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Racle J, Gfeller D. How to Predict Binding Specificity and Ligands for New MHC-II Alleles with MixMHC2pred. Methods Mol Biol 2024; 2809:215-235. [PMID: 38907900 DOI: 10.1007/978-1-0716-3874-3_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/24/2024]
Abstract
MHC-II molecules are key mediators of antigen presentation in vertebrate species and bind to their ligands with high specificity. The very high polymorphism of MHC-II genes within species and the fast-evolving nature of these genes across species has resulted in tens of thousands of different alleles, with hundreds of new alleles being discovered yearly through large sequencing projects in different species. Here we describe how to use MixMHC2pred to predict the binding specificity of any MHC-II allele directly from its amino acid sequence. We then show how both MHC-II ligands and CD4+ T cell epitopes can be predicted in different species with our approach. MixMHC2pred is available at http://mixmhc2pred.gfellerlab.org/ .
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Affiliation(s)
- Julien Racle
- Department of Oncology UNIL CHUV, Ludwig Institute for Cancer Research, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland
- Agora Cancer Research Centre, Lausanne, Switzerland
- Swiss Cancer Center Leman (SCCL), Lausanne, Switzerland
| | - David Gfeller
- Department of Oncology UNIL CHUV, Ludwig Institute for Cancer Research, University of Lausanne, Lausanne, Switzerland.
- Swiss Institute of Bioinformatics (SIB), Lausanne, Switzerland.
- Agora Cancer Research Centre, Lausanne, Switzerland.
- Swiss Cancer Center Leman (SCCL), Lausanne, Switzerland.
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2
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Hartnell F, Esposito I, Swadling L, Brown A, Phetsouphanh C, de Lara C, Gentile C, Turner B, Dorrell L, Capone S, Folgori A, Barnes E, Klenerman P. Characterizing Hepatitis C Virus-Specific CD4 + T Cells Following Viral-Vectored Vaccination, Directly Acting Antivirals, and Spontaneous Viral Cure. Hepatology 2020; 72:1541-1555. [PMID: 32012325 PMCID: PMC7610807 DOI: 10.1002/hep.31160] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Accepted: 01/07/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND AIMS Induction of functional helper CD4+ T cells is the hallmark of a protective immune response against hepatitis C virus (HCV), associated with spontaneous viral clearance. Heterologous prime/boost viral vectored vaccination has demonstrated induction of broad and polyfunctional HCV-specific CD8+ T cells in healthy volunteers; however, much less is known about CD4+ T-cell subsets following vaccination. APPROACH AND RESULTS We analyzed HCV-specific CD4+ T-cell populations using major histocompatibility complex class II tetramers in volunteers undergoing HCV vaccination with recombinant HCV adenoviral/modified vaccinia Ankara viral vectors. Peptide-specific T-cell responses were tracked over time, and functional (proliferation and cytokine secretion) and phenotypic (cell surface and intranuclear) markers were assessed using flow cytometry. These were compared to CD4+ responses in 10 human leukocyte antigen-matched persons with HCV spontaneous resolution and 21 chronically infected patients treated with directly acting antiviral (DAA) therapy. Vaccination induced tetramer-positive CD4+ T cells that were highest 1-4 weeks after boosting (mean, 0.06%). Similar frequencies were obtained for those tracked following spontaneous resolution of disease (mean, 0.04%). In addition, the cell-surface phenotype (CD28, CD127) memory subset markers and intranuclear transcription factors, as well as functional capacity of peptide-specific CD4+ T-cell responses characterized after vaccination, are comparable to those following spontaneous viral resolution. In contrast, helper responses in chronic infection were infrequently detected and poorly functional and did not consistently recover following HCV cure. CONCLUSIONS Helper CD4+ T-cell phenotype and function following HCV viral vectored vaccination resembles "protective memory" that is observed following spontaneous clearance of HCV. DAA cure does not promote resurrection of exhausted CD4+ T-cell memory in chronic infection.
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Affiliation(s)
- Felicity Hartnell
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUnited Kingdom
| | - Ilaria Esposito
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUnited Kingdom
| | - Leo Swadling
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUnited Kingdom
| | - Anthony Brown
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUnited Kingdom
| | | | - Catherine de Lara
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUnited Kingdom
| | | | - Bethany Turner
- Jenner Vaccine TrialsNuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
| | - Lucy Dorrell
- Jenner Vaccine TrialsNuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom
| | | | | | - Eleanor Barnes
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUnited Kingdom,Jenner Vaccine TrialsNuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom,NIHR Biomedical Research Centre OxfordJohn Radcliffe HospitalOxfordUnited Kingdom,Translational Gastroenterology UnitJohn Radcliffe HospitalOxfordUnited Kingdom
| | - Paul Klenerman
- Peter Medawar Building for Pathogen ResearchUniversity of OxfordOxfordUnited Kingdom,Jenner Vaccine TrialsNuffield Department of MedicineUniversity of OxfordOxfordUnited Kingdom,NIHR Biomedical Research Centre OxfordJohn Radcliffe HospitalOxfordUnited Kingdom,Translational Gastroenterology UnitJohn Radcliffe HospitalOxfordUnited Kingdom
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3
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Animal Models Used in Hepatitis C Virus Research. Int J Mol Sci 2020; 21:ijms21113869. [PMID: 32485887 PMCID: PMC7312079 DOI: 10.3390/ijms21113869] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
The narrow range of species permissive to infection by hepatitis C virus (HCV) presents a unique challenge to the development of useful animal models for studying HCV, as well as host immune responses and development of chronic infection and disease. Following earlier studies in chimpanzees, several unique approaches have been pursued to develop useful animal models for research while avoiding the important ethical concerns and costs inherent in research with chimpanzees. Genetically related hepatotropic viruses that infect animals are being used as surrogates for HCV in research studies; chimeras of these surrogate viruses harboring specific regions of the HCV genome are being developed to improve their utility for vaccine testing. Concurrently, genetically humanized mice are being developed and continually advanced using human factors known to be involved in virus entry and replication. Further, xenotransplantation of human hepatocytes into mice allows for the direct study of HCV infection in human liver tissue in a small animal model. The current advances in each of these approaches are discussed in the present review.
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Rehermann B, Thimme R. Insights From Antiviral Therapy Into Immune Responses to Hepatitis B and C Virus Infection. Gastroenterology 2019; 156:369-383. [PMID: 30267712 PMCID: PMC6340757 DOI: 10.1053/j.gastro.2018.08.061] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Revised: 08/05/2018] [Accepted: 08/21/2018] [Indexed: 12/17/2022]
Abstract
There are 257 million persons worldwide with chronic hepatitis B virus (HBV) infection, a leading causes of liver cancer. Almost all adults with acute HBV infection have a rapid immune response to the virus, resulting in life-long immunity, but there is no cure for individuals with chronic HBV infection, which they acquire during early life. The mechanisms that drive the progression of HBV through distinct clinical phases to end-stage liver disease are poorly understood. Likewise, it is not clear whether and how immune responses can be modulated to allow control and/or clearance of intrahepatic HBV DNA. We review the innate and adaptive immune responses to acute and chronic HBV infections and responses to antiviral therapy. Comparisons with hepatitis C virus infection provide insights into the reversibility of innate inflammatory responses and the potential for successful therapy to recover virus-specific memory immune responses.
