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1.
Nat Rev Gastroenterol Hepatol ; 19(11): 727-745, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35859026

RESUMO

Globally, 296 million people are infected with hepatitis B virus (HBV), and approximately one million people die annually from HBV-related causes, including liver cancer. Although there is a preventative vaccine and antiviral therapies suppressing HBV replication, there is no cure. Intensive efforts are under way to develop curative HBV therapies. Currently, only a few biomarkers are available for monitoring or predicting HBV disease progression and treatment response. As new therapies become available, new biomarkers to monitor viral and host responses are urgently needed. In October 2020, the International Coalition to Eliminate Hepatitis B Virus (ICE-HBV) held a virtual and interactive workshop on HBV biomarkers endorsed by the International HBV Meeting. Various stakeholders from academia, clinical practice and the pharmaceutical industry, with complementary expertise, presented and participated in panel discussions. The clinical utility of both classic and emerging viral and immunological serum biomarkers with respect to the course of infection, disease progression, and response to current and emerging treatments was appraised. The latest advances were discussed, and knowledge gaps in understanding and interpretation of HBV biomarkers were identified. This Roadmap summarizes the strengths, weaknesses, opportunities and challenges of HBV biomarkers.


Assuntos
Hepatite B Crônica , Hepatite B , Humanos , Vírus da Hepatite B , Hepatite B Crônica/diagnóstico , Hepatite B Crônica/tratamento farmacológico , Antivirais/uso terapêutico , Replicação Viral , Biomarcadores , Progressão da Doença , Hepatite B/diagnóstico , Hepatite B/tratamento farmacológico
3.
Annu Rev Virol ; 8(1): 437-458, 2021 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586871

RESUMO

Chronic hepatitis B virus (HBV) infection is the leading cause of liver cirrhosis and hepatocellular carcinoma, estimated to be globally responsible for ∼800,000 deaths annually. Although effective vaccines are available to prevent new HBV infection, treatment of existing chronic hepatitis B (CHB) is limited, as the current standard-of-care antiviral drugs can only suppress viral replication without achieving cure. In 2016, the World Health Organization called for the elimination of viral hepatitis as a global public health threat by 2030. The United States and other nations are working to meet this ambitious goal by developing strategies to cure CHB, as well as prevent HBV transmission. This review considers recent research progress in understanding HBV pathobiology and development of therapeutics for the cure of CHB, which is necessary for elimination of hepatitis B by 2030.


Assuntos
Hepatite B Crônica , Hepatite B , Antivirais/uso terapêutico , Hepatite B/tratamento farmacológico , Hepatite B/prevenção & controle , Vírus da Hepatite B , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/prevenção & controle , Humanos , Replicação Viral
4.
BMC Public Health ; 21(1): 1004, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-34044808

RESUMO

BACKGROUND: An estimated between 257 and 292 million people live with chronic HBV globally. While much is known about the causes, and epidemiology of HBV, little is understood about the quality of life and impact of HBV on those living with the infection. METHODS: A random sample of HBV-related email queries sent to the Hepatitis B Foundation, a U.S.-based non-profit organization, over a 12-month period in 2018-2019 were retrieved, tabulated, and analyzed qualitatively to highlight information needs and explore the experiences of people living with HBV and their families and loved ones. Codebook development was informed by the literature and through line-by-line reading of a sub-sample of queries. Data analysis was facilitated by NVivo12 software. Data were coded independently by two members of the research team and intercoder reliability was assessed to assure coding accuracy throughout the coding phase. RESULTS: A total of 338 queries from people around the globe were identified and analyzed. The analysis revealed three thematic groups: 1) health-specific challenges associated with diagnosis and treatment, 2) emotional needs related to experiences with HBV stigma, discrimination, fear, social isolation, and distress and 3) informational needs related to HBV prevention and transmission, and interpretation of laboratory tests. CONCLUSIONS: People living with HBV are in need of information to manage their disease and prevent its spread. Analysis of queries uncovered significant misconceptions about HBV transmission and treatment. Additionally, the emotional and psychological impact of an HBV diagnosis on those living with the infection is significant. There is a clear need for patient and community education to expand knowledge and awareness of HBV globally to achieve 2030 WHO HBV elimination goals.


