scholarly journals Determination of the human antibody response to the epitope defined by the hepatitis C virus-neutralizing monoclonal antibody AP33

2007 ◽  
Vol 88 (11) ◽  
pp. 2991-3001 ◽  
Author(s):  
Alexander W. Tarr ◽  
Ania M. Owsianka ◽  
Dhanya Jayaraj ◽  
Richard J. P. Brown ◽  
Timothy P. Hickling ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Natural Infection ◽  
Acute Infection ◽  
Hcv Infection ◽  
Human Antibody ◽  
Human Mabs ◽  
Chronic Hcv ◽  
New Treatments

Hepatitis C virus (HCV) is a major cause of liver disease worldwide and there is a pressing need for the development of a preventative vaccine as well as new treatments. It was recently demonstrated that the mouse monoclonal antibody (mAb) AP33 potently neutralizes infectivity of HCV pseudoparticles (HCVpp) carrying E1E2 envelopes representative of all of the major genotypes of HCV. This study determined the prevalence of human serum antibodies reactive to the region of HCV E2 recognized by AP33. Antibodies recognizing this region were present in less than 2.5 % of sera obtained from individuals with chronic HCV infection. A similar prevalence was found in a smaller cohort of individuals who had experienced an acute infection, suggesting that AP33-like antibodies do not play a major role in natural clearance of HCV infection. Sera exhibited different patterns of reactivity to a panel of peptides representing circulating variants, highlighting the presence of distinct epitopes in this region. Only two sera contained antibodies that could recognize a specific AP33-reactive peptide mimotope. AP33-like antibodies made a measurable contribution to the ability of these sera to inhibit E2–CD81 interaction, but not to the overall neutralization of cell entry. Together, these data show that antibodies to the AP33 epitope are not commonly generated during natural infection and that generation of such antibodies via vaccination may require modified immunogens to focus the generation of specific antibodies. Importantly, individuals harbouring AP33-like antibodies are an important potential source of human mAbs for future therapeutic development.

Genetic polymorphisms as the predictors of response to antiviral treatment in chronic hepatitis C virus infection

2011 ◽  
Vol 152 (22) ◽  
pp. 876-881
Author(s):  
Alajos Pár
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Genetic Polymorphisms ◽  
Chronic Hepatitis C ◽  
Genome Wide Association Study ◽  
Antiviral Treatment ◽  
Hcv Infection ◽  
Snp Analysis ◽  
Chronic Hcv

The review discusses the genetic polymorphisms involved in the pathogenesis of hepatitis C virus (HCV) infection, that may determine the outcome of disease. In this field earlier both certain major histocompatibility complex (MHC) alleles and some cytokine gene variants have also been studied. Recently, the genome-wide association study (GWAS) and targeted single nucleotide polymorphism (SNP) analysis have revealed that a variant in the promoter region of interleukin-28B (IL-28B) gene is strongly linked to viral clearance and it may be the strongest pretreatment predictor of treatment response in chronic hepatitis C. Last year it was shown that two genetic variants leading to inosine triphosphatase deficiency protect against haemolytic anemia in patients receiving ribavirin during antiviral treatment for chronic HCV infection. Orv. Hetil., 2011, 152, 876–881.

scholarly journals Analysis of Successful Immune Responses in Persons Infected with Hepatitis C Virus

2000 ◽  
Vol 191 (9) ◽  
pp. 1499-1512 ◽  
Author(s):  
Franziska Lechner ◽  
David K.H. Wong ◽  
P. Rod Dunbar ◽  
Roger Chapman ◽  
Raymond T. Chung ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Lymphocyte ◽  
Cytotoxic T Lymphocyte ◽  
Acute Infection ◽  
Hcv Infection ◽  
Ctl Response ◽  
Acute Hcv ◽  
Ifn Γ ◽  
Acute Hcv Infection

Although hepatitis C virus (HCV) infection is very common, identification of patients during acute infection is rare. Consequently, little is known about the immune response during this critical stage of the disease. We analyzed the T lymphocyte response during and after acute resolving HCV infection in three persons, using interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) and human histocompatibility leukocyte antigen (HLA) peptide tetramer assays. Acute infection was associated with a broadly directed T helper and cytotoxic T lymphocyte (CTL) response, which persisted after resolution of clinical hepatitis and clearance of viremia. At the earliest time point studied, highly activated CTL populations were observed that temporarily failed to secrete IFN-γ, a “stunned” phenotype, from which they recovered as viremia declined. In long-term HCV-seropositive persons, CTL responses were more common in persons who had cleared viremia compared with those with persistent viremia, although the frequencies of HCV-specific CTLs were lower than those found in persons during and after resolution of acute HCV infection. These studies demonstrate a strong and persistent CTL response in resolving acute HCV infection, and provide rationale to explore immune augmentation as a therapeutic intervention in chronic HCV infection.

