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.

scholarly journals Monoclonal Antibodies against Extracellular Domains of Claudin-1 Block Hepatitis C Virus Infection in a Mouse Model

2015 ◽  
Vol 89 (9) ◽  
pp. 4866-4879 ◽  
Author(s):  
Masayoshi Fukasawa ◽  
Shotaro Nagase ◽  
Yoshitaka Shirasago ◽  
Manami Iida ◽  
Mayo Yamashita ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hcv Infection ◽  
Dependent Manner ◽  
Entry Inhibitors ◽  
High Affinity ◽  
Extracellular Domains ◽  
Very High

ABSTRACTHepatitis C virus (HCV) entry into host cells is a complex process requiring multiple host factors, including claudin-1 (CLDN1). Safe and effective therapeutic entry inhibitors need to be developed. We isolated a human hepatic Huh7.5.1-derived cell mutant that is nonpermissive to HCV, and comparative microarray analysis showed that the mutant was CLDN1 defective. Four hybridomas were obtained, which produced monoclonal antibodies (MAbs) that interacted with the parental Huh7.5.1 cell but not with the CLDN1-defective mutant. All MAbs produced by these hybridomas specifically bound to human CLDN1 with a very high affinity and prevented HCV infection of Huh7.5.1 cells in a dose-dependent manner, without apparent cytotoxicity. Two selected MAbs also inhibited HCV infection of human liver-chimeric mice without significant adverse effects. CLDN1 may be a potential target to prevent HCV infectionin vivo. Anti-CLDN1 MAbs may hence be promising candidates as novel anti-HCV agents.IMPORTANCESafe and effective therapeutic entry inhibitors against hepatitis C virus (HCV) are very useful for combination therapies with other anti-HCV drugs, such as direct-acting antivirals. In this study, we first showed an effective strategy for developing functional monoclonal antibodies (MAbs) against extracellular domains of a multimembrane-spanning target protein, claudin-1 (CLDN1), by using parental cells expressing the intact target membrane protein and target-defective cells. The established MAbs against CLDN1, which had a very high affinity for intact CLDN1, efficiently inhibitedin vitroandin vivoHCV infections. These anti-CLDN1 MAbs are promising leads for novel entry inhibitors against HCV.

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 Binding of Hepatitis C Virus E2 Glycoprotein to CD81 Does Not Correlate with Species Permissiveness to Infection

2000 ◽  
Vol 74 (13) ◽  
pp. 5933-5938 ◽  
Author(s):  
Annalisa Meola ◽  
Andrea Sbardellati ◽  
Bruno Bruni Ercole ◽  
Mauro Cerretani ◽  
Monica Pezzanera ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hcv Infection ◽  
Host Cells ◽  
Primate Species ◽  
Enzyme Linked Immunosorbent Assay ◽  
E2 Glycoprotein ◽  
Critical Residue ◽  
Human Molecule

ABSTRACT Hepatitis C virus (HCV) glycoprotein E2 binds to human cells by interacting with the CD81 molecule, which has been proposed to be the viral receptor. A correlation between binding to CD81 and species permissiveness to HCV infection has also been reported. We have determined the sequence of CD81 from the tamarin, a primate species known to be refractory to HCV infection. Tamarin CD81 (t-CD81) differs from the human molecule at 5 amino acid positions (155, 163, 169, 180, and 196) within the large extracellular loop (LEL), where the binding site for E2 has been located. Soluble recombinant forms of human CD81 (h-CD81), t-CD81, and African green monkey CD81 (agm-CD81) LEL molecules were analyzed by enzyme-linked immunosorbent assay for binding to E2 glycoprotein. Both h-CD81 and t-CD81 molecules were able to bind E2. Competition experiments showed that the two receptors cross-compete and that the t-CD81 binds with stronger affinity than the human molecule. Recently, h-CD81 residue 186 has been characterized as the critical residue involved in the interaction with E2. Recombinant CD81 mutant proteins were expressed to test whether human and tamarin receptors interacted with E2 in a comparable manner. Mutation of residue 186 (F186L) dramatically reduced the binding capability of t-CD81, a result that has already been demonstrated for the human receptor, whereas the opposite mutation (L186F) in agm-CD81 resulted in a neat gain of binding activity. Finally, the in vitro data were confirmed by detection of E2 binding to cotton-top tamarin (Saguinus oedipus) cell line B95-8 expressing endogenous CD81. These results indicate that the binding of E2 to CD81 is not predictive of an infection-producing interaction between HCV and host cells.

scholarly journals Pan-genotypic Hepatitis C Virus Inhibition by Natural Products Derived from the Wild Egyptian Artichoke

