scholarly journals Expression of Hepatitis C Virus E2 Ectodomain in E. coli and Its Application in the Detection of Anti-E2 Antibodies in Human Sera

2004 ◽  
Vol 36 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Jing Liu ◽  
Xin-Xin Zhang ◽  
Shen-Ying Zhang ◽  
Min Lu ◽  
Yu-Ying Kong ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Western Blot ◽  
Mammalian Cells ◽  
Rabbit Antiserum ◽  
Hcv Rna ◽  
Target Cells ◽  
E Coli ◽  
Specificity And Sensitivity ◽  
Human Sera

Abstract The second envelope glycoprotein (E2) of hepatitis C virus has been shown to bind human target cells and has become a major target for the development of anti-HCV vaccines. Anti-E2 antibodies have been suggested to be of clinical significance in diagnosis, treatment and prognosis of hepatitis C. However, large-scale expression and purification of E2 proteins in mammalian cells is difficult. As an alternative, E2 fragment (aa 385–730) with a four-amino-acid mutation (aa 568–571 PCNI to RVTS) was expressed as hexa-histidine-tagged full length protein [E2N730(m)] in E. coli and purified to over 85% purity. Purified E2N730(m) was specifically recognized by homologous hepatitis C patient serum in Western blot, suggesting that it displayed E2-specific antigenicity. Rabbit antiserum raised against E2N730(m) recognized E2 glycoproteins expressed in mammalian cells in Western blot. Purified E2N730(m) was used to detect anti-E2 antibodies in human sera and showed better specificity and sensitivity than previously reported C-terminally truncated E2 fragment (aa 385–565). Association between anti-E2 antibodies in patient sera and HCV RNA status was also demonstrated using this E. coli-derived protein. E2N730(m) might serve as an inexpensive alternative to mammalian cell-expressed E2 proteins in clinical and research applications.

scholarly journals High-density lipoproteins reduce the neutralizing effect of hepatitis C virus (HCV)-infected patient antibodies by promoting HCV entry

2006 ◽  
Vol 87 (9) ◽  
pp. 2577-2581 ◽  
Author(s):  
Cécile Voisset ◽  
Anne Op de Beeck ◽  
Pauline Horellou ◽  
Marlène Dreux ◽  
Thierry Gustot ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Physiological Activity ◽  
Scavenger Receptor ◽  
High Density ◽  
High Density Lipoproteins ◽  
Target Cells ◽  
Lipid Uptake ◽  
Human Sera

The neutralizing activity of anti-hepatitis C virus (HCV) antibodies is attenuated by a factor present in human sera, which has been proposed to be high-density lipoproteins (HDLs). HDLs have also been shown to facilitate the entry of HCV pseudoparticles (HCVpp) into target cells. Here, the aim of the study was to determine whether HDL-mediated facilitation of HCVpp and infectious HCV (HCVcc) entry and attenuation of neutralization are two related phenomena. The data indicated that HDLs attenuate neutralization at a constant rate. In addition, as for HDL-mediated facilitation of HCVpp entry, attenuation of neutralization depended on the expression of the scavenger receptor BI (SR-BI) and its selective lipid-uptake function. Finally, kinetic experiments showed that HDL-mediated facilitation of HCVpp entry is more rapid than virus neutralization. Altogether, these observations indicate that HCV is exploiting the physiological activity of SR-BI for promoting its entry into target cells, which consequently also protects the virus against neutralizing antibodies.

scholarly journals Complement-Mediated Enhancement of Antibody Function for Neutralization of Pseudotype Virus Containing Hepatitis C Virus E2 Chimeric Glycoprotein

2002 ◽  
Vol 76 (5) ◽  
pp. 2150-2158 ◽  
Author(s):  
Keith Meyer ◽  
Arnab Basu ◽  
Craig T. Przysiecki ◽  
L. Martin Lagging ◽  
Adrian M. Di Bisceglie ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Rabbit Antiserum ◽  
Virus Neutralization ◽  
Classical Pathway ◽  
Neutralization Activity ◽  
E2 Glycoprotein ◽  
Pseudotype Virus ◽  
Human Sera ◽  
Hcv E2 Glycoprotein

