Immunization with EmCRT-Induced Protective Immunity against Echinococcus multilocularis Infection in BALB/c Mice

Abstract

Alveolar echinococcosis (AE) is a severe parasitic zoonosis caused by the larval stage of Echinococcus multilocularis. The identification of the antigens eliciting acquired immunity during infection is important for vaccine development against Echinococcus infection. Here, we identified that E. multilocularis calreticulin (EmCRT), a ubiquitous protein with a Ca2+-binding ability, could be recognized by the sera of mice infected with E. multilocularis. The native EmCRT was expressed on the surface of E. multilocularis larvae as well as in the secreted products of metacestode vesicles and protoscoleces (PSCs). The coding DNA for EmCRT was cloned from the mRNA of the E. multilocularis metacestode vesicles and a recombinant EmCRT protein (rEmCRT) was expressed in E. coli. Mice immunized with soluble rEmCRT formulated with Freund’s adjuvant (FA) produced a 43.16% larval vesicle weight reduction against the challenge of E. multilocularis PSCs compared to those that received the PBS control associated with a high titer of IgG, IgG1 and IgG2a antibody responses as well as high levels of Th1 cytokines (IFN-γ and IL-2) and Th2 cytokines (IL-4, IL-5 and IL-10), produced by splenocytes. Our results suggest that EmCRT is an immunodominant protein secreted by E. multilocularis larvae and a vaccine candidate that induces partial protective immunity in vaccinated mice against Echinococcus infection.

Current status and future prospects of Echinococcus multilocularis vaccine candidates: A systematic review

“… Mice immunized with soluble rEmCRT formulated with Freund's adjuvant produced a 43.16% larval vesicle weight reduction against the challenge of E. multilocularis PSCs high titer of IgG, IgG1 and IgG2a antibody responses as well as high levels of Th1 cytokines (IFN-γ and IL-2) and Th2 cytokines (IL-4, IL-5 and IL-10. 10 ( Chen et al, 2022 ) Gp50 Eg95 B antigen - - Dog Pig Dab/2 mice 5 E. multilocularis protoscoleces (i.o.) Ag B antigen family dominated in early stage metacestodes, GP50antigen family dominated inactivated oncospheres andEg95 antigen are dominated in non-activated and activated oncospheres.…”

Basic Operative Tactics for Pulmonary Echinococcosis in the Era of Endostaplers and Energy Devices

“…Therefore, resection of a pulmonary nodule through a laparotomy and transdiaphragmatic approach has also been described in the literature [ 46 ]. Interestingly, accumulating recent research is focused on developing vaccines against E. granulosus and E. multilocularis infections [ 47 , 48 , 49 ].…”

Echinococcus multilocularis Calreticulin Interferes with C1q-Mediated Complement Activation

“…E. multilocularis used in this study was originally obtained from an infected fox in Hulunbeier Pasture of Inner Mongolia, China [ 30 ], and maintained in Kunming mice as metacestode vesicles as described [ 31 ]. The crude somatic extracts of protoscoleces (PSCs) and metacestode vesicles, and vesicle fluid protein were obtained according to our previously established protocol [ 29 ]. His-tagged recombinant Em CRT (r Em CRT) was expressed in E. coli BL21 under induction of 0.4 mM IPTG and purified by Ni-affinity chromatography (Beyotime Biotechnology, Shanghai, China) as described [ 29 ].…”

“…The crude somatic extracts of protoscoleces (PSCs) and metacestode vesicles, and vesicle fluid protein were obtained according to our previously established protocol [ 29 ]. His-tagged recombinant Em CRT (r Em CRT) was expressed in E. coli BL21 under induction of 0.4 mM IPTG and purified by Ni-affinity chromatography (Beyotime Biotechnology, Shanghai, China) as described [ 29 ].…”

“…In our previous research, we provided evidence that E. multilocularis calreticulin ( Em CRT) is expressed on the surface of E. multilocularis larvae as well as in the secreted products of protoscoleces (PSCs) and metacestode vesicles. Mice immunized with recombinant Em CRT achieved protective immunity against E. multilocularis infection [ 29 ], indicating its potential as a vaccine candidate. In the current study, we investigated whether Em CRT bound to human complement C1q that was involved in the protective immunity against host complement attack.…”