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Affiliation(s)
- Barbara Rehermann
- Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland.
| | - Robert Thimme
- Klinik für Innere Medizin II, University Hospital Freiburg, Faculty of Medicine, Hugstetter Straße 55, 79106 Freiburg, Germany
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5
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Burm R, Collignon L, Mesalam AA, Meuleman P. Animal Models to Study Hepatitis C Virus Infection. Front Immunol 2018; 9:1032. [PMID: 29867998 PMCID: PMC5960670 DOI: 10.3389/fimmu.2018.01032] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/25/2018] [Indexed: 12/18/2022] Open
Abstract
With more than 71 million chronically infected people, the hepatitis C virus (HCV) is a major global health concern. Although new direct acting antivirals have significantly improved the rate of HCV cure, high therapy cost, potential emergence of drug-resistant viral variants, and unavailability of a protective vaccine represent challenges for complete HCV eradication. Relevant animal models are required, and additional development remains necessary, to effectively study HCV biology, virus–host interactions and for the evaluation of new antiviral approaches and prophylactic vaccines. The chimpanzee, the only non-human primate susceptible to experimental HCV infection, has been used extensively to study HCV infection, particularly to analyze the innate and adaptive immune response upon infection. However, financial, practical, and especially ethical constraints have urged the exploration of alternative small animal models. These include different types of transgenic mice, immunodeficient mice of which the liver is engrafted with human hepatocytes (humanized mice) and, more recently, immunocompetent rodents that are susceptible to infection with viruses that are closely related to HCV. In this review, we provide an overview of the currently available animal models that have proven valuable for the study of HCV, and discuss their main benefits and weaknesses.
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Affiliation(s)
- Rani Burm
- Laboratory of Liver Infectious Diseases, Department of Clinical Chemistry, Microbiology and Immunology, Faculty of Medicine and Health Sciences, Ghent University, Gent, Belgium
| | - Laura Collignon
- Laboratory of Liver Infectious Diseases, Department of Clinical Chemistry, Microbiology and Immunology, Faculty of Medicine and Health Sciences, Ghent University, Gent, Belgium
| | - Ahmed Atef Mesalam
- Laboratory of Liver Infectious Diseases, Department of Clinical Chemistry, Microbiology and Immunology, Faculty of Medicine and Health Sciences, Ghent University, Gent, Belgium.,Therapeutic Chemistry Department, National Research Centre (NRC), Cairo, Egypt
| | - Philip Meuleman
- Laboratory of Liver Infectious Diseases, Department of Clinical Chemistry, Microbiology and Immunology, Faculty of Medicine and Health Sciences, Ghent University, Gent, Belgium
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6
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Rybczynska J, Campbell K, Kamili S, Locarnini S, Krawczynski K, Walker CM. CD4+ T Cells Are Not Required for Suppression of Hepatitis B Virus Replication in the Liver of Vaccinated Chimpanzees. J Infect Dis 2015; 213:49-56. [PMID: 26324781 DOI: 10.1093/infdis/jiv348] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 06/12/2015] [Indexed: 01/12/2023] Open
Abstract
Humans vaccinated with hepatitis B virus (HBV) surface antigen (HBsAg) sometimes develop humoral and cellular immunity to HBV proteins such as core and polymerase that are not vaccine components, providing indirect evidence that vaccine-induced immunity is not sterilizing. We previously described CD4(+) T-cell immunity against HBsAg and polymerase in chimpanzees after vaccination and HBV challenge. Here, vaccinated chimpanzees with protective levels of anti-HBsAg antibodies were rechallenged with HBV after antibody-mediated CD4(+) T-cell depletion. HBV DNA was detected in liver for at least 3 months after rechallenge, but virus replication was suppressed, as revealed by the absence of HBV DNA and HBsAg in serum. These observations provide direct virological evidence for nonsterilizing immunity in individuals with anti-HBsAg antibodies and are consistent with translation of HBV proteins to prime immune responses. They also indicate that CD4(+) T cells were not required for suppression of HBV replication in previously vaccinated individuals.
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Affiliation(s)
- Jolanta Rybczynska
- Department of Pathology, Medical University of Warsaw, Poland Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Saleem Kamili
- Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Stephen Locarnini
- Victorian Infectious Disease Reference Laboratory, North Melbourne, Australia
| | - Krzysztof Krawczynski
- Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Christopher M Walker
- Center for Vaccines and Immunity, Nationwide Children's Hospital Department of Pediatrics, College of Medicine, The Ohio State University, Columbus
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Abdel-Hady KM, Gutierrez AH, Terry F, Desrosiers J, De Groot AS, Azzazy HME. Identification and retrospective validation of T-cell epitopes in the hepatitis C virus genotype 4 proteome: an accelerated approach toward epitope-driven vaccine development. Hum Vaccin Immunother 2015; 10:2366-77. [PMID: 25424944 DOI: 10.4161/hv.29177] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
With over 150 million people chronically infected worldwide and millions more infected annually, hepatitis C continues to pose a burden on the global healthcare system. The standard therapy of hepatitis C remains expensive, with severe associated side effects and inconsistent cure rates. Vaccine development against the hepatitis C virus has been hampered by practical and biological challenges posed by viral evasion mechanisms. Despite these challenges, HCV vaccine research has presented a number of candidate vaccines that progressed to phase II trials. However, those efforts focused mainly on HCV genotypes 1 and 2 as vaccine targets and barely enough attention was given to genotype 4, the variant most prevalent in the Middle East and central Africa. We describe herein the in silico identification of highly conserved and immunogenic T-cell epitopes from the HCV genotype 4 proteome, using the iVAX immunoinformatics toolkit, as targets for an epitope-driven vaccine. We also describe a fast and inexpensive approach for results validation using the empirical data on the Immune Epitope Database (IEDB) as a reference. Our analysis identified 90 HLA class I epitopes of which 20 were found to be novel and 19 more had their binding predictions retrospectively validated; empirical data for the remaining 51 epitopes was insufficient to validate their binding predictions. Our analysis also identified 14 HLA class II epitopes, of which 8 had most of their binding predictions validated. Further investigation is required regarding the efficacy of the identified epitopes as vaccine targets in populations where HCV genotype 4 is most prevalent.
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Affiliation(s)
- Karim M Abdel-Hady
- a Department of Chemistry; School of Sciences and Engineering; The American University in Cairo; New Cairo, Egypt
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8
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Dienstag JL, Delemos AS. Viral Hepatitis. MANDELL, DOUGLAS, AND BENNETT'S PRINCIPLES AND PRACTICE OF INFECTIOUS DISEASES 2015:1439-1468.e7. [DOI: 10.1016/b978-1-4557-4801-3.00119-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2025]
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Abstract
UNLABELLED Liver tolerance is manifest as a bias toward immune unresponsiveness, both in the context of a major histocompatibility complex-mismatched liver transplant and in the context of liver infection. Two broad classes of mechanisms account for liver tolerance. The presentation of antigens by different liver cell types results in incomplete activation of CD8(+) T cells, usually leading to initial proliferation followed by either clonal exhaustion or premature death of the T cell. Many liver infections result in relatively poor CD4(+) T-cell activation, which may be because liver antigen-presenting cells express a variety of inhibitory cytokines and coinhibitor ligands. Poor CD4(+) T-cell activation by liver antigens likely contributes to abortive activation, exhaustion, and early death of CD8(+) T cells. In addition, a network of active immunosuppressive pathways in the liver is mediated mostly by myeloid cells. Kupffer cells, myeloid-derived suppressor cells, and liver dendritic cells both promote activation of regulatory T cells and suppress CD8(+) and CD4(+) effector T cells. This suppressive network responds to diverse inputs, including signals from hepatocytes, sinusoidal endothelial cells, and hepatic stellate cells. CONCLUSION Though liver tolerance may be exploited by pathogens, it serves a valuable purpose. Hepatitis A and B infections occasionally elicit a powerful immune response sufficient to cause fatal massive liver necrosis. More commonly, the mechanisms of liver tolerance limit the magnitude of intrahepatic immune responses, allowing the liver to recover. The cost of this adaptive mechanism may be incomplete pathogen eradication, leading to chronic infection.
