华支睾吸虫感染大鼠血清和胆汁抗体水平动态变化分析

Dynamic changes of antibody level in the serum and bile juice of rats infected and reinfected with Clonorchis sinensis

目的观察大鼠初感染和再感染华支睾吸虫后血清和胆汁中抗体的动态变化,探讨抗体反应与抵抗再感染的关系。方法健康SD大鼠.经口感染100个囊蚴/只,4周后部分SD大鼠给予吡喹酮治疗,虫卵阴转后再感染100个囊蚴。于初感染和再感染前后不同时间收集SD大鼠血清和胆汁,剖检动物,收集并计数虫体,计算虫体回收率和抵抗率。用ELISA法检测胆汁和血清中抗体。结果再感染健康SD大鼠后12周虫体回收率<5%,抵抗率>90%,免疫抑制鼠对再感染无抵抗。血清特异IgG于初感染后第2周上升,抗虫治疗后4周与治前水平相当,再感染后无显著变化。血清总IgE于初感染第2周后缓慢上升.治疗后下降至正常,再感染后第1周现高峰,免疫抑制鼠IgE水平降低。血清总IgA于初感染后1周出现一高峰.再感染后无显著变化。血清特异性IgA于初感染第1周起上升,治疗后明显下降,再感染后无显著变化。初感染鼠胆汁IgA于第1周稍有上升后很快下降,治疗后大幅度上升,再感染后在高水平波动。免疫抑制鼠胆汁IgA保持在较低水平。结论再感染早期血清IgE快速上升以及治疗后胆汁中高IgA水平可能与大鼠抵抗华支睾吸虫再感染有关。

Objective For probing into the mechanism of rat resistant to reinfection with Clonorchis sinensis, the antibody responses in serum and bile juice of rats were observed. Methods SD rats were primarily infected with 100 metacercaria of C. sinensis per rat. After 4 weeks some infected rats were treated with praziquantel and then reinfected with the same number of metacercaria. Sera and bile samples were collected before and after different time of primary infection and reinfection and the worms were recoveried from the livers. The antibodies in serum and bile were detected with ELISA. Results Worm recovery rates at 12 weeks post-infection in healthy reinfected rats were less than 5% with resistant rate over 90% while immunosuppression rats showed no resistance. Specific IgG in serum elevated from the second week of infection and did not change significantly in cured rats or during reinfection. Total IgE in serum increased slowly from 2 week post primary infection and decreased to normal level at 4 weeks post but increased quickly at the first week of reinfection and no IgE response was observed in the immunosuppressed rats. Specific IgA in serum elevated from 1 week post infection but decreased to normal in cured rats. Total IgA in bile did not increase in primary infection but was quite high in cured rats and fluctuated at high level in reinfection. Conclusion Quick IgE response in the early reinfection and high level of IgA in bile of cured rats may have important roles in the resistance.