Vertical transmission of hepatitis B virus: propositions and future directions.

ABSTRACT: Chronic hepatitis B virus (HBV) infection due to vertical transmission remains a critical concern with regards to eliminating HBV infection. Implementation of hepatitis B vaccine, the foundation to prevent perinatal and horizontal transmission, has reduced the prevalence of HBV by >80%. In countries where the hepatitis B immune globulin (HBIG) is available, such as China and the United States, the administration of HBIG and hepatitis B vaccine to the infants of mothers who are positive for hepatitis B surface antigen has become a standard practice and is effective in preventing vertical transmission. Accumulating evidence on the efficacy and safety of antiviral prophylaxis during pregnancy indicates the probability of attaining the goal of the World Health Organization to eliminate hepatitis by 2030. In this review, we discuss the transmission routes, diagnostic criteria, and preventive strategies for vertical transmission. A preventive program that includes screening before pregnancy, antiviral prophylaxis during pregnancy, and postpartum immunoprophylaxis provides "perfect strategies" to eliminate vertical transmission. However, there is still a notable gap between "perfect strategies" and real-world application, including insufficient coverage of timely birth dose vaccine and the efficacy and necessity of HBIG, especially in mothers who are negative for hepatitis B envelope antigen. In particular, there is a clear need for a comprehensive long-term safety profile of antiviral prophylaxis. Therefore, feasible and cost-effective preventive strategies need to be determined across regions. Access also needs to be scaled up to meet the demands for prophylaxis and prevalence targets.

Characteristics of Peripheral Lymphocyte Subsets in Patients With Acute-On-Chronic Liver Failure Associated With Hepatitis B.

Background and Aims: Acute-on-chronic liver failure (ACLF) is a rare, but dramatic clinical syndrome. There is substantial evidence suggesting that immunity-mediated inflammation plays an important role in HBV-ACLF. Our aim was to characterize the proportion and cell counts of peripheral blood lymphocyte subsets in acute-on-chronic liver failure patients caused by HBV infection. Methods: One hundred and seventeen patients were enrolled in this study, including those with HBV-related ACLF (HBV-ACLF; n = 70), and HBV related non-ACLF patients (HBV non-ACLF; n = 47). Demographics, clinical and laboratory data at hospital admission were retrospectively analyzed. The percentage and cell count of peripheral lymphocyte subsets were evaluated by flow cytometry. Comparison analysis was performed by t-test or non-parametric Mann-Whitney U-test. Actuarial probabilities of death were calculated by the Kaplan-Meier method. Results: Both circulating lymphocyte count and lymphocyte percentage were significantly reduced in patients with HBV-ACLF (P < 0.001). The CD8+ T cell, CD4+ T cell, and CD16+CD56+ NK cell counts were significantly decreased in HBV-ACLF. Consistently, flow cytometric analysis showed that CD8+ T cell counts were significantly decreased in non-survivors, while no significant differences were found in CD4+ T cell, CD19+ B cell, or CD56+CD16+ NK cell counts. Furthermore, the group with the lower CD8+ T cell count displayed a significantly higher mortality rate compared with the group with the higher CD8+ T cell count. Conclusions: The abnormal prevalence of lymphocyte subsets may be important in the pathogenesis of HBV-ACLF. The decrease in CD8+ T cell counts may be related to poor survival in HBV-ACLF patients.

Efficacy and safety of elbasvir/grazoprevir in treatment-naive Chinese adults with hepatitis C virus infection: A randomized trial.

