Chitosan-functionalized graphene oxide as adjuvant in HEV P239 vaccine.

Searching appropriate adjuvants for vaccine is a potent method to intense the immune efficacy. In the present study, we developed a novel Hepatitis E virus (HEV) vaccine by utilizing chitosan modified nano-graphene oxide (GO-CS) as an adjuvant to support HEV antigen P239 protein (GO/CS/P239). The characterization of GO/CS/P239 was observed by atomic force microscope. The safety of GO/CS/P239 was measured by CCK-8 method, hemolysis test and acute challenge test. The anti-HEV titers and cytokines production were analyzed by double antibody sandwich ELISA. As the results showed, by contrast with a vaccine that contained only the P239 protein, GO/CS/P239 vaccine can promote immune cells to produce more IgG antibodies and cytokines, which were able to stimulate the organism to produce stronger both cellular and humoral immunity. Collectively, GO/CS/P239 particles have been demonstrated to be safe both in vitro and in vivo, and can facilitate sufficient immune response to protect organisms from virus infection, which suggested that our exploration offers a promising alternative vaccine that can control HEV infection.