细粒棘球蚴Eg14-3-3重组疫苗诱导小鼠细胞因子的动态观察

Dynamic investigation of cytokines in mice immunized with Echinococcus granulosus

目的观察重组疫苗Eg14-3-3免疫后及厡头蚴攻击感染后不同阶段6种细胞因子的动态变化,在分子水平上研究重组疫苗的免疫学机制。方法研究采用r Eg14-3-3和PBS分别免疫两组ICR小鼠,每隔两周免疫1次,在第3次免疫后4周,活的原头蚴攻击感染,在免疫后和攻击感染后不同时间静脉采血分离血清,ELISA法对血清中IL-2、IFN-γ、TNF-α、IL-4、IL-5、IL-10水平变化进行检测。结果 r Eg14-3-3组小鼠6种细胞因子水平在免疫后和感染后高于PBS对照组,其中Th1类细胞因子IL-2、IFN-γ、TNF-α水平在第10周(急性感染期)达到峰值,30周后(感染慢性期)迅速降低并较长时间维持在高于免疫前水平,Th2类细胞因子IL-4、IL-5、IL-10免疫后水平相对无明显升高,在第18周后逐渐升高,30周达到峰值后逐渐降低,较长时间维持在相对较高水平;PBS组Th1类细胞因子在感染前无明显升高,原头蚴攻击感染后迅速升高,在第18周达到峰值后逐步降低,在相对较长时期维持相对较高水平。Th2类细胞因子IL-4、IL-5、IL-10维持在较低水平,攻击感染后水平缓慢升高,IL-4在18周达到峰值后降低并长期维持相对较高水平,IL-5、IL-10在第30周水平达到峰值后逐步降低并长期维持相对较高水平。结论 r Eg14-3-3可诱导有效的Th1型细胞介导的细胞免疫和Th2型细胞介导的体液免疫,两种反应共同参与重组疫苗诱导的免疫保护作用。

Objective To investigate the dynamic changes of IL-2, IFN-γ, TNF-α, IL-4, IL-5 and IL-10 in mice immunized with Eg14-3-3 and then challenged by Echinococcus granulosus protoscoleces. Methods ICR mice were subcutaneously immunized every two weeks for altogether three times with rEg14-3-3, followed by the challenge with Echinococcus granulosus protoscoleces intraperitoneally four weeks after the third immunization. The PBS control group mice were operated in the same way. We collected mouse serum from tail vessel at different time points after immunization and challenge. The serum levels of IL-2、IFN-γ、TNF-α、IL-4、IL-5、 and IL-10 were examined with enzyme-linked immunosorbent assay. Results The levels of the six cytokines were higher after immunization and challenge infection in rEg14-3-3 group than in PBS control group. The immunized mice generated a great deal of Thl cells, namely, IL-2, IFN-γ and TNF-α, after immunization and showed a peak at week 10 （acute infection phase）, then the level decreased rapidly at week 30 （chronic infection phase）, and maintained a high level for a long time. In contrast, Th2 cells like IL-4, IL-5 and IL-10 kept a low level until week 18, peaked at week 30, and then decreased gradually but maintained a relatively high level for a long time. For PBS control group, IL-2, 1FN-γ and TNF-α did not increase obviously before infection, but increased rapidly after challenge infection and peaked at week 18; then the level decreased gradually and maintained a high level for a long time. On the other hand, IL-4, IL-5 and IL-10 kept a low level, but increased gradually after challenge infection. IL-4 peaked at week 18 while IL-5 and IL-10 peaked at week 30, and then they all decreased slowly but maintained a relatively high level for a long time. Conclusion Eg14-3-3 can induce significant antibody response by Th2 cells and cell-mediated immunity response by Thl cells. Both Thl and Th2 cells participate in the anti-echinococcusis protective immunity.