BACKGROUND AND AIM: In China, clinical experience with direct-acting antiviral treatments for hepatitis C virus (HCV) infection is still emerging. C-CORAL is a phase 3, multinational, placebo-controlled, double-blind trial of elbasvir/grazoprevir (EBR/GZR) in participants with HCV infection from the Asia-Pacific region and Russia. Here, we report the data from participants enrolled in China. METHODS: Treatment-naive participants with chronic HCV genotype (GT) 1, GT4, or GT6 infection were randomly assigned to receive 50 mg EBR/100 mg GZR for 12 weeks (immediate-treatment group, ITG) or placebo followed by deferred treatment with EBR/GZR (deferred-treatment group, DTG). The primary efficacy end-point was sustained virologic response at 12 weeks after completing treatment (SVR12), and the primary safety end-point was a comparison of safety between participants receiving EBR/GZR and placebo (NCT02251990; Protocol PN-5172-067). RESULTS: A total of 152 participants in China were randomly assigned (ITG, n = 115; DTG, n = 37). SVR12 was achieved in 96.7% (146/151) participants overall and in 97.3% (142/146) of those with GT1b infection. Four participants relapsed (GT1b, n = 3; GT6a, n = 1). Drug-related AEs were reported in 25 (21.7%) and 9 (24.3%) participants receiving EBR/GZR and placebo, respectively; no drug-related serious adverse events (AEs) occurred. Two (1.7%) participants receiving EBR/GZR had late hepatic transaminase elevations. Patient-reported outcomes indicate improved quality of life at follow-up week 4 in participants receiving EBR/GZR compared to placebo. CONCLUSION: EBR/GZR administered for 12 weeks represents a highly effective and safe treatment option for Chinese individuals with HCV GT1 infection.

Roles of hepatic stellate cells in acute liver failure: From the perspective of inflammation and fibrosis.

Acute liver failure (ALF) usually results in hepatocellular dysfunction and coagulopathy and carries a high mortality rate. Hepatic stellate cells (HSCs) are famous for their role in liver fibrosis. Although some recent studies revealed that HSCs might participate in the pathogenesis of ALF, the accurate mechanism is still not fully understood. This review focuses on the recent advances in understanding the functions of HSCs in ALF and revealed both protective and promotive roles during the pathogenesis of ALF: HSC activation participates in the maintenance of cell attachment and the architecture of liver tissue via extracellular matrix production and assists liver regeneration by producing growth factors; and HSC inflammation plays a role in relaying inflammation signaling from sinusoids to parenchyma via secretion of inflammatory cytokines. A better understanding of roles of HSCs in the pathogenesis of ALF may lead to improvements and novel strategies for treating ALF patients.

Natural Killer Group 2A Expressed on Both Peripheral CD3-CD56+NK Cells and CD3+CD8+T Cells Plays a Pivotal Negative Regulatory Role in the Progression of Hepatitis B Virus-Related Acute-on-Chronic Liver Failure.

To explore the role of surface receptors natural killer group 2A (NKG2A) and natural killer group 2D (NKG2D) on CD3+CD8+T cells and CD3-CD56+NK cells in the progression of hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF), we measured the expression of NKG2A and NKG2D on the surface of these 2 types of circulating cells by flow cytometry in 3 groups. One group consists of 36 patients with chronic hepatitis B (CHB), another one consists of 22 patients with HBV-related ACLF, and the last one has 12 normal controls (NC). The experimental result indicated that there was no significant difference in the proportion of CD3+CD8+T cells in total lymphocytes between the 3 groups. However, the percentage of CD3-CD56+NK cells in ACLF group was evidently higher than that in the CHB group (P < 0.05). In addition, the expression of NKG2D on CD3+CD8+T cells in the ACLF group was significantly lower than that in the CHB group (P < 0.05), but there were no statistically significant differences in its percentages on CD3-CD56+NK cells between the 3 groups. The expression of NKG2A on CD3+CD8+T cells in the ACLF group was significantly higher than that in the NC group (P < 0.05), and on NK cells was significantly higher than that in the CHB group (P < 0.05) and NC group (P < 0.01). The increase in ratios of NKG2A to NKG2D on CD3+CD8+T cells and CD3-CD56+NK cells in the ACLF group was significantly more than that in the CHB group and NC group. The results indicate that the imbalance between NKG2A and NKG2D may contribute to the progression of HBV-related ACLF mediated by CD3-CD56+NK cells and CD3+CD8+T cells. Compared with NKG2D, NKG2A expressed on both peripheral CD3-CD56+NK cells and CD3+CD8+T cells plays a more pivotal negative regulatory role in the progression of HBV-related ACLF.

