The role of DCs in the immunopathogenesis of chronic HBV infection and the methods of inducing DCs maturation.

Chronic hepatitis B virus (HBV) infection is the result of an inadequate immune response towards the virus. Dendritic cells (DCs), as the most efficient professional antigen-presenting cells (APCs), possess the strongest antigen presenting the effect in the body and can stimulate the initial T cell activation and proliferation. DCs of patients with chronic HBV infection are impaired, resulting in more tolerogenic rather than immunogenic responses, which may contribute to viral persistence. Recently, numerous methods have been developed to induce DCs maturation. To date, recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) combined with interleukin-4 (rhIL-4) has been a classic culture combination to DCs. The recently classified type III interferon group interferon-λ (IFN-λ) displays antiviral, antitumor, and immunoregulatory activity. In our laboratory, we demonstrate that IFN-λ1 combined with rhGM-CSF and rhIL-4 can significantly increase the expression of DC surface molecules and the secretion of interleukin-12 (IL-12) and interferon-γ (IFN-γ) in patients with chronic hepatitis B infection. In this review, we emphasize on the role of DCs in the immunopathogenesis of chronic HBV infection. Importantly, we systematic review that the latest update in the current status of knowledge on the methods of inducing DCs maturation in anti-HBV immunity. What's more, we conclude that IFN-λ1 combined with GM-CSF and IL-4 can induce DCs maturation, which could become a possibility to be applied to the autologus dendritic cell vaccine to treat chronic hepatitis B.

Virological responses in chronic hepatitis C patients undergoing prolonged therapy with low-dose Peg-IFNα-2a.

BACKGROUND/AIMS: Standard dose therapy with pegylated interferon α-2a (Peg-IFNα-2a) and ribavirin is not suitable for all patients because of the side effects. This study aims to evaluate the virological responses of low-dose but long-course Peg-IFNα-2a therapy compared with standard therapy. METHODOLOGY: Ninety patients with chronic hepatitis C were divided into three groups according to their tolerance to Peg-IFNα-2a. The courses of treatment were 96 or 48 weeks respectively in patients with HCV genotypes 1b or 2a in the 67.5 µg and 90 µg groups, and were 48 or 24 weeks in the 180 µg groups. Serum HCV RNA was quantified to determine RVR, EVR, SVR and ETR. RESULTS: There were no statistical differences in HCV RNA load, HCV genotype at the baseline of the three groups (p>0.05). The rates of RVR, EVR, SVR and ETR (no significant differences in each group), were 63.04%, 82.61%, 71.74% and 85.87% in all 92 patients. Genotype 1b (95% CI=11.97-82.89; p=0.0075) and RVR (95% CI=0.12-0.53; p<0.001) were important predictors of SVR. CONCLUSIONS: Patients with low-dose but long-course Peg-IFNα-2a therapy had similar virological responses compared to those with standard therapy. HCV genotype and RVR were independent predictors of SVR.

[PD-1 expression in HBcAg-specific CD8+ T cells of adolescents with chronic HBV infection].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

[Dynamic changes in programmed death-1 expression on the surface of T cells in chronic hepatitis C patients undergoing interferon therapy].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

[Role of endoplasmic reticulum stress in alcoholic liver disease-related hepatocyte apoptosis].

OBJECTIVE: To investigate the role of endoplasmic reticulum stress (ERS) in alcoholic liver disease (ALD)-related hepatocyte apoptosis. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

CD-g-CS nanoparticles for enhanced antibiotic treatment of Staphylococcus xylosus infection.

Staphylococcus xylosus (S. xylosus)-induced cow mastitis is an extremely serious clinical problem. However, antibiotic therapy does not successfully treat S. xylosus infection because these bacteria possess a strong biofilm formation ability, which significantly reduces the efficacy of antibiotic treatments. In this study, we developed ceftiofur-loaded chitosan grafted with ß-cyclodextrins (CD-g-CS) nanoparticles (CT-NPs) using host-guest interaction. These positively charged nanoparticles improved bacterial internalization, thereby significantly improving the effectiveness of antibacterial treatments for planktonic S. xylosus. Moreover, CT-NPs effectively inhibited biofilm formation and eradicated mature biofilms. After mammary injection in a murine model of S. xylosus-induced mastitis, CT-NPs significantly reduced bacterial burden and alleviated inflammation, thereby achieving optimized therapeutic efficiency for S. xylosus infection. In conclusion, this treatment strategy could improve the efficiency of antibiotic therapeutics and shows great potential in the treatment of S. xylosus infections.

Anticancer activity, attenuation on the absorption of calcium in mitochondria, and catalase activity for manganese complexes of N-substituted di(picolyl)amine.

In order to find multifunction anticancer complexes, three Mn(II) complexes of N-substituted di(2-pyridylmethyl)amine were characterized and used as agents to interfere with the functions of mitochondria and the metabolite of O(2) in cancer cells. It was found that carboxylate-bridged dimanganese(II) systems are good models of catalase and exhibit good inhibition of the proliferation of U251 and HeLa cells. The inhibiting activity of these manganese(II) complexes on the tumor cells in vitro was related to their disproportionating H(2)O(2) activity. The reaction of carboxylate-bridged dimanganese Mn(II) complex with H(2)O(2) forms a stable Mn(III)-(µ-O)(2)-Mn(IV) complex. Extensive experimental results show that chloride-bridged dimanganese(II) complexes could inhibit the swelling of calcium(II) overloaded mitochondria, and carboxylate-bridged manganese(II) complexes enhance the swelling of calcium(II) overloaded mitochondria. These results indicate that the interactions between Mn(II) complexes of N-substituted di(picolyl)amine and mitochondria are influenced by the structure and conformation of the complexes. Mn(II) complexes of N-substituted di(picolyl)amine could be developed as multifunctional anticancer complexes to interfere with the absorption of calcium(II) in mitochondria and the metabolite of O(2) through the H(2)O(2) or ROS involved signaling induced apoptosis of cancer cells.

The formation of a luminescent Mn(III,IV) intermediate of bis(2-pyridylmethyl)amine and acetone assistant its intramolecular C-H oxidation.

The dinuclear Mn(II) complexes of bis(2-pyridylmethyl)amine (dpa) reacted with H(2)O(2) producing a fluorescent dioxodimanganese(III,IV) intermediate [(dpa)Mn(2)Cl(2)(µ-O(2))(OHdpa)](3+), which was characterized by IR, UV, ESR, ES-MS and fluorescence spectra. ES-MS data show that this intermediate could bind an acetone molecule forming dioxodimanganese(III,IV)-acetone adduct [(dpa)Mn(2)Cl(2)(µ-O)(CH(3)COCH(3))(OHdpa)](3+). The emission of dioxodimanganese(III,IV)-acetone at 378 nm was stronger than that of dioxodimanganese(III,IV) complex. Excess acetone molecules promoted the intramolecular C-H oxidation and the formation of one dimensional chain Mn(II) complex [(2-picolinic-acid)Mn(H(2)O)(2)Cl(O)](n) through possible intramolecular oxygen transfer reaction.

[The virological response in prolonged therapy of chronic hepatitis C with low-dose peginterferon alpha-2a].

OBJECTIVE: To investigate the virological response in prolonged therapy of chronic hepatitis C (CHC) with low-dose peginterferon alpha-2a. METHODS: 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. RESULTS: 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. CONCLUSION: 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.