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Background: Hydrodynamic injection (HI) of hepatitis B virus (HBV) mouse model is an useful tool for HBV related research in vivo. However, only 40% of C57/BL6 mice injected with 10 μg HBV genome contained plasmid (pAAV-HBV1.2), serum HBsAg more than 6 months and none of the BALB/c mice injected with 10 μg pAAV-HBV1.2 plasmid DNA, serum HBsAg positive more than 4 weeks in the previous study., Methods: In this study, C57/BL6 and BALB/c mice were hydrodynamic injected with different doses of pAAV-HBV1.2 plasmid DNA. HBV related serum markers were detected by ELISA. ALT levels in the serum were measured using full automated biochemistry analyzer. HBcAg positive cells in the liver were detected by immunohistochemical staining. The mRNA levels of IRF3, ISGs including ISG15, OAS, PKR and immune factors including IFNγ, TNFα, TGFβ, IL-6, IL-10, PDL1 in liver of the mice were quantified by qRT-PCR., Results: The results showed that the mice injected with 100 μg high-concentration or 1 μg low-concentration of pAAV-HBV1.2 plasmid DNA did not excert dominant influence on HBV persistence. In contrast, injection of 5 μg intermediate-dose of pAAV-HBV1.2 plasmid DNA led to significant prolonged HBsAg expression and HBV persistence in both C57/BL6 (80% of the mice with HBsAg positive more than 6 months) and BALB/c (60% of the mice with HBsAg positive more than 3 months) mice. IFNγ was significant up-regulated in liver of the mice injected with 1 μg or 100 μg pAAV-HBV1.2 plasmid DNA. TNFα was up-regulated significantly in liver of the mice injected with 100 μg pAAV-HBV1.2 plasmid DNA. Moreover, PDL1 was significant up-regulated in liver of the mice injected with 5 μg pAAV-HBV1.2 plasmid DNA., Conclusion: In this paper we demonstrated that, in the HBV HI mouse model, the concentration of injected pAAV-HBV1.2 plasmid DNA contributes to the diverse kinetics of HBsAg and HBeAg in the serum as well as HBcAg expression level in the liver, which then determined the HBV persisternce, while the antiviral factors IFNγ, TNFα as well as immune negative regulatory factor PDL1 play important roles on HBV persistence.

Background: Hydrodynamic injection (HI) of hepatitis B virus (HBV) mouse model is an useful tool for HBV related research in vivo. However, only 40% of C57/BL6 mice injected with 10 μg HBV genome contained plasmid (pAAV-HBV1.2), serum HBsAg more than 6 months and none of the BALB/c mice injected with 10 μg pAAV-HBV1.2 plasmid DNA, serum HBsAg positive more than 4 weeks in the previous study. Methods: In this study, C57/BL6 and BALB/c mice were hydrodynamic injected with different doses of pAAV-HBV1.2 plasmid DNA. HBV related serum markers were detected by ELISA. ALT levels in the serum were measured using full automated biochemistry analyzer. HBcAg positive cells in the liver were detected by immunohistochemical staining. The mRNA levels of IRF3, ISGs including ISG15, OAS, PKR and immune factors including IFNγ, TNFα, TGFβ, IL-6, IL-10, PDL1 in liver of the mice were quantified by qRT-PCR. Results: The results showed that the mice injected with 100 μg high-concentration or 1 μg low-concentration of pAAVHBV1.2 plasmid DNA did not excert dominant influence on HBV persistence. In contrast, injection of 5 μg intermediatedose of pAAV-HBV1.2 plasmid DNA led to significant prolonged HBsAg expression and HBV persistence in both C57/BL6 (80% of the mice with HBsAg positive more than 6 months) and BALB/c (60% of the mice with HBsAg positive more than 3 months)mice. IFNγ was significant up-regulated in liver of the mice injected with 1 μg or 100 μg pAAV-HBV1.2 plasmid DNA. TNFα was up-regulated significantly in liver of the mice injected with 100 μg pAAV-HBV1.2 plasmid DNA. Moreover, PDL1 was significant up-regulated in liver of the mice injected with 5 μg pAAV-HBV1.2 plasmid DNA. Conclusion: In this paper we demonstrated that, in the HBV HI mouse model, the concentration of injected pAAV-HBV1.2 plasmid DNA contributes to the diverse kinetics of HBsAg and HBeAg in the serum as well as HBcAg expression level in the liver, which then determined the HBV persisternce, while the antiviral factors IFNγ, TNFα as well as immune negative regulatory factor PDL1 play important roles on HBV persistence. [ABSTRACT FROM AUTHOR]

