A Mendelian randomization study investigating causal links between gut microbiota or metabolites and chronic hepatitis B.

Objective: This study aimed to explore the potential causal relationship between the gut microbiota and/or its metabolites and the progression of chronic hepatitis B (CHB). Method: The gut microbiota was used as the exposure factor. The training set exposure data were obtained from the China Nucleotide Sequence Archive (CNSA). Genome-wide association study (GWAS) data from Asia were used as the outcome variables. Outcome data for both the training and validation sets were sourced from the GWAS Catalog database. A dual-sample Mendelian randomization approach was used to analyze the causal relationships, with the inverse variance-weighted method serving as the main analytical strategy. Sensitivity analysis was conducted to assess the robustness of Mendelian randomization analysis results. Result: In the training set database, analysis using the inverse variance-weighted method revealed a positive correlation between Fusobacterium varium and chronic hepatitis B [OR = 1.122, 95% CI (1.016, 1.240), p = 0.022]. Conversely, Veillonella parvula exhibited a negative correlation with chronic hepatitis B [OR = 0.917, 95% CI (0.852, 0.987), p = 0.021]. Sensitivity analysis revealed no evidence of pleiotropy and heterogeneity. No gut microbiota metabolites with a causal effect on chronic hepatitis B were identified. Additionally, no associations between the gut microbiota and the progression of chronic hepatitis B were found in the validation data from the European cohort. Conclusion: This study suggests that F. varium may facilitate the progression of chronic hepatitis B, whereas V. parvula may impede it. No causal relationships between gut microbiota metabolites and chronic hepatitis B were established.

High expression of circulating exosomal PD-L1 contributes to immune escape of hepatocellular carcinoma and immune clearance of chronic hepatitis B.

OBJECTIVE: To investigate the expression of programmed death ligand-1 (PD-L1) in circulating exosomes, and to define the role of exosomal PD-L1 in promoting immune escape mechanism during chronic hepatitis B infection (CHB) and related liver diseases. METHODS: The levels of PD-L1 expressed in exosomes were detected by ELISA. CD8+T cells were sorted and cytotoxicity test was assessed by flow cytometry. PD-L1 protein expression in hepatocellular carcinoma (HCC) and normal adjacent tissues were detected by immunohistochemistry. RESULTS: Circulating exosomal PD-L1 levels were significantly higher in patients with CHB and HCC than in healthy controls (F =7.46, P=0.001). Levels of CD107a on CD8+T cells in patients with CHB receiving PD-L1 blocking antibody were significantly lower than in patients receiving isotype blocking antibody (t = 4.96, P < 0.01). Levels of TNF-α in cell culture supernatants of the PD-L1 blocking antibody group were significantly higher than in the isotype blocking antibody group (t =5.92, P < 0.01). Compared with patients receiving isotype blocking antibody, levels of CD107a on CD8+T cells significantly increased in patients with HCC receiving anti-PD-L1 antibody (t = 3.51, P<0.05). Compared with adjacent tissues, the levels of PD-L1 protein expression in HCC tissues were slightly higher; however, no significant difference between the two groups was observed. CONCLUSIONS: PD-L1 blockade in exosomes might promote the cytotoxic function of CD8+T cells and inhibit immune evasion during progression of HCC. Blocking PD-L1 in exosomes reduced the cytotoxic function of CD8+T cells in patients with CHB while enhancing the production of proinflammatory cytokines.

Corrigendum: High expression of nectin-1 indicates a poor prognosis and promotes metastasis in hepatocellular carcinoma.

[This corrects the article DOI: 10.3389/fonc.2022.953529.].

High expression of nectin-1 indicates a poor prognosis and promotes metastasis in hepatocellular carcinoma.