Assuntos
Hepatite B , Qualidade de Vida , Acessibilidade aos Serviços de Saúde , Hepatite B/epidemiologia , Humanos , Pesquisa Qualitativa , Reprodutibilidade dos Testes
5.
JCI Insight ; 6(7)2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33621209

RESUMO

Studies of human hepatitis B virus (HBV) immune pathogenesis are hampered by limited access to liver tissues and technologies for detailed analyses. Here, utilizing imaging mass cytometry (IMC) to simultaneously detect 30 immune, viral, and structural markers in liver biopsies from patients with hepatitis B e antigen+ (HBeAg+) chronic hepatitis B, we provide potentially novel comprehensive visualization, quantitation, and phenotypic characterizations of hepatic adaptive and innate immune subsets that correlated with hepatocellular injury, histological fibrosis, and age. We further show marked correlations between adaptive and innate immune cell frequencies and phenotype, highlighting complex immune interactions within the hepatic microenvironment with relevance to HBV pathogenesis.


Assuntos
Hepatite B Crônica/patologia , Citometria por Imagem/métodos , Fígado/imunologia , Fígado/virologia , Adolescente , Adulto , Fatores Etários , Biópsia , Criança , Feminino , Antígenos E da Hepatite B/metabolismo , Hepatite B Crônica/imunologia , Humanos , Processamento de Imagem Assistida por Computador , Imunidade Inata , Antígenos Comuns de Leucócito/metabolismo , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
PLoS One ; 13(10): e0206835, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30372488

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0203149.].

7.
PLoS One ; 13(8): e0203149, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30169533

RESUMO

BACKGROUND: We previously developed a logistic regression algorithm that uses AFP, age, gender, ALK and ALT levels to improve the detection of hepatocellular carcinoma (HCC). In 3,158 patients from 5 independent sites, this algorithm, referred to as the "Doylestown" algorithm, increased the AUROC of AFP 4% to 12% and had equal benefit regardless of tumor size or the etiology of liver disease. AIMS: Analysis of the Doylestown algorithm using samples from individuals taken before their diagnosis of HCC. METHODS: Here, the algorithm was tested using samples at multiple time points from (a) patients with established chronic liver disease, without HCC (120 patients) and (b) 116 patients with HCC diagnosis (85 patients with early stage HCC and 31 patients with recurrent HCC), taken at the time of, and up to 12 months prior to cancer diagnosis. RESULTS: Among patients who developed HCC, comparing the Doylestown algorithm at a fixed cut-off to AFP at 20 ng/mL, the Doylestown algorithm increased the True Positive Rate (TPR) in identification of HCC from 36 to 50%, at a time point of 12 months prior to the conventional HCC detection. Similar results were obtained in those patients with recurrent HCC, where the Doylestown algorithm increased TPR in detection of HCC from 18% to 59%, at 12 months prior to detection of recurrence. CONCLUSIONS: This algorithm significantly improves the prediction of HCC by AFP alone and may have value in the early detection of HCC.


Assuntos
Algoritmos , Carcinoma Hepatocelular/diagnóstico , Detecção Precoce de Câncer/métodos , Neoplasias Hepáticas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Diagnóstico Diferencial , Feminino , Humanos , Modelos Lineares , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Sensibilidade e Especificidade , Carga Tumoral , Adulto Jovem
8.
Antiviral Res ; 158: 185-198, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30145242

RESUMO

Similar to other mammalian viruses, the life cycle of hepatitis B virus (HBV) is heavily dependent upon and regulated by cellular (host) functions. These cellular functions can be generally placed in to two categories: (a) intrinsic host restriction factors and innate defenses, which must be evaded or repressed by the virus; and (b) gene products that provide functions necessary for the virus to complete its life cycle. Some of these functions may apply to all viruses, but some may be specific to HBV. In certain cases, the virus may depend upon the host function much more than does the host itself. Knowing which host functions regulate the different steps of a virus' life cycle, can lead to new antiviral targets and help in developing novel treatment strategies, in addition to improving a fundamental understanding of viral pathogenesis. Therefore, in this review we will discuss known host factors which influence key steps of HBV life cycle, and further elucidate therapeutic interventions targeting host-HBV interactions.