Background: Schistosomiasis is a significant health problem in more than 70 countries distributed between Africa, Asia and South America, with an infection rate of one in 30 individuals. Data on Schistosomiasis, Hepatitis B virus (HBV) and Hepatitis C virus (HCV) co-infection are scarce; however, there is a high prevalence in countries where schistosomiasis is endemic. Methods: A systematic search was performed on published data from 1980-2014. Published papers in the databases Google, Medline, PubMed, and MiPc library were searched using the keywords epidemiology, pathogenesis and outcomes of HBV, HCV and schistosomiasis and data were extracted from the relevant studies. Results: The prevalence of HBV/schistosomiasis co-infection in countries where schistosomiasis is endemic was high, ranging between 9.6 to approximately 64% in Egypt, and a maximum of 15.8% among hospitalized patients in Brazil. Concurrent infection between HBV and schistosomiasis is often associated with countries where schistosomiasis is endemic and may lead to chronic liver inflammation. Similarly, HCV infection rates in schistosomiasis populations range from 1% in Ethiopia reaching up to 50% in Egypt. Conclusion: There is controversy regarding the effects of HBV and HCV on schistosomiasis and vice versa. Vaccination might be a solution to the era of schistosomiasis and co-infection with HBV and HCV. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via the original article. [ABSTRACT FROM AUTHOR]

Proteins, RNA, DNA, lipids, and carbohydrates are only some of the molecular components found in exosomes released by tumor cells. They play an essential role in healthy and diseased cells as messengers of short- and long-distance intercellular communication. However, since exosomes are released by every kind of cell and may be found in blood and other bodily fluids, they may one day serve as biomarkers for a wide range of disorders. In many pathological conditions, including cancer, inflammation, and infection, they play a role. It has been shown that the biogenesis of exosomes is analogous to that of viruses and that the exosomal cargo plays an essential role in the propagation, dissemination, and infection of several viruses. Bidirectional modulation of the immune response is achieved by the ability of exosomes associated with viruses to facilitate immunological escape and stimulate the body's antiviral immune response. Recently, exosomes have received a lot of interest due to their potential therapeutic use as biomarkers for viral infections such as human immunodeficiency virus (HIV), Hepatitis B virus (HBV), Hepatitis C virus (HCV), Epstein–Barr virus (EBV), and SARS-CoV-2. This article discusses the purification procedures and detection techniques for exosomes and examines the research on exosomes as a biomarker of viral infection. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) infection is a problem in several regions of the world with limited resources. Blood samples dried on filter paper (DBS) have been successfully used to diagnose and monitor several infectious diseases. In Mexico there is an urgent need for an affordable and easy sampling method for viral load (VL) testing and monitoring of chronic HBV infection. The purpose of this work was to validate the utility of DBS samples for monitoring HBV infection in patients from Mexico City., Methods: Matched samples of plasma and DBS on filter paper from 47 HBV infected patients from the Instituto Mexicano del Seguro Social (IMSS), were included. To evaluate the DNA stability and purity from DBS stored at different temperature conditions, samples from ten patients were stored at 4 degree, 25 degree, and 37 degree C for 7 days. After DBS elution and DNA extraction, the purity of these samples was determined measuring the O.D. rate 260/280. The DBS utility for molecular studies was assessed with PCR assays to amplify a 322 bp fragment from the "a" determinant region of the HBV "S" gene. The VL from all samples was determined to evaluate the correlation between plasma and DBS matched samples., Results: The quality of the DNA from DBS specimen is not adversely affected by storage at 4 degree, 25 degree and 37 degree C for up 7 days. Statistical ANOVA analyses did not show any significant difference. The same amplification efficiency was observed between DNA templates from samples stored at different temperatures. The Pearson correlation between the VL from DBS and plasma matched samples was 0.93 (p = 0.01). The SD was 1.48 for DBS vs.1.32 for Plasma, and an average of log10 copies/mL of 5.32 vs. 5.53. ANOVA analysis did not show any statistically significant difference between the analyzed groups (p = 0.92)., Conclusion: The results provide strong evidence that the isolation and quantification of DNA-HBV from DBS is a viable alternative for patient monitoring, and molecular characterization of the virus variants circulating in Mexico.

