Influenza specific functional antibodies in mannose conjugated chitosan-based influenza nanovaccine vaccinated pigs 2086

Abstract Description We investigated functional antibodies in pigs vaccinated intranasally with mannose conjugated and unconjugated chitosan nanoparticle based whole inactivated H1N2 swine influenza A virus (SwIAV) (Chit-SwIAV-NPs and mChit-SwIAV-NPs) vaccine (Exp#1); mChit-SwIAV-NPs plus STING agonist (S100) encapsulated (mChit-SwIAV+S100-eNPs) or surface adsorbed (mChit-SwIAV+S100-sNPs) vaccine (Exp#2). We used chimeric MDCK cells stably expressing influenza hemagglutinin (HA) gene of SwIAV H1N1 to delineate HA specific antibody-dependent cell cytotoxicity (ADCC) and antibody-mediated complement-dependent cell cytotoxicity (CDC) functions. Our results revealed that serum of Exp #1 collected at day post challenge (DPC) 6 displayed specific ADCC activity, while both DPC0 and DPC6 collected serum samples of Exp #2 had ADCC function. The CDC mediating antibody function was relatively higher in commercial multivalent SwIAV and mChit-SwIAV+S100-eNPs vaccinates. Different types of nanovaccine candidates induced various levels of cross reactive ADCC and CDC antibodies, while commercial vaccine elicited profoundly high virus neutralizing and HA inhibition antibodies. In conclusion, we delineated ADCC, CDC, HA inhibition, avidity and virus neutralizing SwIAV-specific functional antibodies in intranasal vaccinated pig samples. Our data may provide insights into various effector functions of antibodies induced by candidate intranasal vaccines that contribute to influenza specific immunity in pigs. Funding Sources USDA NIFA: 2019-67015-29814 and 2022-67015-36349 Topic Categories Veterinary and Comparative Immunology (VET)