Objectives: Nectins are a new class of cell-adhesion molecules that play an important role in tumorigenesis and disease progression. The aim of this study was to investigate the prognostic and pathogenetic roles of nectins in hepatocellular carcinoma (HCC). Methods: The expression levels of the nectin family in HCC and their role in prognosis were analyzed by bioinformatics analysis based on The Cancer Genome Atlas (TCGA) liver hepatocellular carcinoma database. The correlations between nectins and immune cells were analyzed using TIMER. The functional enrichment of the nectin-1 coexpression network was evaluated in TCGA cohort, and the expression levels of nectin-1 were detected by immunohistochemistry and Western blot analysis. A Transwell kit was used for cell migration experiments. Cell proliferation was analyzed using Cell Counting Kit-8. Results: The expression levels of nectin-1 protein in the cancer tissues of 28 patients with HCC were higher than those in paracancerous tissues. The Kaplan-Meier plotter analysis showed that the high expression of all nectin family numbers was related to the poor prognosis of HCC patients. The abnormal expression of nectin-1 effectively distinguished the prognosis at different stages and grades of HCC. The high expression of 17 methylation sites of the nectin-1 gene was related to the high overall survival of HCC patients. Kyoto Encyclopedia of Genes and Genomes analysis of genes negatively correlated with nectin-1, revealing their close relation to the regulation of the immune-effector process. Pearson's correlation analysis showed that nectin-1 was significantly positively correlated with multiple immune genes and B cells, CD4+ T cells, macrophages, neutrophils, and dendritic cell infiltration. Cell proliferation of the knockdown (KD) group decreased significantly compared to the NC-KD group. The number of metastatic cells in the KD group decreased significantly compared to that in the NC-KD group. Conclusions: Abnormal expression of nectins and multiple methylation sites closely correlates with poor prognosis in HCC patients. Nectins are related to immune cell infiltration and immune-related genes. In particular, nectin-1 can promote the proliferation and migration of liver cancer cells and distinguish the prognosis at different stages and grades of HCC. Nectin-1 might be a new potential molecular marker for prognostic evaluation and also a therapeutic target for HCC.

Effect of portal vein thrombosis on the prognosis of patients with cirrhosis without a liver transplant: A systematic review and meta-analysis.

BACKGROUND: Portal vein thrombosis (PVT) is a relatively common complication of cirrhosis. However, the effect of PVT on the prognosis might not be unequivocal. A systematic review and meta-analysis were performed to investigate the effect of PVT on the prognosis of patients with cirrhosis who have not received a liver transplant. METHODS: Three databases, including PubMed, EMBASE, and Cochrane Library, were searched for studies published up to March 2020. The survival or mortality rate of patients with PVT served as the main index to evaluate the prognosis of these patients. Hepatic decompensation served as the index of disease progression. Meta-analyses were conducted using Review Manager software 5.2. RESULTS: Sixteen clinical studies were included and analyzed. PVT was associated with an increased risk of mortality in patients with decompensated cirrhosis. According to the meta-analysis, patients with cirrhosis presenting with PVT had a lower 1-year survival rate than patients without PVT (odds ratio (OR), 0.32; 95% confidence interval (CI), 0.14-0.75; P = .008). The cumulative survival rates were similar between the 2 groups at 3 years (OR, 1.04; 95% CI, 1.00-1.08; P = .06), 5 years (OR, 1.33; 95% CI, 0.71-2.48; P = .38) and 10 years (OR, 1.24; 95% CI, 0.79-1.93; P = .35). PVT was associated with a higher mortality rate in patients with Child-Pugh class B and C disease. A significantly increased risk of death was observed in patients with complete PVT. Patients with both PVT and cirrhosis had a higher rate of decompensation than patients without PVT. CONCLUSIONS: The presence of PVT might exert a slight effect on the overall prognosis of patients with cirrhosis. PVT might mainly affect the short-term prognosis by increasing hepatic decompensation events in patients with cirrhosis. However, PVT might not influence the long-term prognosis of patients with cirrhosis.

Development and validation of epithelial mesenchymal transition-related prognostic model for hepatocellular carcinoma.

Epithelial cell transformation (EMT) plays an important role in the pathogenesis and metastasis of hepatocellular carcinoma (HCC). We aimed to establish a genetic risk model to evaluate HCC prognosis based on the expression levels of EMT-related genes. The data of HCC patients were collected from TCGA and ICGC databases. Gene expression differential analysis, univariate analysis, and lasso combined with stepwise Cox regression were used to construct the prognostic model. Kaplan-Meier curve, receiver operating characteristic (ROC) curve, calibration analysis, Harrell's concordance index (C-index), and decision curve analysis (DCA) were used to evaluate the predictive ability of the risk model or nomogram. GO and KEGG were used to analyze differently expressed EMT genes, or genes that directly or indirectly interact with the risk-associated genes. A 10-gene signature, including TSC2, ACTA2, SLC2A1, PGF, MYCN, PIK3R1, EOMES, BDNF, ZNF746, and TFDP3, was identified. Kaplan-Meier survival analysis showed a significant prognostic difference between high- and low-risk groups of patients. ROC curve analysis showed that the risk score model could effectively predict the 1-, 3-, and 5-year overall survival rates of patients with HCC. The nomogram showed a stronger predictive effect than clinical indicators. C-index, DCA, and calibration analysis demonstrated that the risk score and nomogram had high accuracy. The single sample gene set enrichment analysis results confirmed significant differences in the types of infiltrating immune cells between patients in the high- and low-risk groups. This study established a new prediction model of risk gene signature for predicting prognosis in patients with HCC, and provides a new molecular tool for the clinical evaluation of HCC prognosis.

