Search results for "Hepatitis B Surface Antigens"

showing 10 items of 102 documents

Translation of hepatitis B virus (HBV) surface proteins from the HBV pregenome and precore RNAs in Semliki Forest virus-driven expression.

2004

Hepatitis B virus (HBV) pregenome RNA (pgRNA) serves as a translation template for the HBV core (HBc) protein and viral polymerase (Pol). HBV precore RNA (pcRNA) directs the synthesis of the precore (preC) protein, a precursor of the hepatitis B e antigen (HBeAg). pgRNA and pcRNA were expressed in the Semliki Forest virus (SFV) expression system. Besides the HBc and preC proteins, there was revealed the synthesis of all three forms of HBV surface (HBs) proteins: long (LHBs), middle (MHBs) and short (SHBs), the start codons of which are located more than 1000 nt downstream of the HBc and preC start codons. Moreover, other HBV templates, such as 3′-truncated pgRNA lacking 3′ direct repeat and…

HBV RNA encapsidation signal epsilonHepatitis B virusvirusesGene ExpressionLeaky scanningDNA-Directed DNA Polymerasemedicine.disease_causeSemliki Forest virusVirus ReplicationCell LineViral Envelope ProteinsVirologymedicineAnimalsHepatitis B e AntigensRNA MessengerCloning MolecularProtein PrecursorsHepatitis B virusHepatitis B Surface Antigensbiologyvirus diseasesRNA virusTemplates Geneticbiology.organism_classificationVirologyMolecular biologyHepatitis B Core AntigensImmunohistochemistrySemliki forest virusdigestive system diseasesGenetic translationHBeAgHepadnaviridaeProtein BiosynthesisRNA ViralThe Journal of general virology
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Concomitant cellular expression of heat shock regulated genes of hepatitis B virus surface antigen and of human growth hormone by a NIH-3T3 cell line.

1993

A plasmid carrying a DNA fragment of hepatitis B virus, coding for the pre-S2 and the entire S region of the surface antigen (HBsAg), placed under the control of the promoter of the human 70 kDa heat shock protein gene (hsp70), was introduced into Line 6, a recombinant cell line that was selected from NIH-3T3 cells previously transfected with a similar construct coding for the human growth hormone cDNA gene (chGH) and with the plasmid pEJ carrying the Ha-rasEJ activated cellular oncogene. The resulting cell line, EMS8, expressed: (1) hsp70/HBsAg and hsp70/hGH hybrid genes, (2) the human Ha-rasEJ oncogene, and (3) the neomycin resistance gene, the two last plasmid markers being used for cell…

HBsAgHepatitis B Surface AntigensHealth Toxicology and MutagenesisCell BiologyTransfection3T3 CellsBiologyToxicologyMolecular biologyRecombinant ProteinsHsp70Cell LineMicePlasmidCell cultureHeat shock proteinGrowth HormoneGene expressionAnimalsHumansHybridization GeneticRNA MessengerPeptide Chain Initiation TranslationalGeneHeat-Shock ProteinsCell biology and toxicology
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Relationship of pre-S encoded antigens in liver and clinical manifestations of chronic hepatitis B infection.

2008

Pre-S1 and pre-S2 encoded antigens of hepatitis B virus were localized in liver tissue using monoclonal antibodies. They were found to be exclusively expressed in the cytoplasm of liver cells. Cell bound pre-S1 encoded protein was often detected in patients with chronic liver disease and viremia. Only a small number of the HBsAg positive cells also contained pre-S1 antigen. There was no correlation with nuclear HBcAg. Livers of non-viremic HBsAg carriers contained many HBsAg expressing liver cells, that were frequently also positive for pre-S2 encoded protein but contained no detectable pre-S1 encoded protein at all. It remains open whether cell bound pre-S2 containing proteins of middle si…

HBsAgHepatitis B virusBiopsyRadioimmunoassayViremiaBiologyChronic liver diseaseImmunoenzyme Techniques03 medical and health sciencesLiver disease0302 clinical medicineAntigenmedicineHumans030304 developmental biologyHepatitis0303 health sciencesHepatitis B Surface AntigensHepatologyvirus diseasesmedicine.diseasebiology.organism_classificationHepatitis BVirology3. Good healthHBcAgHepadnaviridaeLiverImmunologyCarrier State030211 gastroenterology & hepatologyLiver
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Hepatic expression patterns of the large and middle hepatitis B virus surface proteins in viremic and nonviremic chronic hepatitis B.

