Abstract: 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.

Key words: Lupus erythematosus, systemic, DNA Methylation, Perforin