miRNA-548ah promotes the replication and expression of hepatitis B virus by targeting histone deacetylase 4.

AIM: Many studies have shown that some microRNAs (miRNAs) play an important role in the pathogenesis of chronic hepatitis B (CHB) infection. In this study, we aimed to explore the role and molecular mechanism of miRNA-548ah in the replication and expression of the hepatitis B virus (HBV). MAIN METHODS: Overexpression and knockdown of miRNA-548ah were performed in three hepatoma cell lines with HBV replication and in a murine HBV model injected with adenovirus HBV vector. The effect of miRNA-548ah on its target gene, histone deacetylase (HDAC) 4, were confirmed in in vitro studies and further investigated in liver tissues from CHB patients. KEY FINDINGS: miRNA-548ah significantly increased the expression of HBV in hepatoma cell lines and in a HBV mouse model. The expression level of covalently closed circular DNA (cccDNA) in the miRNA-548ah mimics group was significantly higher than the negative control group and significantly lower in the miRNA-548ah inhibitor group. The HBV core antigen promotes the expression of miRNA-548ah in hepatocytes. Finally, we observed a negative correlation between the expression of miRNA-548ah and HDAC4 in the liver tissue of patients with CHB. SIGNIFICANCE: miRNA-548ah promoted the replication and expression of HBV through the regulation of the target gene, HDAC4. Inhibition of HDAC4 by miRNA-548ah might influence the deacetylation state of histones binding to cccDNA, thereby enhancing the replication of cccDNA. The HBV core antigen might increase the expression of miRNA-548ah. These results may provide new potential molecular targets for the prevention and treatment of CHB.

HBeAg Seroconversion in HBeAg-Positive Chronic Hepatitis B Patients Receiving Long-Term Nucleos(t)ide Analog Treatment: A Systematic Review and Network Meta-Analysis.

BACKGROUND: HBeAg seroconversion is an important intermediate outcome in HBeAg-positive chronic hepatitis B (CHB) patients. This study aimed to compare the effect of nucleos(t)ide analogs (NAs) on HBeAg seroconversion in treating CHB with lamivudine, adefovir, telbivudine, entecavir, and tenofovir. METHODS: Network meta-analysis of NA treatment-induced HBeAg seroconversion after 1-2 years of treatment was performed. In addition, NA treatment-induced HBeAg seroconversion after 3-5 years of treatment was systematically evaluated. RESULTS: A total of 31 articles were included in this study. Nine and five studies respectively reporting on 1- and 2-year treatment were included in our network meta-analysis. In addition, 6, 5, and 5 studies, respectively reporting on 3-, 4-, and 5-year treatment were included in our systematic evaluation. Telbivudine showed a significantly higher HBeAg seroconversion rate after a 1 year treatment period compared to the other NAs (odds ratio (OR) = 3.99, 95% CI 0.68-23.6). This was followed by tenofovir (OR = 3.36, 95% CI 0.70-16.75). Telbivudine also showed a higher seroconversion rate compared to the other NAs after a 2 year treatment period, (OR = 1.38, 95% CI 0.92-2.22). This was followed by entecavir (OR = 1.14, 95% CI 0.72-1.72). No significant difference was observed between spontaneous induction and long-term telbivudine treatment-induced HBeAg seroconversion. However, entecavir and tenofovir treatment-induced HBeAg seroconversions were significantly lower than spontaneous seroconversion. CONCLUSION: Long-term treatment with potent anti-HBV drugs, especially tenofovir and entecavir, may reduce HBeAg seroconversion compared with spontaneous HBeAg seroconversion rate. Telbivudine treatment, whether short term or long term, is associated with higher HBeAg seroconversion compared with the other NAs. However, the high rates of drug resistance likely limit the application of telbivudine.