Insulin Resistance Predicts Virological Response to Interferon-α in Chronic Hepatitis B Patients.

GOALS: To elucidate impact of insulin resistance (IR) on the response to interferon-α (IFN-α) therapy in chronic hepatitis B (CHB) patients. BACKGROUND: Metabolic factors influencing the virological response of CHB patients on IFN-α treatment are still unexplored. STUDY: Eighty CHB patients were treated with IFN-α for 48 weeks. The IR was evaluated by homeostasis model assessment of IR (HOMA-IR) before treatment. Viral load and biochemical parameters were measured at 12, 24, and 48 weeks after starting treatment, and then 24 weeks after the end of treatment. IFN-γ and tumor necrosis factor-α were tested at baseline and 12 weeks of treatment. RESULTS: Pretreatment HOMA-IR proved to be the only independent predictor of primary nonresponse, as well as the pretreatment HOMA-IR, viral load and primary nonresponse were independently associated with virological response at 24, 48 weeks of treatment and at the follow-up endpoint. The significant higher virological relapse rate in patients with IR was observed in patients with virological response at 48 weeks of treatment. The mean HOMA-IR was significantly lower in virological responders than in virological nonresponders. The secretion of IFN-γ and tumor necrosis factor-α was not induced in patients with IR at 12 weeks after IFN-α treatment. CONCLUSIONS: Our data suggest that IR is strongly associated with virological response, thus reflecting the important role played by metabolic factors in the viral kinetics during IFN-α treatment. These findings suggested clinical application of pretreatment HOMA-IR could enable treatment outcome to be predicted and treatment regimens to be determined.

In vitro immunomodulatory activity of interferon alpha on toll-like receptor 9 signaling pathway in chronic hepatitis B.

Interferon alpha (IFN-α) is registered for chronic hepatitis B (CHB) treatment. However, the antiviral mechanism of IFN-α and the biological function of many IFN-α responsive genes have not been fully elucidated. We investigated to determine the regulative effect of IFN-α on toll-like receptor (TLR) 9 signaling in peripheral blood mononuclear cells (PBMCs) from CHB patients in vitro. We examined the changes of expression and function of TLR9 signaling pathway in the PBMCs with different treatment methods and investigated the synergism of IFN-α and TLR9 ligand on antiviral cytokine secretions in vitro. The data showed that, for the TLR9 signaling pathway, IFN-α not only augmented the expressions of TLR9 signal transduction molecules but also activated the TLR9 signal function. This study has clearly demonstrated that the TLR9 ligand could stimulate PBMCs that have been pretreated with IFN-α. Furthermore, the quantity of antiviral cytokines secreted by the pretreated PBMCs was greater than those without pretreatment. The interaction between IFN-α and TLR9 ligand appears to be synergistic. Data revealed IFN-α could influence TLR9 signaling transduction and synergistically improve the immune efficacy of TLR9 ligand against CHB. The present study suggests a potential novel mechanism for the antiviral activity against hepatitis B virus and a new individualized antiviral strategy.

A functional variant at miR-34a binding site in toll-like receptor 4 gene alters susceptibility to hepatocellular carcinoma in a Chinese Han population.

