CD4+ CD25+ Foxp3+及CD4+ CD25- Foxp3+调节性T细胞在小鼠衰老过程中的变化规律

目的分析小鼠脾细胞中CD4⁺ CD25⁺ Foxp3⁺及CD4⁺ CD25^- Foxp3⁺调节性T细胞随小鼠年龄增长的变化, 探讨调节性T细胞与衰老的关系。方法2个月(青年)、6个月(中年)和15个月(老年)小鼠各5只，无菌取脾脏制备单个脾细胞悬液，首先用PECy5-CD4抗体和FITC-CD25抗体进行细胞表面染色，PBS洗涤后，经打孔液和固定液处理，最后用PE-Foxp3抗体进行核内染色，并用流式细胞仪检测CD4⁺调节性T细胞的变化。结果脾脏中CD4⁺ T细胞的数量在不同年龄小鼠间变化不大，CD4⁺ T细胞中CD4⁺ CD25⁺ T细胞的数量也无明显改变，但随小鼠年龄的增长CD4⁺ Foxp3⁺ T细胞的数量明显升高，15个月小鼠CD4⁺ Foxp3⁺ T数量高达（16.83±0.44）%，明显高于2个月和6个月小鼠（P＜0.01）。随着年龄的增长CD25⁺ Foxp3⁺调节性T细胞数量逐渐减低，CD25⁺ Foxp3⁺ T细胞在15个月和6个月小鼠脾细胞中的数量明显低于2个月小鼠（P＜0.05）；而CD25^- Foxp3⁺ 调节性T瞎胞的数量随着年龄的增长持续升高(P＜0.01)；随着年龄的增长小鼠脾细胞中CD4⁺ CD25⁺ Foxp3⁺ T细胞与CD4⁺ CD25^- Foxp3⁺ T细胞的比值呈下降趋势。结论小鼠衰老过程中CD4⁺ CD25⁺ Foxp3⁺ T细胞的数量明显下降，而CD4 ⁺CD25^- Foxp3⁺ T细胞的数量明显上升，提示这两群调节性T细胞亚群在小鼠衰老中可能发挥不同作用。

Changes of CD4+ CD25+ Foxp3+ and CD4+ CD25- Foxp3+ regulatory T cells in aging of mice

To explore the relationship between T cells and aging. Methods15 mice were divided into three groups: the 2-month (young), the 6 -month (middle aged) and the 15-month (aged) groups. Splenocyte suspensions were prepared in sterile conditions. Surface marks were stained with the PECy5-conjugated CD4 antibody and the FITC-conjugated CD25 antibody. After being washed with PBS, cells were treated with stiletto fluid and fixation fluid and stained with the PE-conjugated Foxp3 antibody. The proportion of CD4⁺ regulatory T cells was analyzed by flow cytometry. ResultsThe proportion of CD4⁺ T cells and CD4⁺ CD25⁺ /CD4⁺ T cells in splenocytes had no significant differences among the three groups. But the proportion of CD4⁺ Foxp3⁺ T cells was significantly elevated with an increase of age. The proportion of CD4+ Foxp3+ T cells was(16.83±0.44)% in aged mice, which was obviously higher than young and middle-aged mice（P＜0.01）, and the proportion of CD25⁺ Foxp3⁺ regulatory T cells gradually decreased. The proportion of CD25⁺ Foxp3⁺ T cells in the aged group or in middle-aged mice was lower than that in young mice（P＜0.05）.　However, the proportion of CD25^- Foxp3⁺ regulatory T cells continuously elevated with an increase of age. Its proportion in aged mice was significantly higher than that in middle-aged mice(P＜0.01), and that in middle-aged mice was higher than that in young mice(P＜0.01). In addition, the ratio of CD4⁺ CD25⁺ Foxp3⁺ T to CD4⁺ CD25^- Foxp3⁺ T cells showed a decreasing tendency with an increase of age. ConclusionThe proportion of CD4⁺ CD25⁺ Foxp3⁺ T cells shows an decreasing tendency with an increase of age, however, the proportion of CD4⁺ CD25^- Foxp3⁺ T cells shows an increasing tendency. These suggest that the two regulatory subsets play different roles in aging.