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Affiliation(s)
- Ian N Crispe
- Department of Pathology, University of Washington Medical Center, Seattle, WA 98195, USA
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10
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Abdel-Hakeem MS, Shoukry NH. Protective immunity against hepatitis C: many shades of gray. Front Immunol 2014; 5:274. [PMID: 24982656 PMCID: PMC4058636 DOI: 10.3389/fimmu.2014.00274] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 05/27/2014] [Indexed: 12/11/2022] Open
Abstract
The majority of individuals who become acutely infected with hepatitis C virus (HCV) develop chronic infection and suffer from progressive liver damage while approximately 25% are able to eliminate the virus spontaneously. Despite the recent introduction of new direct-acting antivirals, there is still no vaccine for HCV. As a result, new infections and reinfections will remain a problem in developing countries and among high risk populations like injection drug users who have limited access to treatment and who continue to be exposed to the virus. The outcome of acute HCV is determined by the interplay between the host genetics, the virus, and the virus-specific immune response. Studies in humans and chimpanzees have demonstrated the essential role of HCV-specific CD4 and CD8 T cell responses in protection against viral persistence. Recent data suggest that antibody responses play a more important role than what was previously thought. Individuals who spontaneously resolve acute HCV infection develop long-lived memory T cells and are less likely to become persistently infected upon reexposure. New studies examining high risk cohorts are identifying correlates of protection during real life exposures and reinfections. In this review, we discuss correlates of protective immunity during acute HCV and upon reexposure. We draw parallels between HCV and the current knowledge about protective memory in other models of chronic viral infections. Finally, we discuss some of the yet unresolved questions about key correlates of protection and their relevance for vaccine development against HCV.
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Affiliation(s)
- Mohamed S Abdel-Hakeem
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM) , Montréal, QC , Canada ; Département de Microbiologie, Infectiologie et Immunologie, Faculté de Médecine, Université de Montréal , Montréal, QC , Canada ; Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University , Cairo , Egypt
| | - Naglaa H Shoukry
- Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM) , Montréal, QC , Canada ; Département de Médecine, Faculté de Médecine, Université de Montréal , Montréal, QC , Canada
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11
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Rehermann B. Pathogenesis of chronic viral hepatitis: differential roles of T cells and NK cells. Nat Med 2013; 19:859-68. [PMID: 23836236 DOI: 10.1038/nm.3251] [Citation(s) in RCA: 375] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 05/30/2013] [Indexed: 02/08/2023]
Abstract
Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for 57% of cases of liver cirrhosis and 78% of cases of primary liver cancer worldwide and cause a million deaths per year. Although HBV and HCV differ in their genome structures, replication strategies and life cycles, they have common features, including their noncytopathic nature and their capacity to induce chronic liver disease, which is thought to be immune mediated. However, the rate of disease progression from chronic hepatitis to cirrhosis varies greatly among infected individuals, and the factors that regulate it are largely unknown. This review summarizes our current understanding of the roles of antigen-specific and nonspecific immune cells in the pathogenesis of chronic hepatitis B and C and discusses recent findings that identify natural killer cells as regulators of T cell function and liver inflammation.
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Affiliation(s)
- Barbara Rehermann
- Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, US National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA.
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12
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El-Awady MK, El Gendy M, Waked I, Tabll AA, El Abd Y, Bader El Din N, El Shenawy R, Allam A, Abdelhafez TH, Dawood RM. WITHDRAWN: Immunogenicity and safety of HCV E1E2 peptide vaccine in chronically HCV-infected patients who did not respond to interferon based therapy. Vaccine 2013:S0264-410X(13)01065-7. [PMID: 23962537 DOI: 10.1016/j.vaccine.2013.07.074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 07/20/2013] [Accepted: 07/30/2013] [Indexed: 02/07/2023]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Mostafa K El-Awady
- Microbial Biotechnology Department, National Research Center, Dokki, 12622 Giza, Egypt.
| | - Mohamed El Gendy
- National Liver Institute, Shebeen El Kom, Menofyia University, Egypt
| | - Imam Waked
- National Liver Institute, Shebeen El Kom, Menofyia University, Egypt
| | - Ashraf A Tabll
- Microbial Biotechnology Department, National Research Center, Dokki, 12622 Giza, Egypt
| | - Yasmin El Abd
- Microbial Biotechnology Department, National Research Center, Dokki, 12622 Giza, Egypt
| | - Noha Bader El Din
- Microbial Biotechnology Department, National Research Center, Dokki, 12622 Giza, Egypt
| | - Reem El Shenawy
- Microbial Biotechnology Department, National Research Center, Dokki, 12622 Giza, Egypt
| | - Aleef Allam
- National Liver Institute, Shebeen El Kom, Menofyia University, Egypt
| | - Tawfeek H Abdelhafez
- Microbial Biotechnology Department, National Research Center, Dokki, 12622 Giza, Egypt
| | - Reham M Dawood
- Microbial Biotechnology Department, National Research Center, Dokki, 12622 Giza, Egypt
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13
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Hepatitis C virus adaptation to T-cell immune pressure. ScientificWorldJournal 2013; 2013:673240. [PMID: 23554569 PMCID: PMC3608127 DOI: 10.1155/2013/673240] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 02/17/2013] [Indexed: 01/07/2023] Open
Abstract
Replication of the hepatitis C virus (HCV) is an error-prone process. This high error rate results in the emergence of viral populations (quasispecies) within hosts and contributes to interhost variability. Numerous studies have demonstrated that both viral and host factors contribute to this viral diversity, which can ultimately affect disease outcome. As the host's immune response is an important correlate of infection outcome for HCV, many of these viral variations are strongly influenced by T-cell immune pressure and accordingly constitute an efficient strategy to subvert such pressures (viral adaptations). This paper will review the data on viral diversity observed between and within hosts infected with HCV from the acute to the chronic stage of infection and will focus on viral adaptation to the host's T-cell immune response.
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14
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Zhou Y, Callendret B, Xu D, Brasky KM, Feng Z, Hensley LL, Guedj J, Perelson AS, Lemon SM, Lanford RE, Walker CM. Dominance of the CD4(+) T helper cell response during acute resolving hepatitis A virus infection. ACTA ACUST UNITED AC 2012; 209:1481-92. [PMID: 22753925 PMCID: PMC3409494 DOI: 10.1084/jem.20111906] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hepatitis A virus (HAV) infection typically resolves within 4-7 wk but symptomatic relapse occurs in up to 20% of cases. Immune mechanisms that terminate acute HAV infection, and prevent a relapse of virus replication and liver disease, are unknown. Here, patterns of T cell immunity, virus replication, and hepatocellular injury were studied in two HAV-infected chimpanzees. HAV-specific CD8(+) T cells were either not detected in the blood or failed to display effector function until after viremia and hepatitis began to subside. The function of CD8(+) T cells improved slowly as the cells acquired a memory phenotype but was largely restricted to production of IFN-γ. In contrast, CD4(+) T cells produced multiple cytokines when viremia first declined. Moreover, only CD4(+) T cells responded during a transient resurgence of fecal HAV shedding. This helper response then contracted slowly over several months as HAV genomes were eliminated from liver. The findings indicate a dominant role for CD4(+) T cells in the termination of HAV infection and, possibly, surveillance of an intrahepatic reservoir of HAV genomes that decays slowly. Rapid contraction or failure to sustain such a CD4(+) T cell response after resolution of symptoms could increase the risk of relapsing hepatitis A.
