Induction of protective T-helper 1 immune responses against Echinococcus granulosus in mice by a multi-T-cell epitope antigen based on five proteins

In this study, we designed an experiment to predict a potential immunodominant T-cell epitope and evaluate the protectivity of this antigen in immunised mice. The T-cell epitopes of the candidate proteins (EgGST, EgA31, Eg95, EgTrp and P14-3-3) were detected using available web-based databases. The synthesised DNA was subcloned into the pET41a+ vector and expressed in Escherichia coli as a fusion to glutathione-S-transferase protein (GST). The resulting chimeric protein was then purified by affinity chromatography. Twenty female C57BL/6 mice were immunised with the antigen emulsified in Freund's adjuvant. Mouse splenocytes were then cultured in Dulbecco's Modified Eagle's Medium in the presence of the antigen. The production of interferon-γ was significantly higher in the immunised mice than in the control mice (> 1,300 pg/mL), but interleukin (IL)-10 and IL-4 production was not statistically different between the two groups. In a challenge study in which mice were infected with 500 live protoscolices, a high protectivity level (99.6%) was demonstrated in immunised BALB/C mice compared to the findings in the control groups [GST and adjuvant (Adj) ]. These results demonstrate the successful application of the predicted T-cell epitope in designing a vaccine against Echinococcus granulosus in a mouse model.

Changes of splenocyte subsets in mice immunized with recombinant Bb-Eg95-EgA31 vaccine against Echinococcus granulosus / 中国人兽共患病学报

To investigate the weight reduction of hydatid cyst and level of splenocyte subsets in mice immunized with recombinant Bifidobacteria bifidum (Bb) Bb-Eg95-EgA31 vaccine of Echinococcus granulosus (Eg) and challenged with Eg protoscoleces,BALB/c mice were immunized with the vaccine subcutaneously,intramuscularly,intranasally or orally.Then the mice were challenged with 50 Eg protoscoleces on 8~(th) week after vaccination and killed on 25~(th) week after infection.The weight of hydatid cyst was measured and the reduction of the weight was calculated.The spleens were collected for splenocytes preparation.CD_4~+ and CD_8~+ T cells were determined by flow cytometry(FCM),and the blank vector,Bb or MRS were set as control.The hydatid cyst weight was reduced by 45.33%,41.33%,70.67% and 62.67% respectively for the 4 immunization groups.Number of CD_4~+ and CD_8~+ subsets in the immunization groups was more than that in the control group.CD_4~+ and the ratio of CD_4~+/CD_8~+ in the intranasal or oral immunization group was much higher than that in the subcutaneous or intramuscular immunization group.It's concluded that CD_4~+ and CD_8~+T cells may play an important role in the protection induced by recombinant Eg95-EgA31 vaccine of Eg.In addition,intranasal and oral vaccinations could be the better ways for immunization.

Dynamic observation on Th1/Th2 type immune response in mice immunized with recombinant Bb-Eg95-EgA31 vaccine of Echinococcus granulosus / 重庆医科大学学报

Objective:To dynamically observe changes of Th1/Th2 type immune responses in mice immunized with recombinant Bifidobacteria bifidum(Bb)-Eg95-EgA31 vaccine of Echinococcus granulosus(Eg).Methods:BALB/c mice were vaccinated by 5?108 colony forming unit(CFU) orally and 5?105CFU intranasally respectively.Mice were killed on week 2,4,6,8,10,12,14,16,18 and 20 after immunization respectively,sera were collected to measure the levels of IgG,its subclasses and IgE by enzyme linked immunosorbent assay(ELISA);Spleens were removed to determine the levels of IFN-?,IL-12,TNF-?and IL-10 of splenocyte culture supernatant by ELISA.Results:Oral immunization mice showed higher levels of IgG,IgG2a,IgG2b,IgG1,IgG3 and IgE on the 8～10th week,2～20th week,2～20th week,4～8th week,6～12th week and 10th week respectively,while IFN-?,IL-12,TNF-?and IL-10 on the 2～16th week,2～12th week,2～6th week and 4～12th week post vaccination respectively;Intranasal immunization mice showed higher levels of IgG,IgG2a,IgG2b,IgG1,IgG3 and IgE during the 4～10th week,4～20th week,2～20th week,2～12th week,4～12th week and 10～12th week respectively,while IFN-?,IL-12,TNF-?and IL-10 on the 2～8th week,2～12th week,2～8th week and 6～16th week post vaccination respectively.Conclusion:Mixed Th1/Th2 type immune responses may be induced in mice immunized with the recombinant Bb-Eg95-EgA31 vaccine of Echinococcus granulosus.Oral and intranasal inoculation are two better immune routes,and the former is better than the latter.