Assuntos
Antivirais/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/fisiologia , Hepatite B/tratamento farmacológico , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/fisiologia , Animais , Capsídeo/metabolismo , DNA Viral , Vírus da Hepatite B/genética , Vírus da Hepatite B/patogenicidade , Hepatócitos/efeitos dos fármacos , Hepatócitos/virologia , Interações Hospedeiro-Patógeno/genética , Humanos , Estágios do Ciclo de Vida , Fígado/virologia , Nucleocapsídeo , Transcrição Reversa/efeitos dos fármacos , Proteínas do Envelope Viral/metabolismo , Montagem de Vírus/fisiologia , Ligação Viral , Internalização do Vírus/efeitos dos fármacos , Replicação Viral
10.
Antiviral Res ; 150: 93-100, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29248746

RESUMO

In early 2017, the Hepatitis B Foundation invited 30 experts in the fields of hepatitis B and liver cancer research to identify projects they deemed important to the goal of finding a cure for chronic hepatitis B and D and the diseases with which these viral infections are associated. They were also asked to identify general categories of research and to prioritize sub-project topics within those areas. The experts generally agreed on broadly defined areas of research, but there was usually little difference between the highest and lowest scoring projects; for the most part, all programs described in this document were considered valuable and necessary. An executive summary of this discussion was recently published (Alter et al., Hepatology 2017). The present manuscript reports the areas of research identified by the workshop participants, provides a brief rationale for their selection, and attempts to express differences among the priorities assigned to each area of research, when such distinctions were expressed.


Assuntos
Antivirais/farmacologia , Vírus da Hepatite B/efeitos dos fármacos , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/virologia , Pesquisa , Humanos
11.
Proteomics Clin Appl ; 11(9-10)2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28561948

RESUMO

PURPOSE: Cholangiocarcinoma (CCA) is a malignancy of the bile ducts. The purpose of this discovery study was to identify effective serum markers for surveillance of cholangiocarcinoma. EXPERIMENTAL DESIGN: Using a glycomic method, patients with CCA were determined to have increased levels of alpha-1,3 and alpha-1,6 linked fucosylated glycan. Proteomic analysis of the serum fucosylated proteome identified proteins such as alpha-2-macroglobulin, kininogen, hemopexin, fetuin-A, alpha-1 anti-trypsin, and ceruloplasmin as being hyperfucosylated in HCC. The levels of these glycoproteins in 109 patients with CCA, primary sclerosing cholangitis (PSC), and control patients were compared to the performance of CA-19-9, the current "gold standard" assay for cholangiocarcinoma. RESULTS: Fucosylated Fetuin-A (fc-Fetuin-A) had the best ability to differentiate CCA from PSC, with an AUROC of 0.812 or 0.8665 at differentiating CCA from those with PSC or other liver disease. CA-19-9 had poor ability to differentiate PSC from cholangiocarcinoma (AUROC of 0.625). CONCLUSION AND CLINICAL RELEVANCE: Using glycomic and proteomic methods we identified a set of proteins that contain altered glycan in the sera of those with CCA. One of these proteins, fucosylated Fetuin-A may have value in the surveillance of people at risk for the development of cholangiocarcinoma.


Assuntos
Neoplasias dos Ductos Biliares/metabolismo , Biomarcadores Tumorais/metabolismo , Colangiocarcinoma/metabolismo , Fucose/metabolismo , Proteômica , alfa-2-Glicoproteína-HS/metabolismo , Neoplasias dos Ductos Biliares/sangue , Neoplasias dos Ductos Biliares/diagnóstico , Colangiocarcinoma/sangue , Colangiocarcinoma/diagnóstico , Feminino , Fucose/sangue , Glicosilação , Humanos , Masculino , Pessoa de Meia-Idade
12.
Antimicrob Agents Chemother ; 60(2): 925-35, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26621620

RESUMO

The aminoglycoside Geneticin (G418) is known to inhibit cell culture proliferation, via virus-specific mechanisms, of two different virus genera from the family Flaviviridae. Here, we tried to determine whether Geneticin can selectively alter the switching of the nucleotide 1 to 570 RNA region of hepatitis C virus (HCV) and, if so, whether this inhibits viral growth. Two structure-dependent RNases known to specifically cleave HCV RNA were tested in the presence or absence of the drug. One was the Synechocystis sp. RNase P ribozyme, which cleaves the tRNA-like domain around the AUG start codon under high-salt buffer conditions; the second was Escherichia coli RNase III, which recognizes a double-helical RNA switch element that changes the internal ribosome entry site (IRES) from a closed (C) conformation to an open (O) one. While the drug did not affect RNase P activity, it did inhibit RNase III in the micromolar range. Kinetic studies indicated that the drug favors the switch from the C to the O conformation of the IRES by stabilizing the distal double-stranded element and inhibiting further processing of the O form. We demonstrate that, because the RNA in this region is highly conserved and essential for virus survival, Geneticin inhibits HCV Jc1 NS3 expression, the release of the viral genomic RNA, and the propagation of HCV in Huh 7.5 cells. Our study highlights the crucial role of riboswitches in HCV replication and suggests the therapeutic potential of viral-RNA-targeted antivirals.