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Affiliation(s)
- Yan Zhou
- Center for Vaccines and Immunity, the Research Institute at Nationwide Children’s Hospital, Columbus, OH 43205, USA
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Ullah S, Shah MAA, Riaz N. Recent Advances in Development of DNA Vaccines Against Hepatitis C virus. INDIAN JOURNAL OF VIROLOGY : AN OFFICIAL ORGAN OF INDIAN VIROLOGICAL SOCIETY 2012; 23:253-60. [PMID: 24293811 DOI: 10.1007/s13337-012-0058-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 02/03/2012] [Indexed: 01/28/2023]
Abstract
Hepatitis C is one of the foremost challenging diseases all over the world. No vaccine has been developed, yet against Hepatitis C virus (HCV). This is partly due to the high mutation rate in the HCV genome, which generates new genotypes and sub genotypes. A mass of efforts have been devoted for the development of an efficient vaccine against HCV. DNA Vaccines, an emerging field of Vaccinology, grasp strong potential to be the most reliable and efficient mode of vaccination in the future. This technology is under investigation currently. Incredibly diverse approaches have been applied as an endeavor to develop a potent DNA vaccine against HCV. The HCV structural genes and the virus like particles have been attempted and so far the results are quite promising in the Lab animals. As there is no proper animal model for HCV infection except chimpanzees, it is very difficult to articulate whether these vaccines will also be pertinent in humans or not. This review will focus on different approaches being used for the development of DNA vaccines, the major tribulations in designing a DNA vaccine against HCV as well as the future prospects for the improvement of under trials DNA vaccines developed against HCV.
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Affiliation(s)
- Sami Ullah
- NUST Center of Virology and Immunology, National University of Science and Technology, Islamabad, Pakistan
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16
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Darling JM, Lemon SM, Fried MW. Hepatitis C. SCHIFF'S DISEASES OF THE LIVER 2011:582-652. [DOI: 10.1002/9781119950509.ch25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2025]
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Azadniv M, Bowers WJ, Topham DJ, Crispe IN. CD4+ T cell effects on CD8+ T cell location defined using bioluminescence. PLoS One 2011; 6:e16222. [PMID: 21283759 PMCID: PMC3024405 DOI: 10.1371/journal.pone.0016222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 12/16/2010] [Indexed: 02/07/2023] Open
Abstract
T lymphocytes of the CD8+ class are critical in delivering cytotoxic function and in controlling viral and intracellular infections. These cells are “helped” by T lymphocytes of the CD4+ class, which facilitate their activation, clonal expansion, full differentiation and the persistence of memory. In this study we investigated the impact of CD4+ T cells on the location of CD8+ T cells, using antibody-mediated CD4+ T cell depletion and imaging the antigen-driven redistribution of bioluminescent CD8+ T cells in living mice. We documented that CD4+ T cells influence the biodistribution of CD8+ T cells, favoring their localization to abdominal lymph nodes. Flow cytometric analysis revealed that this was associated with an increase in the expression of specific integrins. The presence of CD4+ T cells at the time of initial CD8+ T cell activation also influences their biodistribution in the memory phase. Based on these results, we propose the model that one of the functions of CD4+ T cell “help” is to program the homing potential of CD8+ T cells.
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Affiliation(s)
- Mitra Azadniv
- David H. Smith Center for Microbiology and Immunology, Aab Institute for Biomedical Research, University of Rochester Medical Center, Rochester, New York, United States of America
| | - William J. Bowers
- Department of Neurology, Center for Aging and Developmental Biology, Aab Institute for Biomedical Research, University of Rochester Medical Center, Rochester, New York, United States of America
| | - David J. Topham
- David H. Smith Center for Microbiology and Immunology, Aab Institute for Biomedical Research, University of Rochester Medical Center, Rochester, New York, United States of America
| | - Ian N. Crispe
- Seattle Biomedical Research Institute, Seattle, Washington, United States of America
- * E-mail:
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Mueller M, Spangenberg HC, Kersting N, Altay T, Blum HE, Klenerman P, Thimme R, Semmo N. Virus-specific CD4+ T cell responses in chronic HCV infection in blood and liver identified by antigen-specific upregulation of CD154. J Hepatol 2010; 52:800-11. [PMID: 20416967 DOI: 10.1016/j.jhep.2009.12.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Revised: 11/30/2009] [Accepted: 12/19/2009] [Indexed: 01/27/2023]
Abstract
BACKGROUND & AIMS Virus-specific CD4+ T cells play a major role in hepatitis C virus (HCV) infection. Viral clearance is associated with vigorous and multispecific CD4+ T cell responses, while chronic infection has been shown to be associated with weak or absent T cell responses. Most of these studies, however, have used functional assays to analyse virus-specific CD4+ T cell responses. Therefore, the important question, of whether virus-specific CD4+ T cells are completely absent or primarily impaired in specific effector functions during chronic infection, has yet to be analysed in detail. METHODS To address this issue, a novel assay, where CD4+ T cell frequencies can be determined by de novo CD154 (CD40 ligand) expression in response to HCV antigens, was used in a cohort of chronically infected HCV patients and patients who spontaneously resolved HCV infection. These responses were compared to functional assays, such as the IFN-gamma ELISpot and flow cytometry-based proliferative assays. RESULTS Our results reveal that using the CD154 assay, virus-specific CD4+ T cells are readily detectable during chronic HCV infection albeit at a lower frequency when compared to patients who spontaneously resolved the infection. Importantly, no CD4+ T cell responses were detectable from these patients when using functional assays. Finally, these cell populations were enriched in the intrahepatic compartment. CONCLUSIONS Our findings suggest that HCV-specific CD4+ T cell responses are readily detectable in chronic HCV infection and enriched in the infected liver.
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Affiliation(s)
- Mareike Mueller
- Department of Medicine II, University Hospital Freiburg, Freiburg, Germany
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19
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Fuller MJ, Shoukry NH, Gushima T, Bowen DG, Callendret B, Campbell KJ, Hasselschwert DL, Hughes AL, Walker CM. Selection-driven immune escape is not a significant factor in the failure of CD4 T cell responses in persistent hepatitis C virus infection. Hepatology 2010; 51:378-87. [PMID: 19918975 PMCID: PMC2821874 DOI: 10.1002/hep.23319] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UNLABELLED Immune escape driven by selection pressure from virus-specific CD8 T cells has been demonstrated in both chimpanzees and humans infected with the hepatitis C virus (HCV). Although escape mutations have also been characterized in major histocompatibility complex (MHC) class II-restricted HCV epitopes, it is unknown whether selection-driven immune escape by CD4 T cell epitopes is a significant factor in the failure of these responses or contributes to persistent infection. To address this issue, evolution of MHC class I- and class II-restricted HCV epitopes was compared in four chimpanzees persistently infected with the virus for more than 10 years. We identified an amino acid change in a CD4 epitope of the HCV NS3 protein in one of the chimpanzees 3 years after infection. This mutation resulted in diminished activation, cytokine production (interferon-gamma and interleukin-2), and proliferation by an epitope-specific CD4 T cell line. We expanded our analysis to determine if mutations were common in multiple CD4 versus CD8 T cell epitopes in the four chronically infected animals. Whereas we observed mutations in over 75% of CD8 T cell epitopes analyzed in this study, only 18% of CD4 T cell epitopes analyzed showed amino acid changes. The frequency of changes in class II epitopes was not different from flanking regions, so CD4 T cells rarely exert selection pressure against the HCV genome. CONCLUSION Apparent mutational escape can occur in MHC class II-restricted epitopes, but this is uncommon when compared with class I-restricted epitopes in the same individual. This indicates that other mechanisms for silencing CD4 T cells are dominant in persistent HCV infections.