Background: Hepatitis B virus (HBV) infection in Nigeria has remained a Public Health issue. It is a major cause of mortality, especially in developing countries. Vertical transmission of hepatitis B virus infection is thought to be a major route of transmission in low resource areas. In spite of this, routine antenatal screening for hepatitis B infection is not yet practiced in many Nigerian hospitals. This paper present the findings of a study conducted among antenatal women in Nnewi, Nigeria. Methods: It was a cross-sectional study carried out over a 3-month period (August - October, 2009). Recruitment of 480 women attending antenatal clinics in Nnewi, Nigeria was done by simple random sampling using computer generated random numbers. HBsAg screening was done using rapid ELISA Kits. Statistical analysis was computed using STATA 11 package. The results were subjected to analysis using cross tabulations to explore statistical relationships between variables. Chi square test was used to explore proportional relationship between groups. The level of statistical significance was set at p < 0.05 (providing 95% confidence interval). Results: Four hundred and eighty pregnant women were recruited into the study. Of these, 40 tested positive to HBsAg, accounting for 8.3% of the sample population. The age of the subjects studied varied from 14 to 45 years (mean age - 24.3 years) while the mean parity was 2.18. The HIV/HBV co-infection rate was 4.2%. The vertical transmission rate was 51.6%. There were statistically significant relationships between HBV infection and previous history of tribal marks/tattoos (χ² = 27.39, P = 0.001, df = 1), history of contact with previously infected HBV patients (χ² = 23.11, P = 0.001, df = 1) and occupation of the women (χ² = 51.22, P = 0.001, df = 1). Multiple sexual partners, blood transfusion, dental manipulations, sharing of sharps/needles, and circumcision were not significant modes of transmission. There was no statistically significant relationship between maternal age, educational level and HBV infection. Conclusion: The authors argued that hepatitis B screening in pregnancy should be made routine practice in Nigeria because of the low pick up rate of the infection based only on risk factors for the disease. [ABSTRACT FROM AUTHOR]

Background: Chronic infection with hepatitis B virus (HBV) has been proved highly associated with the development of hepatocellular carcinoma (HCC). Aims: The purpose of the study is to investigate the association between HBV preS region quasispecies and HCC development, as well as to develop HCC diagnosis model using HBV preS region quasispecies. Methods: A total of 104 chronic hepatitis B (CHB) patients and 117 HBV-related HCC patients were enrolled. HBV preS region was sequenced using next generation sequencing (NGS) and the nucleotide entropy was calculated for quasispecies evaluation. Sparse logistic regression (SLR) was used to predict HCC development and prediction performances were evaluated using receiver operating characteristic curves. Results: Entropy of HBV preS1, preS2 regions and several nucleotide points showed significant divergence between CHB and HCC patients. Using SLR, the classification of HCC/CHB groups achieved a mean area under the receiver operating characteristic curve (AUC) of 0.883 in the training data and 0.795 in the test data. The prediction model was also validated by a completely independent dataset from Hong Kong. The 10 selected nucleotide positions showed significantly different entropy between CHB and HCC patients. The HBV quasispecies also classified three clinical parameters, including HBeAg, HBVDNA, and Alkaline phosphatase (ALP) with the AUC value greater than 0.6 in the test data. Conclusions: Using NGS and SLR, the association between HBV preS region nucleotide entropy and HCC development was validated in our study and this could promote the understanding of HCC progression mechanism. [ABSTRACT FROM AUTHOR]