Serologic, Virologic, and Histologic Characteristics of Chronic Phase Hepatitis C Virus Disease in Children Infected by Transfusion

PEDIATRICS ◽  
1994 ◽  
Vol 94 (6) ◽  
pp. 919-922
Author(s):  
Suguru Matsuoka ◽  
Katsuyoshi Tatara ◽  
Yasunobu Hayabuchi ◽  
Yoshiyuki Taguchi ◽  
Kazuhiro Mori ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Acute Infection ◽  
Chronic Phase ◽  
Hcv Infection ◽  
Core Antigen ◽  
Hcv Rna ◽  
Histologic Evidence ◽  
Group A ◽  
Group B

Objective. We studied the time course of hepatic dysfunction, seropositivity to hepatitis C virus (HCV) antibodies, viremia, and histologic evidence of hepatic injury to evaluate the course of HCV infection in children infected by blood transfusion. Patients and methods. Twenty-nine patients (ages 4 to 18 years) who underwent open-heart surgeries for congenital heart disease were grouped into three categories based on alterations in serum alanine aminotransferase (ALT) levels: Group A, acute infection; Group B, subacute infection; and Group C, chronic infection. Results. In Group C, all 13 patients had detectable HCV RNA in serum. In contrast, all patients in Group A had no detectable HCV RNA. In Group B, one of nine patients had detectable HCV RNA and two of four patients examined had persistent chronic hepatitis by histologic criteria. Antibodies directed against C100-3 antigen or core-antigen were more useful than second-generation HCV antibody assays in determining the relationship between viremia and immunologic response. Infection with HCV genotype II and the presence of higher HCV RNA copy numbers were associated with histologic evidence of hepatic damage. Conclusion. An abnormal ALT value is frequently associated with viremia, and biochemically resolved acute infection reflects clearance of HCV. However, a normal ALT does not always reflect an absence of hepatocyte damage and HCV replication in patients with subacute disease. The measures outlined in this study are useful indicators of disease activity during the chronic phase of post-transfusion HCV infection.

scholarly journals Monoclonal Antibody AP33 Defines a Broadly Neutralizing Epitope on the Hepatitis C Virus E2 Envelope Glycoprotein

2005 ◽  
Vol 79 (17) ◽  
pp. 11095-11104 ◽  
Author(s):  
Ania Owsianka ◽  
Alexander W. Tarr ◽  
Vicky S. Juttla ◽  
Dimitri Lavillette ◽  
Birke Bartosch ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Envelope Glycoprotein ◽  
Envelope Protein ◽  
Hypervariable Region ◽  
Neutralizing Antibody ◽  
Broadly Neutralizing Antibody ◽  
New Treatments ◽  
Potent Neutralization

ABSTRACT Hepatitis C virus (HCV) remains a significant threat to the general health of the world's population, and there is a pressing need for the development of new treatments and preventative vaccines. Here, we describe the generation of retrovirus-based pseudoparticles (HCVpp) incorporating a panel of full-length E1E2 clones representative of the major genotypes 1 through 6, and their application to assess the reactivity and neutralizing capability of antisera and monoclonal antibodies raised against portions of the HCV E2 envelope protein. Rabbit antisera raised against either the first hypervariable region or ectodomain of E2 showed limited and strain specific neutralization. By contrast, the monoclonal antibody (MAb) AP33 demonstrated potent neutralization of infectivity against HCVpp carrying E1E2 representative of all genotypes tested. The concentration of AP33 required to achieve 50% inhibition of infection by HCVpp of diverse genotypes ranged from 0.6 to 32 μg/ml. The epitope recognized by MAb AP33 is linear and highly conserved across different genotypes of HCV. Thus, identification of a broadly neutralizing antibody that recognizes a linear epitope is likely to be of significant benefit to future vaccine and therapeutic antibody development.

scholarly journals Proteasome Activator PA28γ-Dependent Nuclear Retention and Degradation of Hepatitis C Virus Core Protein

2003 ◽  
Vol 77 (19) ◽  
pp. 10237-10249 ◽  
Author(s):  
Kohji Moriishi ◽  
Tamaki Okabayashi ◽  
Kousuke Nakai ◽  
Kyoji Moriya ◽  
Kazuhiko Koike ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Regulatory Protein ◽  
Hcv Infection ◽  
Nuclear Retention ◽  
Proteasome Activator ◽  
Hcv Core Protein ◽  
Core Proteins ◽  
Chronic Hcv

ABSTRACT Hepatitis C virus (HCV) core protein plays an important role in the formation of the viral nucleocapsid and a regulatory protein involved in hepatocarcinogenesis. In this study, we have identified proteasome activator PA28γ (11S regulator γ) as an HCV core binding protein by using yeast two-hybrid system. This interaction was demonstrated not only in cell culture but also in the livers of HCV core transgenic mice. These findings are extended to human HCV infection by the observation of this interaction in liver specimens from a patient with chronic HCV infection. Neither the interaction of HCV core protein with other PA28 subtypes nor that of PA28γ with other Flavivirus core proteins was detected. Deletion of the PA28γ-binding region from the HCV core protein or knockout of the PA28γ gene led to the export of the HCV core protein from the nucleus to the cytoplasm. Overexpression of PA28γ enhanced the proteolysis of the HCV core protein. Thus, the nuclear retention and stability of the HCV core protein is regulated via a PA28γ-dependent pathway through which HCV pathogenesis may be exerted.