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Affiliation(s)
- Michael J. Fuller
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, Columbus, OH
| | - Naglaa H. Shoukry
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, Columbus, OH
| | - Toshifumi Gushima
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, Columbus, OH
| | - David G. Bowen
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, Columbus, OH
| | - Benoit Callendret
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, Columbus, OH
| | - Katherine J. Campbell
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, Columbus, OH
| | | | - Austin L. Hughes
- Division of Biological Sciences, University of South Carolina, Columbia, SC
| | - Christopher M. Walker
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children’s Hospital, Columbus, OH, College of Medicine and Public Health, The Ohio State University, Columbus, OH
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20
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Krishnadas DK, Li W, Kumar R, Tyrrell DL, Agrawal B. HCV-core and NS3 antigens play disparate role in inducing regulatory or effector T cells in vivo: Implications for viral persistence or clearance. Vaccine 2009; 28:2104-14. [PMID: 20045096 DOI: 10.1016/j.vaccine.2009.12.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Revised: 12/11/2009] [Accepted: 12/15/2009] [Indexed: 12/17/2022]
Abstract
A distinguishing feature of HCV is its ability to persist in majority of the infected people. We investigated the role of HCV-core and NS3 in inducing effector T cells to mediate antiviral immunity. Our studies revealed that immunization with recombinant adenoviral vector containing HCV-core or NS3 leads to differential development of regulatory vs. effector T cells in mice, resulting in distinct outcomes of virus infection. For the first time, our studies directly demonstrate that HCV-core enhances both CD4(+) and CD8(+) T(regs) which possibly contribute to persistent infection, whereas HCV NS3 induces both CD4(+) and CD8(+) effector T cells to allow viral clearance.
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Affiliation(s)
- Deepa K Krishnadas
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
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21
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Acute hepatitis C in HIV-infected patients: rare spontaneous clearance correlates with weak memory CD4 T-cell responses to hepatitis C virus. AIDS 2009; 23:2079-89. [PMID: 19710595 DOI: 10.1097/qad.0b013e328330ed24] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES To explore the parameters of specific immunity to hepatitis C virus (HCV) associated with virus clearance during acute HCV infection in HIV coinfection. METHODS HIV-infected patients without prior HCV infection were prospectively enrolled for acute hepatitis C and followed up over 15 months. HCV-specific T cells were assessed by proliferation, ELISpot, intracellular cytokine staining and pentamer assays. Pegylated-interferon-alpha and ribavirin were proposed if HCV persisted at M3. RESULTS Thirty eight acutely HCV-infected HIV-positive patients were enrolled. HCV genotypes were predominantly 4 and 1. Five patients (13%) showed spontaneous clearance and 20 initiated treatment, of whom 13 (65%) showed sustained virologic responses. Before M3, HCV-specific proliferative responses observed in 35% cases, were associated with lower HCV viral load (P = 0.04) and predictive of spontaneous clearance (P = 0.02), particularly anti-NS4 responses (P = 0.03). These HCV-specific proliferative responses were associated with HIV-p24-specific responses (P = 0.002) independently from the HIV stage. Interferon-gamma-producing T cells specific for HCV were detectable ex vivo in 81% cases but at low intensity (<150 spot forming cells/10 peripheral blood mononuclear cells) and were independent of the HCV outcome. Low frequencies of pentamer-positive HCV-specific CD8 cells (0.01-0.05%) detected in nine of 12 patients were mainly effector-memory PD-1-negative T cells. Twelve days of HCV-specific in-vitro culture induced amplification of CD4 T cells coproducing interleukin-2 and interferon-gamma but rarely of CD8 T cells. CONCLUSION Acute HCV infection in HIV-coinfected patients is characterized by a low rate of spontaneous clearance and weak HCV-specific memory T cells, not strictly related to HIV-induced immune defects, and which correlate with virus clearance.
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22
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HCV animal models: a journey of more than 30 years. Viruses 2009; 1:222-40. [PMID: 21994547 PMCID: PMC3185497 DOI: 10.3390/v1020222] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 08/05/2009] [Accepted: 08/18/2009] [Indexed: 12/13/2022] Open
Abstract
In the 1970s and 1980s it became increasingly clear that blood transfusions could induce a form of chronic hepatitis that could not be ascribed to any of the viruses known to cause liver inflammation. In 1989, the hepatitis C virus (HCV) was discovered and found to be the major causative agent of these infections. Because of its narrow tropism, the in vivo study of this virus was, especially in the early days, limited to the chimpanzee. In the past decade, several alternative animal models have been created. In this review we review these novel animal models and their contribution to our current understanding of the biology of HCV.
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23
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Kinetic analysis by real-time PCR of hepatitis C virus (HCV)-specific T cells in peripheral blood and liver after challenge with HCV. J Virol 2008; 82:10487-92. [PMID: 18715926 DOI: 10.1128/jvi.00588-08] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intrahepatic virus-specific CD8(+) T cells are thought to be important for the control of hepatitis C virus (HCV) infection, yet the precise kinetics for the expansion of epitope-specific T cells over the course of infection are difficult to determine with currently available methods. We used a real-time PCR assay to measure the frequency of clonotypic HCV-specific CD8(+) T cells in peripheral blood and snap-frozen liver biopsy specimens of two chimpanzees (Pan troglodytes) with previously resolved HCV infection who were rechallenged with HCV. In response to rechallenge, the magnitude of each clonotypic response was 10-fold higher in the liver than in the blood, and the peak clonotype frequency was concurrent with the peak viral load. The higher frequency of HCV-specific clonotypes in the liver than in peripheral blood was maintained for at least 3 months after the clearance of viremia. After antibody-mediated CD8(+) T-cell depletion and another viral challenge, the rebound of these clonotypes was seen prior to an appreciable reconstitution of CD8(+) T-cell values and, again, at higher frequencies in the liver than in peripheral blood. These data demonstrate the importance of intrahepatic virus-specific CD8(+) T cells for the clearance of infection and the rapid kinetics of expansion after virus challenge.