Assuntos
Antivirais/farmacologia , Gentamicinas/farmacologia , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , RNA Viral/química , Linhagem Celular Tumoral/virologia , Códon de Iniciação , Hepacivirus/patogenicidade , Humanos , Cinética , Conformação de Ácido Nucleico , RNA Viral/metabolismo , Ribonuclease III/química , Ribonuclease III/metabolismo , Ribonuclease P/química , Ribonuclease P/metabolismo , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos
14.
Cancer Prev Res (Phila) ; 9(2): 172-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26712941

RESUMO

Biomarkers for the early diagnosis of hepatocellular carcinoma (HCC) are needed to decrease mortality from this cancer. However, as new biomarkers have been slow to be brought to clinical practice, we have developed a diagnostic algorithm that utilizes commonly used clinical measurements in those at risk of developing HCC. Briefly, as α-fetoprotein (AFP) is routinely used, an algorithm that incorporated AFP values along with four other clinical factors was developed. Discovery analysis was performed on electronic data from patients who had liver disease (cirrhosis) alone or HCC in the background of cirrhosis. The discovery set consisted of 360 patients from two independent locations. A logistic regression algorithm was developed that incorporated log-transformed AFP values with age, gender, alkaline phosphatase, and alanine aminotransferase levels. We define this as the Doylestown algorithm. In the discovery set, the Doylestown algorithm improved the overall performance of AFP by 10%. In subsequent external validation in over 2,700 patients from three independent sites, the Doylestown algorithm improved detection of HCC as compared with AFP alone by 4% to 20%. In addition, at a fixed specificity of 95%, the Doylestown algorithm improved the detection of HCC as compared with AFP alone by 2% to 20%. In conclusion, the Doylestown algorithm consolidates clinical laboratory values, with age and gender, which are each individually associated with HCC risk, into a single value that can be used for HCC risk assessment. As such, it should be applicable and useful to the medical community that manages those at risk for developing HCC.


Assuntos
Algoritmos , Biomarcadores Tumorais/sangue , Carcinoma Hepatocelular/diagnóstico , Cirrose Hepática/diagnóstico , Neoplasias Hepáticas/diagnóstico , Carcinoma Hepatocelular/sangue , Estudos de Casos e Controles , Estudos de Coortes , Seguimentos , Humanos , Técnicas Imunoenzimáticas , Cirrose Hepática/sangue , Neoplasias Hepáticas/sangue , Modelos Logísticos , Estadiamento de Neoplasias , Prognóstico , Curva ROC , alfa-Fetoproteínas/análise
15.
Antiviral Res ; 121: 69-81, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26112647

RESUMO

This year marks the 50th anniversary of the discovery of the Australia antigen (Blumberg et al., 1965), which in 1967 was identified to be the hepatitis B virus (HBV) surface antigen. Even though several antiviral medications have been in use for the management of chronic HBV infection for more than 20years, sustained clearance of HBsAg, similar to the sustained viral response (SVR) or cure in chronic hepatitis C, occurs in only a minority of treated patients. Moreover, even after 10years of effective suppression of HBV viremia with current therapy, there is only a 40-70% reduction in deaths from liver cancer. Recent success in developing antivirals for hepatitis C that are effective across all genotypes has renewed interest in a similar cure for chronic HBV infection. In this article, we review a wave of newly identified drug targets, investigational compounds and experimental strategies that are now under clinical evaluation or in preclinical development. The paper forms part of a symposium in Antiviral Research on "An unfinished story: From the discovery of the Australia antigen to the development of new curative therapies for hepatitis B."