Background: Chronic hepatitis B virus (HBV) infection (CHB) is a significant public health problem that could benefit from treatment with immunomodulators. Here we describe a set of therapeutic HBV vaccines that target the internal viral proteins. Methods: Vaccines are delivered by chimpanzee adenovirus vectors (AdC) of serotype 6 (AdC6) and 7 (AdC7) used in prime only or prime-boost regimens. The HBV antigens are fused into an early T cell checkpoint inhibitor, herpes simplex virus (HSV) glycoprotein D (gD), which enhances and broadens vaccine-induced cluster of differentiation (CD8)+ T cell responses. Results: Our results show that the vaccines are immunogenic in mice. They induce potent CD8+ T cell responses that recognize multiple epitopes. CD8+ T cell responses increase after a boost, although the breadth remains similar. In mice, which carry high sustained loads of HBV particles due to a hepatic infection with an adeno-associated virus (AAV)8 vector expressing the 1.3HBV genome, CD8+ T cell responses to the vaccines are attenuated with a marked shift in the CD8+ T cells' epitope recognition profile. Conclusions: Our data show that in different stains of mice including those that carry a human major histocompatibility complex (MHC) class I antigen HBV vaccines adjuvanted with a checkpoint inhibitor induce potent and broad HBV-specific CD8+ T cell responses and lower but still detectable CD4+ T cell responses. CD8+ T cell responses are reduced and their epitope specificity changes in mice that are chronically exposed to HBV antigens. Implications for the design of therapeutic HBV vaccines are discussed. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) serum markers during typical acute self-limited infection are usually depicted as a composite of traditional HBV markers. The current study updates and expands our knowledge of acute hepatitis B with quantitative molecular and serological data on longitudinal samples from five plasmapheresis donors with acute HBV. Methods: 137 longitudinal samples from five plasmapheresis donors with acute HBV were tested, four with self-limited infection and one who developed persistent infection. Testing included quantitative hepatitis B surface antigen (HBsAg), antibodies to HBV antigens, quantitative HBV e antigen (HBeAg), HBV DNA, quantitative HBV core-related antigen (HBcrAg), the highly sensitive ARCHITECT HBsAg NEXT (HBsAgNx) assay, and a quantitative research assay for HBV pregenomic RNA (pg RNA). Results: Peak levels of HBV DNA and HBsAg differed by several orders of magnitude among the panels (2.2 × 105–2.7 × 109 IU/ml for HBV DNA and 7.9–1.1 × 105 IU/ml for HBsAg). HBsAg levels peaked an average of 2.8 days after the HBV DNA peak. The overall duration of observed HBsAg positivity was increased by the more sensitive HBsAgNx assay compared to the quantitative assay in four panels. Intermittently detectable low-level HBV DNA was observed after HBsAg loss in three panels. Peak HBeAg levels occurred 2–20 days after the DNA peak and ranged from 1.1 to 4.5 × 103 IU/ml. In four panels with resolution of infection, anti-HBs levels indicating immunity (≥ 10 mIU/ml) were detected 19–317 days after the HBV DNA peak. Maximum HBcrAg concentrations ranged from 1 × 105 to > 6.4 × 106 U/ml and correlated with HBeAg values (R2 = 0.9495) and with HBV DNA values (R2 = 0.8828). Peak pgRNA values ranged from 1.6 × 103 to 1.4 × 108 U/ml and correlated with HBV DNA (R2 = 0.9013). Conclusion: Traditional and new/novel HBV biomarkers were used to generate molecular and serological profiles for seroconversion panels spanning the early to late phases of acute HBV. Seroconversion profiles were heterogeneous and may be instructive in appreciating the spectrum of acute profiles relative to the typical composite representation. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) is a DNA virus belonging to the Hepadnaviridae family that has limited tissue and species specificity. Due to the persistence of HBV covalently closed circular DNA (cccDNA) in host cells after HBV infection, current antiviral drugs cannot eradicate HBV. Therefore, the development of an active cell culture system supporting HBV infection has become the key to studying HBV and developing effective therapeutic drugs. Main body: This review summarizes the significant research achievements in HBV cell culture systems in vitro, including embryonic hepatocytes and primary hepatocytes, which support the virus infection process most similar to that in the body and various liver tumor cells. The discovery of the bile-acid pump sodium-taurocholate co-transporting polypeptide (NTCP) as the receptor of HBV has advanced our understanding of HBV biology. Subsequently, various liver cancer cells overexpressing NTCP that support HBV infection have been established, opening a new door for studying HBV infection. The fact that induced pluripotent stem cells that differentiate into hepatocyte-like cells support HBV infection provides a novel idea for the establishment of an HBV cell culture system. Conclusion: Because of the host and tissue specificity of HBV, a suitable in vitro HBV infection system is critical for the study of HBV pathogenesis. Nevertheless, recent advances regarding HBV infection in vitro offer hope for better studying the biological characteristics of HBV, the pathogenesis of hepatitis B, the screening of anti-HBV drugs and the mechanism of carcinogenesis. [ABSTRACT FROM AUTHOR]

