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Bogomolov P, Alexandrov A, Voronkova N, Macievich M, Kokina K, Petrachenkova M, Lehr T, Lempp FA, Wedemeyer H, Haag M, Schwab M, Haefeli WE, Blank A, Urban S. Treatment of chronic hepatitis D with the entry inhibitor myrcludex B: First results of a phase Ib/IIa study. J Hepatol 2016; 65:490-8. [PMID: 27132170 DOI: 10.1016/j.jhep.2016.04.016] [Citation(s) in RCA: 268] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 03/19/2016] [Accepted: 04/19/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS The therapeutic option for patients with chronic hepatitis delta virus infection (CHD) is limited to interferon alpha with rare curative outcome. Myrcludex B is a first-in-class entry inhibitor inactivating the hepatitis B virus (HBV) and hepatitis D virus (HDV) receptor sodium taurocholate co-transporting polypeptide. We report the interim results of a pilot trial on chronically infected HDV patients treated with myrcludex B, or pegylated interferon alpha (PegIFNα-2a) or their combination. METHODS Twenty-four patients with CHD infection were equally randomized (1:1:1) to receive myrcludex B, or PegIFNα-2a or their combination. Patients were evaluated for virological and biochemical response and tolerability of the study drugs at weeks 12 and 24. RESULTS Myrcludex B was well tolerated and no serious adverse event occurred. Although hepatitis B surface antigen levels remained unchanged, HDV RNA significantly declined at week 24 in all cohorts. HDV RNA became negative in two patients each in the Myrcludex B and PegIFNα-2a cohorts, and in five patients of the Myrcludex B+PegIFNα-2a cohort. ALT decreased significantly in the Myrcludex B cohort (six of eight patients), and HBV DNA was significantly reduced at week 24 in the Myrcludex B+PegIFNα-2a cohort. Virus kinetic modeling suggested a strong synergistic effect of myrcludex B and PegIFNα-2a on both HDV and HBV. CONCLUSIONS Myrcludex B showed a strong effect on HDV RNA serum levels and induced ALT normalization under monotherapy. Synergistic antiviral effects on HDV RNA and HBV DNA in the Myr-IFN cohort indicated a benefit of the combination of entry inhibition with PegIFNα-2a to treat CHD patients. LAY SUMMARY Myrcludex B is a new drug to treat hepatitis B and D infection. After 24weeks of treatment with myrcludex B and/or pegylated interferon α-2a, HDV R NA, a relevant marker for hepatitis D infection, decreased in all patients with chronic hepatitis B and D. Two of eight patients which received either myrcludex B or pegylated interferon α-2a, became negative for HDV RNA, and five of seven patients who received both drugs at the same time became negative. The drug was well tolerated.
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Affiliation(s)
- Pavel Bogomolov
- Moscow Regional Research Clinical Institute named after M.F. Vladimirsky, 61/2 Schepkina str., 129110 Moscow, Russia; Centrosoyuz Clinical Hospital, 57 Gilyarovskogo str., Moscow 129110, Russia
| | | | - Natalia Voronkova
- Moscow Regional Research Clinical Institute named after M.F. Vladimirsky, 61/2 Schepkina str., 129110 Moscow, Russia; Centrosoyuz Clinical Hospital, 57 Gilyarovskogo str., Moscow 129110, Russia
| | - Maria Macievich
- Moscow Regional Research Clinical Institute named after M.F. Vladimirsky, 61/2 Schepkina str., 129110 Moscow, Russia; Centrosoyuz Clinical Hospital, 57 Gilyarovskogo str., Moscow 129110, Russia
| | - Ksenia Kokina
- Moscow Regional Research Clinical Institute named after M.F. Vladimirsky, 61/2 Schepkina str., 129110 Moscow, Russia; Centrosoyuz Clinical Hospital, 57 Gilyarovskogo str., Moscow 129110, Russia
| | - Maria Petrachenkova
- Moscow Regional Research Clinical Institute named after M.F. Vladimirsky, 61/2 Schepkina str., 129110 Moscow, Russia; Centrosoyuz Clinical Hospital, 57 Gilyarovskogo str., Moscow 129110, Russia
| | - Thorsten Lehr
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123 Saarbrücken, Germany
| | - Florian A Lempp
- German Center for Infection Research (DZIF), Heidelberg Partner Site, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; Department of Infectious Diseases, Molecular Virology, Heidelberg University Hospital, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
| | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany
| | - Mathias Haag