Expression profile and clinical significance of miRNAs at different stages of chronic hepatitis B virus infection.

OBJECTIVE: To study the expression profile and clinical significance of microRNAs (miRNAs) at different stages of chronic hepatitis B virus (HBV) infection. METHODS: The miRNA expression profiles of peripheral blood mononuclear cells (PBMCs) at different stages of chronic HBV infection were screened using miRNA microarray and validated using real-time quantitative polymerase chain reaction (qPCR). RESULTS: Significant differences in miRNA expression profiles of PBMCs were observed between patients in IA and IT phases of CHB. Expression was significantly down-regulated in the former but up-regulated in the latter group. No significant differences in inactive hepatitis B surface antigen carriers were observed. Changes in expression of six miRNAs determined by real-time qPCR were consistent with those determined by microarray. Areas under the receiver operation characteristic curve of the six miRNAs distinguishing immune tolerance and clearance of chronic HBV infection were 99.4%, 98.4%, 96.7%, 100%, 100%, and 99.6%. Positive correlation was found between the levels of hsa- miR-146a and ALT (r = 0.56, P < 0.01) while negative correlation was found between the levels of hsa-miR-548ah-5p and HBV DNA (r = -0.73, P < 0.01). CONCLUSIONS: Abnormal expression of miRNAs and the resulting gradual decline in the various immune states of patients with chronic HBV infection may play important roles in maintenance of the immune homeostatic mechanisms of chronic HBV infection. Hsa-miR-548ah-5p, hsa-miR-3191-5p and hsa-miR-4711-3p can be used as potential molecular markers to distinguish among different stages of chronic HBV infection.

Non-invasive Analysis of Genomic Copy Number Variation in Patients with Hepatocellular Carcinoma by Next Generation DNA Sequencing.

To explore new molecular diagnosis approaches for early detection and differential diagnosis of hepatocellular carcinoma (HCC), we analyzed genomic copy number variations (CNV) using plasma cell-free DNA from patients with HCC by next generation DNA sequencing. Plasma samples from 31 patients with HCC and 8 patients with chronic hepatitis or cirrhosis were analyzed. In HCC group, most samples with large tumor size (tumor dimension greater than 50 mm) showed CNVs that are visually recognizable at chromosome CNV plots, few samples with small tumor and none samples with chronic liver diseases showed CNVs recognizable at CNV plots. CNV Z score analysis showed significant CNVs in samples with HCC and chronic liver diseases although more significant changes were found in HCC group, some are differentially valuable (such as gain in 1q, 7q, and 19q in HCC), while others are less differentially valuable (such as loss in 4q, 13q, gain in 17q, 22q). We proposed a CNV scoring method that generated positive result in 26 of the 31 HCC patients (83.9%) or 11 of the 16 HCC with tumor dimension 50 mm or less (68.8%) or 4 of the 7 HCC with tumor dimension 30 mm or less (57.1%), while all the 8 samples with chronic hepatitis or cirrhosis scored negative. Ten HCC patients had normal or low serum AFP levels, among them, 7 were scored positive by CNV analysis, including 4 with tumor dimension 50 mm or less. Our study suggested that non-invasive genomic CNV analysis using plasma samples could be a valuable tool for early detection and differential diagnosis of HCC. Although CNV analysis itself cannot establish the diagnosis, it can help identify patients at high risk for HCC among patients with chronic liver diseases, which would prompt closer and more frequent surveillance for early tumor detection and intervention.

MiRNA-548ah, a potential molecule associated with transition from immune tolerance to immune activation of chronic hepatitis B.

