scholarly journals Recombinant human monoclonal antibodies against different conformational epitopes of the E2 envelope glycoprotein of hepatitis C virus that inhibit its interaction with CD81

2000 ◽  
Vol 81 (10) ◽  
pp. 2451-2459 ◽  
Author(s):  
Tobias Allander ◽  
Katarina Drakenberg ◽  
Aster Beyene ◽  
Domenico Rosa ◽  
Sergio Abrignani ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Envelope Glycoprotein ◽  
Human Monoclonal Antibodies ◽  
High Affinity ◽  
Fab Fragments ◽  
Genotype 1A

The antibody response to the envelope proteins of hepatitis C virus (HCV) may play an important role in controlling the infection. To allow molecular analyses of protective antibodies, we isolated human monoclonal antibodies to the E2 envelope glycoprotein of HCV from a combinatorial Fab library established from bone marrow of a chronically HCV-infected patient. Anti-E2 reactive clones were selected using recombinant E2 protein. The bone marrow donor carried HCV genotype 2b, and E2 used for selection was of genotype 1a. The antibody clones were expressed as Fab fragments in E. coli, and as Fab fragments and IgG1 in CHO cells. Seven different antibody clones were characterized, and shown to have high affinity for E2, genotype 1a. Three clones also had high affinity for E2 of genotype 1b. They all bind to conformation-dependent epitopes. Five clones compete for the same or overlapping binding sites, while two bind to one or two other epitopes of E2. Four clones corresponding to the different epitopes were tested as purified IgG1 for blocking the CD81–E2 interaction in vitro; all four were positive at 0·3–0·5  μg/ml. Thus, the present results suggest the existence of at least two conserved epitopes in E2 that mediate inhibition of the E2–CD81 interaction, of which one appeared immunodominant in this donor.

scholarly journals Identification and Characterization of Broadly Neutralizing Human Monoclonal Antibodies Directed against the E2 Envelope Glycoprotein of Hepatitis C Virus

2009 ◽  
Vol 83 (23) ◽  
pp. 12473-12482 ◽  
Author(s):  
Teresa J. Broering ◽  
Kerry A. Garrity ◽  
Naomi K. Boatright ◽  
Susan E. Sloan ◽  
Frantisek Sandor ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Envelope Glycoprotein ◽  
Cross Reactivity ◽  
Human Antibody ◽  
Human Monoclonal Antibodies ◽  
Genotype 1A ◽  
Neutralizing Monoclonal Antibody

ABSTRACT Nearly all livers transplanted into hepatitis C virus (HCV)-positive patients become infected with HCV, and 10 to 25% of reinfected livers develop cirrhosis within 5 years. Neutralizing monoclonal antibody could be an effective therapy for the prevention of infection in a transplant setting. To pursue this treatment modality, we developed human monoclonal antibodies (HuMAbs) directed against the HCV E2 envelope glycoprotein and assessed the capacity of these HuMAbs to neutralize a broad panel of HCV genotypes. HuMAb antibodies were generated by immunizing transgenic mice containing human antibody genes (HuMAb mice; Medarex Inc.) with soluble E2 envelope glycoprotein derived from a genotype 1a virus (H77). Two HuMAbs, HCV1 and 95-2, were selected for further study based on initial cross-reactivity with soluble E2 glycoproteins derived from genotypes 1a and 1b, as well as neutralization of lentivirus pseudotyped with HCV 1a and 1b envelope glycoproteins. Additionally, HuMAbs HCV1 and 95-2 potently neutralized pseudoviruses from all genotypes tested (1a, 1b, 2b, 3a, and 4a). Epitope mapping with mammalian and bacterially expressed proteins, as well as synthetic peptides, revealed that HuMAbs HCV1 and 95-2 recognize a highly conserved linear epitope spanning amino acids 412 to 423 of the E2 glycoprotein. The capacity to recognize and neutralize a broad range of genotypes, the highly conserved E2 epitope, and the fully human nature of the antibodies make HuMAbs HCV1 and 95-2 excellent candidates for treatment of HCV-positive individuals undergoing liver transplantation.

scholarly journals Preclinical Evaluation of Two Neutralizing Human Monoclonal Antibodies against Hepatitis C Virus (HCV): a Potential Treatment To Prevent HCV Reinfection in Liver Transplant Patients

2006 ◽  
Vol 80 (6) ◽  
pp. 2654-2664 ◽  
Author(s):  
Rachel Eren ◽  
Dorit Landstein ◽  
Dov Terkieltaub ◽  
Ofer Nussbaum ◽  
Arie Zauberman ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Liver Transplant ◽  
Immune Complexes ◽  
Human Liver ◽  
Human Monoclonal Antibodies ◽  
Transplant Patients