Toll-like receptor 4 (TLR4) plays a key role in prompting the innate or immediate response. A growing body of evidence suggests that genetic variants of TLR4 gene were associated with the development of cancers. This study aimed to investigate the relationship of a functional variant (rs1057317) at microRNA-34a (miR-34a) binding site in toll-like receptor 4 gene and the risk of hepatocellular carcinoma. A single center-based case-control study was conducted. In this study, the polymerase chain reaction (PCR) and direct sequencing were used to genotype sequence variants of TLR4 in 426 hepatocellular carcinoma cases and 438 controls. The modification of rs1057317 on the binding of hsa-miR-34a to TLR4 messenger RNA (mRNA) was measured by luciferase activity assay. Individuals carrying the AA genotypes for the rs1057317 were associated significantly with increased risk of hepatocellular carcinoma comparing with those carrying wild-type homozygous CC genotypes (adjusted odds ratio [OR] by sex and age, from 1.116 to 2.452, P = 0.013). The activity of the reporter vector was lower in the reporter vector carrying C allele than the reporter vector carrying A allele. Furthermore, the expression of TLR4 was detected in the peripheral blood mononucleated cell of hepatocellular carcinoma (HCC) patients, suggesting that mRNA and protein levels of TLR4 might be associated with SNP rs1057317. Collectively, these results suggested that the risk of hepatocellular carcinoma was associated with a functional variant at miR-34a binding site in toll-like receptor 4 gene. miR-34a/TLR4 axis may play an important role in the development of hepatocellular carcinoma.

Serum IL-21 levels associated with chronic hepatitis B and hepatitis B-related liver failure.

The aim of the present study was to investigate the role of interleukin (IL)-21 in chronic hepatitis B virus (HBV) infection. IL-21 stimulates T and B cell responses and plays a role in the control of chronic viral infections. Serum IL-21 levels were measured by enzyme immunoassay in 109 patients with chronic HBV infection at various clinical stages, as well as in 19 healthy controls (HCs). The proportion of T cells producing IL-21 in the peripheral blood was assessed by intracellular cytokine staining and flow cytometry. Mean serum IL-21 levels in patients with chronic hepatitis B (CHB) and the HCs were 303.54±152.77 pg/ml and 68.24±9.06 pg/ml, respectively (P=0.003). In addition, the mean serum IL-21 level in patients with hepatitis B-related acute-on-chronic liver failure (HB-ACLF) was 455.38±412.38 pg/ml, which exhibited a statistically significant difference when compared with the HCs (P=0.000). Serum IL-21 levels were highest in the patients with HB-ACLF (455.38±412.38 pg/ml) and exhibited a significant difference when compared with the CHB patients (P=0.04). The mean serum IL-21 levels in patients with cirrhosis also increased, but there was no statistically significant difference when compared with the HCs (P=0.82). The frequency of IL-21+CD4+ cells also increased compared with the HCs and correlated with the number and percentage of lymphocytes in the peripheral blood. Serum IL-21 levels increased in CHB and HB-ACLF patients. Relatively low serum IL-21 levels in CHB may have a causal role in the persistence of HBV infection. Higher serum levels in HB-ACLF may activate T and B cells to eliminate the virus or injure the liver via the release of inflammatory cytokines.

[Combined immunoprophylaxis induces changes in anti-hepatitis B surface protein titer in infants born to mothers with positivity for hepatitis B surface antigen].