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Auerbachstraße 112, 70376 Stuttgart, Germany; University of Tübingen, Tübingen, Germany; German Center for Infection Research (DZIF), Tübingen Partner Site, E.-Aulhorn-Str. 6, 72076 Tübingen, Germany
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Auerbachstraße 112, 70376 Stuttgart, Germany; University of Tübingen, Tübingen, Germany; German Center for Infection Research (DZIF), Tübingen Partner Site, E.-Aulhorn-Str. 6, 72076 Tübingen, Germany; Department of Clinical Pharmacology, University Hospital Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany; Department of Pharmacy and Biochemistry, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany
| | - Walter E Haefeli
- German Center for Infection Research (DZIF), Heidelberg Partner Site, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; Department of Clinical Pharmacology and Pharmacoepidemiology, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany
| | - Antje Blank
- German Center for Infection Research (DZIF), Heidelberg Partner Site, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; Department of Clinical Pharmacology and Pharmacoepidemiology, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg, Germany.
| | - Stephan Urban
- German Center for Infection Research (DZIF), Heidelberg Partner Site, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany; Department of Infectious Diseases, Molecular Virology, Heidelberg University Hospital, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
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Seitz S, Iancu C, Volz T, Mier W, Dandri M, Urban S, Bartenschlager R. A Slow Maturation Process Renders Hepatitis B Virus Infectious. Cell Host Microbe 2016; 20:25-35. [PMID: 27321908 DOI: 10.1016/j.chom.2016.05.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 03/14/2015] [Accepted: 05/09/2016] [Indexed: 01/22/2023]
Abstract
Hepatitis B virus (HBV) replication is strictly limited to the liver. Virions attach to hepatocytes through interactions of the viral PreS envelope protein domain with heparan sulfate proteoglycans (HSPGs). However, HSPG is ubiquitously present on many cell types, suggesting that HBV employs mechanisms to avoid attachment at extrahepatic sites. We demonstrate that HBV particles are released from cells in an inactive form with PreS hidden in the interior. These HSPG-non-binding (N-type) particles develop receptor binding competence by translocating PreS across the envelope onto their surface. Conversion into HSPG-binding (B-type) particles occurs spontaneously and renders HBV infectious. Low-dose inoculation of mice with human liver xenografts demonstrates superiority of N-type particles in establishing infections, while mature B-type virions, generated via N-type conversion, are profoundly impaired, correlating with non-selective accumulation in extrahepatic tissues. This dynamic topology switch represents a maturation process utilized by HBV to most likely avoid non-productive docking outside the liver.
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Affiliation(s)
- Stefan Seitz
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany.
| | - Caroline Iancu
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
| | - Tassilo Volz
- Department of Medicine and Center for Internal Medicine, University Medical Center, Hamburg-Eppendorf, 20246 Hamburg, Germany; German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel and Heidelberg Partner Sites, 20246 Hamburg and 69120 Heidelberg, Germany
| | - Walter Mier
- Department of Nuclear Medicine, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Maura Dandri
- Department of Medicine and Center for Internal Medicine, University Medical Center, Hamburg-Eppendorf, 20246 Hamburg, Germany; German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel and Heidelberg Partner Sites, 20246 Hamburg and 69120 Heidelberg, Germany
| | - Stephan Urban
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany; German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel and Heidelberg Partner Sites, 20246 Hamburg and 69120 Heidelberg, Germany
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany; German Center for Infection Research (DZIF), Hamburg-Lübeck-Borstel and Heidelberg Partner Sites, 20246 Hamburg and 69120 Heidelberg, Germany; Division of Virus-Associated Carcinogenesis, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, 69120 Heidelberg, Germany.