1990

The envelope of hepatitis B virus consists of large, middle, and small hepatitis B surface proteins. Recent data from in vitro studies suggest that intracellular expression and distribution of the three polypeptides may be variable. These observations in artificial expression systems prompted this analysis of the occurrence and distribution of the three hepatitis B surface proteins in the liver tissue of substantial viremic (hepatitis B virus DNA- and hepatitis B e antigen-positive) and low-viremic or nonviremic (hepatitis B virus DNA-negative, anti-hepatitis B e antigen-positive) carriers by specific monoclonal antibodies against large, middle, and small proteins. Patients with an active f…

HBsAgHepatitis B virusHepatitis B virus DNA polymerasemedicine.disease_causeHepatitis B virus PRE betaImmunoenzyme Techniques03 medical and health sciences0302 clinical medicineViral Envelope ProteinsmedicineHumansViremiaProtein Precursors030304 developmental biologyHepatitis ChronicHepatitisHepatitis B virus0303 health sciencesHepatitis B Surface AntigensHepatologybiologyGastroenterologyAntibodies MonoclonalHepatitis Bmedicine.diseasebiology.organism_classificationHepatitis BVirologyMolecular biology3. Good healthHBeAgHepadnaviridaeLiverDNA Viral030211 gastroenterology & hepatologyGastroenterology
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Enhancement of Gene Expression by Somatic Hybridization with Primary Cells: High-Level Synthesis of the Hepatitis B Surface Antigen in Monkey Vero Ce…

1990

Vero cells transfected with the S gene encoding the surface antigen (HBsAg) of the hepatitis B virus (HBV) synthesize HBsAg at low levels. We have obtained a large increase in S gene expression by somatic hybridization of Vero cells with primary hepatocytes, which are the natural target cells for HBV infection. Fusion with cells other than hepatocytes did not enhance expression of the S gene. The Vero/hepatocyte hybrid clones analyzed are stable and have maintained a high level of HBsAg synthesis over prolonged periods. Hybrid cell lines may be of general interest for the high-level synthesis of proteins using cloned genes.

HBsAgLiver cytologyvirusesGenetic VectorsBiomedical EngineeringGene ExpressionBioengineeringHybrid CellsBiologyKidneyTransfectionmedicine.disease_causeApplied Microbiology and BiotechnologyCell LineAntigenChlorocebus aethiopsmedicineAnimalsVero CellsHepatitis B virusHepatitis B Surface AntigensCell fusionvirus diseasesTransfectionVirologyMolecular biologydigestive system diseasesLiverCell cultureVero cellRNAMolecular MedicinePapioBiotechnologyNature Biotechnology
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Immunohistochemical Characterization of 130 Cases of Primary Hepatic Carcinomas

1987

Primary liver carcinoma (PLC) may express a certain number of markers. Here we communicate results of an analysis of five such markers (alpha-1-antitrypsin--AAT--, carcino-embryonic antigen --CEA--, alpha-fetoprotein --AFP--, and superficial --HBsAg-- and core --HBcAg-- antigens of hepatitis B virus) by means of PAP techniques in 130 cases of PLC, comparing the neoplastic tissue and the non-tumorous liver. Three variants of PLC are distinguished: hepatocarcinoma (HC) (108 cases); cholangiocarcinoma (CC) (19 cases); and three cases of hepatocholangiocarcinoma (HCC). AAT was positive in 29 HC, 2 HCC, and negative in all 19 CC. CEA appeared positive in 16 HC, 16 CC and only one HCC. AFP was po…

HBsAgPathologymedicine.medical_specialtyCarcinoma HepatocellularCirrhosismedicine.disease_causePathology and Forensic MedicineImmunoenzyme TechniquesAdenoma Bile DuctAntigenCarcinomamedicineHumansneoplasmsTumor markerHepatitis B virusHepatitis B Surface Antigensbusiness.industryLiver NeoplasmsCell Biologymedicine.diseaseHepatitis B Core AntigensImmunohistochemistrydigestive system diseasesCarcinoembryonic AntigenHBcAgalpha 1-AntitrypsinImmunohistochemistryalpha-FetoproteinsbusinessPathology - Research and Practice
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Polyalbumin receptors, hepatitis B surface antigen (HBsAg), and HBsAg/IgM complexes in HBsAg positive patients with and without delta superinfection.

1985

Receptors for polymerized human albumin are found at high litres during high-level hepatitis B virus (HBV) replication and in small amounts in chronic low-level infection. Complexes between hepatitis B surface antigen (HBsAg) and IgM without specificity for HbsAg are expressed in a pattern similar to that of receptors. Anti-albumin antibodies could be involved in their formation. Delta infection depresses the synthesis of gene products of HBV. To assess whether delta modifies the expression of receptors on HBsAg and the level of HBsAg/IgM complexes, and if anti-albumin antibodies are actually part of the complex, we tested sera from 86 subjects with acute and chronic HBV infection. Our find…

