Abstract:

Objective To study the early immune activation and dynamic changes between the attenuated cercariae immunized mice and the normal infected mice. Methods The dendritic cell surface molecules CD11c and T cell surface molecule CD25 expression differences and CD3+CD25+/CD3+ T ratio of the early spleen and/or lung of the attenuated cercariae immunized mice and normal mice were assayed and compared by FCM and IHC, and the immune activation and dynamics of T cells were analyzed. Results CD3+CD25+/CD3 + T ratio in the spleen cells 7 days post-infection in the immunized group and the normal infected group were （19.52±3.65）% and （22.12±3.24）%, respectively; the rates of 14 days and 21days post-infection were （28.73±3.94）%, (13.68±3.64）% and（26.43±0.4）%, and (14.42±2.24）%, respectively. The expressions of CD11c+DC in the lung of the two groups were (1.05±0.16)%, (0.96±0.15)%, (1.34±0.15)%, (1.09±0.17)%, (1.49±0.14)%, (0.97±0.16）%, respectively; the expressions in the spleen were （2.05±0.26）%, (1.95±0.18)%, (2.24±0.25)%, (2.17±0.25)%, (2.18±0.26)%, and (2.06±0.18）%, respectively, in the 7, 14 and 21 days post-infection. The expressions of CD25+T cells in the lung of the two groups were （1.24±0.13）%, (1.17±0.16)%; (1.48±0.11)%, (1.25±0.13)%, (1.55±0.14)%, and (0.97±0.12）%, respectively; the expressions in the spleen were （3.25±0.22）%, (2.93±0.20)%, (4.57±0.23)%, (3.69±0.24)% and (4.28±0.24)%, (3.86±0.26）%, respectively, in the 7, 14 and 21 days post-infection.. The CD3+CD25+/CD3 + T rate in the infection control group was significantly higher than that in the cercariae attenuated group, while 14, 21 days post-infection the rates of the attenuated group were significantly higher than those in the normal control group. In the 7, 14 and 21 days post-infection, the lung tissue of the attenuated cercariae immunized mice raised more CD1lc+DC and CD25+ T cells than that of the normal infected mice did. Conclusions In 7 and 14 days post-infection, the activation of T cells of the immune group and the activation of pulmonary dendritic cells are higher than those in the control group, suggesting that attenuated cercariae in the lungs can raise more antigen presenting cells and their activation.

Key words: Schistosoma japonicum, Attenuated cercariae, Dendritic cells, T cells, Immune response, Mouse

摘要：

目的 比较辐照致弱日本血吸虫尾蚴免疫小鼠与正常感染小鼠早期免疫活化程度及其动态变化差异。方法 采用流式细胞术（FCM）和免疫组织化学（IHC）方法比较辐照致弱尾蚴免疫小鼠与正常感染小鼠早期脾组织和/或肺组织中树突状细胞（DC）表面分子CD11c、T细胞表面分子CD25表达差异及脾细胞和外周血中CD3+CD25+/CD3+T细胞比例，分析T细胞免疫活化程度及其动态变化。结果 在感染后7 d，脾细胞中的CD3+CD25+/CD3+T细胞比例致弱尾蚴免疫组为（19.52±3.65）%，明显低于正常感染组的（22.12±3.24）%；而在第14、21天，致弱尾蚴免疫组这一比例分别为（28.73±3.94）%和（26.43±0.4）%，均高于正常感染组的（13.68±3.64）%和（14.42±2.24）%。在攻击感染后7、14、21 d，致弱尾蚴免疫组与正常感染组小鼠在肺组织中的CD11c+ DC表达率分别为（1.05±0.16）%和（0.96±0.15）%、（1.34±0.15）%和（1.09±0.17）%、（1.49±0.14）%和（0.97±0.16）%，脾组织中CD11c+ DC表达率分别为（2.05±0.26）%和（1.95±0.18）%、（2.24±0.25）%和（2.17±0.25）%、（2.18±0.26）%和（2.06±0.18）%。在攻击感染后7、14、21 d，致弱尾蚴免疫组与正常感染组小鼠在肺组织中CD25+T细胞表达率分别为（1.24±0.13）%和（1.17±0.16）%、（1.48±0.11）%和（1.25±0.13）%、（1.55±0.14）%和（0.97±0.12）%，脾组织中CD25+T细胞表达率分别为（3.25±0.22）%和（2.93±0.20）%、（4.57±0.23）%和（3.69±0.24）%、（4.28±0.24）%和（3.86±0.26）%，紫外线辐照致弱尾蚴免疫小鼠较正常感染小鼠在攻击感染后第7、14、21天能在肺组织募集更多的CD1lc+ DC并激活更多的CD25+T细胞。结论 致弱日本血吸虫尾蚴免疫小鼠在攻击感染后14、21 d，小鼠体内T细胞激活程度和肺部DC活化程度均高于正常感染组，提示致弱尾蚴在肺部可募集更多抗原递呈细胞并使之活化。

关键词: 日本血吸虫, 致弱尾蚴, 树突状细胞, T细胞, 免疫应答, 小鼠