ABSTRACT We previously reported a number of features of hepatitis C virus (HCV) chimeric glycoproteins related to pseudotype virus entry into mammalian cells. In this study, pseudotype virus was neutralized by HCV E2 glycoprotein-specific antibodies and infected human sera. Neutralization (50% reduction of pseudotype virus plaque formation) was observed with two human immunoglobulin G1 monoclonal antibodies (MAbs) at concentrations of between 2.5 and 10 μg/ml. A hyperimmune rabbit antiserum to an E2 hypervariable region 1 (HVR1) mimotope also exhibited an HCV E2 pseudotype virus neutralization titer of ∼1/50. An E1 pseudotype virus used as a negative control was not neutralized to a significant level (<1/10) by these MAbs or rabbit antiserum to E2 HVR1. Since HCV probably has a lipid envelope, the role of complement in antibody-mediated virus neutralization was examined. Significant increases in the neutralization titers of the human MAbs (∼60- to 160-fold higher) and rabbit antiserum to HVR1 mimotopes (∼10-fold higher) were observed upon addition of guinea pig complement. Further, these studies suggested that complement activation occured primarily by the classical pathway, since a deficiency in the C4 component led to a significant decrease in the level of virus neutralization. This same decrease was not observed with factor B-deficient complement. We also determined that 9 of 56 HCV-infected patient sera (16%) had detectable pseudotype virus neutralization activity at serum dilutions of between 1/20 and 1/50 and that complement addition enhanced the neutralization activity of some of the HCV-infected human sera. Taken together, these results suggest that during infection, HCV E2 glycoprotein induces a weak neutralizing antibody response, that those antibodies can be measured in vitro by the surrogate pseudotype virus plaque reduction assay, and that neutralization function can be augmented by complement.

scholarly journals RNA-Binding Protein hnRNP D Modulates Internal Ribosome Entry Site-Dependent Translation of Hepatitis C Virus RNA

2008 ◽  
Vol 82 (24) ◽  
pp. 12082-12093 ◽  
Author(s):  
Ki Young Paek ◽  
Chon Saeng Kim ◽  
Sung Mi Park ◽  
Jong Heon Kim ◽  
Sung Key Jang
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Mammalian Cells ◽  
Rna Binding ◽  
Ribosome Profiling ◽  
Hcv Rna ◽  
Entry Site ◽  
Nontranslated Region ◽  
Hnrnp D ◽  
Hcv Ires

ABSTRACT Hepatitis C virus (HCV) is one of the major causative agents of virus-related hepatitis, liver cirrhosis, and hepatocellular carcinoma in humans. Translation of the HCV polyprotein is mediated by an internal ribosomal entry site (IRES) in the 5′ nontranslated region of the genome. Here, we report that a cellular protein, hnRNP D, interacts with the 5′ border of HCV IRES (stem-loop II) and promotes translation of HCV mRNA. Overexpression of hnRNP D in mammalian cells enhances HCV IRES-dependent translation, whereas knockdown of hnRNP D with small interfering RNAs (siRNAs) inhibits translation. In addition, sequestration of hnRNP D with an interacting DNA oligomer inhibits the translation of HCV mRNA in an in vitro system. Ribosome profiling experiments reveal that HCV RNA is redistributed from heavy to light polysome fractions upon suppression of the hnRNP D level using specific siRNA. These results collectively suggest that hnRNP D plays an important role in the translation of HCV mRNA through interactions with the IRES. Moreover, knockdown of hnRNP D with siRNA significantly hampers infection by HCV. A potential role of hnRNP D in HCV proliferation is discussed.

scholarly journals Liraglutide Inhibits Hepatitis C Virus Replication Through an AMP Activated Protein Kinase Dependent Mechanism

2019 ◽  
Vol 20 (18) ◽  
pp. 4569 ◽  
Author(s):  
Mei-Yueh Lee ◽  
Wei-Chun Chen ◽  
Wei-Hao Hsu ◽  
Szu-Chia Chen ◽  
Jin-Ching Lee
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protein Kinase ◽  
Western Blot ◽  
Cell Viability ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Adenosine Monophosphate ◽  
Hcv Rna ◽  
Dependent Manner

Insulin resistance and diabetes are both associated with chronic hepatitis C virus (HCV) infection, and the glucagon-like peptide-1(GLP-1) receptor agonist, liraglutide, is a common therapy for diabetes. Our aim was to investigate whether liraglutide treatment can inhibit HCV replication. A cell culture-produced HCV infectious system was generated by transfection of in vitro-transcribed genomic JFH-1 ribonucleic acid (RNA) into Huh-7.5 cells. Total RNA samples were extracted to determine the efficiency of HCV replication. The Ava5 cells were treated with liraglutide and cell viability was calculated. A Western blot analysis of the protein expression was performed. The immunoreactive blot signals were also detected. Liraglutide activated GLP-1 receptors in the HCV infectious system, and inhibited subgenomic HCV RNA replication in the HuH-7.5 cells. The Western blot analysis revealed both HCV protein and replicon RNA were reduced after treatment with liraglutide in a dose-dependent manner. Liraglutide decreased the cell viability of HCV RNA at an optimum concentration of 120 μg/mL, activated the 5′ adenosine monophosphate-activated protein kinase (AMPK) and the phosphorylated- transducer of regulated cyclic adenosine monophosphate (CAMP) response element-binding protein 2 (TORC2), thereby decreasing the cell viability of phosphoenolpyruvate carboxykinase (PEPCK) and G6pase RNA Therefore, we conclude that liraglutide can inhibit HCV replication via an AMPK/TORC2-dependent pathway.

