC-CIT formulation administered by intranasal route secreted more IFN-γ, it significantly decreased the IgG2a/IgG1 ratio and a less immune response was induced. Altogether, the ISC-adjuvanted influenza PR8 antigen could be considered as a powerful intramuscular antigen delivery system for producing a variety of prophylactic and therapeutic vaccines.