OBJECTIVE: The present study aims to identify the differently expressed microRNA (miRNA) molecules and target genes of miRNA in the immune tolerance (IT) and immune activation (IA) stages of chronic hepatitis B (CHB). METHODS: miRNA expression profiles of peripheral blood mononuclear cells (PBMCs) at the IT and IA stages of CHB were screened using miRNA microarrays and authenticated using a quantitative real-time polymerase chain reaction (RT-PCR). Gene ontology (GO) and the Kyoto encyclopedia of genes and genomes (KEGG) were used to analyze the significant functions and pathways of possible target genes of miRNAs. Assays of the gain and loss of function of the miRNAs were performed to verify the target genes in THP-1 cell lines. The luciferase reporter test was used on 293T cells as direct targets. RESULTS: Significantly upregulated miR-548 and miR-4804 were observed in the miRNA microarrays and confirmed by RT-PCR in PBMCs at the IT and IA stages of CHB. GO and KEGG analysis revealed that MiR-548 and miR-4804 could be involved in numerous signaling pathways and protein binding activity. IFNγR1 was predicted as a target gene and validated as the direct gene of MiR-548. Significant negative correlation was found between the miR-548ah and mRNA levels of IFN-γR1 in CHB patients. CONCLUSIONS: The abnormal expression profiles of miRNA in PBMCs could be closely associated with immune activation of chronic HBV infection. miR-548, by targeting IFN-γR1, may represent a mechanism that can facilitate viral pathogenesis and help determine new therapeutic molecular targets.

Screening and bioinformatic analysis of microRNA-associated immune clearance in patients with chronic hepatitis B.

OBJECTIVE: This study aimed to perform screening and bioinformatic analysis of microRNA (miRNA) molecules associated with immune clearance in chronic hepatitis B (CHB) patients. METHODS: Peripheral blood mononuclear cells (PBMCs) of CHB patients and healthy individuals were collected and detected by microarray. The target genes of differentially expressed miRNA molecules were predicted using three databases. Their molecular pathways and functions were analyzed by bioinformatics methods. RESULTS: Compared with healthy individuals, 52 differentially expressed miRNA molecules were found in PBMCs of CHB patients, of which 33 were up-regulated and 19 were down-regulated. A total of 354 target genes were predicted in up-regulated miRNA molecules, and 1935 target genes were predicted in down-regulated miRNA molecules. MiRNA-mRNA network analysis showed that some target genes might be regulated, and constituted complex molecular networks with hsa-miR-520d-5p, hsa-miR-106a-5p, hsa-miR-30a-5p, and hsa-miR-29b-3p. Gene ontology and pathway analyses showed that several molecular pathways might be affected by up- or down-regulated miRNA molecules. CONCLUSION: Abnormal expression of multiple miRNA molecules in PBMCs of CHB patients might be involved in immune clearance pathogenesis through the regulation of multiple molecular pathways and target genes.

Role of T follicular helper cells and their associated molecules in the pathogenesis of chronic hepatitis B virus infection.

In this study, we investigated the roles of T follicular helper (TFH) cells and related molecules in the pathogenesis of chronic hepatitis B virus (HBV) infection. The levels of circulating TFH cells and their surface CD40 ligand (CD40L), as well as CD19(+) B cells and their surface CD40 expression were detected by flow cytometry. Peripheral blood plasma interleukin (IL)-21 levels were detected by enzyme-linked immunosorbent assay (ELISA). Compared with hepatitis B surface antibody (HBsAb)(-) and HBsAb(+) healthy controls, the percentage of TFH cells and their surface CD40L expression significantly increased in patients with chronic HBV infection, particularly those with chronic hepatitis B (P<0.05). The percentage of CD19(+) B cells significantly increased in chronic hepatitis B patients and CD40 expression levels on the CD19(+) B cell surface in chronic HBV infection decreased compared with those in the healthy controls (P<0.05). Compared with the healthy controls, the plasma IL-21 level in chronic hepatitis B patients was significantly increased in chronic HBV carriers and decreased in inactive hepatitis B surface antigen (HBsAg) carriers (P<0.05). The TFH cell percentage, B cell percentage and IL-21 expression did not significantly differ between the hepatitis B e-antigen (HBeAg)(-) and HBeAg(+) chronic hepatitis B groups (P>0.05). The abnormal expression of TFH cells and IL-21 is related to the dysfunction of immune response during chronic HBV infection. The interaction of CD19(+) B cells with TFH cells via their CD40 and CD40L molecules may also play an important role in this process.

Mechanism and efficacy of mobilization of granulocyte colony-stimulating factor in the treatment of chronic hepatic failure.