Gene delivery of antiviral therapeutics to anatomical sites where viruses accumulate and persist is a promising approach for the next generation of antiviral therapies. Recombinant adeno-associated viruses (AAV) are one of the leading vectors for gene therapy applications that deliver gene-editing enzymes, antibodies, and RNA interference molecules to eliminate viral reservoirs that fuel persistent infections. As long-lived viral DNA within specific cellular reservoirs is responsible for persistent hepatitis B virus, Herpes simplex virus, and human immunodeficiency virus infections, the discovery of AAV vectors with strong tropism for hepatocytes, sensory neurons and T cells, respectively, is of particular interest. Identification of natural isolates from various tissues in humans and non-human primates has generated an extensive catalog of AAV vectors with diverse tropisms and transduction efficiencies, which has been further expanded through molecular genetic approaches. The AAV capsid protein, which forms the virions' outer shell, is the primary determinant of tissue tropism, transduction efficiency, and immunogenicity. Thus, over the past few decades, extensive efforts to optimize AAV vectors for gene therapy applications have focused on capsid engineering with approaches such as directed evolution and rational design. These approaches are being used to identify variants with improved transduction efficiencies, alternate tropisms, reduced sequestration in non-target organs, and reduced immunogenicity, and have produced AAV capsids that are currently under evaluation in pre-clinical and clinical trials. This review will summarize the most recent strategies to identify AAV vectors with enhanced tropism and transduction in cell types that harbor viral reservoirs. [ABSTRACT FROM AUTHOR]

Background: Liver cancer has become one of the most common cancers and has a high mortality rate. Hepatocellular carcinoma is one of the most common liver cancers, and its occurrence and development process are associated with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. Main body The serious consequences of chronic hepatitis virus infections are related to the viral invasion strategy. Furthermore, the viral escape mechanism has evolved during long-term struggles with the host. Studies have increasingly shown that suppressor of cytokine signaling (SOCS) proteins participate in the viral escape process. SOCS proteins play an important role in regulating cytokine signaling, particularly the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway. Cytokines stimulate the expression of SOCS proteins, in turn, SOCS proteins inhibit cytokine signaling by blocking the JAK-STAT signaling pathway, thereby achieving homeostasis. By utilizing SOCS proteins, chronic hepatitis virus infection may destroy the host's antiviral responses to achieve persistent infection. Conclusions: This review provides recent knowledge regarding the role of SOCS proteins during chronic hepatitis virus infection and provides some new ideas for the future treatment of chronic hepatitis. [ABSTRACT FROM AUTHOR]

Background: Reactivation of hepatitis B virus is a common complication that occurs in patients with hepatitis B virus (HBV) infection who have received cytotoxic chemotherapy or immunosuppressive therapy. This clinical phenomenon not only occurs in overt HBV infection patients but also occurs in patients with resolved HBV infection. Previous research has confirmed that epirubicin and dexamethasone can stimulate HBV replication and expression directly rather than indirectly through immunosuppression. Mitomycin and 5-fluorouracil are currently used as cytotoxic chemotherapy drugs for cancer patients. Leflunomide and mycophenolic acid are regarded as immunosuppressants for autoimmune diseases, and numerous clinical studies have reported that these drugs can reactivate HBV replication. In this study, we aimed to investigate whether mitomycin, 5-fluorouracil, leflunomide and mycophenolic acid induce HBV reactivation directly rather than indirectly through immunosuppression. Methods: To observe the effect of mitomycin, 5-fluorouracil, leflunomide and mycophenolic acid on HBV replication and expression, we employed HepG2.2.15 and HBV-NLuc-35 cells as a cell model. Next, by native agarose gel electrophoresis (NAGE), quantitative PCR (qPCR), luciferase assay and HBV