scholarly journals Human VAP-B Is Involved in Hepatitis C Virus Replication through Interaction with NS5A and NS5B

2005 ◽  
Vol 79 (21) ◽  
pp. 13473-13482 ◽  
Author(s):  
Itsuki Hamamoto ◽  
Yorihiro Nishimura ◽  
Toru Okamoto ◽  
Hideki Aizaki ◽  
Minyi Liu ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Mammalian Cells ◽  
Transmembrane Domain ◽  
Nonstructural Protein ◽  
Coiled Coil ◽  
Hcv Rna ◽  
Subgenomic Replicon ◽  
A Cell ◽  
Subtype A

ABSTRACT The hepatitis C virus (HCV) nonstructural protein (NS) 5A is a phosphoprotein that associates with various cellular proteins and participates in the replication of the HCV genome. Human vesicle-associated membrane protein-associated protein (VAP) subtype A (VAP-A) is known to be a host factor essential for HCV replication by binding to both NS5A and NS5B. To obtain more information on the NS5A protein in HCV replication, we screened human brain and liver libraries by a yeast two-hybrid system using NS5A as bait and identified VAP-B as an NS5A-binding protein. Immunoprecipitation and mutation analyses revealed that VAP-B binds to both NS5A and NS5B in mammalian cells and forms homo- and heterodimers with VAP-A. VAP-A interacts with VAP-B through the transmembrane domain. NS5A interacts with the coiled-coil domain of VAP-B via 70 residues in the N-terminal and 341 to 344 amino acids in the C-terminal polyproline cluster region. NS5A was colocalized with VAP-B in the endoplasmic reticulum and Golgi apparatus. The specific antibody to VAP-B suppressed HCV RNA replication in a cell-free assay. Overexpression of VAP-B, but not of a mutant lacking its transmembrane domain, enhanced the expression of NS5A and NS5B and the replication of HCV RNA in Huh-7 cells harboring a subgenomic replicon. In the HCV replicon cells, the knockdown of endogenous VAP-B by small interfering RNA decreased expression of NS5B, but not of NS5A. These results suggest that VAP-B, in addition to VAP-A, plays an important role in the replication of the HCV genome.

scholarly journals An Automated Immunoblot Method for Detection of IgG Antibodies to Hepatitis C Virus: a Potential Supplemental Antibody Confirmatory Assay

2019 ◽  
Vol 57 (3) ◽  
Author(s):  
Maja Kodani ◽  
Miranda Martin ◽  
Vivianne Landgraf de Castro ◽  
Jan Drobeniuc ◽  
Saleem Kamili
Keyword(s):  
United States ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
The United States ◽  
Ease Of Use ◽  
Screening Tests ◽  
Fourth Generation ◽  
Hcv Rna ◽  
Specificity And Sensitivity ◽  
Confirmatory Assay

ABSTRACT An estimated 41,200 people were newly infected with hepatitis C virus (HCV) in 2016 in the United States. Screening tests for antibodies to HCV may generate up to 32% false positivity in low-risk populations. Current Centers for Disease Control and Prevention (CDC) screening recommendations do not require confirmatory testing of a screening anti-HCV-positive test; however, confirmation is valuable for surveillance in the absence of HCV RNA testing. A recombinant immunoblot assay (RIBA) was used as a confirmatory assay for anti-HCV-reactive samples but was discontinued in 2013. Another anti-HCV confirmatory assay, INNO-LIA, is commercially available in Europe but is not approved by the Food and Drug Administration (FDA) in the United States. We report the development of an anti-HCV assay that was performed on an automated immunoblot platform using a fourth-generation HCV recombinant fusion protein. Based on testing of 70 well-characterized samples, of which 40 were HCV RNA and anti-HCV positive, 15 were HCV RNA positive/anti-HCV negative, and 15 were HCV RNA and anti-HCV negative, the specificity and sensitivity of the HCV-WES assay were 100% and 95%, respectively. Concordance between INNO-LIA and HCV-WES was determined by testing 205 HCV RNA-negative/anti-HCV-positive samples, of which 149 (72.7%) were positive by HCV-WES, while 146 (71.2%) were positive by INNO-LIA. We have shown proof of concept for the use of this test for confirmation of screened anti-HCV results. The HCV-WES assay has advantages over manual Western blot assays and INNO-LIA, including ease of use, lower cost, and reduced hands-on time.

