title: [Demethylation pattern of PD-1 gene in promoter region is associated with the PD-1 expression on peripheral blood mononuclear cells in chronic hepatitis B patients].
abstract: OBJECTIVE
  To observe the expression variations and influencing factors of programmed death one (PD-1) and DNA demethylation of PD-1 promoter on peripheral blood mononuclear cells (PBMCs) in chronic hepatitis B (CHB) patients and further investigate the relationship between the demethylation pattern of PD-1 gene in promoter region and the PD-1 expression on PBMC in CHB patients.
  
  
  METHODS
  A total of 162 subjects, including 144 CHB patients and 18 healthy blood donors, were enrolled. The expression of PD-1 on PBMCs was detected by flow cytometry. And the serum HBV markers, HBV DNA load and liver function were also measured. DNA of PBMCs was treated with sodium bisulfite; the PD-1 promoter fragments were amplified by polymerase chain reaction (PCR) and then transformed into Escherichia coli. Positive clones were selected for sequencing and the methylation status of fragments of PD-1 promoter was examined.
  
  
  RESULTS
  With the PD-1 expression in normal controls (10.8% ± 4.4%) as a baseline level, the expression of PD-1 in CHB patients significantly increased. In CHB patients, the serum expression of PD-1 in PBMCs from patients with positive HBeAg (27.1% ± 18.4%) was much higher than that from those with negative HBeAg (19.6% ± 15.6%). And the expression level of PD-1 was not correlated with serum HBV DNA load and serum level of alanine aminotransferase. The results of bisulfite genomic sequencing showed that demethylation probability of some CG points in PD-1 promoter region (-601, -553, -538, -483, -463, -317 bp) were significantly correlated with PD-1 expression level (P < 0.05).
  
  
  CONCLUSIONS
  The demethylation pattern of PD-1 gene in promoter region is associated with the PD-1 expression on PBMC in CHB patients.
authors: Department of Infectious Diseases, Central South University, Changsha, China.
authors: Min
authors: M
authors: Zhang
authors: Xin-qiang
authors: XQ
authors: Xiao
authors: Su-fang
authors: SF
authors: Liu
authors: Yun-sheng
authors: YS
authors: Liang
authors: Mi-lin
authors: ML
authors: Peng
authors: Yun
authors: Y
authors: Xu
authors: Guo-zhong
authors: GZ
authors: Gong
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D019175:DNA Methylation; D004279:DNA, Viral / Q000097:blood; D005260:Female; D019694:Hepatitis B, Chronic / Q000097:blood*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D061026:Programmed Cell Death 1 Receptor / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D055815:Young Adult
chemical_list: D004279:DNA, Viral; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor