scholarly journals Previously Infected Chimpanzees Are Not Consistently Protected against Reinfection or Persistent Infection after Reexposure to the Identical Hepatitis C Virus Strain

2008 ◽  
Vol 82 (16) ◽  
pp. 8183-8195 ◽  
Author(s):  
Jens Bukh ◽  
Robert Thimme ◽  
Jean-Christophe Meunier ◽  
Kristina Faulk ◽  
Hans Christian Spangenberg ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Persistent Infection ◽  
Neutralizing Antibodies ◽  
Hcv Infection ◽  
Case Scenario ◽  
Cell Responses ◽  
Genotype 1A ◽  
Cellular Immune

ABSTRACT Protective immunity after resolved hepatitis C virus (HCV) infection has been reported. However, the breadth of this immunity has remained controversial, and the role of neutralizing antibodies has not been well-defined. In the present study, two chimpanzees (CH96A008 and CH1494) with resolved monoclonal H77C (genotype 1a) infection were rechallenged with low-dose homologous H77C virus about 12 months after viral clearance; CH96A008 became persistently infected, and CH1494 had transient viremia lasting 2 weeks. CH1494 was subsequently either partially or completely protected following five homologous rechallenges with monoclonal H77C or polyclonal H77 and after six heterologous rechallenges with HC-J4 (genotype 1b) or HC-J6 (genotype 2a) viruses. Subsequently, a final challenge with H77C resulted in persistent HCV infection. In both chimpanzees, serum neutralizing antibodies against retroviral pseudoparticles bearing the H77C envelope proteins were not detected during the initial infection or during rechallenge. However, anamnestic cellular immune responses developed during the initial homologous rechallenge, in particular in CH96A008, which developed a persistent infection. Polyprotein sequences of viruses recovered from CH1494 after the two homologous rechallenges that resulted in transient viremia were identical with the H77C virus. In contrast, the polyprotein sequences of viruses recovered from both chimpanzees after homologous rechallenge resulting in persistent infection had numerous changes. These findings have important implications for our understanding of immunity against HCV; even in the best-case scenario with autologous rechallenge, low-level viral persistence was seen in the presence of primed T-cell responses.

scholarly journals The role of neutralizing antibodies in hepatitis C virus infection

2012 ◽  
Vol 93 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Victoria C. Edwards ◽  
Alexander W. Tarr ◽  
Richard A. Urbanowicz ◽  
Jonathan K. Ball
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Primary Liver Cancer ◽  
Protective Role ◽  
Hcv Infection ◽  
Comprehensive Overview ◽  
Therapeutic Benefits ◽  
Natural Target

Hepatitis C virus (HCV) is a blood-borne virus estimated to infect around 170 million people worldwide and is, therefore, a major disease burden. In some individuals the virus is spontaneously cleared during the acute phase of infection, whilst in others a persistent infection ensues. Of those persistently infected, severe liver diseases such as cirrhosis and primary liver cancer may develop, although many individuals remain asymptomatic. A range of factors shape the course of HCV infection, not least host genetic polymorphisms and host immunity. A number of studies have shown that neutralizing antibodies (nAb) arise during HCV infection, but that these antibodies differ in their breadth and mechanism of neutralization. Recent studies, using both mAbs and polyclonal sera, have provided an insight into neutralizing determinants and the likely protective role of antibodies during infection. This understanding has helped to shape our knowledge of the overall structure of the HCV envelope glycoproteins – the natural target for nAb. Most nAb identified to date target receptor-binding sites within the envelope glycoprotein E2. However, there is some evidence that other viral epitopes may be targets for antibody neutralization, suggesting the need to broaden the search for neutralization epitopes beyond E2. This review provides a comprehensive overview of our current understanding of the role played by nAb in HCV infection and disease outcome and explores the limitations in the study systems currently used. In addition, we briefly discuss the potential therapeutic benefits of nAb and efforts to develop nAb-based therapies.

scholarly journals Immunity in Chimpanzees Chronically Infected with Hepatitis C Virus: Role of Minor Quasispecies in Reinfection