ABSTRACT Passive immunotherapy is potentially effective in preventing reinfection of liver grafts in hepatitis C virus (HCV)-associated liver transplant patients. A combination of monoclonal antibodies directed against different epitopes may be advantageous against a highly mutating virus such as HCV. Two human monoclonal antibodies (HumAbs) against the E2 envelope protein of HCV were developed and tested for the ability to neutralize the virus and prevent human liver infection. These antibodies, designated HCV-AB 68 and HCV-AB 65, recognize different conformational epitopes on E2. They were characterized in vitro biochemically and functionally. Both HumAbs are immunoglobulin G1 and have affinity constants to recombinant E2 constructs in the range of 10−10 M. They are able to immunoprecipitate HCV particles from infected patients' sera from diverse genotypes and to stain HCV-infected human liver tissue. Both antibodies can fix complement and form immune complexes, but they do not activate complement-dependent or antibody-dependent cytotoxicity. Upon complement fixation, the monoclonal antibodies induce phagocytosis of the immune complexes by neutrophils, suggesting that the mechanism of viral clearance includes endocytosis. In vivo, in the HCV-Trimera model, both HumAbs were capable of inhibiting HCV infection of human liver fragments and of reducing the mean viral load in HCV-positive animals. The demonstrated neutralizing activities of HCV-AB 68 and HCV-AB 65 suggest that they have the potential to prevent reinfection in liver transplant patients and to serve as prophylactic treatment in postexposure events.

scholarly journals Definition of a Conserved Immunodominant Domain on Hepatitis C Virus E2 Glycoprotein by Neutralizing Human Monoclonal Antibodies

2008 ◽  
Vol 82 (12) ◽  
pp. 6061-6066 ◽  
Author(s):  
Zhen-Yong Keck ◽  
Ta-Kai Li ◽  
Jinming Xia ◽  
Meital Gal-Tanamy ◽  
Oakley Olson ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Human Monoclonal Antibodies ◽  
Hcv Genotypes ◽  
Genotype 1A ◽  
E2 Glycoprotein ◽  
Contact Residues ◽  
Definition Of

ABSTRACT Development of a successful hepatitis C virus (HCV) vaccine requires the definition of neutralization epitopes that are conserved among different HCV genotypes. Five human monoclonal antibodies (HMAbs) are described that cross-compete with other antibodies to a cluster of overlapping epitopes, previously designated domain B. Each HMAb broadly neutralizes retroviral pseudotype particles expressing HCV E1 and E2 glycoproteins, as well as the infectious chimeric genotype 1a and genotype 2a viruses. Alanine substitutions of residues within a region of E2 involved in binding to CD81 showed that critical E2 contact residues involved in the binding of representative antibodies are identical to those involved in the binding of E2 to CD81.

scholarly journals Monoclonal Antibodies against Occludin Completely Prevented Hepatitis C Virus Infection in a Mouse Model

2018 ◽  
Vol 92 (8) ◽  
pp. e02258-17 ◽  
Author(s):  
Yoshimi Shimizu ◽  
Yoshitaka Shirasago ◽  
Masuo Kondoh ◽  
Tetsuro Suzuki ◽  
Takaji Wakita ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Tight Junction ◽  
Hcv Infection ◽  
Host Cells ◽  
Entry Inhibitors ◽  
High Affinity ◽  
Very High

ABSTRACT Hepatitis C virus (HCV) entry into host cells is a multistep process requiring various host factors, including the tight junction protein occludin (OCLN), which has been shown to be essential for HCV infection in in vitro cell culture systems. However, it remains unclear whether OCLN is an effective and safe target for HCV therapy, owing to the lack of binders that can recognize the intact extracellular loop domains of OCLN and prevent HCV infection. In this study, we successfully generated four rat anti-OCLN monoclonal antibodies (MAbs) by the genetic immunization method and unique cell differential screening. These four MAbs bound to human OCLN with a very high affinity (antibody dissociation constant of <1 nM). One MAb recognized the second loop of human and mouse OCLN, whereas the three other MAbs recognized the first loop of human OCLN. All MAbs inhibited HCV infection in Huh7.5.1-8 cells in a dose-dependent manner without apparent cytotoxicity. Additionally, the anti-OCLN MAbs prevented both cell-free HCV infection and cell-to-cell HCV transmission. Kinetic studies with anti-OCLN and anti-claudin-1 (CLDN1) MAbs demonstrated that OCLN interacts with HCV after CLDN1 in the internalization step. Two selected MAbs completely inhibited HCV infection in human liver chimeric mice without apparent adverse effects. Therefore, OCLN would be an appropriate host target for anti-HCV entry inhibitors, and anti-OCLN MAbs may be promising candidates for novel anti-HCV agents, particularly in combination with direct-acting HCV antiviral agents. IMPORTANCE HCV entry into host cells is thought to be a very complex process involving various host entry factors, such as the tight junction proteins claudin-1 and OCLN. In this study, we developed novel functional MAbs that recognize intact extracellular domains of OCLN, which is essential for HCV entry into host cells. The established MAbs against OCLN, which had very high affinity and selectivity for intact OCLN, strongly inhibited HCV infection both in vitro and in vivo. Using these anti-OCLN MAbs, we found that OCLN is necessary for the later stages of HCV entry. These anti-OCLN MAbs are likely to be very useful for understanding the OCLN-mediated HCV entry mechanism and might be promising candidates for novel HCV entry inhibitors.

