SLE患者T淋巴细胞穿孔素基因启动子区域甲某化状态的探索

Methylation status of perforin gene promoter in T cells of patients with systemic lupus erythematosus

目的探讨系统性红斑狼疮(SLE)T淋巴细胞穿孔素基因启动子区域DNA甲基化状态及其在发病机制中的作用。方法分离9例活动期SLE患者和7例正常人对照外周血CD4^+与CD8^+T细胞,并分别提取DNA。采用亚硫酸氢钠-测序法对CD4^+与CD8^+T细胞穿孔素基因启动子区域DNA甲基化水平进行检测。结果在穿孔素基因启动子区域,正常对照组CD4^+T细胞平均甲基化水平显著高于CD8^+T细胞(P<0.05)。活动期SLE患者CD4^+T细胞平均甲基化水平显著低于正常对照组(P<0.05),而CD8^+T细胞与正常对照组的差异则无统计学意义(P>0.05)。结论活动期SLE患者的CD4^+T淋巴细胞的穿孔素基因启动子区域处于低甲基化状态。

Objective To investigate the methylation status of perforin gene promoter in T cells of systemic lupus erythematosus （ SLE ）. Methods Peripheral blood CD4^＋ and CD8^＋ T cells of 9 patients with active SLE and 10 healthy control subjects were isolated with a magnetic cell sorting system （MACS）. Genomic DNA was extracted from the isolated cells. Bisulfite DNA sequencing was performed to determine the methylation status of perforin gene promoter. Results In healthy control subjects, the average methylation index of perforin gene promoter was significantly higher in CD4^＋ T cells than in CD8^＋ T cells （ 0.49 vs 0.25, P 〈 0.01 ）. The average methylation index of perforin gene promoter in CD4^＋ T cells from patients with active SLE was significantly lower than that in the control group （ 0.28 vs 0.49, P 〈 0.01 ）, whereas no significant difference was found between the two groups in that in CD8^＋ T cells （ 0.29 vs 0.25, active SLE vs control, P 〉 0.05 ）. Conclusion The results suggest that perforin gene promoter in CD4^＋ T cells from patients with active SLE is significantly hypomethylated.