1998 ◽  
Vol 72 (3) ◽  
pp. 1725-1730 ◽  
Author(s):  
Colby A. Wyatt ◽  
Linda Andrus ◽  
Betsy Brotman ◽  
Fannie Huang ◽  
Dong-Hun Lee ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Primary Infection ◽  
Hcv Infection ◽  
Natural Evolution ◽  
Genotype 1A ◽  
Natural Progression ◽  
Chronic Hcv Infection ◽  
Chronic Hcv

ABSTRACT We have previously reported that chimpanzees chronically infected with hepatitis C virus (HCV) could be reinfected, even with the original infecting strain. In this study we tested the hypothesis that this might reflect the presence of minor quasispecies to which there was little or no immunity. To evaluate this hypothesis, we sequenced multiple clones taken at intervals after primary infection and rechallenge from four chronically infected chimpanzees. The inoculum used in these studies (HCV-H, genotype 1a) revealed 17 separate variants among 46 clones sequenced. Following challenge, each of the four challenged animals showed marked alterations of their quasispecies distribution. The new variants, which appeared 1 to 6 weeks after challenge, were either identical to or closely resembled variants present in the challenge inoculum. These results, paralleled by an increase in viremia in some of the challenged animals, suggest that quasispecies in the challenge inoculum were responsible for signs of reinfection and that there was little immunity. However, the newly emerged quasispecies completely took over infection in only one animal. In the remaining three chimpanzees the prechallenge quasispecies were able to persist. The natural evolution of infection within chimpanzees resulted in variants able to compete with the inoculum variants. Whether through reexposure or the natural progression of infection, newly emerged quasispecies are likely to play a role in the pathogenesis of chronic HCV infection.

scholarly journals Broadly Neutralizing Antibodies Targeting New Sites of Vulnerability in Hepatitis C Virus E1E2

2019 ◽  
Vol 93 (14) ◽  
Author(s):  
Michelle D. Colbert ◽  
Andrew I. Flyak ◽  
Clinton O. Ogega ◽  
Valerie J. Kinchen ◽  
Guido Massaccesi ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Infected Individual ◽  
Hcv Infection ◽  
Broadly Neutralizing Antibodies ◽  
Genotype 1A ◽  
Antigenic Sites

ABSTRACTIncreasing evidence indicates that broadly neutralizing antibodies (bNAbs) play an important role in immune-mediated control of hepatitis C virus (HCV) infection, but the relative contribution of neutralizing antibodies targeting antigenic sites across the HCV envelope (E1 and E2) proteins is unclear. Here, we isolated thirteen E1E2-specific monoclonal antibodies (MAbs) from B cells of a single HCV-infected individual who cleared one genotype 1a infection and then became persistently infected with a second genotype 1a strain. These MAbs bound six distinct discontinuous antigenic sites on the E1 protein, the E2 protein, or the E1E2 heterodimer. Three antigenic sites, designated AS108, AS112 (an N-terminal E1 site), and AS146, were distinct from previously described antigenic regions (ARs) 1 to 5 and E1 sites. Antibodies targeting four sites (AR3, AR4-5, AS108, and AS146) were broadly neutralizing. These MAbs also displayed distinct patterns of relative neutralizing potency (i.e., neutralization profiles) across a panel of diverse HCV strains, which led to complementary neutralizing breadth when they were tested in combination. Overall, this study demonstrates that HCV bNAb epitopes are not restricted to previously described antigenic sites, expanding the number of sites that could be targeted for vaccine development.IMPORTANCEWorldwide, more than 70 million people are infected with hepatitis C virus (HCV), which is a leading cause of hepatocellular carcinoma and liver transplantation. Despite the development of potent direct acting antivirals (DAAs) for HCV treatment, a vaccine is urgently needed due to the high cost of treatment and the possibility of reinfection after cure. Induction of multiple broadly neutralizing antibodies (bNAbs) that target distinct epitopes on the HCV envelope proteins is one approach to vaccine development. However, antigenic sites targeted by bNAbs in individuals with spontaneous control of HCV have not been fully defined. In this study, we characterize 13 monoclonal antibodies (MAbs) from a single person who cleared an HCV infection without treatment, and we identify 3 new sites targeted by neutralizing antibodies. The sites targeted by these MAbs could inform HCV vaccine development.