Quantitation of hepatitis C virus RNA production in two human bone marrow-derived B-cell lines infected in vitro

1997 ◽  
Vol 148 (2) ◽  
pp. 147-151 ◽  
Author(s):  
S. Iacovacci ◽  
L. Bertolini ◽  
A. Manzin ◽  
M.B. Valli ◽  
M. Battaglia ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Cell Lines ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Hepatitis C Virus Rna ◽  
Virus Rna

scholarly journals Preclinical Profile and Clinical Efficacy of a Novel Hepatitis C Virus NS5A Inhibitor, EDP-239

2016 ◽  
Vol 60 (10) ◽  
pp. 6207-6215 ◽  
Author(s):  
Christopher M. Owens ◽  
Bradley B. Brasher ◽  
Alex Polemeropoulos ◽  
Michael H. J. Rhodin ◽  
Nicole McAllister ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Nonstructural Protein ◽  
Viral Rna ◽  
Controlled Clinical Trial ◽  
Genotype 1A ◽  
Pharmacokinetic Properties ◽  
Direct Acting

ABSTRACTEDP-239, a novel hepatitis C virus (HCV) inhibitor targeting nonstructural protein 5A (NS5A), has been investigatedin vitroandin vivo. EDP-239 is a potent, selective inhibitor with potency at picomolar to nanomolar concentrations against HCV genotypes 1 through 6. In the presence of human serum, the potency of EDP-239 was reduced by less than 4-fold. EDP-239 is additive to synergistic with other direct-acting antivirals (DAAs) or host-targeted antivirals (HTAs) in blocking HCV replication and suppresses the selection of resistancein vitro. Furthermore, EDP-239 retains potency against known DAA- or HTA-resistant variants, with half-maximal effective concentrations (EC50s) equivalent to those for the wild type. In a phase I, single-ascending-dose, placebo-controlled clinical trial, EDP-239 demonstrated excellent pharmacokinetic properties that supported once daily dosing. A single 100-mg dose of EDP-239 resulted in reductions in HCV genotype 1a viral RNA of >3 log10IU/ml within the first 48 h after dosing and reductions in genotype 1b viral RNA of >4-log10IU/ml within 96 h. (This study has been registered at ClinicalTrials.gov under identifier NCT01856426.)

scholarly journals In VitroandIn VivoAntiviral Activity and Resistance Profile of the Hepatitis C Virus NS3/4A Protease Inhibitor ABT-450

2014 ◽  
Vol 59 (2) ◽  
pp. 988-997 ◽  
Author(s):  
Tami Pilot-Matias ◽  
Rakesh Tripathi ◽  
Daniel Cohen ◽  
Isabelle Gaultier ◽  
Tatyana Dekhtyar ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Agents ◽  
Cross Resistance ◽  
Hcv Rna ◽  
Genotype 1 ◽  
Common Amino Acid ◽  
Direct Acting Antiviral ◽  
Genotype 1A

ABSTRACTThe development of direct-acting antiviral agents is a promising therapeutic advance in the treatment of hepatitis C virus (HCV) infection. However, rapid emergence of drug resistance can limit efficacy and lead to cross-resistance among members of the same drug class. ABT-450 is an efficacious inhibitor of HCV NS3/4A protease, with 50% effective concentration values of 1.0, 0.21, 5.3, 19, 0.09, and 0.69 nM against stable HCV replicons with NS3 protease from genotypes 1a, 1b, 2a, 3a, 4a, and 6a, respectively.In vitro, the most common amino acid variants selected by ABT-450 in genotype 1 were located in NS3 at positions 155, 156, and 168, with the D168Y variant conferring the highest level of resistance to ABT-450 in both genotype 1a and 1b replicons (219- and 337-fold, respectively). In a 3-day monotherapy study with HCV genotype 1-infected patients, ABT-450 was coadministered with ritonavir, a cytochrome P450 3A4 inhibitor shown previously to markedly increase peak, trough, and overall drug exposures of ABT-450. A mean maximum HCV RNA decline of 4.02 log10was observed at the end of the 3-day dosing period across all doses. The most common variants selected in these patients were R155K and D168V in genotype 1a and D168V in genotype 1b. However, selection of resistant variants was significantly reduced at the highest ABT-450 dose compared to lower doses. These findings were informative for the subsequent evaluation of ABT-450 in combination with additional drug classes in clinical trials in HCV-infected patients. (Study M11-602 is registered at ClinicalTrials.gov under registration no. NCT01074008.)

scholarly journals CS-SELEX Generates High-Affinity ssDNA Aptamers as Molecular Probes for Hepatitis C Virus Envelope Glycoprotein E2

PLoS ONE ◽  
2009 ◽  
Vol 4 (12) ◽  
pp. e8142 ◽  
Author(s):  
Fang Chen ◽  
Yilan Hu ◽  
Dongqing Li ◽  
Haidan Chen ◽  
Xiao-Lian Zhang
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Envelope Glycoprotein ◽  
Molecular Probes ◽  
Virus Envelope ◽  
High Affinity ◽  
Glycoprotein E2
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