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NTCP opens the door for hepatitis B virus infection. Antiviral Res 2015; 121:24-30. [DOI: 10.1016/j.antiviral.2015.06.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/03/2015] [Accepted: 06/08/2015] [Indexed: 02/07/2023]
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Giavazzi F, Salina M, Cerbino R, Bassi M, Prosperi D, Ceccarello E, Damin F, Sola L, Rusnati M, Chiari M, Chini B, Bellini T, Buscaglia M. Multispot, label-free biodetection at a phantom plastic-water interface. Proc Natl Acad Sci U S A 2013; 110:9350-5. [PMID: 23696673 PMCID: PMC3677498 DOI: 10.1073/pnas.1214589110] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Recognizing and quantifying specific biomolecules in aqueous samples are constantly needed in research and diagnostic laboratories. As the typical detection procedures are rather lengthy and involve the use of labeled secondary antibodies or other agents to provide a signal, efforts have been made over the last 10 y to develop alternative label-free methods that enable direct detection. We propose and demonstrate an extremely simple, low-cost, label-free biodetector based on measuring the intensity of light reflected by the interface between a fluid sample and an amorphous fluoropolymer substrate having a refractive index very close to that of water and hosting various antibodies immobilized in spots. Under these index-matching conditions, the amount of light reflected by the interface allows straightforward quantification of the amount of antigen binding to each spot. Using antibodies targeting heterologous immunoglobulins and antigens commonly used as markers for diagnoses of hepatitis B and HIV, we demonstrate the limit of detection of a few picograms per square millimeter of surface-bound molecules. We also show that direct and real-time access to the amount of binding molecules allows the precise extrapolation of adhesion rates, from which the concentrations of antigens in solution can be estimated down to fractions of nanograms per milliliter.
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Affiliation(s)
- Fabio Giavazzi
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, 20090 Segrate, Italy
- Proxentia S.r.l., 20135 Milan, Italy
| | - Matteo Salina
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, 20090 Segrate, Italy
- Proxentia S.r.l., 20135 Milan, Italy
| | - Roberto Cerbino
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, 20090 Segrate, Italy
| | - Mattia Bassi
- Materials Science Department, Solvay Specialty Polymers Research and Development Center, 20021 Bollate, Italy
| | - Davide Prosperi
- Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, 20126 Milan, Italy
| | - Erica Ceccarello
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, 20090 Segrate, Italy
- Proxentia S.r.l., 20135 Milan, Italy
| | - Francesco Damin
- Istituto di Chimica del Riconoscimento Molecolare–Consiglio Nazionale delle Ricerche, 20131 Milan, Italy
| | - Laura Sola
- Istituto di Chimica del Riconoscimento Molecolare–Consiglio Nazionale delle Ricerche, 20131 Milan, Italy
| | - Marco Rusnati
- Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia, 25123 Brescia, Italy; and
| | - Marcella Chiari
- Istituto di Chimica del Riconoscimento Molecolare–Consiglio Nazionale delle Ricerche, 20131 Milan, Italy
| | - Bice Chini
- Istituto di Neuroscienze–Consiglio Nazionale delle Ricerche, 20129 Milan, Italy
| | - Tommaso Bellini
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, 20090 Segrate, Italy
| | - Marco Buscaglia
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, 20090 Segrate, Italy
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Fine mapping of pre-S sequence requirements for hepatitis B virus large envelope protein-mediated receptor interaction. J Virol 2009; 84:1989-2000. [PMID: 20007265 DOI: 10.1128/jvi.01902-09] [Citation(s) in RCA: 177] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Previous studies showed that the N-terminal 75 amino acids of the pre-S1 domain of the hepatitis B virus (HBV) L protein are essential for HBV and hepatitis delta virus (HDV) infectivity. Consistently, synthetic lipopeptides encompassing this sequence or only parts of it efficiently block HBV and HDV infection, presumably through specific interference with a cellular receptor. Crucial for both virus infectivity and the inhibitory activity of the peptides are N-terminal myristoylation and a highly conserved motif within the N-terminal 48 amino acids. To refine the sequence requirements, we synthesized a series of HBV pre-S1 peptides containing deletions, point mutations, d-amino acid exchanges, or genotype-specific sequence permutations. Using the HepaRG cell line and a genotype D-derived virus, we determined the specific inhibitory activities of the peptides and found that (i) lipopeptides with an artificial consensus sequence inhibit HBV genotype D infection more potently than the corresponding genotype D peptides; (ii) point mutations, d-amino acid exchanges, or deletions introduced into the highly conserved part of the pre-S1 domain result in an almost complete loss of activity; and (iii) the flanking sequences comprising amino acids 2 to 8, 16 to 20, and, to a less pronounced extent, 34 to 48 gradually increase the inhibitory activity, while amino acids 21 to 33 behave indifferently. Taken together, our data suggest that HBV pre-S1-mediated receptor interference and, thus, HBV receptor recognition form a highly specific process. It requires an N-terminal acyl moiety and a highly conserved sequence that is present in primate but not rodent or avian hepadnaviruses, indicating different entry pathways for the different family members.