OBJECTIVE: To conduct a prospective randomized controlled trial of infants born to hepatitis B virus (HBV) surface antigen (HBsAg)-positive mothers in order to investigate the dynamic changes in the titer of anti-HBV surface protein (HBS) induced by treatment with combined immunoprophylaxis (200 IU hepatitis B immunoglobulin (HBIG) and 5 or 10 mug yeast recombinant hepatitis B vaccine), to compare the protective effect of 5 and 10 mug hepatitis B vaccine, and to provide an immunization strategy, monitoring mode and booster immunization schedule for the high-risk group. METHODS: Two-hundred-and-sixty-nine infants born to HBsAg positive mothers were given combined immunoprophylaxis at birth, and the venous blood samples (at birth, and 1, 7 and 12 months) were tested for HBV DNA load, and HBsAg and anti-HBS titers. RESULTS: The overall 1-year protective rate of combined immunoprophylaxis was 95.9%. There was no significant difference between the infectious rates of infants given the 5 mug or the 10 mug hepatitis B vaccine (x2 = 0.876, P = 0.377). The geometric mean titers (GMTs) of anti-HBS were 144.1 mIU/ml at 1-month old and 564.9 mIU/ml at the age of 7 months old (the highest point), but declined to 397.6 mIU/ml at the age of 12 months old. The rate of infants with anti-HBS titer less than 100 mIU/ml was 20.9%, and that of less than 10 mIU/ml was 7.4% at 7-month-old; the rate of infants with anti-HBS titer less than 100 mIU/ml increased to 30.2% and that of less than 10 mIU/ml increased to 15.9% at 12-month-old. At 7-month-old, the GMT of the 10 mug vaccine group was higher than that of the 5 mug vaccine group (675.3 mIU/ml vs. 25.0 mIU/ml, P = 0.001) and the rate of infants with anti-HBS titer less than 10 mIU/ml was significantly lower in the 10 mug vaccine group (2.3% vs. 12.6%, P = 0.002); at 12-month-old, the rate of infants with anti-HBS titer less than 100 mIU/ml was also significantly lower in the 10 mug group (20.6% vs. 40.2%, P = 0.001). CONCLUSION: Combined immunoprophylaxis is therapeutically efficacious for treating infants born to HBsAg positive mothers. Monitoring these infants' anti-HBs titer will help to identify non- or low-responders in a timely manner. The high-dose hepatitis B vaccine is preferable to the low-dose, and should be considered for use in immunization strategies for these infants.

Hepatitis B virus infection in clustering of infection in families with unfavorable prognoses in northwest China.

Hepatitis B virus (HBV) infection and its associated liver diseases have characteristics of familial clustering in China. However, the reasons for this are not understood fully. To address this issue, the prevalence HBV infection and the characteristics of unfavorable prognoses in clustering of infection in families in northwest China were investigated. Families with clustering of infection and unfavorable prognoses were enrolled, and general information and serum samples were collected. The clinical features and sequelae of HBV infection were compared among the blood relatives (including the first-, second-, and third-degree blood relatives) and spouses using the chi-square test or Fisher's exact test. A total of 102 clusterings of infection families with unfavorable prognoses were interviewed. In the first-, second-, and third-degree blood relatives and spouses, the prevalences of cirrhosis of the liver were 29.2%, 11.9%, and 8.7%, respectively, while those of hepatocellular carcinoma (HCC) were 21.8%, 1.4%, and 4.3%, respectively (P<0.05). The mean ages of the onset of cirrhosis of the liver in the first-, second-, and third-degree blood relatives and spouses were 57 ± 9.91, 47 ± 9.96, 38 ± 10.35, and 57 ± 8.49 years, respectively, while the mean ages of the onset of HCC were 60 ± 7.92, 49 ± 8.57, 41 ± 3.54, and 50 ± 0 years, respectively, (P<0.05). The first-, second-, and third-degree blood relatives from clustering of infection in families with unfavorable prognoses had prevalences of cirrhosis or HCC in descending order of relationship. The findings suggest that genetic factors may be associated with a familial tendency for cirrhosis of the liver and HCC.

Restoring the Treg cell to Th17 cell ratio may alleviate HBV-related acute-on-chronic liver failure.

