日本血吸虫感染小鼠CD4^+CD25^+Foxp3^+ T细胞的动态变化及其意义

Dynamic changes in CD4^+CD25^+Foxp3^+ regulatory T cells in mice infected with Schistosoma japonicum

目的分析小鼠脾细胞中CD4+CD25+Foxp3+T细胞在日本血吸虫感染后的动态变化,探讨CD4+CD25+Foxp3+T细胞与血吸虫感染的关系。方法常规逸出尾蚴,感染小鼠24只,随机分为4组,同时设立阴性对照。感染后第3、6、9、12周分批处死小鼠,取脾脏制备单细胞悬液,用FITC-CD4和PE-CD25单抗进行细胞表面染色,洗涤后,经打孔液和固定液处理,再用PE-cy5-Foxp3抗体进行核内染色,流式细胞仪检测CD4+CD25+Foxp3+调节性T细胞的变化。结果小鼠感染血吸虫后第3、6、9、12周脾细胞中CD4+CD25+Foxp3+T细胞百分率分别为(2.57±0.13)%、(1.77±0.21)%、(1.10±0.05)%和(0.83±0.04)%,呈逐步下降趋势(P<0.05);CD4+CD25-Foxp3+T细胞百分率分别为(0.25±0.007)%、(0.27±0.13)%、(0.38±0.15)%和(0.35±0.07)%,差异无统计学意义(P>0.05)。未感染小鼠脾细胞中CD4+CD25+Foxp3+T细胞百分率分别为(2.63±0.09)%、(3.13±0.47)%、(2.78±0.19)%和(2.82±0.12)%,差异无统计学意义(P>0.05);CD4+CD25-Foxp3+T细胞百分率分别为(0.35±0.10)%、(0.43±0.13)%、(0.30±0.08)%和(0.31±0.09)%,差异无统计学意义(P>0.05)。感染组与未感染组相比从第6周开始脾细胞中CD4+CD25+Foxp3+T细胞百分率显著下降(P<0.05),CD4+CD25-Foxp3+T细胞百分率差异无统计学意义(P>0.05)。结论CD4+CD25+Foxp3+T细胞在日本血吸虫感染中具有免疫抑制作用,与血吸虫虫卵肉芽肿慢性病变具有相关性。

Objective To analyze the dynamics of CD4^＋CD25^＋Foxp^3＋ T ceils in spleen cells of mice infected with ce cariae of Schistosoma japonicum and investigate the relationship between CD4^＋CD25^＋Foxp^3＋ T ceils and the infection of S. japonicum Methods Twenty-four mice were infected by cercariae and divided into 4 groups, and 24 mice were uninfected. At 3, 6, 9, and 12 weeks after infection, the mice were sacrificed. A spleen single cell suspension was prepared and flow cytometry analysis was performed on the CD4^＋CD25^＋Foxp^3＋ T cells of spleen cells stained with anti- FITC CD4, PE-CD25, or PE CY5-FOXP3 monoclonal antibody. Results At 3, 6, 9, and 12 weeks, the percentage of CD4^＋ CD25^- Foxp^3＋ T cells in infected mice was （2.57±0.13） %, （1.77±0.21） %, （1.10±0.05） %, and （0.83＋0. 04） %, indicating a gradual decline （P〈0.05）. The percentage of CD4^＋ CD25^- Foxp^3＋ T cells were （0.25±0. 007） %, （0.27±0. 13） %, （0.38±0. 15） %, and （0.35±0.07） %, indicating that the difference was not statistically significant（P 〉0.05）. For uninfected mice, the percentage of CD4^＋ CD25^- Foxp^3＋ T cells was （2.63±0.09）%, （3. 13±0.47）%, （2. 78±0.19） % , and （2. 82±0. 12）%（P〉0.05）, and the percentage of CD4^＋ CD25^- Foxp^3＋ T cells was （0.35± 0.10）%, （0.43±0.13）%, （0. 30±0. 08） % , and （0.31±0.09）%（P〉0.05）; differences in both were not statistically significant. Compared to uninfected mice, the CD4^＋CD25^＋Foxp^3＋ T cells in infected mice declined markedly 6 weeks after infection（P〈0.05）, but the difference in CD4^＋ CD25^- Foxp^3＋ T cells was not statistically significant（P〉0.05）. Conclusion This study suggested that CD4^＋ CD25^＋ Foxp^3＋ T cells act to suppress the immune system during infection with S. japonicum and are associated with chronic egg granuloma.