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Bohne F, Chmielewski M, Ebert G, Wiegmann K, Kürschner T, Schulze A, Urban S, Krönke M, Abken H, Protzer U. T cells redirected against hepatitis B virus surface proteins eliminate infected hepatocytes. Gastroenterology 2008; 134:239-47. [PMID: 18166356 DOI: 10.1053/j.gastro.2007.11.002] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Accepted: 10/11/2007] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS The final goal in hepatitis B therapy is eradication of the hepatitis B virus (HBV) replication template, the so-called covalently closed circular DNA (cccDNA). Current antiviral treatment of chronic hepatitis B depends on interferon alpha or nucleoside analogues inhibiting the viral reverse transcriptase. Despite treatment, cccDNA mostly persists in the host cell nucleus, continues to produce hepatitis B surface antigen (HBsAg), and causes relapsing disease. We therefore aimed at eliminating persistently infected hepatocytes carrying HBV cccDNA by redirecting cytolytic T cells toward HBsAg-producing cells. METHODS We designed chimeric T-cell receptors directed against HBV surface proteins present on HBV-infected cells and used them to graft primary human T cells with antibody-like specificity. The receptors were composed of a single chain antibody fragment directed against HBV S or L protein fused to intracellular signalling domains of CD3xi and the costimulatory CD28 molecule. RESULTS Our results show that these chimeric receptors, when retrovirally delivered and expressed on the cell surface, enable primary human T cells to recognize HBsAg-positive hepatocytes, release interferon gamma and interleukin 2, and, most importantly, lyse HBV replicating cells. When coincubated with HBV-infected primary human hepatocytes, these engineered, antigen-specific T cells selectively eliminated HBV-infected and thus cccDNA-positive target cells. CONCLUSIONS Elimination of HBV cccDNA-positive hepatocytes following antiviral therapy is a major therapeutic goal in chronic hepatitis B, and adoptive transfer of grafted T cells provides a promising novel therapeutic approach. However, T-cell therapy may also cause liver damage and therefore needs further preclinical evaluation.
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Affiliation(s)
- Felix Bohne
- Molecular Infectiology, University Hospital Cologne, Koeln, Germany
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Engelke M, Mills K, Seitz S, Simon P, Gripon P, Schnölzer M, Urban S. Characterization of a hepatitis B and hepatitis delta virus receptor binding site. Hepatology 2006; 43:750-60. [PMID: 16557545 DOI: 10.1002/hep.21112] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Insights into the early infection events of the human hepatitis B (HBV) and hepatitis delta virus (HDV) have been limited because of the lack of a cell culture system supporting the full replication cycle for these important pathogens. The human hepatoma cell line HepaRG allows the experimental induction of a differentiated state, thereby gaining susceptibility toward HBV and HDV infection. We recently identified HBV envelope protein-derived lipopeptides comprising amino acids 2 though 48 of the preS-domain of the L-surface protein, which block infection already at picomolar concentrations. To map the responsible sequence for the peptides' activity we describe an Escherichia coli expression system that permits myristoylation and investigated recombinant HBVpreS-GST fusion proteins with deletion- and point-mutations for their ability to prevent HBV and HDV infection. We found that (1) a myristoylated HBVpreS/2-48-GST fusion protein efficiently interferes with HBV infection of HepaRG cells; (2) deletions and point mutations in the highly conserved preS1 sequence between amino acids 11 through 21 result in the loss of infection inhibition activity; (3) hepatitis B viruses carrying single amino acid exchanges within this region lose infectivity; and (4) HDV infection of HepaRG cells can be inhibited by myristoylated HBVpreS peptides with the same specificity. In conclusion, HBV and HDV use at least one common step to enter hepatocytes and require a highly conserved preS1-sequence within the L-protein. This step is exceptionally sensitive toward inactivation by acylated HBVpreS1 peptides, which therefore represent a novel group of entry inhibitors that could be used for the treatment of hepatitis B and D.