AIM: To investigate the role of T helper 17 cells (Th17) and regulatory T cells (Treg) in hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF). METHODS: We enrolled 79 patients with HBV infection into the study, 50 patients with HBV-related ACLF and 29 patients with chronic hepatitis B (CHB), from the First Affiliated Hospital of Medical College from January 2009 to June 2012. The ACLF patients were diagnosed according to the criteria recommended by The 19(th) Conference of the Asian Pacific Association for the Study of the Liver in 2009. Twenty healthy individuals with a similar gender and age structures to the two patient groups were also included as the normal controls (NC). Of the 50 ACLF patients, 28 were subsequently classified as non-survivors: 19 patients died from multi-organ failure, 3 underwent liver transplantation, and 6 discontinued therapy during follow-up because of financial reasons. The remaining 22 ACLF patients whose liver and anticoagulation function recovered to nearly normal levels within the next 6 mo were classified as survivors. The number of circulating Treg and Th17 cells was determined upon diagnosis and during the 8th week of follow-up through flow cytometry. RESULTS: The percentage of circulating Treg cells in the ACLF group was significantly higher than that in the CHB group (5.50% ± 1.15% vs 3.30% ± 1.13%, P < 0.01). The percentages of circulating Th17 cells in the ACLF and the CHB groups were significantly higher than that in the NC group (6.32% ± 2.22% vs 1.56% ± 0.44%, P < 0.01; 3.53% ± 1.65% vs 1.56% ± 0.44%, P < 0.01). No significant difference in Treg cell to Th17 cell ratio was observed between the ACLF group and the CHB group (0.98 ± 0.44 vs 1.12 ± 0.64, P = 0.991), whereas those in the two HBV infection groups were significantly lower than that in the NC group (1.85 ± 1.22; both P < 0.01). The percentage of Treg cells in the survivors during the 8(th) week of follow-up was significantly lower than that during peak ACLF severity [total bilirubin (TBIL) peak] (3.45% ± 0.97% vs 5.18% ± 1.02%, P < 0.01). The percentage of Th17 cells in survivors during the 8(th) week of follow-up was significantly lower than that during the peak TBIL (2.89% ± 0.60% vs 5.24% ± 1.46%; P < 0.01). The Treg cell to Th17 cell ratio during the 8(th) week of follow-up was significantly higher than that during the TBIL peak (1.22 ± 0.36 vs 1.10 ± 0.54; P < 0.05). CONCLUSION: Restoring the Treg cell to Th17 cell ratio during the follow-up phase of ACLF could maintain the immune system at a steady state, which favours good prognosis.

[Relationship between the expression of HBV mRNA in embryos and father-to-infant HBV transmission].

OBJECTIVE: To investigate father-to-infant transmission of hepatitis B virus (HBV) by detecting HBV mRNA in the IVF embryos with paternal HBV infection. METHODS: We collected 18 discarded IVF embryos (9 cases) with paternal chronic HBV infection, and detected HBV mRNA in the embryos by single-cell RT-PCR. RESULTS: HBV mRNA positive signals were found in 1 of the 18 embryos with paternal serum HBV positive markers (5.6%), but no specific HBV mRNA signals were observed in the 84 embryos of the negative control group. Follow-up visits revealed no significant difference between the experimental and negative control groups either in the rate of clinical pregnancy (P > 0.05) or in that of early abortion (P > 0.05). The IVF embryo with paternal HBV mRNA positive signals was successfully implanted, but early abortion occurred. HBV infection was not transmitted to progeny in either of the two groups. CONCLUSION: The positive results of HBV mRNA indicate that HBV can get into early-cleavage embryos through sperm and replicate there, which may be the main channel of father-to-infant transmission. HBV may interfere with the development of embryos, and even result in abortion and other adverse outcomes.

Correlation of AIM2 expression in peripheral blood mononuclear cells from humans with acute and chronic hepatitis B.

The AIM2 (absent in melanoma 2) protein promotes host defenses against invading viruses and pathogenic bacteria through corresponding adapter molecules leading to the initiation of innate immune responses. We investigated the expression of AIM2 in peripheral blood mononuclear cells (PBMCs) from patients with acute hepatitis B (AHB) and chronic hepatitis B (CHB) during different clinical phases, and analyzed the correlation between AIM2 and clinical profiles in these groups. This study indicated that there is higher expression of AIM2, IL-1ß, and IL-18 in AHB compared with expression in CHB. The expression of AIM2 mRNA was significantly negatively correlated with serum hepatitis B virus (HBV) load, HBeAg, and significantly positively correlated with IL-1ß and IL-18 in AHB patients and CHB patients with immune clearance, which suggests that AIM2 expression is correlated with the immune clearance of HBV in the host. We summarized that there is a higher immune status in AHB, and a lower immune response in CHB. This suggests that the down-regulation of AIM2 may be associated with the chronic development of HB.