2015 ◽  
Vol 90 (4) ◽  
pp. 1918-1930 ◽  
Author(s):  
Mahmoud Fahmi Elsebai ◽  
George Koutsoudakis ◽  
Verónica Saludes ◽  
Gemma Pérez-Vilaró ◽  
Ari Turpeinen ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Sesquiterpene Lactones ◽  
Hcv Infection ◽  
Target Cells ◽  
Content Type ◽  
Water Extracts ◽  
Entry Inhibitors ◽  
Cell Cell

ABSTRACTHepatitis C virus (HCV) infection is the leading cause of chronic liver diseases. Water extracts of the leaves of the wild Egyptian artichoke (WEA) [Cynara cardunculusL. var.sylvestris(Lam.) Fiori] have been used for centuries in the Sinai Peninsula to treat hepatitis symptoms. Here we isolated and characterized six compounds from the water extracts of WEA and evaluated their HCV inhibition capacitiesin vitro. Importantly, two of these compounds, grosheimol and cynaropicrin, inhibited HCV with half-maximal effective concentrations (EC50s) in the low micromolar range. They inhibited HCV entry into target cells and were active against both cell-free infection as well as cell-cell transmission. Furthermore, the antiviral activity of both compounds was pan-genotypic as HCV genotypes 1a, 1b, 2b, 3a, 4a, 5a, 6a, and 7a were inhibited. Thus, grosheimol and cynaropicrin are promising candidates for the development of new pan-genotypic entry inhibitors of HCV infection.IMPORTANCEBecause there is no preventive HCV vaccine available today, the discovery of novel anti-HCV cell entry inhibitors could help develop preventive measures against infection. The present study describes two compounds isolated from the wild Egyptian artichoke (WEA) with respect to their structural elucidation, absolute configuration, and quantitative determination. Importantly, both compounds inhibited HCV infectionin vitro. The first compound was an unknown molecule, and it was designated “grosheimol,” while the second compound is the known molecule cynaropicrin. Both compounds belong to the group of sesquiterpene lactones. The mode of action of these compounds occurred during the early steps of the HCV life cycle, including cell-free and cell-cell infection inhibition. These natural compounds present promising candidates for further development into anti-HCV therapeutics.

scholarly journals Hepatitis C Virus Glycan-Dependent Interactions and the Potential for Novel Preventative Strategies

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 685
Author(s):  
Emmanuelle V. LeBlanc ◽  
Youjin Kim ◽  
Chantelle J. Capicciotti ◽  
Che C. Colpitts
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Immune Evasion ◽  
Hcv Infection ◽  
Major Contributor ◽  
Effective Management ◽  
Hcv Treatment ◽  
Entry Inhibitors ◽  
Chronic Hepatitis C Virus

Chronic hepatitis C virus (HCV) infections continue to be a major contributor to liver disease worldwide. HCV treatment has become highly effective, yet there are still no vaccines or prophylactic strategies available to prevent infection and allow effective management of the global HCV burden. Glycan-dependent interactions are crucial to many aspects of the highly complex HCV entry process, and also modulate immune evasion. This review provides an overview of the roles of viral and cellular glycans in HCV infection and highlights glycan-focused advances in the development of entry inhibitors and vaccines to effectively prevent HCV infection.

scholarly journals Characterization of Hepatitis C Virus Interaction with Heparan Sulfate Proteoglycans

2015 ◽  
Vol 89 (7) ◽  
pp. 3846-3858 ◽  
Author(s):  
Yan Xu ◽  
Pierre Martinez ◽  
Karin Séron ◽  
Guangxiang Luo ◽  
Fabrice Allain ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Apolipoprotein E ◽  
Heparan Sulfate ◽  
Heparan Sulfate Proteoglycans ◽  
Hcv Infection ◽  
Host Cells ◽  
Envelope Glycoproteins ◽  
Length Unit