HBsAgRadioimmunoassayEnzyme-Linked Immunosorbent AssayReceptors Cell SurfaceSerum Albumin HumanAntigen-Antibody ComplexHepatitis b surface antigenmedicine.disease_causeVirologymedicineHumansReceptorSerum AlbuminHepatitis B virusHepatitis B Surface AntigensbiologyAlbuminvirus diseasesReceptors AlbuminHepatitis BVirologydigestive system diseasesTiterInfectious DiseasesViral replicationImmunoglobulin MImmunologyAcute DiseaseChronic Diseasebiology.proteinAntibodyJournal of medical virology
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Fine-mapping of the B-cell epitope domain at the N-terminus of the preS2 region of the hepatitis B surface antigen

2002

In this study, we report the exact localization and substitutional characterization of a B-cell epitope domain at the N-terminus of the preS2 region of the hepatitis B surface antigen. A set of deletion variants containing preS2 sequences of different length was generated on the basis of frCP as a carrier. It was found after Western blot analysis that three monoclonal antibodies (MAbs) (2-11B1, 3-11C2, HB.OT10) recognized the linear preS2 sequence within the amino acid (aa) stretch 3-WNSTTFHQTLQDP-13. The importance of each aa residue of the epitope was proved by comparison of antibody binding to alanine-substituted peptides in both free-peptide and Pepscan variants.

HBsAgmedicine.drug_classBlotting WesternMolecular Sequence DataImmunologyMonoclonal antibodyEpitopeMiceViral Envelope ProteinsmedicineAnimalsImmunology and AllergyAmino Acid SequenceProtein PrecursorsPeptide sequenceHepatitis B Surface AntigensLinear epitopebiologyAntibodies MonoclonalMolecular biologyEpitope mappingPepscanbiology.proteinEpitopes B-LymphocyteAntibodyEpitope MappingJournal of Immunological Methods
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Prophylaxis and treatment of hepatitis B in immunocompromised patients.

2007

The literature on hepatitis B virus (HBV) in immunocompromised patients is heterogeneous and referred mainly to the pre-antivirals era. Today a rational approach to the problem of hepatitis B in these patients provides for: (a) the evaluation of HBV markers and of liver condition in all subjects starting immunosuppressive therapies (baseline), (b) the treatment with antivirals (therapy) of active carriers, (c) the pre-emptive use of antivirals (prophylaxis) in inactive carriers, especially if they are undergoing immunosuppressive therapies judged to be at high risk, (d) the biochemical and hepatitis B surface antigen (HBsAg) monitoring (or universal prophylaxis, in case of high risk immunos…

HBsAgmedicine.medical_specialtyHepatitis C virusmedicine.medical_treatmentLiver transplantationTransplantmedicine.disease_causeGastroenterologyAntiviral AgentsImmunocompromised HostAnimals; Antiviral Agents; Carrier State; Hepatitis B; Hepatitis B Core Antigens; Hepatitis B Surface Antigens; Humans; Immunocompromised Host; Liver Transplantation; Tissue Donors; TransplantationAntivirals; HBV; Immunosuppression; Transplants;Internal medicineHBVMedicineAnimalsHumansAntiviralHepatitis B virusTransplantationHepatitis B Surface AntigensHepatologybusiness.industryGastroenterologyvirus diseasesHepatitis Bmedicine.diseaseHepatitis BHepatitis B Core Antigensdigestive system diseasesTissue DonorsLiver TransplantationTransplantationHBeAgImmunologyCarrier StateHepatitis D virusbusinessImmunosuppression
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Behavior of a Short preS1 Epitope on the Surface of Hepatitis B Core Particles

1999

The major immunodominant region of hepatitis B core particles is widely recognized as the most prospective target for the insertion of foreign epitopes, ensuring their maximal antigenicity and immunogenicity. This region was mapped around amino acid residues 79-81, which were shown by electron cryo-microscopy to be located on the tips of the spikes protruding from the surface of hepatitis B core shells. Here we tried to expose a model sequence, the short immunodominant hepatitis B preS1 epitope 31-DPAFR-35, onto the tip of the spike, with simultaneous deletion of varying stretches from the major immunodominant region of the HBc molecule. Accessibility to the monoclonal anti-preS1 antibody M…

Hepatitis B virusAntigenicityRecombinant Fusion ProteinsGenetic VectorsMolecular Sequence DataClinical BiochemistryAntigen presentationmedicine.disease_causeBiochemistryEpitopeMicemedicineAnimalsHumansAmino Acid SequenceProtein PrecursorsMolecular BiologyPeptide sequenceHepatitis B virusAntigen PresentationMice Inbred BALB CHepatitis B Surface AntigensbiologyImmunodominant EpitopesChemistryImmunogenicityHepatitis B Core AntigensVirologyPolyclonal antibodiesbiology.proteinEpitopes B-LymphocyteFemaleRabbitsAntibodyPlasmidsBiological Chemistry
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