Assuntos
Antivirais/farmacologia , Antivirais/uso terapêutico , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/imunologia , Hepatite B Crônica/tratamento farmacológico , Animais , Antivirais/isolamento & purificação , Descoberta de Drogas/tendências , Humanos
16.
Sci Rep ; 5: 10478, 2015 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-26000761

RESUMO

Hepatitis B virus (HBV) is a hepatotropic virus causing hepatitis, cirrhosis and hepatocellular carcinoma (HCC). The methylation status of the HBV DNA in its different forms can potentially provide insight into the pathogenesis of HBV-related liver diseases, including HCC, however this is unclear. The goal of this study is to obtain comprehensive DNA methylation profiles of the three putative CpG islands in the HBV DNA in infected livers, with respect to liver disease progression. The extent of methylation in these CpG islands was first assessed using bisulfite PCR sequencing with a small set of tissue samples, followed by analysis using both quantitative bisulfite-specific PCR and quantitative methylation-specific PCR assays in a larger sample size (n = 116). The level of HBV CpG island 3 methylation significantly correlated with hepatocarcinogenesis. We also obtained, for the first time, evidence of rare, non-CpG methylation in CpG island 2 of the HBV genome in infected liver. Comparing methylation of the HBV genome to three known HCC-associated host genes, APC, GSTP1, and RASSF1A, we did not identify a significant correlation between these two groups.


Assuntos
Metilação de DNA , DNA Viral/análise , Vírus da Hepatite B/genética , Fígado/virologia , Proteína da Polipose Adenomatosa do Colo/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , Ilhas de CpG , DNA Viral/metabolismo , Genótipo , Glutationa S-Transferase pi/genética , Humanos , Fígado/metabolismo , Hepatopatias/metabolismo , Hepatopatias/virologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Proteínas Supressoras de Tumor/genética
17.
Hepatol Res ; 45(11): 1110-23, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25382672

RESUMO

AIM: Aberrant methylation of the promoter, P2, and the first exon, E1, regions of the tumor suppressor gene RASSF1A, have been associated with hepatocellular carcinoma (HCC), albeit with poor specificity. This study analyzed the methylation profiles of P1, P2 and E1 regions of the gene to identify the region of which methylation most specifically corresponds to HCC and to evaluate the potential of this methylated region as a biomarker in urine for HCC screening. METHODS: Bisulfite DNA sequencing and quantitative methylation-specific polymerase chain reaction assays were performed to compare methylation of the 56 CpG sites in regions P1, P2 and E1 in DNA isolated from normal, hepatitic, cirrhotic, adjacent non-HCC, and HCC liver tissue and urine samples for the characterization of hypermethylation of the RASSF1A gene as a biomarker for HCC screening. RESULTS: In tissue, comparing HCC (n = 120) with cirrhosis and hepatitis together (n = 70), methylation of P1 had an area under the receiver operating characteristics curve (AUROC) of 0.90, whereas methylation of E1 and P2 had AUROC of 0.84 and 0.72, respectively. At 90% sensitivity, specificity for P1 methylation was 72.9% versus 38.6% for E1 and 27.1% for P2. Methylated P1 DNA was detected in urine in association with cirrhosis and HCC. It had a sensitivity of 81.8% for α-fetoprotein negative HCC. CONCLUSION: Among the three regions analyzed, methylation of P1 is the most specific for HCC and holds great promise as a DNA marker in urine for screening of cirrhosis and HCC.

18.
Inflamm Bowel Dis ; 19(13): 2796-800, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24185312

RESUMO

BACKGROUND: Patients with inflammatory bowel disease have higher proportions of immunoglobulin G (IgG) antibodies lacking N-galactose, also called agalactosyl IgG, in their serum. Such agalactosyl IgGs have been associated with disease activity and the immunogenicity of biologics. The aim was to describe the relationship between circulating levels of a subset of agalactosyl IgGs (anti-α-Gal) and Crohn's disease (CD) phenotypes. METHODS: Prospectively collected serum samples of a well-characterized cohort of patients with inflammatory bowel disease and controls were used. Serum anti-α-Gal levels were measured by a high-affinity enzyme-linked immunosorbent assay and referenced to a standard control. RESULTS: Serum samples from 167 subjects were tested; 62 with CD, 76 with ulcerative colitis, and 29 controls. Agalactosyl anti-α-Gal levels were significantly higher in active CD than in active ulcerative colitis (P = 0.0043) or healthy controls (P < 0.0001). Among patients with CD, agalactosyl anti-α-Gal levels were significantly higher in those with a history of arthritis, than those without (P = 0.0002), but lower in those taking immunomodulators (P = 0.03). There was no correlation between agalactosyl anti-α-Gal levels and indices of Crohn's severity, including C-reactive protein levels or Harvey-Bradshaw index. Patients who were primary or secondary nonresponders to infliximab had similar agalactosyl anti-α-Gal levels to clinical responders. CONCLUSIONS: Patients with CD have greater amounts of agalactosylated anti-α-Gal antibodies in their serum, particularly in those with associated joint disease. This increase seems to be independent of indices of disease activity, but is influenced by immunomodulator use.