[Expression of COX-2 and PPARg in the livers of patients with acute on chronic HBV-related liver failure and their relationship with clinic parameters].

OBJECTIVE: To study the expressions of cyclooxygenase-2 (COX-2) and Peroxisome proliferator-activated receptor gamma (PPARg) in liver of patients with hepatitis B virus (HBV) related acute-on-chronic liver failure (ACLF) and their correlation with clinical parameters. METHODS: 35 patients with ACLF, 35 patients with HBV related chronic liver failure (CLF), 27 patients with chronic hepatitis B(CHB) and 15 normal control were enrolled to study the expressions of COX-2 and PPARg in the liver tissues by immunohistochemical staining, and to analyze the correlation of the COX-2 and PPARg levels in liver tissues with clinical parameters. RESULTS: COX-2 was distinctly expressed in the cytoplasm of the hepatocytes, but PPARg was mostly expressed in the nuclei of the hepatocytes and also could be seen in the cytoplasm. The expressions of COX-2 in the liver of ACLF, CLF and CHB groups increased significantly as compared with NC group (z = -5.18, -4.50, -5.32, P is less than 0.01). The levels of COX-2 in ACLF livers also increased evidently as compared with CLF groups (z = -1.98, P is less than 0.05). The expression levels of PPARg in ACLF liver tissues were much higher than the other three groups, and statistical significances existed between ACLF group and the other two groups (CLF, NC groups) (z = -2.62, -4.28, P is less than 0.01). In ACLF group, the expression of COX-2 correlated with MELD score (r = 0.337, P is less than 0.05) and the expression of PPARg correlated with HBV DNA load (r = 0.348, P is less than 0.05). Clinical data showed that the levels of AST, TBil, CHOL, PT, INR, FIB and MELD score in ACLF group were significantly different from that in CLF, CHB and NC groups. CONCLUSIONS: COX-2 expressed in liver may be a marker to reflect the degree of inflammation and injury of liver tissue. The PPARg expression of liver could be increased during chronic HBV infection and may be a protective mechanism against liver injury.

Asialoglycoprotein receptor interacts with the preS1 domain of hepatitis B virus in vivo and in vitro.

BACKGROUND: The preS1 domain of the large envelope protein has been identified as an essential viral structure involved in hepatitis B virus (HBV) attachment. However, the cellular receptor(s) for HBV has not yet been identified. AIMS: To identify a cell-surface receptor for HBV, which could elucidate the molecular mechanism of HBV infection. METHODS: A novel yeast two-hybrid system was used to screen proteins interacting with the preS1 region of HBV. Their interaction was verified by yeast cotransformation, coimmunoprecipitation and mammalian two-hybrid assay, while their intracellular and tissue localization was analyzed by confocal microscopy and immunohistochemistry, respectively. RESULTS: Asialoglycoprotein receptor (ASGPR) interacted specifically and directly with the preS1 domain of HBV in vivo and in vitro. The levels of expression of preS1 and ASGPR in the liver were similar and correlated with each other. CONCLUSIONS: ASGPR is a candidate receptor for HBV that mediates further steps of HBV entry.

[Construction of a bait plasmid containing HBV PreS1 gene in a yeast two-hybrid system and evaluation of its toxicity and self-activation].