BACKGROUND/AIMS: To explore the efficacy of G-CSF mobilization in the treatment of chronic liver failure (CLF) and the mechanism of its action. METHODOLOGY: The proportions of cluster-of-differentiation (CD)-34+ cells and their receptor-CXCR4 were detected by flow cytometry in patients with different types of chronic HBV infection. The levels of chemokines and cytokines were measured by enzyme-linked immunosorbent assay. RESULTS: The proportion of CD34+ cells in patients with cirrhosis was significantly increased compared with the healthy controls (p<0.05) and was increased obviously after treatment by G-CSF mobilization (p<0.01). The expression levels of SDF-1, SCF and MMP-9 were significantly elevated in patients with chronic hepatitis B and liver cirrhosis (p<0.01). The expression levels of SCF and MMP-9 were significantly elevated after treatment with G-CSF (p<0.05). No significant differences were found in the levels of total bilirubin, albumin and prothrombin time between the treated and control groups; furthermore, no significant differences were observed in the cure and improvement rates between the two groups. CONCLUSIONS: The basal levels of stem cell mobilization in patients with liver cirrhosis might be associated with the repair of liver injury. G-CSF could promote hematopoietic stem cell mobilization through regulation of the expression levels of stem-cell-mobilization-related factors in patients with liver cirrhosis. No apparent effects of G-CSF therapy on both liver function and short-term prognosis in patients with liver cirrhosis were confirmed.

Association of T regulatory cells with natural course and response to treatment with interferon-α in patients with chronic hepatitis B infection.

BACKGROUND: Regulatory T cell populations, particularly CD4(+)CD25(+) T regulatory cells, have been implicated in the persistence of hepatitis B virus (HBV) infection. However, no clear relationship has been established between the frequency of CD4(+)CD25(+) T regulatory cells in the peripheral blood and either the disease phases in the natural history of chronic HBV infection or in the response to interferon-α therapy. METHODS: In the present study, three different common markers of CD4(+)CD25(+) T regulatory cells were used to determine the numbers of T regulatory cells in healthy controls and in patients with chronic HBV infection. RESULTS: No significant difference was found when samples were gated for CD25(hi) and CD25(+)FoxP3(+) T cells. A significant correlation was found between the number of CD4(+) Treg cells that gated with CD25(+)FoxP3(+) and CD25(+)CD127(low/-) in healthy controls and in patients with chronic hepatitis B (CHB) (r = 0.67, 0.59; P < 0.01). The percentages of Treg cells were (8.56 ± 2.01)% in asymptomatic carriers (Asc), (8.74 ± 3.04)% in inactive HBsAg carriers, (10.7 ± 2.93)% in CHB and (7.42 ± 1.28)% in healthy controls (F = 11.1, P < 0.001). The percentage of Treg cells in patients with CHB was higher than in asymptomatic HBV patients, inactive HBsAg carriers, or healthy controls (P < 0.01). The proportion of CD4(+)CD25(+)CD127(low/-) T cells in patients who responded to interferon-α was (11.9 ± 3.3)%, (9.1 ± 2.4)% and (9.0 ± 2.9)% at baseline, week 12 and week 24 after treatment, respectively (Z = 2.42, P < 0.05; Z = 2.67, P < 0.01). CONCLUSIONS: These results suggest that the proportion of the CD4(+)CD25(+) regulatory T cells might be affected by the application of different markers in process to detect T regulatory cells. The frequency of Treg cells was increased in patients with CHB, which might be associated with the disease activity of these patients and contribute to prevention of extensive liver damage. A decline in Treg cells at week 12 of treatment might be associated with a better response to treatment with interferon-α.

Application of interferon response-related gene array to the antiviral treatment outcome in chronic hepatitis C.

BACKGROUND/AIMS: It has been known that viral factors such as genotype and viral load have a major influence on the outcome of antiviral treatment. Nevertheless, researchers have become increasingly aware that host genetic factors can modulate the response to antiviral treatment. The underlying mechanisms for the varying virologic response rates to IFNalpha-based antiviral therapy are unknown. METHODOLOGY: RNA was isolated from peripheral blood monocytes from treatment-naïve patients with chronic hepatitis C before and at the end of treatment. Gene expression was measured using SuperArray microarrays and compared to that of healthy controls. RESULTS: Ten patients were classified as rapid responders (RRs) and seven patients as non-RRs according to the serum HCV RNA level after 4 weeks of treatment in 17 patients with CHC. Compared with healthy controls, nine and eighteen different expression genes were found significantly in patients with RR and N-RR, respectively. Five different expression genes were found between the patients with RR and N-RR. Two genes that were down-regulated were found between HCV genotype 1b and genotype 2a. Seven different expression genes that were all down-regulated were found between the patients with ETVR and N-ETVR. CONCLUSIONS: (1) The down-regulation of some IFN response-related genes are associated with null response to treat with interferon. (2) It should be HCV genotype 1b is more successful in inducing the down-regulation of IFN response-related genes than HCV genotype 2a, thus contribute to the resistance to IFN.