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24
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Mizukoshi E, Eisenbach C, Edlin BR, Newton KP, Raghuraman S, Weiler-Normann C, Tobler LH, Busch MP, Carrington M, McKeating JA, O’Brien TR, Rehermann B. Hepatitis C virus (HCV)-specific immune responses of long-term injection drug users frequently exposed to HCV. J Infect Dis 2008; 198:203-12. [PMID: 18505381 PMCID: PMC2699613 DOI: 10.1086/589510] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Injection drug users (IDUs) who successfully clear hepatitis C virus (HCV) have a reduced risk of developing chronic reinfection, despite their continuing exposure to the virus. To identify immunological correlates for this apparent protection, we studied HCV-specific immune responses in long-term IDUs (duration, >10 years). METHODS HCV-specific T cell responses were assessed in proliferation, enzyme-linked immunospot (ELISPOT), interferon (IFN)-gamma secretion, and cytotoxicity assays, whereas HCV-specific antibodies were assessed in enzyme immunoassays (EIAs), chemiluminescent assays, and in vitro neutralization assays. RESULTS HCV-specific T cell proliferation and IFN-gamma production were more common in nonviremic EIA-positive IDUs (16 [94%] of 17 IDUs) than in viremic EIA-positive IDUs (9 [45%] of 20 IDUs) (P= .003). They were also noted in 16 (62%) of 26 nonviremic EIA-negative IDUs. In contrast, 19 (90%) of 21 viremic IDUs displayed neutralizing antibodies (nAbs), compared with 9 (56%) of 16 nonviremic EIA-positive IDUs (P= .04) and 0 of 24 nonviremic EIA-negative IDUs. Nonviremic IDUs with nAbs were older (P= .0115) than those without nAbs, but these groups did not differ in terms of either injection drug use duration or HCV-specific T cell responses. CONCLUSION The reduced risk of HCV persistence in IDUs previously recovered from HCV infection correlated with T cell responses, and prolonged antigenic stimulation appears to be required to maintain humoral responses.
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Affiliation(s)
- Eishiro Mizukoshi
- Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda
| | - Christoph Eisenbach
- Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda
| | - Brian R. Edlin
- University of California, San Francisco
- Center for the Study of Hepatitis C, Weill Medical College, Cornell University, New York, New York
| | - Kimberly P. Newton
- Center for the Study of Hepatitis C, The Rockefeller University, New York, New York
| | - Sukanya Raghuraman
- Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda
| | - Christina Weiler-Normann
- Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda
| | | | - Michael P. Busch
- University of California, San Francisco
- Blood Systems Research Institute, San Francisco, California
| | - Mary Carrington
- Laboratory of Genomic Diversity, Science Applications International Cooperation–Frederick, National Cancer Institute at Frederick, Frederick, Maryland
| | - Jane A. McKeating
- Center for the Study of Hepatitis C, The Rockefeller University, New York, New York
| | - Thomas R. O’Brien
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda
| | - Barbara Rehermann
- Immunology Section, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda
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25
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Induction of broad CD4+ and CD8+ T-cell responses and cross-neutralizing antibodies against hepatitis C virus by vaccination with Th1-adjuvanted polypeptides followed by defective alphaviral particles expressing envelope glycoproteins gpE1 and gpE2 and nonstructural proteins 3, 4, and 5. J Virol 2008; 82:7492-503. [PMID: 18508900 DOI: 10.1128/jvi.02743-07] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Broad, multispecific CD4(+) and CD8(+) T-cell responses to the hepatitis C virus (HCV), as well as virus-cross-neutralizing antibodies, are associated with recovery from acute infection and may also be associated in chronic HCV patients with a favorable response to antiviral treatment. In order to recapitulate all of these responses in an ideal vaccine regimen, we have explored the use of recombinant HCV polypeptides combined with various Th1-type adjuvants and replication-defective alphaviral particles encoding HCV proteins in various prime/boost modalities in BALB/c mice. Defective chimeric alphaviral particles derived from the Sindbis and Venezuelan equine encephalitis viruses encoding either the HCV envelope glycoprotein gpE1/gpE2 heterodimer (E1E2) or nonstructural proteins 3, 4, and 5 (NS345) elicited strong CD8(+) T-cell responses but low CD4(+) T helper responses to these HCV gene products. In contrast, recombinant E1E2 glycoproteins adjuvanted with MF59 containing a CpG oligonucleotide elicited strong CD4(+) T helper responses but no CD8(+) T-cell responses. A recombinant NS345 polyprotein also stimulated strong CD4(+) T helper responses but no CD8(+) T-cell responses when adjuvanted with Iscomatrix containing CpG. Optimal elicitation of broad CD4(+) and CD8(+) T-cell responses to E1E2 and NS345 was obtained by first priming with Th1-adjuvanted proteins and then boosting with chimeric, defective alphaviruses expressing these HCV genes. In addition, this prime/boost regimen resulted in the induction of anti-E1E2 antibodies capable of cross-neutralizing heterologous HCV isolates in vitro. This vaccine formulation and regimen may therefore be optimal in humans for protection against this highly heterogeneous global pathogen.
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26
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Price DA, Bitmansour AD, Edgar JB, Walker JM, Axthelm MK, Douek DC, Picker LJ. Induction and evolution of cytomegalovirus-specific CD4+ T cell clonotypes in rhesus macaques. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:269-80. [PMID: 18097028 DOI: 10.4049/jimmunol.180.1.269] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
CMV infection induces robust CD4+ T cell responses in immunocompetent hosts that orchestrate immune control of viral replication, dissemination, and disease. In this study, we characterized the clonotypic composition of CD4+ T cell populations specific for rhesus CMV (RhCMV) in chronically infected adult rhesus macaques (RM) and in juvenile RM undergoing primary RhCMV infection and subsequent secondary challenge with RhCMV. In adult RM with established chronic infection, RhCMV-specific CD4+ T cell populations exhibited stable, pauciclonal structures with skewed hierarchies dominated by two or three clonotypes. During primary infection, in contrast, the initial RhCMV-specific CD4+ T cell populations were highly polyclonal and progressive evolution to the chronic pattern manifest in adults occurred over the ensuing 2-3 years. Clear patterns of clonal succession were observed during this maturation process, such that clonotypes present in the acute phase were largely replaced over time. However, rechallenge with RhCMV expanded virus-specific CD4+ T cell clonotypes identified solely during acute infection. These findings indicate that, during persistent viral infection, substantial selection pressures and ongoing clonotype recruitment shape the specific CD4+ T cell repertoire and that rapidly exhausted or superseded clonotypes often remain within the memory T cell pool.
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Affiliation(s)
- David A Price
- Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom.
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27
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Li W, Krishnadas DK, Kumar R, Tyrrell DLJ, Agrawal B. Priming and stimulation of hepatitis C virus-specific CD4+ and CD8+ T cells against HCV antigens NS4, NS5a or NS5b from HCV-naive individuals: implications for prophylactic vaccine. Int Immunol 2007; 20:89-104. [DOI: 10.1093/intimm/dxm121] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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28
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Abstract
Hepatitis C virus (HCV) infection is a major cause of liver damage, with virus-induced end-stage disease such as liver cirrhosis and hepatocellular carcinoma resulting in a high rate of morbidity and mortality worldwide. Evidence that CD4+ T cell responses to HCV play an important role in the outcome of acute infection has been shown in several studies. However, the mechanisms behind viral persistence and the failure of CD4+ T cell responses to contain virus are poorly understood. During chronic HCV infection, HCV-specific CD4+ T cell responses are relatively weak or absent whereas in resolved infection these responses are vigorous and multispecific. Persons with a T-helper type I profile, which promotes cellular effector mechanisms are thought to be more likely to experience viral clearance, but the overall role of these cells in the immunopathogenesis of chronic liver disease is not known. To define this, much more data is required on the function and specificity of virus-specific CD4+ T cells, especially in the early phases of acute disease and in the liver during chronic infection. The role and possible mechanisms of action of CD4+ T cell responses in determining the outcome of acute and chronic HCV infection will be discussed in this review.