e antigen (HBeAg) enzyme-linked immunosorbent assay (ELISA) we detected changes in HBV replication and expression induced by these drugs. We also investigated whether lamivudine could inhibit the observed phenotype. SPSS 18.0 software was employed for statistical analysis, One-way ANOVA was used to compare multiple groups. Results: Expression of HBV capsids and HBeAg in HepG2.2.15 cells was increased by increasing concentration of mitomycin, 5-fluorouracil, leflunomide, and mycophenolic acid. This phenomenon was also demonstrated in HBV-NLuc-35 cells, and the expression of capsids and luciferase activity increased in the same concentration-dependent manner. Replication levels of intracellular capsid DNA and extracellular HBV DNA in HepG2.2.15 cells gradually increased in a dose-dependent manner. In addition, although epirubicin, mitomycin, 5-fluorouracil, dexamethasone, leflunomide and mycophenolic acid enhanced HBV replication, lamivudine inhibited this process. Conclusion: Our study confirmed that mitomycin, 5-fluorouracil, leflunomide and mycophenolic acid directly upregulated HBV replication and expression in vitro. This effect was investigated not only in HepG2.2.15 cells but also in the HBV-NLuc-35 replication system. Moreover, this effect could be prevented by nucleoside analogs, such as lamivudine (LAM). Thus, for patients with HBV infection, prophylactic antiviral therapy is necessary before receiving cytotoxic chemotherapy or immunosuppressive therapy. [ABSTRACT FROM AUTHOR]

Background: LIN28B is involved in multiple cellular developmental processes, tissue inflammatory response and tumourigenesis. The association of LIN28B polymorphisms with hepatitis B virus (HBV) infection remains unknown. Methods: This study investigated the association of LIN28B rs314277, rs314280, rs369065 and rs7759938 polymorphisms in patients with chronic HBV infection, a major cause of liver disease including hepatocellular carcinoma (HCC). A total of 781 individuals including 515 cases of chronic HBV infection (91 asymptomatic carrier status, 128 chronic hepatitis, 127 cirrhosis and 169 HCC), 97 HBV infection resolvers and 169 healthy controls were investigated. Results: LIN28 rs314280 genotypes GA + AA were higher in resolver and controls than patients (P = 0.011). Patients had significantly lower rs314280 allele A than resolvers (P = 0.031, OR 0.689, 95%CI 0.491–0.969) or controls (P = 0.034, OR 0.741, 95%CI 0.561–0.978). In dominant model, patients had significantly lower rs314280 genotypes AA+GA than controls (P = 0.008, OR 0.623, 95%CI 0.439–0.884). LIN28 rs7759938 genotypes TC + CC were higher in resolvers and controls than patients (P = 0.015). Patients had significantly lower rs7759938 allele C than resolvers (P = 0.048, OR 0.708, 95%CI 0.503–0.999). In dominant model, patients had significantly lower rs7759938 genotypes TC + CC than controls (P = 0.010, OR 0.632, 95%CI 0.445–0.897). Chronic hepatitis patients had lower frequency of rs369065 genotype TC than asymptomatic carriers, cirrhosis and HCC (P = 0.019). Conclusions: These results suggest that LIN28 rs314280 and rs7759938 may be related to the susceptibility of chronic HBV infection. Further studies are warranted to examine the association of LIN28B polymorphisms with HBV-related diseases, especially HCC. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) infection remains as one of the major public health problems in the world. Type I interferon (IFN) plays an essential role in antiviral defense by induced expression of a few hundred interferon stimulated genes (ISGs), including ubiquitin-specific protease 18 (USP18). The expression level of USP18 was elevated in the pretreatment liver tissues of chronic hepatitis B(CHB) patients who did not respond to IFN treatment. Thus, this study was designed to investigate the effects of USP18 on HBV replication/production. Methods: The levels of wild type USP18(WT-USP18) and USP18 catalytically inactive form C64S were up-regulated by plasmids transfection in HepAD38 cells, respectively. Real-time PCR and ELISA were used to quantify HBV replication. Type I IFN signaling pathway was monitored at three levels: p-STAT1 (western Blot), interferon stimulated response element (ISRE) activity (dual luciferase assay) and ISGs expression (real time PCR). Results: Our data demonstrated that overexpression of either WT-USP18 or USP18-C64S inactive mutant increased the intracellular viral pgRNA, total DNA, cccDNA, as well as HBV DNA levels in the culture supernatant, while silencing USP18 led to opposite effect on HBV production. In addition, upregulated WT-USP18 or USP18-C64S suppressed ISRE activity and the expression levels of p-STAT1 and ISGs. Conclusion: USP18 promoted HBV replication via inhibiting type I IFN signaling pathway, which was independent of its protease activity. [ABSTRACT FROM AUTHOR]