Preliminary identification and analysis of point mutations correlated with response to interferon-alpha in hepatitis B virus post-transcriptional regulatory elements.

BACKGROUND: It is still unclear whether viral genetic variability influences response to interferon (IFN)-alpha treatment. Recent reports suggest that IFN-alpha effects may be associated with hepatitis B virus (HBV) post-transcriptional regulation. This study was designed to explore the heterogeneity of HBV post-transcriptional regulatory elements (HPRE) and the relationship between the diversity of HPRE and the response to IFN-alpha treatment. METHODS: The HPRE sequences from 31 Chinese patients infected with HBV were determined by directly sequencing of polymerase chain reaction (PCR) product, and comparing them to those from Caucasian patients. Subsequently, eukaryotic expression vectors containing HPRE at various points were constructed and transfected into HepG2 cells, which were then exposed to recombinant human cytokines. RESULTS: The T to C point mutation at nt 1504 and the C to T (G) at nt 1508 in HPRE were found in 21 and 19 patients with chronic hepatitis B, respectively; the C to T point mutation at nt 1509 was found in 17 patients. These point mutations did not exist in the HPRE of the Caucasian patients. The activity of the CAT gene obviously increased in the case of T to C point mutation at nt 1504, but did not change in the case of the C to T (G) mutations at nt 1508 and 1509. The activity of the CAT gene at these point mutations of HPRE could be inhibited by IFN-alpha/gamma and tumor necrosis factor (TNF)-alpha except for the point mutations at nt 1508 of HPRE which may escape the suppression role of IFN-alpha on HPRE. CONCLUSIONS: There are point mutations between the HPRE of Chinese and Caucasian HBV patients, which might be correlated with response to IFN-alpha. The variation of HPRE might affect the function of HPRE and influence the regulative function of IFN-alpha other than that of IFN-gamma or TNF-alpha on HPRE.

Preliminary identification and analysis of different points related with response to interferon-alpha in HBV post-transcriptional regulatory element.

OBJECTIVE: To screen the differential points related with response to interferon-alpha in HBV post-transcriptional regulatory element (HPRE). METHODS: HPRE sequence of 31 Chinese patients with HBV infection were detected by direct sequencing of PCR products. Differential points in HPRE between Chinese patients and White patients were compared. RESULTS: The T to C differential point at nt 1 504 and C to T(G) at nt 1 508 were found respectively in HPRE of 21 and 19 patients with chronic hepatitis B, the C to T differential point at nt 1 509 were found in 17 cases. These differential points were not found in HPRE of the White patients. The relationship between the HPRE differential points and the levels of HBV DNA was not observed. CONCLUSION: There were differential points in the HPRE between Chinese and White HBV patients, which might be correlated with response to interferon-alpha.

[Effect of IFN-gamma and TNF-alpha on hepatitis B virus posttranscriptional regulatory elements].

OBJECTIVE: To explore the effect of IFN-gamma and TNF-alpha on hepatitis B virus posttranscriptional regulatory elements. METHODS: The objective eukaryotic expression vectors were constructed by molecular cloning and PCR-based site-directed mutagensis in vitro, and identification was performed using PCR and sequencing analysis. CAT assays were performed by using ELISA kit. RESULTS: The eukaryotic expression vectors containing HPRE segment and mutating point were constructed successfully as confirmed by sequencing analysis. The normalized CAT activity from recombinant pDM138 and control produced in transfected cells incubated in the absence of cytokine were 896 +/- 214 and 37 +/- 11 pg/ml, respectively. After incubation with IFN-gamma, TNF-alpha and IFN-gamma + TNF-alpha, the normalized CAT activity from recombinant pDM138 produced in transfected cells were 324 +/- 57, 396 +/- 82 and 175 +/- 36 pg/ml, respectively (t = 5.19,4.39, 6.68, P < 0.01). The effect of IFN-gamma and TNF-alpha were dose dependent over a range of 0 to 1,000 U/ml. CONCLUSION: The expression of HBV gene may be regulated by IFN-gamma and TNF-alpha through inhibiting the function of HPRE.