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Affiliation(s)
- Matthias Engelke
- Department of Molecular Virology, Otto-Meyerhof-Zentrum (OMZ), University of Heidelberg, Heidelberg, Germany
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Hu WG, Wei J, Xia HC, Yang XX, Li F, Li GD, Wang Y, Zhang ZC. Identification of the immunogenic domains in HBsAg preS1 region using overlapping preS1 fragment fusion proteins. World J Gastroenterol 2005; 11:2088-94. [PMID: 15810073 PMCID: PMC4305776 DOI: 10.3748/wjg.v11.i14.2088] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: The incorporation of hepatitis B virus (HBV) preS1 region into epitope-based vaccines against HBV has been accepted widely, but the incorporate site and size of preS1 sequence is controversial. Therefore our purpose was to further investigate its immunogenic domains for the epitope-based hepatitis B vaccine design.
METHODS: Eight GST fusion proteins containing overlapping preS1 fragments in preS1 (21-119) region were expressed in E.coli. Using these purified fusion proteins, the immunogenic domains in preS1 region were identified in detail in mice and humans by Western blot analysis and ELISA.
RESULTS: The results in mice showed that the immu-nogenic domains mainly existed in preS1 (21-59) and preS1 (95-109). Similarly, these fragments had strong immunogenicity in humans; whereas the other parts except for preS1 (60-70) also had some immunogenicity. More importantly, a major immunogenic domain, preS1 (34-59), which has much stronger immunogenicity, was identified. Additionally, the antibodies against some preS1 fragments, especially preS1 (34-59), were speculated to be virus-neutralizing.
CONCLUSION: Eight GST fusion proteins containing overlapping preS1 fragments were prepared successfully. They were used for the study on the immunogenic dom-ains in preS1 (21-119) region. The preS1 (34-59) fragm-ents were the major immunogenic domains in the preS1 region, and the antibodies against these fragments were speculated to be virus-neutralizing. Therefore, the incorporation of preS1 (34-59) fragments into epitope-based HBV vaccines may be efficient for enhancement of immune response. Additionally, the results also imply that there are more complex immune responses to preS1 region and more abundant immunogenic domains in humans.
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Affiliation(s)
- Wei-Guo Hu
- Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-yang Road, Shanghai 200031, China
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Gripon P, Cannie I, Urban S. Efficient inhibition of hepatitis B virus infection by acylated peptides derived from the large viral surface protein. J Virol 2005; 79:1613-22. [PMID: 15650187 PMCID: PMC544121 DOI: 10.1128/jvi.79.3.1613-1622.2005] [Citation(s) in RCA: 267] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The lack of an appropriate in vitro infection system for the major human pathogen hepatitis B virus (HBV) has prevented a molecular understanding of the early infection events of HBV. We used the novel HBV-infectible cell line HepaRG and primary human hepatocytes to investigate the interference of infection by HBV envelope protein-derived peptides. We found that a peptide consisting of the authentically myristoylated N-terminal 47 amino acids of the pre-S1 domain of the large viral envelope protein (L protein) specifically prevented HBV infection, with a 50% inhibitory concentration (IC50) of 8 nM. The replacement of myristic acid with other hydrophobic moieties resulted in changes in the inhibitory activity, most notably by a decrease in the IC50 to picomolar concentrations for longer unbranched fatty acids. The obstruction of HepaRG cell susceptibility to HBV infection after short preincubation times with the peptides suggested that the peptides efficiently target and inactivate a receptor at the hepatocyte surface. Our data both shed light on the molecular mechanism of HBV entry into hepatocytes and provide a basis for the development of potent hepadnaviral entry inhibitors as a novel therapeutic concept for the treatment of hepatitis Beta.