scholarly journals Adaptive Immune Response against Hepatitis C Virus

2020 ◽  
Vol 21 (16) ◽  
pp. 5644
Author(s):  
Janine Kemming ◽  
Robert Thimme ◽  
Christoph Neumann-Haefelin
Keyword(s):  
Immune Response ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Persistent Infection ◽  
Adaptive Immune Response ◽  
Hcv Infection ◽  
Viral Escape ◽  
Continuous Exposure ◽  
Adaptive Immune ◽  
Adaptive Immune Cells

A functional adaptive immune response is the major determinant for clearance of hepatitis C virus (HCV) infection. However, in the majority of patients, this response fails and persistent infection evolves. Here, we dissect the HCV-specific key players of adaptive immunity, namely B cells and T cells, and describe factors that affect infection outcome. Once chronic infection is established, continuous exposure to HCV antigens affects functionality, phenotype, transcriptional program, metabolism, and the epigenetics of the adaptive immune cells. In addition, viral escape mutations contribute to the failure of adaptive antiviral immunity. Direct-acting antivirals (DAA) can mediate HCV clearance in almost all patients with chronic HCV infection, however, defects in adaptive immune cell populations remain, only limited functional memory is obtained and reinfection of cured individuals is possible. Thus, to avoid potential reinfection and achieve global elimination of HCV infections, a prophylactic vaccine is needed. Recent vaccine trials could induce HCV-specific immunity but failed to protect from persistent infection. Thus, lessons from natural protection from persistent infection, DAA-mediated cure, and non-protective vaccination trials might lead the way to successful vaccination strategies in the future.

scholarly journals Hepatitis C Virus Attenuates Mitochondrial Lipid β-Oxidation by Downregulating Mitochondrial Trifunctional-Protein Expression

2015 ◽  
Vol 89 (8) ◽  
pp. 4092-4101 ◽  
Author(s):  
Yutaka Amako ◽  
Tsubasa Munakata ◽  
Michinori Kohara ◽  
Aleem Siddiqui ◽  
Chris Peers ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Persistent Infection ◽  
Liver Steatosis ◽  
Hcv Infection ◽  
Host Cells ◽  
Type I ◽  
Mrna Levels ◽  
Mitochondrial Lipid ◽  
Mitochondrial Trifunctional Protein

ABSTRACTThe course of hepatitis C virus (HCV) infection and disease progression involves alterations in lipid metabolism, leading to symptoms such as hypocholesterolemia and steatosis. Steatosis can be induced by multiple mechanisms, including increases in lipid biosynthesis and uptake, impaired lipoprotein secretion, and/or attenuation of lipid β-oxidation. However, little is known about the effects of HCV on lipid β-oxidation. A previous proteomics study revealed that HCV interacted with both the α- and β-subunits of the mitochondrial trifunctional protein (MTP), an enzyme complex which catalyzes the last 3 steps of mitochondrial lipid β-oxidation for cellular energy production. Here we show that in HCV-infected Huh7.5 cells, lipid β-oxidation was significantly attenuated. Consistently with this, MTP protein and mRNA levels were suppressed by HCV infection. A loss-of-function study showed that MTP depletion rendered cells less responsive to alpha interferon (IFN-α) treatment by impairing IFN-stimulated gene expression. These aspects of host-virus interaction explain how HCV alters host energy homeostasis and how it may also contribute to the establishment of persistent infection in the liver.IMPORTANCEHCV infection triggers metabolic alterations, which lead to significant disease outcomes, such as fatty liver (steatosis). This study revealed that HCV impairs mitochondrial lipid β-oxidation, which results in low lipid combustion. On the other hand, the HCV-induced defects in metabolic status played an important role in the control of the type I interferon system. Under the conditions of impaired lipid β-oxidation, host cells were less responsive to the ability of exogenously added IFN-α to suppress HCV replication. This suggests that interference with lipid β-oxidation may assist the virus in the establishment of a long-term, persistent infection. Further understanding of this aspect of virus-host interaction may lead to improvements in the current standard therapy.

