Gold nanoparticles conjugating recombinant influenza hemagglutinin trimers and flagellin enhanced mucosal cellular immunity

We screened two facile gold nanoparticles (AuNPs) surface conjugation strategies specific to recombinant trimetric A/Aichi/2/68(H3N2) hemagglutinin (HA) and TLR5 agonist flagellin (FliC): metal chelating method shows potentially high conjugation efficacy of HA; click chemistry method shows high stability and could appropriate FliC protein conformations, thus promises better immunostimulation ability of adjuvants. Intranasal co-administration of AuNPs-HA and AuNPs-FliC can elicit stronger systemic and mucosal IgG and IgA due to the enhanced crosslinking of multiple immunoglobulins on B cell surface. Additionally, particular adjuvant could also effectively activate antigen presenting cells (APCs) for better antigen presentation and cross-presentation to improve cellular immunity response.90