[Dynamic changes in PD-1, TLR3, and TLR4 surface expression on peripheral blood mononuclear cells in chronic hepatitis C patients undergoing peg-IFNalpha-2a plus ribavirin combination therapy].

OBJECTIVE: To investigate the dynamic changes in expression of programmed death (PD)-1, Toll-like receptor (TLR)3, and TLR4 on the surface of peripheral blood mononuclear cells (PBMCs) in patients with chronic hepatitis C (CHC) that occur in response to pegylated-interferon alpha-2a (peg-IFNalpha-2a) plus ribavirin (RBV) combination therapy, and to analyze the relation to achievement of sustained virological response (SVR). METHODS Twenty-three CHC patients and 10 healthy controls were enrolled in the study. All CHC patients underwent 48 weeks of combination therapy with peg-IFNalpha-2a (180 microg, subcutaneous injection, once weekly) plus RBV (15 microg/kg, oral, once daily). Total PBMCs were isolated from both groups (CHC patients at treatment week 0, 12, 24, and 48 and post-treatment week 24; controls at enrollment) and subjected to flow cytometric analysis of PD-1, TLR3, and TLR4 surface expression. In addition, serum levels of alanine aminotransferase (ALT) and hepatitis C virus (HCV) RNA levels were analyzed by enzymatic assay and the AmpliPrep/COBAS (Roche) nucleic acid amplification test, respectively. SVR was defined as undetectable levels of HCV RNA at post-treatment week 24. Intergroup differences were assessed by one-way ANOVA. RESULTS: The expression ratios of PD-1, TLR4 and PD-1: TLR4 on PBMCs were significantly higher in CHC patients before therapy than in the healthy controls (45.20 +/- 7.12% vs. 16.82 +/- 4.13%, 58.45 +/- 15.13% vs. 21.09 +/- 2.89%, and 35.54 +/- 7.69% vs. 14.12 +/- 2.89%; all P < 0.05). In contrast, the expression ratios of TLR3 and PD-1:TLR3 were slightly, but not significantly, higher in CHC patients before therapy than in the healthy controls (P > 0.05). During the course of peg-IFNalpha-2a plus RBV combination therapy, the expression ratios of PD-1 and TLR4 on PBMCs showed a decreasing trend, while TLR3 expression showed an increasing trend. Furthermore, CHB patients who achieved SVR at post-treatment week 24 had a significantly different expression ratio of PD-1 and TLR3 than those who did not achieve SVR (P < 0.05). CONCLUSION: Surface expression of PD-1, TLR4, and PD-1:TLR4 is up-regulated in the total PBMCs of CHC patients. Peg-IFNalpha-2a plus RBV treatment-induced suppression of HCV replication results in a significant reduction in PD-1 and TLR4 expression on the surface of PBMCs, but a remarkably elevated level of TLR3 expression. The dynamic change in PD-1 and TLR3 expression on PBMCs that occurs during antiviral therapy may be related to achievement of SVR.

[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].

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). CONCLUSION: The demethylation pattern of PD-1 gene in promoter region is associated with the PD-1 expression on PBMC in CHB patients.