Background: Occult hepatitis B infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in the serum and/or liver in HBsAg-negative individuals. OBI is associated with the risk of viral transmission, especially in developing countries, and with progressive liver disease and reactivation in immunosuppressive patients. The objective of this study was to evaluate the relation of OBI to HLA-DP single nucleotide polymorphisms (SNPs) encoding antigen-binding sites for the immune response to HBV infection. As HLA-DP variants affect the mRNA expression of HLA-DPA1 and HLA-DPB1 in the liver, we hypothesised that high levels of HLA-DPA1 and HLA-DPB1 expression favour OBI development. Methods: The study enrolled 456 Indonesian healthy blood donors (HBsAg negative). OBI was defined as the presence of HBV-DNA in at least two of four open reading frames (ORFs) of the HBV genome detected by nested PCR. SNPs in HLA-DPA1 (rs3077) and HLA-DPB1 (rs3135021, rs9277535, and rs2281388) were genotyped using real-time Taqman® genotyping assays. Results: Of 122 samples positive for anti-HBs and/or anti-HBc, 17 were determined as OBI. The minor allele in rs3077 was significantly correlated with OBI [odds ratio (OR) = 3.87, 95% confidence interval (CI) = 1.58-9.49, p = 0.0015]. The prevalence of the minor allele (T) was significantly higher in subjects with OBI than in those without (59% and 33%, respectively). The combination of haplotype markers (TGA for rs3077-rs3135021-rs9277535) was associated with increased risk of OBI (OR = 4.90, 95%CI = 1.12-21.52 p = 0.038). The prevalence of OBI was highest in the isolated anti-HBc group among the three seropositive categories: anti-HBs <500 mIU/ml, anti-HBs =500 mIU/ml, and isolated anti-HBc (29.41%, p = 0.014). Conclusion: Genetic variants of HLA-DP and the presence of anti-HBc are important predictors of OBI in Indonesian blood donors. [ABSTRACT FROM AUTHOR]

Background: Chronic hepatitis B virus (HBV) infection remains an important public health issue. A20, a ubiquitin-editing protein encoded by tumor necrosis factor alpha-inducible protein 3 (TNFAIP3) gene, is complicated in HBV infection and liver injury. The tandem polymorphisms (rs148314165, rs200820567), deletion T followed by a T to A transversion and collectively referred to as TT > A in TNFAIP3, may attenuate A20 expression. Methods: The rs148314165 and rs200820567 polymorphisms were examined using PCR amplification followed by direct sequencing in 419 patients with chronic HBV infection, 77 HBV infection resolvers and 175 healthy controls of Chinese Han ethnicity. Results: The genotypes and alleles of rs148314165 and rs200820567 polymorphisms determined and the haplotypes constructed were consistently identical, confirming the reliable determination of the TT > A variant. The genotypes of rs148314165 and rs200820567 in HBV patients, HBV infection resolvers and healthy controls are in Hardy-Weinberg equilibrium (P > 0. 05). The patients with chronic HBV infection had higher frequency of TT > A variant than healthy controls (6.6% vs. 3.4%; OR, 1.979; 95% CI, 1.046-3.742; P = 0.033). The frequency of TT > A variant between patients with chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma had no significant differences. Conclusions: The TT > A variant of TNFAIP3 may be associated with the susceptibility of chronic HBV infection but not the clinical diseases. Studies in large sample size of HBV patient and control populations are required to further clarify the role of this important variant in chronic HBV infection and the disease progression related to the infection. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) transmission through blood transfusion is reduced by screening for hepatitis B surface antigen (HBsAg). However this method cannot detect the presence of occult hepatitis B virus infection. This study sought to determine the prevalence of occult hepatitis B virus infection among blood donors in Ile-Ife, Nigeria. For the first time in Nigeria we employed an automated real-time PCR- method to investigate the prevalence of occult HBV in blood donors. Methods: Blood donors screened with HBsAg immunochromatographic rapid test kits at the blood transfusion units of two hospitals and found to be negative were recruited into the study. Questionnaires to elicit risk factors for HBV infection were