Efficient antigen cross-presentation through coating conventional aluminum adjuvant particles with PEI

Classical aluminum adjuvant is a deficient antigen carrier for cross-presentation and cross-priming of CD8⁺ cytotoxic T cells. Our previous research has demonstrated that cross-presentation efficiency significantly increased when antigens are conjugated covalently to α-Al₂O₃ nanoparticles. Here we found that coating conventional aluminum adjuvants with polyethyleneimine (PEI) could enhance antigen cross-presentation of DCs (dendritic cells) in vitro and in vivo. PEIs exerted differential effects on antigen cross-presentation. These findings provided an alternative approach to promote the rapid translation of alumina nanoparticles adjuvants into clinical application.