日本血吸虫感染小鼠肝肉芽肿与Th1/Th2细胞因子水平的动态变化

Dynamics of Liver Granuloma and the Relative Changes of Th1/Th2 Cytokine Levels in Mice Infected with Schistosoma Japonicum

目的 观察小鼠感染日本血吸虫后急、慢性期肝肉芽肿病变与Th1/Th2细胞因子的动态变化 ,探讨Th1/Th2在肉芽肿形成及调节中的作用。方法 采用石蜡切片 ,HE染色后观察感染小鼠肉芽肿病变 ,用ELISA双抗夹心法测定小鼠感染后 0、4、6、8和 12周血清及脾淋巴细胞IL 2、IFNγ 和IL 4水平的动态变化。结果 小鼠感染后 6周出现明显肝肉芽肿病变 ,8周肉芽肿反应达高峰 ;12周则明显缩小 ;感染小鼠血清及脾淋巴细胞的Th1细胞因子IL 2和IFNγ 在感染后 4～ 6周开始上升 ,8周达高峰 ,随后下降 ;而Th2细胞因子IL 4在感染后 8周时迅速上升且随感染时间延长而明显升高。结论 Th1细胞因子IL 2和IFNγ 与血吸虫卵肉芽肿的诱导和形成密切相关 ,而Th2细胞因子IL 4可抑制Th1细胞因子在血吸虫病慢性期虫卵肉芽肿自发性免疫调节中起重要作用。

Purpose: To oberve the dynamics of liver granuloma and the relative changes of Th1/Th2 cytokine levels in mice infected with Schistosoma japonicum, and investigate the role of Th1/Th2 in S. japontcum granuloma formation and regulation. Methods: Liver granuloma measurement were performed by histological examination and the ELISA were used for the quantitative determination of IL-2, IFNγ and IL-4 in murine serum and spleen lymphocyte culture medium at 0,4,6,8,10 and 12 wk after infection. Results: At 6 wk liver granuloma formation appeared and at 8 wk liver granuloma peaked. After 12 wk liver granuhoma diminished obviously. Meanwhile, at 4 - 6 wk IL-2, IFNγ and IL-4 began to rise, at 8 wk the levels of Th1 cytokines IL-2 and IFNγ peaked and then declined, and at 8 wk the levels of Th2 cytokines IL -4 were rapidly enhanced and increased obviously with a prolongation of the infection duration. Conclusions: The Th1 cytokines IL-2 and IFNγ were correlated well with S. japonicum granuloma formation and vigour, and the Th2 cytokines IL-4 might play an important role in down-regulating egg granuloma reaction at chronic schistosomiasis by inhibiting the Th1 cytokines.