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Affiliation(s)
- Nasser Semmo
- Nuffield Department of Clinical Medicine, University of Oxford, The Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom
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29
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McNeal MM, Basu M, Bean JA, Clements JD, Choi AHC, Ward RL. Identification of an immunodominant CD4+ T cell epitope in the VP6 protein of rotavirus following intranasal immunization of BALB/c mice. Virology 2007; 363:410-8. [PMID: 17337285 DOI: 10.1016/j.virol.2007.01.041] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Revised: 12/22/2006] [Accepted: 01/24/2007] [Indexed: 10/23/2022]
Abstract
The only lymphocytes required for protection against fecal rotavirus shedding after intranasal immunization of BALB/c (H-2(d)) mice with a chimeric rotavirus VP6 protein (MBPColon, two colonsVP6) and the mucosal adjuvant LT(R192G) are CD4(+) T cells. The purpose of this study was to identify CD4(+) T cell epitopes within VP6 that might be responsible for this protection. To make this determination, spleen cells obtained from BALB/c mice following intranasal immunization with MBPColon, two colonsVP6/LT(R192G) were stimulated in vitro with either MBPColon, two colonsVP6 or overlapping VP6 peptides containing <or=30 amino acids (AA). The numbers of memory (CD44(high)) CD4(+) T cells stimulated to produce T(H)1 and T(H)17 cytokines (IFNgamma and IL-17), as well as the quantities of these cytokines released into the cell supernatants, were then measured relative to those produced in mock-stimulated cells from the same animals. One epitope expected to be found was the VP6 14-mer AA(289-302), previously identified as a CD4(+) T cell epitope in H-2(d) mice. This was not observed but instead the only VP6 epitope identified was AA(242-259), the dominant CD4(+) T cell epitope previously reported after oral, live rotavirus immunization.
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Affiliation(s)
- Monica M McNeal
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
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30
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Castelli FA, Leleu M, Pouvelle-Moratille S, Farci S, Zarour HM, Andrieu M, Auriault C, Ménez A, Georges B, Maillere B. Differential capacity of T cell priming in naive donors of promiscuous CD4+ T cell epitopes of HCV NS3 and Core proteins. Eur J Immunol 2007; 37:1513-23. [PMID: 17492804 DOI: 10.1002/eji.200636783] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
To understand the inter-individual and virus-independent variability of CD4+ T cell responses to HCV components, we evaluated the effect on these responses of HLA II molecules in uninfected healthy donors. Using HLA II-specific binding assays, we identified, in the Core and NS3 proteins, 21 long fragments and 24 15-mer peptides that bound to four to eight of the most preponderant HLA II molecules. We then evaluated the priming capacity of eight long promiscuous peptides in 12 HLA-unrelated healthy donors. The NS3 1250-1264 peptide primed T cells in all the naive donors, while five others were stimulating in at least half of the individuals. We also report sequences that bind to multiple HLA II molecules but are weakly immunogenic. We therefore conclude that (i) broad HLA II specificity is only a prerequisite for a peptide to be stimulating in multiple individuals, and (ii) promiscuous peptides widely differ in their capacity to prime CD4+ T cells from uninfected healthy donors. We suggest that these priming differences result from inter-individual variations in the peptide-specific T cell repertoire. Interestingly, five of the most immunogenic peptides we identified correspond to frequently targeted T cell epitopes in infected patients.
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Affiliation(s)
- Florence A Castelli
- CEA, iBiTecS, Service d'Ingénierie Moléculaire des Protéines, Gif Sur Yvette, France
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31
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Schulze Zur Wiesch J, Lauer GM, Timm J, Kuntzen T, Neukamm M, Berical A, Jones AM, Nolan BE, Longworth SA, Kasprowicz V, McMahon C, Wurcel A, Lohse AW, Lewis-Ximenez LL, Chung RT, Kim AY, Allen TM, Walker BD. Immunologic evidence for lack of heterologous protection following resolution of HCV in patients with non-genotype 1 infection. Blood 2007; 110:1559-69. [PMID: 17475911 PMCID: PMC1975840 DOI: 10.1182/blood-2007-01-069583] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Chronic hepatitis C virus (HCV) infection is typically characterized by a lack of virus-specific CD4(+) T-cell-proliferative responses, but strong responses have been described in a subset of persons with persistent viremia. One possible explanation for these responses is that they were primed by an earlier resolved infection and do not recognize the current circulating virus. We defined all targeted epitopes using overlapping peptides corresponding to a genotype 1a strain in 44 patients chronically infected with different HCV genotypes (GT). Surprisingly, more HCV-specific CD4(+) T-cell responses were detected in patients with chronic non-GT1 infection compared with patients with chronic GT1 infection (P = .017). Notably, we found serologic evidence of a previous exposure to GT1 in 4 patients with non-GT1 infection, and these persons also demonstrated significantly more responses than non-GT1 patients in whom genotype and HCV serotype were identical (P < .001). Comparison of recognition of GT1-specific peptides to peptides representing autologous virus revealed the absence of cross-recognition of the autologous circulating virus. These data indicate that persistent HCV infection can occur in the presence of an HCV-specific T-cell response primed against a heterologous HCV strain, and suggest that clearance of 1 GT does not necessarily protect against subsequent exposure to a second GT.
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Affiliation(s)
- Julian Schulze Zur Wiesch
- Partners AIDS Research Center, Infectious Disease Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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Abstract
The hepatitis C virus (HCV) is a remarkably successful pathogen, establishing persistent infection in more than two-thirds of those who contract it. Its success is related to its abilities to blunt innate antiviral pathways and to evade adaptive immune responses. These two themes may be related. We propose that HCV takes advantage of the impaired innate response to delay the organization of an effective adaptive immune attack. The tolerogenic liver environment may provide cover, prolonging this delay. HCV's error-prone replication strategy permits rapid evolution under immune pressure. Persistent high levels of viral antigens may contribute to immune exhaustion. Finally, the virus may benefit from the efficient enlistment of memory T and B cells in the pursuit of a moving target.
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Affiliation(s)
- Lynn B Dustin
- The Rockefeller University, Center for the Study of Hepatitis C, New York, NY 10021, USA.
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Abstract
Over the past several years, significant progress has been made toward the understanding of hepatitis C virus, especially the development of in vitro cell culture models. The scientific community now has the tools to gain a better understanding of the virus, which should translate into better clinical therapeutic modalities. Many new drugs are currently being evaluated, and a few are already undergoing clinica trials. This article focuses on the current advances in hepatitis C virus virology.
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Affiliation(s)
- Chen Liu
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, 1600 SW Archer Road, Gainesville, FL 32610, USA.
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Bak EJ, Ishii Y, Omatsu T, Kyuwa S, Tetsuya T, Hayasaka I, Yoshikawa Y. Identification and analysis of MHC class II DRB1 (Patr-DRB1) alleles in chimpanzees. ACTA ACUST UNITED AC 2006; 67:134-42. [PMID: 16441484 DOI: 10.1111/j.1399-0039.2006.00539.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The MHC-DRB1 gene is known to display the most extensive allelic polymorphisms among MHC class II genes. We attempted the selective identification of chimpanzee (Pan troglodytes) DRB1 (Patr-DRB1) alleles using the polymerase chain reaction (PCR) technique in three steps: first, we performed Patr-DRB1*02 lineage-specific 8-kb PCR for *02 lineage detection in each chimpanzee; second, we performed 620-bp PCR for amplification of full-length exon 2; and finally, we carried out an insert check using the pattern of microsatellite repeat length variability. In the genomic DNA of 23 chimpanzees, nine Patr-DRB1 alleles containing two new alleles were detected. Our approach provides a relatively effective method of identifying Patr-DRB1 alleles in individual chimpanzees and should also contribute to our understanding of the features of MHC molecules in non-human primates.