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Affiliation(s)
- Philippe Gripon
- Institut National de la Santé et de la Recherche Médicale (INSERM) U522, Hôpital de Pontchaillou, Rennes, France
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Bose B, Chugh DA, Kala M, Acharya SK, Khanna N, Sinha S. Characterization and molecular modeling of a highly stable anti-Hepatitis B surface antigen scFv. Mol Immunol 2003; 40:617-31. [PMID: 14597165 DOI: 10.1016/j.molimm.2003.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We raised a mouse monoclonal antibody (5S) against the 'a' epitope of the Hepatitis B surface antigen (HBsAg) by selecting for binding of the hybridoma supernatant in conditions that usually destabilize protein-protein interactions. This antibody, which was protective in an in vitro assay, had a high affinity with a relative dissociation constant in the nanomolar range. It also displayed stable binding to antigen in conditions that usually destabilize antigen-antibody interactions, like 30% DMSO, 8 M urea, 4 M NaCl, 1 M guanidium HCl and extremes of pH. The variable regions of the antibody were cloned and expressed as an single chain variable fragment (scFv) (A5). A5 had a relative affinity comparable to the mouse monoclonal and showed antigen binding in presence of 20% DMSO, 8 M urea and 3 M NaCl. It bound the antigen in the pH range of 6-8, though its tolerance for guanidium HCl was reduced. Sequence analysis demonstrated a significant increase in the frequency of somatic replacement mutations in CDRs over framework regions in the light but not in the heavy chain. A comparison of the molecular models of the variable regions of the 5S antibody and its germ-line precursor revealed that critical mutations in the heavy and light chains interface resulted in better inter-chain packing and in the movement of CDR H3 and CDR L1 from their germline positions, which may be important for better antigen binding. In addition to providing a reagent for neutralizing for the virus, such an antibody provides a model for the evolution of stable high affinity interaction during antibody maturation.
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Affiliation(s)
- Biplab Bose
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, PIN-110029, India
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Abstract
We have assembled references of 700 articles published in 2001 that describe work performed using commercially available optical biosensors. To illustrate the technology's diversity, the citation list is divided into reviews, methods and specific applications, as well as instrument type. We noted marked improvements in the utilization of biosensors and the presentation of kinetic data over previous years. These advances reflect a maturing of the technology, which has become a standard method for characterizing biomolecular interactions.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT 84132, USA
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Emir S, Büyükpamuk M, Akyüz C, Kutluk T, Güler E, Cağlar K. The comparison of antibody response to different hepatitis b vaccines with and without pre-S2 antigen in children with cancer. Pediatr Hematol Oncol 2002; 19:227-33. [PMID: 12051588 DOI: 10.1080/08880010252899389] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Children with cancer are at an increased risk of hepatitis B infection and chronic liver disease. Since hepatitis B vaccines containing pre-S2 antigen has been recently reported as being more efficient in providing immunization in healthy individuals, the authors compared antibody response to pre-S2-containing vaccine with no-pre-S2-containing hepatitis B vaccine, when given in double doses to 100 children receiving chemotherapy. Patients, aged 1 to 16 years with negative HBV serology, were vaccinated with 2 different types of HBV vaccines between 1997 and 1999. Group 1 received Gen Hevac B containing pre-S2 (n = 41) in a dose of 20 microg for patients younger than 10 years old and 40 microg for older patients. Group 2 was vaccinated at the same dose with hepatitis B vaccines not containing pre-S2 antigen. All vaccinations were repeated at 0, 1, and 6 months. Serum samples were drawn for determination of anti-HBs titers at 1, 3, 6, and 8 months. After the third dose of vaccine, the seroconversion rate was 72% in group 1 and 62% in group 2. The anti-HBs levels were higher in the group receiving pre-S2-containing hepatitis B vaccine. However, the difference between groups was not statistically significant (p > .05). The administration of pre-S2-containing hepatitis B vaccines may give a better seroconversion and higher antibody response to vaccination in children with cancer. But a further large-scale study is needed to confirm this finding.
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Affiliation(s)
- Suna Emir
- Department of Pediatric Oncology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
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