Role of DNA methylation in loss of CD28 on CD4+ CD28-T cells in patients with acute coronary syndrome

Abstract

Objective To investigate the role of abnormal DNA methylation in CD28 expression in patients with acute coronary syndrome(ACS). Methods CD4+ T cells were isolated with MACS.The mRNA levels of CD28 were determined by Real time-PCR after reverse transcription.The methylation status of CD28 promoter regulatory sequences was detected by bisulfite sequencing. Results Compared with normal control, the mRNA levels of CD28 in CD4+ T cells were significantly lowered in patients with ACS[Control vs ACS: (1.066±0.162)vs(0.7401±0.069), P<0.05]. The methylation status of CD28 gene promoter region was significantly higher than that of normal control[Control vs ACS: (24.47±3.17)%vs(43.33±1.52)%, P<0.05]. A negative correlation was found between CD28 promoter methylation and CD28 mRNA level(P=0.01, r=-0.579). Conclusion CD28 gene promoter hypermethylation regulated the CD28 transcriptional repression in CD4+ T cells of ACS patients.DNA methylation is involved in the formation of CD4+ CD28- T cells. Key words: Acute coronary syndrome; CD4+ CD28-T cells; DNA methylation; CD28 gene promoter