An mRNA vaccine encoding Chikungunya virus E2-E1 protein elicits robust neutralizing antibody responses and CTL immune responses

摘要

Arthropod-borne chikungunya virus(CHIKV)infection can cause a debilitating arthritic disease in human.However,there are no specific antiviral drugs and effective licensed vaccines against CHIKV available for clinical use.Here,we developed an m RNA-lipid nanoparticle(m RNA-LNP)vaccine expressing CHIKV E2-E1 antigen,and compared its immunogenicity with soluble recombinant protein s E2-E1 antigen expressed in S2 cells.For comparison,we first showed that recombinant protein antigens mixed with aluminum adjuvant elicit strong antigenspecific humoral immune response and a moderate cellular immune response in C57BL/6 mice.Moreover,s E2-E1vaccine stimulated 12-23 folds more neutralizing antibodies than s E1 vaccine and s E2 vaccine.Significantly,when E2-E1 gene was delivered by an m RNA-LNP vaccine,not only the better magnitude of neutralizing antibody responses was induced,but also greater cellular immune responses were generated,especially for CD8+T cell responses.Moreover,E2-E1-LNP induced CD8~+T cells can perform cytotoxic effect in vivo.Considering its better immunogenicity and convenience of preparation,we suggest that more attention should be placed to develop CHIKV E2-E1-LNP m RNA vaccine.