Production and evaluation of a novel multi-epitope bivalent vaccine against Echinococcus multilocaularis metacestode

Abstract

Alveolar Echinococcosis is a globally widespread zoonotic disease caused by the larval stage of Echinococcus multilocularis (E.m.) and is seriously harmful to human health. In our previous studies, we found that Em-EMY162 has good protective and therapeutic effects against E.m. and the dominant epitopes of Em-EMY162 and Em-TSP3 were also identified. In this study, a mucosal immunity multi-epitope vaccine LTB-ETBM targeting both Em-EMY162 and Em-TSP3 was designed and constructed. Furtherly the immunogenicity and immunoprotection were evaluated in E.m. infected mice model. LTB-ETBM could induce the mice generating high levels of specific IgG against Em-EMY162 and Em-TSP3. Furtherly a Th1/Th2 mixed lymphocyte responses to LTB-ETBM was identified. Moreover, the LTB-ETBM significantly inhibited the formation of cysts in mice challenged with 1000 E.m. protoscoleces. In a therapeutic mouse model injected intraperitoneally with 1000 protoscoleces, vaccination with LTB-ETBM using either Freund's or CpG as an adjuvant significantly decreased the growth of protoscoleces and the formation of cysts. LTB-ETBM may be efficacious for activating the immune system and for use as a prophylactic or therapeutic agent against E.m. infection.