Hepatitis C Virus Infection and B-Cell Non-Hodgkin’s Lymphoma.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4668-4668
Author(s):  
Janet G. Grudeva
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Hcv Infection ◽  
Control Group ◽  
Cell Infection ◽  
Serum Samples ◽  
Pathogenetic Role ◽  
Significant Difference

Backgroud: An increasing number of bacterial and viral infections have been linked with specific subtypes of lymphoma. Preliminary evidence suggests that hepatitis C virus (HCV) might play a pathogenetic role in autoimmune-related, non-malignant B-cell lymphoproliferation, as well as a subset of B-cell non-Hodgkin, s lymphomas (B-NHL), often with extranodal localization. Design and methods: The study was conducted in the Department of Hematology and consisted 149 (86 male, 63 female) untreated patients with a new diagnosis of B-NHL for 5-years period (2000–2004). HCV infection was investigated by testing for HCV antibodies in serum samples. The controls were 587 patients (without intravenous drug users) in other departments of the same hospital. Results: HCV infection was documented in 13 cases (8,4%) with NHL. The infected patients were not clinically relevant cryoglobulinemic activity, increased rate of autoimmune disorders and extranodal localizations prevalence. There was statistically significant difference between the NHL and control group (p<0,01) and no statistically significant difference between man/women carriers (p>0,05) into the NHL group. Overall, the clinical outcome of HCV-positive NHL does not seem to be different from that of NHL patients without HCV infection. However, the evidence of a significant liver injury may predict a worse prognosis in these cases. Conclusions: Our date suggest that HCV infection may be associated with B-NHL. With regard to the mechanism(s) by which HCV might favor B-cell expansion and malignant transformation, most date support an indirect pathogenetic role of the virus as an exogenous trigger. A direct oncogenetic role of HCV by direct cell infection and deregulation has only been hypothesized on the basis of the lymphotropism of the virus.

scholarly journals Hepatitis C Virus (HCV) Infection May Elicit Neutralizing Antibodies Targeting Epitopes Conserved in All Viral Genotypes

PLoS ONE ◽  
2009 ◽  
Vol 4 (12) ◽  
pp. e8254 ◽  
Author(s):  
Nicasio Mancini ◽  
Roberta A. Diotti ◽  
Mario Perotti ◽  
Giuseppe Sautto ◽  
Nicola Clementi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Hcv Infection

scholarly journals The Clearance of Hepatitis C Virus Infection in Chimpanzees May Not Necessarily Correlate with the Appearance of Acquired Immunity

2003 ◽  
Vol 77 (2) ◽  
pp. 862-870 ◽  
Author(s):  
Michael Thomson ◽  
Michelina Nascimbeni ◽  
Michael B. Havert ◽  
Marian Major ◽  
Sophia Gonzales ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
T Cell Responses ◽  
Distinct Pattern ◽  
Hcv Infection ◽  
Interleukin 4 ◽  
Mrna Levels ◽  
Cell Responses ◽  
Ifn Γ

ABSTRACT Clearance of hepatitis C virus (HCV) infection in humans and chimpanzees is thought to be associated with the induction of strong T-cell responses. We studied four chimpanzees infected with HCV derived from an infectious full-length HCV genotype 1b cDNA. Two of the chimpanzees cleared the infection to undetectable levels for more than 12 months of follow-up; the other two became persistently infected. Detailed analyses of HCV-specific immune responses were performed during the courses of infection in these chimpanzees. Only weak and transient T helper responses were detected during the acute phase in all four chimpanzees. A comparison of the frequency of gamma interferon (IFN-γ)-producing CD4+ and CD8+ T cells in peripheral blood by ELISpot assay did not reveal any correlation between viral clearance and T-cell responses. In addition, analyses of IFN-γ, IFN-α, and interleukin-4 mRNA levels in liver biopsies, presumably indicative of intrahepatic T-cell responses, revealed no distinct pattern in these chimpanzees with respect to infection outcome. The present study suggests that the outcome of HCV infection in chimpanzees is not necessarily attributable to HCV sequence variation and that chimpanzees may recover from HCV infection by mechanisms other than the induction of readily detectable HCV-specific T-cell responses.