scholarly journals Serum Immunoglobulin G Antibodies to the GOR Autoepitope Are Present in Patients with Occult Hepatitis C Virus (HCV) Infection despite Lack of HCV-Specific Antibodies

2007 ◽  
Vol 14 (10) ◽  
pp. 1302-1306 ◽  
Author(s):  
Juan A. Quiroga ◽  
Inmaculada Castillo ◽  
Javier Bartolomé ◽  
Vicente Carreño
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Immunoglobulin G ◽  
Hcv Infection ◽  
Hepatic Tissue ◽  
Hcv Rna ◽  
Predictive Values ◽  
Specific Antibodies ◽  
Specificity And Sensitivity

ABSTRACT Antibody responses to the GOR autoepitope are frequently detected among anti-hepatitis C virus (anti-HCV)-positive patients with chronic hepatitis. Sera from 110 anti-HCV-negative patients with occult HCV infection, as diagnosed by detection of HCV RNA in hepatic tissue, were investigated for GOR antibody reactivity. A positive test for anti-GOR immunoglobulin G (IgG) was found for 22 (20%) of them. The frequency and titers of anti-GOR IgG were significantly lower than those in chronic hepatitis C patients (70/110, 63.6%; P < 0.001). Anti-GOR IgG was not detected in any of the 120 patients with HCV-unrelated liver disease. The anti-GOR IgG assay showed specificity and sensitivity values of 100% and 20%, respectively, among the sera from patients with occult HCV infection; the positive and negative predictive values were 100% and 44.3%, respectively. None of the clinical, laboratory, or histological characteristics of the patients with occult HCV infection were different according to GOR antibody status, except that the percentage of HCV RNA-positive hepatocytes was significantly greater (P = 0.042) in patients with occult HCV infection who tested positive for anti-GOR IgG. In conclusion, serum anti-GOR IgG is present in patients with occult HCV infection, despite a lack of detectable HCV-specific antibodies as determined by commercial tests. Testing for anti-GOR IgG in patients in whom HCV RNA is not detected in their sera may help with the identification of a subset of patients with occult HCV infection without the need to perform a liver biopsy.

Prevalence and Risk Factors of Hepatitis C Virus (HCV) in Tehsil Batkhela District Malakand, KPK, Pakistan

2018 ◽  
Vol 9 (06) ◽  
pp. 20251-20256
Author(s):  
Mudassir Khan ◽  
Shahrukh Khan ◽  
Shohra Haider ◽  
Fazal Jalil ◽  
Muhsin Jamal ◽  
...  
Keyword(s):  
Risk Factors ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Skin Color ◽  
Significant Risk ◽  
Rapid Test ◽  
Prevalence Ratio ◽  
Hcv Infection ◽  
Hcv Rna ◽  
Common Symptom

Background: Prevalence of Hepatitis C viral infection and its major risk factors has been found out in population of Batkhela, Khyber Pakhtunkhwa, Pakistan by taking number of volunteers from the interested area. HCV prevalence has not been researched in recent time here in this area, so that’s why we contributed. Materials and Methods: Ab rapid test cassette serum/plasma (USA) kit has been used for the mentioned purpose following by ELISA and finally PCR to find out active infection of virus. ICT positive individuals were reconfirmed by ELISA and then ELISA positive samples were carefully investigated by RT-PCR for Hepatitis C Virus. Results: The study population was of 770 volunteers belonging to the mentioned area of research, 453 males and 317 females. The overall prevalence was found to be 5.32% of HCV in Batkhela. This prevalence ratio was 3.12% in males and 2.20 % in females. 3rd generation ELISA was used to refine ICT positive samples which showed that 37 of the ICT positive samples had antibodies detected by ELISA. To find out active HCV infection, ELISA positive samples were refined by real time PCR which showed 2.98% of prevalence of active HCV infection in Batkhela based on HCV RNA in their blood. Principle Conclusion: Overall prevalence was found 5.32%, contaminated reused syringes and blades at Barbour’s shop, blood transfusion, surgical operations and unhygienic food in stalls etc were found significant risk factors for acquiring HCV infection. Body weakness and pale yellow skin color was common symptom in HCV positive volunteers. Safe sexual activities, blood screening before donation and sterilizing surgical equipment’s can protect us from Hepatitis C Virus.

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