OBJECTIVE: To construct a yeast expression vector of hepatitis B virus (HBV) PreS1 gene using the Sos-recruitment system (SRS), and evaluate the effect of the expression product on the growth of the yeast cells and activation of the reporter gene. METHODS: The coding sequence of HBV preS1 was amplified by PCR and cloned into the yeast expression plasmid pSos. The recombinant bait plasmid pSos- PreS1 was verified by sequencing before transformation into competent yeast cells. The effects of the expression product on the yeast cell growth and activation of the reporter gene were evaluated. RESULTS: The yeast expression vector of HBV PreS1 gene was constructed successfully. The recombinant bait plasmid showed no toxic effect on yeast cdc25H cells without a self-activation of the reporter gene. CONCLUSION: The SRS can be used to study the proteins interacting with HBV PreS1 protein and provides a means for obtaining insight into the pathogenic mechanism of HBV.

Identification of a novel protein binding to hepatitis C virus core protein.

BACKGROUND: Hepatitis C virus (HCV) core protein is a multi-functional viral protein that interacts with several target proteins of both viral and cellular origin. AIM AND METHODS: To gain insight into the mechanism of action of HCV core protein, we used a yeast two-hybrid system to identify the core protein-interacting cellular targets. RESULTS: A cDNA clone encoding an aspartoacylase was obtained, termed aspartoacylase 3 (ACY3). Interaction between ACY3 and HCV core protein was verified using a co-immunoprecipitation assay in vitro, and a mammalian two-hybrid system in vivo. Fluorescence microscopy showed green fluorescence protein-fused ACY3 localized in the cytoplasm. CONCLUSION: Our data suggest that ACY3 is an HCV core binding protein, which may play a role in the development of HCV-associated diseases.

[Cellular localization of HCBP1 and its interaction with HCV core protein in vivo].

OBJECTIVE: To analyze the interaction of hepatitis C virus (HCV) core protein with HCBP1 and observe the expression and cellular localization of HCBP1. METHODS: The cDNA fragments encoding HCV core protein and HCBP1 were amplified by PCR and subsequently cloned into pGEM T vector, respectively. After sequence verification, the two recombined vectors were respectively subcloned into two hybrid plasmids, pM and pVP16. pM-core, pVP16- HCBP1 and the reporter vector pG5CAT were co-transfected into COS-7 cells, and the interaction between HCV core protein and HCBP1 was assayed by detecting CAT gene expression after 48 h. The expression and subcellular localization of the fusion protein in the transfected COS-7 cells were analyzed by Western blotting and fluorescence microscopy, respectively. RESULTS: CAT-ELISA showed that the absorbance of the co-transfection group was significantly higher than that o f the negative control groups but lower than that of the positive control group. Western blotting confirmed the expression of fusion protein in the transfected COS-7 cells. Fluorescence microscopy showed that the fusion protein was distributed mainly in the cytoplasm, and in contrast, diffuse EGFP expression was detected in COS-7 cells transfected with the empty vector. CONCLUSION: Mammalian two-hybrid assay confirms the capacity of HCBP1 to bind HCV core protein, and the expression vector for HCBP1-EGFP fusion gene has been constructed successfully and expressed in COS-7 cells.

[Expression map of immune-related genes on PBMCs in familial clustering patients with chronic virus hepatitis B].

AIM: To investigate peripheral blood mononuclear cells (PBMCs) immune-related gene expression profile in patients with chronic virus hepatitis B(CHB) by oligonucleotide gene array technique. METHODS: PBMCs were collected from the members of a family of clustering hepatitis B virus (HBV) infection including 5 CHB patients and 4 healthy spouses and RNA prepared from PBMCs was hybridized to high-density oligonucleotide arrays(HG-U133A 2.0 Human Gene Chips, Affymetrix), covering the expression of 22 000 human ESTs. Primary scanned image was analyzed with DNT software package. RESULTS: Out of the 22 000 ESTs, 24 different immune-related genes were identified. Among the 24 genes, 7 genes showed increased expression and 17 genes showed decreased expression in CHB compared with those in healthy spouses. The up-regulated genes were mainly associated with adaptive immunity, while the down-regulated genes were associated with innate immunity. CONCLUSION: Our findings suggest that HBV infection alters a broad range of immunity genes expression and innate immunity-associated genes are important in the defense against HBV chronic infection.