ABSTRACTHepatitis C virus (HCV) entry involves binding to cell surface heparan sulfate (HS) structures. However, due to the lipoprotein-like structure of HCV, the exact contribution of virion components to this interaction remains controversial. Here, we investigated the relative contribution of HCV envelope proteins and apolipoprotein E in the HS-binding step. Deletion of hypervariable region 1, a region previously proposed to be involved in HS binding, did not alter HCV virion binding to HS, indicating that this region is not involved in this interaction in the context of a viral infection. Patient sera and monoclonal antibodies recognizing different regions of HCV envelope glycoproteins were also used in a pulldown assay with beads coated with heparin, a close HS structural homologue. Although isolated HCV envelope glycoproteins could interact with heparin, none of these antibodies was able to interfere with the virion-heparin interaction, strongly suggesting that at the virion surface, HCV envelope glycoproteins are not accessible for HS binding. In contrast, results from kinetic studies, heparin pulldown experiments, and inhibition experiments with anti-apolipoprotein E antibodies indicated that this apolipoprotein plays a major role in HCV-HS interaction. Finally, characterization of the HS structural determinants required for HCV infection by silencing of the enzymes involved in the HS biosynthesis pathway and by competition with modified heparin indicated thatN- and 6-O-sulfation but not 2-O-sulfation is required for HCV infection and that the minimum HS oligosaccharide length required for HCV infection is a decasaccharide. Together, these data indicate that HCV hijacks apolipoprotein E to initiate its interaction with specific HS structures.IMPORTANCEHepatitis C is a global health problem. Hepatitis C virus (HCV) infects approximately 130 million individuals worldwide, with the majority of cases remaining undiagnosed and untreated. In most infected individuals, the virus evades the immune system and establishes a chronic infection. As a consequence, hepatitis C is the leading cause of cirrhosis, end-stage liver disease, hepatocellular carcinoma, and liver transplantation. Virus infection is initiated by entry of the virus into the host cell. In this study, we provide new insights into the viral and cellular determinants involved in the first step of HCV entry, the binding of the virus to host cells. We show that apolipoprotein E is likely responsible for virus binding to heparan sulfate and thatN- and 6-O-sulfation of the heparan sulfate proteoglycans is required for HCV infection. In addition, the minimal HS length unit required for HCV infection is a decasaccharide.

scholarly journals In vitro hepatitis C virus infection and hepatic choline metabolism

2019 ◽  
Author(s):  
Kaelan Gobeil Odai ◽  
Conor O’Dwyer ◽  
Rineke Steenbergen ◽  
Tyler A. Shaw ◽  
Tyler M. Renner ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Cultured Cells ◽  
Hcv Infection ◽  
Choline Uptake ◽  
Choline Transport ◽  
Choline Metabolism ◽  
Positive Strand Rna ◽  
Uptake And Metabolism

AbstractCholine is an essential nutrient required for normal neuronal and muscular development, as well as homeostatic regulation of hepatic metabolism. In the liver, choline is incorporated into the main eukaryotic phospholipid, phosphatidylcholine (PC) and can enter one carbon metabolism via mitochondrial oxidation. Hepatitis C virus (HCV) is a hepatotropic positive-strand RNA virus that similar to other positive-strand RNA viruses can impact phospholipid metabolism. In the current study we sought to interrogate the link between choline transport and early HCV infection. Namely, we aimed to investigate how HCV modulates markers of choline metabolism following in vitro infection, while subsequently assessing how the inhibition of choline uptake and metabolism upon concurrent HCV infection may alter early viral replication. Finally, we assessed whether these parameters were consistent between cells cultured in fetal bovine serum (FBS) or human serum (HS), conditions known to differentially affect in vitro HCV infection. We observed that choline transport in FBS-cultured Huh7.5 cells is facilitated by the intermediate affinity transporter choline transporter-like family (CTL), and that CTL1 expression and the incorporation of choline into PC is diminished in 24 h infected FBS-cultured cells. Reciprocally, limiting the availability of choline for PC synthesis resulted in increased HCV replication at this early stage. In chronically HS-cultured Huh7.5 cells, there were no differences in the expression of choline transporters upon HCV infection or alterations to viral replication when choline transport was inhibited compared to control treatments. However, inhibiting choline uptake and metabolism in this system significantly impaired the production of infectious virions in HS-cultured cells. These results suggest that in addition to a known role of choline kinase, the transport of choline, potentially via CTL1, might also represent an important and regulated process during HCV infection.Abstract Figure

scholarly journals In Vitro Selection and Characterization of Hepatitis C Virus Serine Protease Variants Resistant to an Active-Site Peptide Inhibitor

2003 ◽  
Vol 77 (6) ◽  
pp. 3669-3679 ◽  
Author(s):  
Caterina Trozzi ◽  
Linda Bartholomew ◽  
Alessandra Ceccacci ◽  
Gabriella Biasiol ◽  
Laura Pacini ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Serine Protease ◽  
In Vitro Selection ◽  
Three Dimensional ◽  
Host Cells ◽  
Dimensional Structure ◽  
In Vitro Systems

ABSTRACT The hepatitis C virus (HCV) serine protease is necessary for viral replication and represents a valid target for developing new therapies for HCV infection. Potent and selective inhibitors of this enzyme have been identified and shown to inhibit HCV replication in tissue culture. The optimization of these inhibitors for clinical development would greatly benefit from in vitro systems for the identification and the study of resistant variants. We report the use HCV subgenomic replicons to isolate and characterize mutants resistant to a protease inhibitor. Taking advantage of the replicons' ability to transduce resistance to neomycin, we selected replicons with decreased sensitivity to the inhibitor by culturing the host cells in the presence of the inhibitor and neomycin. The selected replicons replicated to the same extent as those in parental cells. Sequence analysis followed by transfection of replicons containing isolated mutations revealed that resistance was mediated by amino acid substitutions in the protease. These results were confirmed by in vitro experiments with mutant enzymes and by modeling the inhibitor in the three-dimensional structure of the protease.