Assuntos
Colite Ulcerativa/imunologia , Doença de Crohn/imunologia , Imunoglobulina G/sangue , Lectinas/imunologia , Adulto , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Colite Ulcerativa/patologia , Doença de Crohn/patologia , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Humanos , Masculino , Fenótipo , Prognóstico , Estudos Prospectivos
19.
PLoS Pathog ; 9(9): e1003613, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24068929

RESUMO

Covalently closed circular DNA (cccDNA) of hepadnaviruses exists as an episomal minichromosome in the nucleus of infected hepatocyte and serves as the transcriptional template for viral mRNA synthesis. Elimination of cccDNA is the prerequisite for either a therapeutic cure or immunological resolution of HBV infection. Although accumulating evidence suggests that inflammatory cytokines-mediated cure of virally infected hepatocytes does occur and plays an essential role in the resolution of an acute HBV infection, the molecular mechanism by which the cytokines eliminate cccDNA and/or suppress its transcription remains elusive. This is largely due to the lack of convenient cell culture systems supporting efficient HBV infection and cccDNA formation to allow detailed molecular analyses. In this study, we took the advantage of a chicken hepatoma cell line that supports tetracycline-inducible duck hepatitis B virus (DHBV) replication and established an experimental condition mimicking the virally infected hepatocytes in which DHBV pregenomic (pg) RNA transcription and DNA replication are solely dependent on cccDNA. This cell culture system allowed us to demonstrate that cccDNA transcription required histone deacetylase activity and IFN-α induced a profound and long-lasting suppression of cccDNA transcription, which required protein synthesis and was associated with the reduction of acetylated histone H3 lysine 9 (H3K9) and 27 (H3K27) in cccDNA minichromosomes. Moreover, IFN-α treatment also induced a delayed response that appeared to accelerate the decay of cccDNA. Our studies have thus shed light on the molecular mechanism by which IFN-α noncytolytically controls hepadnavirus infection.


Assuntos
DNA Circular/metabolismo , DNA Viral/metabolismo , Epigênese Genética , Vírus da Hepatite B do Pato/metabolismo , Hepatócitos/virologia , Interferon-alfa/metabolismo , Transcrição Gênica , Acetilação/efeitos dos fármacos , Animais , Proteínas Aviárias/antagonistas & inibidores , Proteínas Aviárias/biossíntese , Proteínas Aviárias/metabolismo , Linhagem Celular , Galinhas , Regulação para Baixo/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Infecções por Hepadnaviridae/metabolismo , Infecções por Hepadnaviridae/virologia , Vírus da Hepatite B do Pato/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/química , Histona Desacetilases/metabolismo , Histonas/metabolismo , Lisina/química , Biossíntese de Proteínas/efeitos dos fármacos , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Transcrição Gênica/efeitos dos fármacos
20.
Methods Mol Biol ; 1030: 151-61, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23821267

RESUMO

Chronic hepatitis B remains a substantial public health burden affecting approximately 350 million people worldwide, causing cirrhosis and liver cancer, and about 1 million people die each year from hepatitis B and its complications. Hepatitis B is caused by hepatitis B virus (HBV) infection. As an essential component of the viral life cycle, HBV covalently closed circular DNA (cccDNA) is synthesized and maintained at low copy numbers in the nucleus of infected hepatocytes, and serves as the transcription template for all viral RNAs. Therefore, cccDNA is responsible for the establishment of viral infection and persistence. The presence and longevity of cccDNA may also explain the limitations of current antiviral therapy for hepatitis B. Thus, understanding the mechanisms underlying cccDNA formation and regulation is critical in understanding the HBV pathogenesis and finding a cure for hepatitis B. Here we describe a protocol for HBV cccDNA extraction and detection in detail. The procedure includes two major steps: (1) HBV cccDNA extraction by Hirt protein-free DNA extraction method and (2) HBV cccDNA detection by Southern blot analysis. The method is straightforward and reliable for cccDNA assay with cell culture samples, and it is useful for both HBV molecular biology and antiviral research.


Assuntos
Southern Blotting , DNA Circular/isolamento & purificação , DNA Viral/isolamento & purificação , Vírus da Hepatite B/genética , Southern Blotting/métodos , Técnicas de Cultura de Células , Linhagem Celular , Células Hep G2 , Humanos
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