administered and then 10 ml of blood was collected from each donor. Plasma samples obtained from these HBsAg negative blood donors were screened again for HBsAg using an enzyme-linked immunosorbent assay (ELISA) method, and those found negative were screened for the presence of total antibody to the HBV core antigen (anti-HBc) using ELISA method. Those positive to anti-HBc were then tested for HBV DNA, using an automated realtime PCR method. Results: Five hundred and seven blood donors found HBsAg negative by immunochromatographic rapid test kits at both blood transfusion units, were tested for HBsAg using ELISA and 5 (1 %) were HBsAg positive. The 502 found negative were tested for anti-HBc and 354 (70.5 %) were found positive implying previous exposure to HBV and 19 (5.4 %) of the 354 anti-HBc positive had HBV DNA signifying occult HBV infection. No risk factors were found to be associated with the presence of HBV DNA among those who tested positive. Conclusion: Occult HBV infection exists in blood donors in Ile-Ife, Nigeria and the use of HBsAg alone for screening prospective donors will not eliminate the risk of HBV transmission in blood transfusion or stem cell transplantation. [ABSTRACT FROM AUTHOR]

Background: The HBx oncoprotein of hepatitis B virus has been implicated in the development and progression of hepatocellular carcinoma (HCC). HBx engages multiple signalling and growth-promoting pathways to induce cell proliferation and enhance ribosome biogenesis. Interestingly, the levels of Upstream Binding Factor (UBF) required for rDNA transcription and ribosome biogenesis are found elevated in the HCC patients. However, the molecular mechanism of UBF overexpression under the HBx microenvironment and consequent cell transformation remains elusive. Methods: The UBF gene expression was investigated after co-expressing HBx in immortalized human hepatocytes (IHH) and human hepatoma Huh7 cells. Gene expression analysis involved estimation of mRNA level by real-time PCR, western blotting of protein, chromatin immune-precipitation assay, BrdU incorporation assay and soft agar colony formation assay. UBF expression was also investigated in an HBx transgenic mouse model of HCC to get a better mechanistic insight under more physiological conditions. Results: Ectopic expression of HBx in IHH as well as Huh7 cells led to a marked increase in UBF expression both at mRNA and protein levels. Elevated levels of UBF were also observed in the hepatic tumors of HBx transgenic mice. Our ChIP studies revealed a marked increase in the occupancy of c-Myc on the UBF gene promoter in the presence of HBx and increase in its transcription. Enhanced UBF expression under the HBx microenvironment led to a marked increase in cell proliferation and transformation of IHH cells. Conclusions: Our study provides some compelling evidences in support of HBx-mediated increase in UBF levels that abets oncogenic onslaught in hepatic cells by increasing rDNA transcription and ribosome biogenesis. [ABSTRACT FROM AUTHOR]

Background: Hepatitis B virus (HBV) surface antigen (HBsAg) screening in blood banks reduced the risk of HBV transmission through transfusion. However, the detection of occult HBV infection among blood donors is imperative for improving blood safety. The aim of this study was to determine the frequency of occult hepatitis B virus infection among blood donors in Medellin, North West Colombia and to characterize the viral genotypes and mutations. Methods: Serum samples from blood donors with the serological profile HBsAg-/Anti-HBc+ were evaluated by nested or hemi-nested PCR for HBV genome ORF C, ORF S and ORF X. A pairwise analysis was carried out with deduced amino acids sequence of overlapping S/P region. Results: A total of 302 serum samples HBsAg-/Anti-HBc+ from donors recruited in a blood bank in Medellin were evaluated by PCR for the HBV genome. Six samples (1.98%) were identified as occult HBV infection. The cases were confirmed by sequencing and viral load analysis. All HBV strains were genotype F, subgenotype F3. The amino acid substitutions sY100H, sV184A, and sK141N were detected in ORF S and rtL108P, rtR110G, rtL180M, rtR192C, rtT150S, and rtL187V in ORF P. Conclusions: This is the first report and characterization of OBI cases in blood donors in Colombia. Six from 302 donors HBsAg-/Anti-HBc+ were identified. The mutations rtL108P, rtR110G, rtR192C, rtT150S and rtI187V were characterized for the first time in these samples. Further studies are necessary to explore if these mutations could potentially impair HBsAg production. [ABSTRACT FROM AUTHOR]