Tan Ming-Juan, Zhang Yong-Chen, Wang Yong, Hu Wei, Liang Yue-Jin, Zhang Li
Department of Pathogen Biology, Nanjing Medical University, Nanjing 210029, China.
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 2008 Jun 30;26(3):166-9, 173.
To investigate the suppressive effect of CD4+CD25+ regulatory T cells from mice infected with Schistosoma japonicum.
BALB/c mice were infected with S. japonicum. At 6 and 13 weeks post-infection, the spleens were removed and CD4+CD25+ T cells were separated by magnetic beads. In in vitro experiments, CD4+CD25+ T Cells were cocultured with CD4+CD25- T cells. The inhibitory role of the CD4+CD25+ T cells was assessed by [3H] thymidine incorporation method and the cytokines in the cultural supernatant were detected by ELISA. In in vivo experiments, mice inoculated with irradiated cercariae of S. japonicum were adoptively transferred with CD4+CD25+ T cells isolated from the mice chronically infected with S. japonicum. The intracellular cytokine expressions of splenocytes were performed by flow cytometry, and sera IgG1 and IgG2a antibodies against irradiated cercaria antigens were detected by ELISA.
In vitro, CD4+CD25+ T cells were able to suppress the proliferation of CD4+CD25- T cells when stimulated with SEA, compared with single CD4+CD25- T cells culture (cpm 7615 +/- 1 058) (P < 0.01). Furthermore, CD4+CD25+ T cells isolated from mice chronically infected with S. japonicum presented higher suppressive efficacy (cpm 2 336 +/- 490), compared with that isolated from the acutely infected mice (cmp 4 467 +/- 144) (P < 0.05). Meanwhile, CD4+CD25+ T cells isolated from mice with the acute infection inhibited the cytokine secretion by CD4+CD25- T cells and the suppression rate was 32.0% for IL-4 (P < 0.05), 66.3% for IFN-gamma (P < 0.01) and 63.2% for IL-2 (P < 0.01), respectively, and CD4+CD25+ T cells isolated from mice with the chronic infection, the suppression rate was 28.4% for IL-4 (P < 0.05), 60.1% for IFN-gamma (P < 0.01) and 58.3% for IL-2 (P < 0.01), respectively. In vivo, IFN-gamma secretion and IgG2a antibody production of mice adoptively transferred with CD4+CD25+ T cells from the chronically infected mice were suppressed when mice were inoculated with irradiated cercariae of S. japonicum (P < 0.05).
CD4+CD25+ T cells isolated from mice infected with S. japonicum have played roles of Th1-dominant immune suppression.
研究日本血吸虫感染小鼠的CD4+CD25+调节性T细胞的抑制作用。
用日本血吸虫感染BALB/c小鼠。感染后6周和13周，取出脾脏，通过磁珠分离CD4+CD25+ T细胞。在体外实验中，将CD4+CD25+ T细胞与CD4+CD25- T细胞共培养。采用[3H]胸腺嘧啶核苷掺入法评估CD4+CD25+ T细胞的抑制作用，并用ELISA法检测培养上清中的细胞因子。在体内实验中，将感染日本血吸虫尾蚴的小鼠经辐射后，过继性转移从慢性感染日本血吸虫的小鼠中分离出的CD4+CD25+ T细胞。通过流式细胞术检测脾细胞内细胞因子的表达，并用ELISA法检测血清中针对辐射尾蚴抗原的IgG1和IgG2a抗体。
在体外，与单独培养的CD4+CD25- T细胞（每分钟计数7615±1058）相比，用SEA刺激时，CD4+CD25+ T细胞能够抑制CD4+CD25- T细胞的增殖（P<0.01）。此外，与从急性感染小鼠中分离出的CD4+CD25+ T细胞（每分钟计数4467±144）相比，从慢性感染日本血吸虫的小鼠中分离出的CD4+CD25+ T细胞具有更高的抑制效力（每分钟计数2336±490）（P<0.05）。同时，从急性感染小鼠中分离出的CD4+CD25+ T细胞抑制了CD4+CD25- T细胞的细胞因子分泌，IL-4的抑制率为32.0%（P<0.05），IFN-γ的抑制率为66.3%（P<0.01），IL-2的抑制率为63.2%（P<0.01）；从慢性感染小鼠中分离出的CD4+CD25+ T细胞，IL-4的抑制率为28.4%（P<0.05），IFN-γ的抑制率为60.1%（P<0.01），IL-2的抑制率为58.3%（P<0.01）。在体内，当给接种日本血吸虫辐射尾蚴的小鼠过继性转移来自慢性感染小鼠的CD4+CD25+ T细胞时，小鼠的IFN-γ分泌和IgG2a抗体产生受到抑制（P<）。
从感染日本血吸虫的小鼠中分离出的CD4+CD25+ T细胞发挥了以Th1为主的免疫抑制作用。