Role of Anti-Hepatitis C Virus (HCV) Treatment in HCV-Related, Low-Grade, B-Cell, Non-Hodgkin's Lymphoma: A Multicenter Italian Experience

2005 ◽  
Vol 23 (3) ◽  
pp. 468-473 ◽  
Author(s):  
Daniele Vallisa ◽  
Patrizia Bernuzzi ◽  
Luca Arcaini ◽  
Stefano Sacchi ◽  
Vittorio Callea ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Antiviral Treatment ◽  
Complete Response ◽  
Hcv Infection ◽  
Low Grade ◽  
Hcv Treatment ◽  
Hematologic Response

Purpose Hepatitis C virus (HCV) is endemic in some areas of Northwestern Europe and the United States. HCV has been shown to play a role in the development of both hepatocellular carcinoma and B-cell non-Hodgkin's lymphoma (B-NHL). The biologic mechanisms underlying the lymphomagenic activity of the virus so far are under investigation. In this study, the role of antiviral (anti-HCV) treatment in B-NHL associated with HCV infection is evaluated. Patients and Methods Thirteen patients with histologically proven low-grade B-NHL characterized by an indolent course (ie, doubling time no less than 1 year, no bulky disease) and carrying HCV infection were enrolled on the study. All patients underwent antiviral treatment alone with pegilated interferon and ribavirin. Response assessment took place at 6 and 12 months. Results Of the twelve assessable patients, seven (58%) achieved complete response and two (16%) partial hematologic response at 14.1 ± 9.7 months (range, 2 to 24 months, median follow-up, 14 months), while two had stable disease with only one patient experiencing progression of disease. Hematologic responses (complete and partial, 75%) were highly significantly associated to clearance or decrease in serum HCV viral load following treatment (P = .005). Virologic response was more likely to be seen in HCV genotype 2 (P = .035), while hematologic response did not correlate with the viral genotype. Treatment-related toxicity did not cause discontinuation of therapy in all but two patients, one of whom, however, achieved complete response. Conclusion This experience strongly provides a role for antiviral treatment in patients affected by HCV-related, low-grade, B-cell NHL.

scholarly journals In Vivo Study of the HC-TN Strain of Hepatitis C Virus Recovered from a Patient with Fulminant Hepatitis: RNA Transcripts of a Molecular Clone (pHC-TN) Are Infectious in Chimpanzees but Not in Huh7.5 Cells

2007 ◽  
Vol 81 (13) ◽  
pp. 7208-7219 ◽  
Author(s):  
Akito Sakai ◽  
Shingo Takikawa ◽  
Robert Thimme ◽  
Jean-Christophe Meunier ◽  
Hans Christian Spangenberg ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Immune Responses ◽  
Disease Severity ◽  
Neutralizing Antibodies ◽  
Viral Evolution ◽  
Acute Infection ◽  
Hcv Infection ◽  
Rna Transcripts

ABSTRACT Both viral and host factors are thought to influence the pathogenesis of hepatitis C virus (HCV) infection. We studied strain HC-TN (genotype 1a), which caused fulminant hepatic failure in a patient and, subsequently, severe hepatitis in a chimpanzee (CH1422), to analyze the relationship between disease severity, host immune response, viral evolution, and outcome. A second chimpanzee (CH1581) was infected from CH1422 plasma, and a third chimpanzee (CH1579) was infected from RNA transcripts of a consensus cDNA of HC-TN (pHC-TN). RNA transcripts of pHC-TN did not replicate in Huh7.5 cells, which were recently found to be susceptible to infection with another fulminant HCV strain (JFH1). The courses of viremia were similar in the three animals. However, CH1581 and CH1579 developed a less severe acute hepatitis than CH1422. CH1579 and CH1422 resolved the infection, whereas CH1581 became persistently infected. CH1579 and CH1581, despite their differing outcomes, both developed significant intrahepatic cellular immune responses, but not antibodies to the envelope glycoproteins or neutralizing antibodies, during the acute infection. We analyzed the polyprotein sequences of virus recovered at five and nine time points from CH1579 and CH1581, respectively, during the first year of follow-up. High mutation rates and high proportions of nonsynonymous mutations suggested immune pressure and positive selection in both animals. Changes were not selected until after the initial decrease in virus titers and after the development of immune responses and hepatitis. Subsequently, however, mutations emerged repeatedly in both animals. Overall, our results indicate that disease severity and outcome of acute HCV infection depend primarily on the host response.

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