scholarly journals In Vitro Hepatitis C Virus Infection and Hepatic Choline Metabolism

Viruses ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 108 ◽  
Author(s):  
Kaelan Gobeil Odai ◽  
Conor O’Dwyer ◽  
Rineke Steenbergen ◽  
Tyler A. Shaw ◽  
Tyler M. Renner ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Post Infection ◽  
Cultured Cells ◽  
Hcv Infection ◽  
Choline Uptake ◽  
Choline Metabolism ◽  
Positive Strand Rna ◽  
Uptake And Metabolism

Choline is an essential nutrient required for normal neuronal and muscular development, as well as homeostatic regulation of hepatic metabolism. In the liver, choline is incorporated into the main eukaryotic phospholipid, phosphatidylcholine (PC), and can enter one-carbon metabolism via mitochondrial oxidation. Hepatitis C virus (HCV) is a hepatotropic positive-strand RNA virus that similar to other positive-strand RNA viruses and can impact phospholipid metabolism. In the current study we sought to interrogate if HCV modulates markers of choline metabolism following in vitro infection, while subsequently assessing if the inhibition of choline uptake and metabolism upon concurrent HCV infection alters viral replication and infectivity. Additionally, we assessed whether these parameters were consistent between cells cultured in fetal bovine serum (FBS) or human serum (HS), conditions known to differentially affect in vitro HCV infection. We observed that choline transport in FBS- and HS-cultured Huh7.5 cells is facilitated by the intermediate affinity transporter, choline transporter-like family (CTL). HCV infection in FBS, but not HS-cultured cells diminished CTL1 transcript and protein expression at 24 h post-infection, which was associated with lower choline uptake and lower incorporation of choline into PC. No changes in other transporters were observed and at 96 h post-infection, all differences were normalized. Reciprocally, limiting the availability of choline for PC synthesis by use of a choline uptake inhibitor resulted in increased HCV replication at this early stage (24 h post-infection) in both FBS- and HS-cultured cells. Finally, in chronic infection (96 h post-infection), inhibiting choline uptake and metabolism significantly impaired the production of infectious virions. These results suggest that in addition to a known role of choline kinase, the transport of choline, potentially via CTL1, might also represent an important and regulated process during HCV infection.

scholarly journals Preclinical Characterization of the Novel Hepatitis C Virus NS3 Protease Inhibitor GS-9451

2013 ◽  
Vol 58 (2) ◽  
pp. 647-653 ◽  
Author(s):  
Huiling Yang ◽  
Margaret Robinson ◽  
Amoreena C. Corsa ◽  
Betty Peng ◽  
Guofeng Cheng ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Activity ◽  
Protease Inhibitor ◽  
Hcv Infection ◽  
Cross Resistance ◽  
Protease Gene ◽  
Ns5a Inhibitor ◽  
Ns3 Protease

ABSTRACTGS-9451 is a selective hepatitis C virus (HCV) NS3 protease inhibitor in development for the treatment of genotype 1 (GT1) HCV infection. Key preclinical properties of GS-9451, includingin vitroantiviral activity, selectivity, cross-resistance, and combination activity, as well as pharmacokinetic properties, were determined. In multiple GT1a and GT1b replicon cell lines, GS-9451 had mean 50% effective concentrations (EC50s) of 13 and 5.4 nM, respectively, with minimal cytotoxicity; similar potency was observed in chimeric replicons encoding the NS3 protease gene of GT1 clinical isolates. GS-9451 was less active in GT2a replicon cells (EC50= 316 nM). Additive to synergisticin vitroantiviral activity was observed when GS-9451 was combined with other agents, including alpha interferon, ribavirin, and the polymerase inhibitors GS-6620 and tegobuvir (GS-9190), as well as the NS5A inhibitor ledipasvir (GS-5885). GS-9451 retained wild-type activity against multiple classes of NS5B and NS5A inhibitor resistance mutations. GS-9451 was stable in hepatic microsomes and hepatocytes from human and three other tested species. Systemic clearance was low in dogs and monkeys but high in rats. GS-9451 showed good oral bioavailability in all three species tested. In rats, GS-9451 levels were ∼40-fold higher in liver than plasma after intravenous dosing, and elimination of GS-9451 was primarily through biliary excretion. Together, these results are consistent with the antiviral activity observed in a recent phase 1b study. The results ofin vitrocross-resistance and combination antiviral assays support the ongoing development of GS-9451 in combination with other agents for the treatment of chronic HCV infection.

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