Direct-acting Antivirals for Hepatitis C Virus in Patients on Maintenance Dialysis

2017 ◽  
Vol 40 (10) ◽  
pp. 531-541 ◽  
Author(s):  
Fabrizio Fabrizi ◽  
Francesca M. Donato ◽  
Piergiorgio Messa
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Severe Renal Impairment ◽  
Controlled Trial ◽  
Hcv Infection ◽  
Direct Acting Antivirals ◽  
Safety And Efficacy ◽  
Maintenance Dialysis ◽  
Chronic Hcv ◽  
Direct Acting

The frequency of hepatitis C virus (HCV) infection remains high in patients with chronic kidney disease (CKD) and plays a detrimental role in mortality in this population. According to the latest survey, the adjusted hazard ratio for HCV-positive versus HCV-negative patients on long-term dialysis was 1.12 (95% CI, 1.05 to 1.20) and 1.10 (95% CI, 0.98 to 1.22) for all-cause and cardiovascular mortality, respectively. An impairment on quality of life has also been documented in HCV-infected patients undergoing regular dialysis. Most clinicians have been so far reluctant to treat hepatitis C in patients with advanced CKD, due to concerns regarding low efficacy and safety of interferon-based regimens. The advent of all-oral, direct-acting antivirals (DAAs) has revolutionized treatment paradigms for HCV, including patients with other comorbidities such as CKD. Two combinations of DAAs have been recently approved for the treatment of HCV in advanced CKD: elbasvir/grazoprevir (evaluated in 1 randomized controlled trial) and ombitasvir/paritaprevir/ritonavir/dasabuvir with or without ribavirin (examined in some observational, single-arm studies). These antiviral combinations have provided high safety and efficacy (SVR12 rates >90%) in HCV-infected patients with stage 4–5 CKD. Sofosbuvir, a nucleotide analogue inhibitor of the HCV NS5B polymerase, is the cornerstone of most anti-HCV current regimens but is not currently recommended for patients with severe renal insufficiency (eGFR <30 mL/min per 1.73 m2). However, several small-sized studies have been published on the safety and efficacy of sofosbuvir-based regimens for patients with hepatitis C on maintenance dialysis>; overall, the viral response was satisfactory (SVR12 rates ranging between 58% and 100%) with a few drug-related drop-outs. Studies are in progress to assess whether ribavirin-free antiviral combinations with novel DAAs are a viable option for patients with severe renal impairment and chronic HCV infection.

IgM and IgA antibodies generated against hepatitis C virus core antigen in patients with acute and chronic HCV infection

1994 ◽  
Vol 39 (9) ◽  
pp. 2022-2031 ◽  
Author(s):  
Shinjiro Sato ◽  
Shigetoshi Fujiyama ◽  
Motohiko Tanaka ◽  
Masafumi Goto ◽  
Yuko Taura ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hcv Infection ◽  
Core Antigen ◽  
Virus Core ◽  
Iga Antibodies ◽  
Chronic Hcv Infection ◽  
Chronic Hcv

scholarly journals Sustained Virological Response after 8-Week Treatment of Simeprevir with Peginterferon α-2a plus Ribavirin in a Japanese Female with Hepatitis C Virus Genotype 1b and IL28B Minor Genotype

2015 ◽  
Vol 9 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Tatsuo Kanda ◽  
Masato Nakamura ◽  
Reina Sasaki ◽  
Shin Yasui ◽  
Shingo Nakamoto ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Adverse Events ◽  
Sustained Virological Response ◽  
Virological Response ◽  
Hcv Infection ◽  
Direct Acting Antivirals ◽  
Chronic Hcv ◽  
Direct Acting ◽  
Peginterferon Α

Direct-acting antivirals with or without peginterferon α (PEG-IFN α) plus ribavirin are now available for the treatment of hepatitis C virus (HCV) infection. Direct-acting antivirals are potent inhibitors of HCV replication, but some of them occasionally possess serious adverse events. We experienced a 64-year-old female with chronic HCV genotype 1b infection who showed elevated alanine aminotransferase of 528 IU/l at week 9 after the commencement of treatment of simeprevir with PEG-IFN α-2a plus ribavirin. However, she achieved sustained virological response at week 24 after the end of treatment. In Japan, we also have to treat elderly patients infected with HCV and/or advanced hepatic fibrosis. Until an effective interferon-free regimen is established, direct-acting antivirals with PEG-IFN plus ribavirin may still play a role in the treatment for certain patients. To avoid serious results from adverse events, careful attention and follow-up will be needed in the treatment course of simeprevir with PEG-IFN plus ribavirin for chronic HCV infection.

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