PD-1 expression in HBcAg-specific CD8+ T cells of adolescents with chronic HBV infection / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the differential expression of programmed death-1 (PD-1) in the hepatitis B core antigen (HBcAg)17-28-specific CD8+ T cell subsets of adolescent patients with chronic hepatitis B virus (HBV) infection during the immune tolerant phase and the immune clearance phase.</p><p><b>METHODS</b>A total of 105 patients between the ages of 12-28 years old (mean age 17.20+/-6.35) with chronic HBV infection and 15 healthy age-matched individuals were enrolled in the study. The patients were divided into two groups according to their current status in immune clearance phase (n = 55) or immune tolerant phase (n = 50), as determined by hepatic biopsy pathology. Flow cytometry was used to detect HLA-A2 type and PD-1 expression on peripheral blood mononuclear cells (PBMC) and HBcAg17-28-specific CD8+ T cells. PD-1 mRNA levels in PBMCs were measured by reverse transcription-polymerase chain reaction (RT-PCR). Independent samples t-test was used to compare means between the two groups, and one-way ANOVA was used to compare means among multiple groups. Pearson's correlation coefficient was used to assess the significance of correlation.</p><p><b>RESULTS</b>The frequency of HBcAg18-27-specific CD8+ T cells was significantly higher in the immune clearance phase group than in the immune tolerant phase group (t = 18.08, P less than 0.01), but the expression of PD-1 on the HBcAg18-27 specific CD8+ T cells was significantly lower in the immune clearance phase group than in the immune tolerant phase group (t = 4.72, P less than 0.01). A negative correlation existed between the frequency of HBcAg18-27-specific CD8+ T cells and PD-1 expression (r = -0.463, P less than 0.01). A positive correlation existed between HBV viral load and PD-1 expression on the HBcAg18-27-specific CD8+ T cells in chronic HBV infection patients (r = 0.882, P less than 0.01), and there was a negative correlation between PD-1 expression levels on HBcAg18-27-specific CD8+ T cells and hepatic tissue inflammation score (r = -0.76, P less than 0.01). PD-1 mRNA in PBMCs was significantly higher in the immune tolerant phase group than in the immune clearance phase group (t = 30.89, P less than 0.01).</p><p><b>CONCLUSION</b>Up-regulated expression of PD-1 is associated with HBV-specific CD8+ T cells and may play a crucial role in inhibiting their function during the immune tolerance phase of chronic HBV infection in adolescents.</p>

Dynamic changes in programmed death-1 expression on the surface of T cells in chronic hepatitis C patients undergoing interferon therapy / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the dynamic changes that occur in T cell subsets, particularly involving the surface expression of programmed death 1 (PD-1), in response to pegylated (Peg)-interferon (IFN) a-2a therapy in patients with chronic hepatitis C virus (HCV) infection.</p><p><b>METHODS</b>Twenty-five patients with HCV genotype 1b chronic infection and 10 healthy controls were enrolled in the study. All the HCV patients received combination antiviral therapy of Peg-IFNa-2a (180 mug/week) plus ribavirin. At treatment weeks 0 (baseline), 4, 12, 24 and 48, the level of PD-1 protein expression on the surface of total peripheral CD8+ and CD4+ T cells was determined by flow cytometry and the level of PD-1 mRNA expression in peripheral blood mononuclear cells (PBMCs) was determined by reverse transcription-polymerase chain reaction. Independent student's t-test were used to compare mean values between the two groups, repeat measure variance analysis was used to compare mean values among multiple groups, and Pearson's correlation coefficient was used to assess correlation significance.</p><p><b>RESULTS</b>Over the course of antiviral therapy, the proportions of CD4+ T cells and CD8+ T cells, as well as the CD4+/CD8+ ratio, increased (F = 81.23, 39.28, and 7.01 respectively; all P less than 0.01). In contrast, the PD-1 protein expression frequency on CD4+ T cells and CD8+ T cells significantly declined (F = 100.11 and 158.40 respectively; all P less than 0.01). The PD-1-mRNA expression level in PBMCs was: 1.40+/-0.26 at baseline, 1.30+/-0.27 at week-4, 1.14+/-0.18 at week-12, 1.06+/-0.26 at week-24, and 0.83+/-0.25 at week-48 (F = 20.09; P less than 0.01). A positive correlation existed between the PD-1 protein expression frequencies on CD4+ T cells and CD8+ T cells and the HCV RNA load detected at baseline (r = 0.82 and 0.75 respectively; all P less than 0.01).</p><p><b>CONCLUSION</b>The ability of Peg-IFN-a-2a-based antiviral therapy to suppress HCV replication may involve reduction of PD-1 protein expression on the surface of CD8+ T cells and CD4+ T cells.</p>

