目的研究细粒棘球绦虫(Eg)重组双歧杆菌(Bh)-Eg95-EgA31融合蛋白免疫小鼠后诱导的免疫应答。方法56只SPF级雌性Balb/c小鼠随机均分7组,分别为重组Bb—Eg95-EgA31皮下注射组(A组)、肌肉注射组(B组)、鼻腔内接种组(c组)、口服灌胃组(D组)、空载体对照组(E组)、Bb对照组(F组)和Bh培养用液体培养基(MRS)对照组(G组)。免疫后8周各组鼠用50个Eg原头节攻击,攻击25周后,处死小鼠,分离细粒棘球蚴包囊并称重,计算囊重抑制率;ELISA检测血清IgG及其亚类和IgE和脾细胞上清液IL-12、IFN-γ、TNF-α和IL-10水平; MTT法测定脾细胞增殖反应;流式细胞仪检测脾CD4+和CD8+t细胞百分比和脾细胞凋亡发生率。结果重组Bb—Eg95-EgA31免疫组小鼠的囊重抑制率分别为45.33%、41.33%、70.67%和62.67%;血清IgG、IgG2a、IgG2b和IgG1水平升高,IgG3和IgE降低;脾IFN-γ、IL-12和TNF—α水平升高,IL-10水平降低;脾T淋巴细胞明显增殖;脾CD4+和CD8+T细胞显著增加;睥细胞凋亡发生率显著降低。结论细粒棘球绦虫重组Bb—Eg95-E—gA31融合蛋白能诱导小鼠产生有效的保护性免疫应答。
With the aim of setting a foundation for preparing vaccine against echinococcosis granulosus, we investigated the immune response in mice induced by recombinant Bifidobacteria bifidum (Bb)-Eg95-EgA31 fusion protein of Echinococcus granulosus (Eg). In this study, 56 SPF Balb/c mice were randomly divided into 7 groups: recombinant Bb-Eg95-EgA31 subcutaneous injection group (group A), intramuscular injection group (group B), intranasal inmmnization group (group C), oral administration group (group D), blank vector control group (group E), Bb control group (group F), and MRS control group (group G). Then all mice were challenged with 50 Eg protoscoleces in the 8th week post inoculation and sacrifced in the 25th week post-inoculation. After calculation, the hydatid cyst weight was reduced by 45.33%, 41.33%, 70.67% and 62.67% respectively in inoculation groups. Enzyme linked imnnmosorbent assay (ELISA) indicated that the sera levels of IgG, IgG2a, IgG2b and lgG1 were remarkably increased while IgG3 and IgE decreased; splenocytes were cultured and ELISA showed that, in the cultur supernatants, the levels of IL-12, IFN-γ, and TNF-α were elevated but the level of IL-10 was lowered; the proliferation of splenocytes was prominently increased confirmed by methyltetrazolium (MTT) assay. Flow cytometry (FCM) illustrated that CD4+and CD8+T cell counts were notably increased, while apoptotic rate was greatly declined. All these results proved that the recombinant Bb-Eg95-EgA31 fusion protein could induce an effective and protective immune response in mice.