日本血吸虫感染小鼠CD_4~+ T淋巴细胞协同刺激分子表达谱及其在介导Th1/Th2极化中的作用

目的观察日本血吸虫感染小鼠不同病期体内及体外培养后脾CD4+T淋巴细胞表面的协同刺激分子表达谱,探讨协同刺激分子介导Th1/Th2极化的作用。方法收集血吸虫感染后4w、7w、12w、16w和20w小鼠及正常小鼠脾CD4+T淋巴细胞,以及上述不同病期经SEA诱导72h后脾淋巴细胞培养上清,用流式细胞术检测细胞表面协同刺激分子CD80、CD86、ICOS、CD40、OX40、4-1BB及PD1表达水平,用ELISA法检测培养上清中的Th1细胞因子IFN-γ,Th2细胞因子IL-4、IL-5、IL-10、IL-13。结果血吸虫感染后小鼠脾CD4+T淋巴细胞表面CD86、ICOS、CD40和OX40的表达均随感染时间延长而上调,其中ICOS和CD86表达上调最为显著;经SEA诱导培养72h后CD86、ICOS亦显著上调表达;培养上清检测发现IFN-γ在4w时呈高表达,7w开始随感染时间延长呈下调表达;IL-4、IL-5、IL-10和IL-13的表达水平则从7w开始明显升高,IL-5的峰值出现在12w,其余均16w达高峰,致20w仍维持在较高水平。结论日本血吸虫感染小鼠CD4+T淋巴细胞协同刺激分子表达水平与Th1/Th2免疫偏移密切相关,其中ICOS、CD86在介导Th2极化中可能具有重要作用。

Effect and expression of costimulatory molecules on regulating Th1/Th2 polarization on mice infected with Schistosoma japonicum

In order to observe the effect of different costimulatory molecules from murine spleen CD＋4T lymphocyte mediating Th1/Th2 polarization,costimulatory molecules were detected in vivoand in vitroat different stages of infection.At week 4,7,12,16,20 after infection,murine spleen CD＋4 T lymphocyte were collected from infected and non-infected mice respectively.Meantime,cultured supernatants of SEA induced lymphocytes were also collected 72 hours after the collections.Expression of costimulatory molecules including CD80,CD86,ICOS,CD40,OX40,4-1BB and PD1 on the surface of CD＋4 T lymphocytes were analyzed by flow cytometry.At the same time,the cytokines IFN-γ from Th1 and IL-4,IL-5,IL-10 and IL-13 from Th2 in cultured supernatants were detected by ELISA on different stages of infection.Results showed that the expression levels of CD86,ICOS,CD40 and OX40 on CD＋4 T lymphocyte of mice infected with Schistosoma japonicumhave increased with infection time,especially the levels of ICOS and CD86 in vivo（P0.01）.Furthermore,expression levels of these 2 costimulatory molecules were dramatically up-regulated after spleen CD＋4 T lymphocyte was stimulated by SEA for 72 hours in vitro.The expression level of IFN-γwas higher at week 4 after infection and began to decrease at week 7.Whereas,the expression levels of IL-4,IL-5,IL-10 and IL-13 rose sharply at week 7.The peak value of IL-5 appeared at week 12 after infection and the others did at week 16,then they remained at a high level until week 20.These findings show that the expression levels of costimulatory molecules on CD＋4 T lymphocyte of mice infected with Schistosoma japonicumwere closely related to immune deviation of Th1/Th2.Moreover,ICOS and CD86 might play a key role in modulating polarization of Th2.