Role of endoplasmic reticulum stress in alcoholic liver disease-related hepatocyte apoptosis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the role of endoplasmic reticulum stress (ERS) in alcoholic liver disease (ALD)-related hepatocyte apoptosis.</p><p><b>METHODS</b>A rat model of ALD was established by continuous intragastric administration of ethanol. At 4, 8, 12, and 16 weeks later, randomly selected rats were sacrificed for serum and liver sample collection. Serum levels of total homocysteine (tHcy) were examined by chemiluminescence analysis. Cystathionine beta-synthase (CBS) activity in liver tissue was measured by chromatometry. The mRNA and protein expressions of ERS-related factors, glucose-regulated protein (GRP)-78, calpain 2 and caspase-12, were analyzed by reverse transcription-polymerase chain reaction and immunohistochemistry, respectively. Hepatocyte apoptosis was detected by the TdT-mediated dUTP nick end labeling assay.</p><p><b>RESULTS</b>At 16 weeks, the ALD rats' livers exhibited diffuse microvesicular adipose degeneration and fibrosis in the liver sinus and portal septa. As the duration of ethanol administration extended, the tHcy levels gradually increased (P less than 0.01), CBS activity decreased (P less than 0.01), gene expression levels of GRP-78, calpain 2, and caspase-12 were up-regulated (P less than 0.01), and protein expression levels of GRP-78 and calpain 2 were gradually increased. However, the protein level of procaspase-12 was found to decrease with increased duration of ethanol administration. Finally, the hepatocyte apoptosis index showed an increasing trend over time (P less than 0.01).</p><p><b>CONCLUSION</b>In our experimental ALD rat model, hepatic apoptosis was detected with increasing frequency over the duration of ALD. Increased apoptosis was likely due to decreased CBS activity causing hyperhomocysteinemia, which further induced ERS and activated the calpain 2 and caspase-12 signaling pathway. These ethanol-induced molecular changes may provoke hepatic apoptosis and subsequently promote the pathogenic processes of alcoholic liver disease.</p>

The virological response in prolonged therapy of chronic hepatitis C with low-dose peginterferon alpha-2a / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the virological response in prolonged therapy of chronic hepatitis C (CHC) with low-dose peginterferon alpha-2a.</p><p><b>METHODS</b>The 92 cases of in-patients with chronic hepatitis C in September 2004 to September 2006 were divided to three groups according the endurance of interferon. The dose of peginterferon alpha-2a was 67.5 microg, 90 microg and 180 microg per week in group A, B and C respectively. The treatment duration of peginterferon alpha-2a was 96 or 48 weeks in HCV genotype 1b and 2a in group A and B, and in the group C the duration was 48 or 24 weeks in genotype 1b and 2a patients respectively. Meanwhile, ribavirin for 900-1200 mg per day combined treated with all patients. The quantitation of serum HCV RNA were conducted to determine the rapid virological response (RVR), early virological response (EVR) and sustained virological response (SVR) respectively.</p><p><b>RESULTS</b>There were no significant difference between the three groups in the rate of RVR, EVR and SVR (P > 0.05). There was a higer rate of RVR, EVR and SVR in the genotype 2a group than the genotype 1b group (P < 0.05). HCV genotype was the independent predictor (OR = 12.78, 95%, CI = 11.97-82.89, P = 0.0075) of SVR.</p><p><b>CONCLUSION</b>There was a similar virological response between prolonged therapy of chronic hepatitis C with low-dose peginterferon alpha-2a and the standard dose and duration. The genotype was the independent predictors of SVR in peginterferon alpha-2a antiviral therapy of chronic hepatitis C.</p>