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Affiliation(s)
- E J Bak
- Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 113-8657, Japan.
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Bak E, Ishii Y, Omatsu T, Kyuwa S, Tanoue T, Hayasaka I, Yoshikawa Y. Sequence analysis of major histocompatibility complex class-II DQB1 (Patr-DQB1) alleles in chimpanzees by polymerase chain reaction-based methods. Hum Immunol 2006; 67:655-63. [PMID: 16916663 DOI: 10.1016/j.humimm.2006.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Indexed: 11/22/2022]
Abstract
The major histocompatibility complex (MHC) class-II genes are described as the genes that encode the antigen-presenting molecule. In particular, functional alleles of MHC class-II genes in nonhuman primates have been analyzed as part of the study of infectious and immune-mediated diseases in animal models and as part of efforts to understand the molecular evolution of human leukocyte antigen. The polymorphisms and sequence analysis of MHC class-II genes in a large number of subjects is necessary for the group management of nonhuman primates. In the present study, we attempted to analyze the DQB1 polymorphism in the common chimpanzee (Pan troglodytes) by exon 2 sequencing. For exact typing of Patr-DQB1 alleles, we carried out polymerase chain reaction-restriction fragment length polymorphism and sequence analysis. In the genomic DNA of 25 chimpanzees, 6 Patr-DQB1 alleles, including 2 new alleles, were detected. Identification and analysis of Patr-DQB1 alleles using this method may contribute to our understanding of Patr-DQB1 allelic diversity in individual chimpanzees and should be useful in facilitating colony management of chimpanzee groups in Japan.
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Affiliation(s)
- EunJung Bak
- Department of Biomedical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
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Li W, Krishnadas DK, Li J, Tyrrell DLJ, Agrawal B. Induction of Primary Human T Cell Responses against Hepatitis C Virus-Derived Antigens NS3 or Core by Autologous Dendritic Cells Expressing Hepatitis C Virus Antigens: Potential for Vaccine and Immunotherapy. THE JOURNAL OF IMMUNOLOGY 2006; 176:6065-75. [PMID: 16670315 DOI: 10.4049/jimmunol.176.10.6065] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Hepatitis C virus (HCV)-specific T cell responses have been suggested to play significant role in viral clearance. Dendritic cells (DCs) are professional APCs that play a major role in priming, initiating, and sustaining strong T cell responses against pathogen-derived Ags. DCs also have inherent capabilities of priming naive T cells against given Ags. Recombinant adenoviral vectors containing HCV-derived Core and NS3 genes were used to endogenously express HCV Core and NS3 proteins in human DCs. These HCV Ags expressing DCs were used to prime and stimulate autologous T cells obtained from uninfected healthy donors. The DCs expressing HCV Core or NS3 Ags were able to stimulate T cells to produce various cytokines and proliferate in HCV Ag-dependent manner. Evidence of both CD4(+) and CD8(+) T cell responses against HCV Core and NS3 generated in vitro were obtained by flow cytometry and Ab blocking experiments. Further, in secondary assays, the T cells primed in vitro exhibited HCV Ag-specific proliferative responses against recombinant protein Ags and also against immunodominant permissive peptide epitopes from HCV Ags. In summary, we demonstrate that the dendritic cells expressing HCV Ags are able to prime the Ag-specific T cells from uninfected healthy individuals in vitro. These studies have implications in designing cellular vaccines, T cell adoptive transfer therapy or vaccine candidates for HCV infection in both prophylactic and therapeutic settings.
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Affiliation(s)
- Wen Li
- Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, 720 Heritage Medical Research Centre, Edmonton, Alberta, Canada
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Caggiari L, Simula MP, Marzotto A, Shiina M, Rehermann B, De Re V. Identification of novel chimpanzee MHC class I and II alleles using an improved sequence-based typing strategy. Hum Immunol 2006; 67:63-72. [PMID: 16698427 DOI: 10.1016/j.humimm.2006.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Indexed: 01/12/2023]
Abstract
The chimpanzee (Pan troglodytes) is a valuable model for the study of infection with hepatitis C virus and hepatitis B virus, to which only humans and chimpanzees are susceptible. Because the cellular immune response plays a crucial role in host defense against these viruses, the analysis of major histocompatibility complex (MHC) (Patr) class I and II allele diversity in chimpanzees is essential for immune response analysis and vaccine development. In the present study, we report a novel, rapid, and sensitive sequence-based typing strategy to identify polymorphisms of the principal Patr class I (Patr-A and Patr-B) and Patr class II (Patr-DQB1 and Patr-DRB1) alleles. Using this method we identified seven novel Patr alleles in 17 chimpanzees, one of them present in 3 chimpanzees. Furthermore, we detected heterozygosity more rapidly and with higher sensitivity than was done with previous techniques that were based on reverse transcription and amplification of messenger RNA followed by molecular cloning and sequencing.
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Affiliation(s)
- Laura Caggiari
- Division of Experimental Oncology I, Department of Pre-clinical and Epidemiological Research, Centro di Riferimento Oncologico, IRCCS-National Cancer Institute, Aviano (PN) Italy
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Schulze zur Wiesch J, Lauer GM, Day CL, Kim AY, Ouchi K, Duncan JE, Wurcel AG, Timm J, Jones AM, Mothe B, Allen TM, McGovern B, Lewis-Ximenez L, Sidney J, Sette A, Chung RT, Walker BD. Broad repertoire of the CD4+ Th cell response in spontaneously controlled hepatitis C virus infection includes dominant and highly promiscuous epitopes. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2005; 175:3603-13. [PMID: 16148104 DOI: 10.4049/jimmunol.175.6.3603] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A vigorous hepatitis C virus (HCV)-specific Th cell response is regarded as essential to the immunological control of HCV viremia. The aim of this study was to comprehensively define the breadth and specificity of dominant HCV-specific CD4(+) T cell epitopes in large cohorts of subjects with chronic and spontaneously resolved HCV viremia. Following in vitro stimulation of PBMC, HCV-specific cell cultures from each subject were screened with an overlapping panel of synthetic 20-mer peptides spanning the entire HCV polyprotein. Of 22 subjects who spontaneously controlled HCV viremia, all recognized at least one of a group of six epitopes situated within the nonstructural (NS) proteins NS3, NS4, and NS5, each of which was detected by >30% of subjects, but most subjects recognized additional, more heterogeneous specificities. In contrast, none of the most frequently targeted epitopes was detected by >5% of persons with chronic infection. The most frequently recognized peptides showed promiscuous binding to multiple HLA-DR molecules in in vitro binding assays and were restricted by different HLA-DR molecules in functional assays in different persons. These data demonstrate that predominant CD4(+) T cell epitopes in persons with resolved HCV infection are preferentially located in the nonstructural proteins and are immunogenic in the context of multiple class II molecules. This comprehensive characterization of CD4(+) T cell epitopes in resolved HCV infection provides important information to facilitate studies of immunopathogenesis and HCV vaccine design and evaluation.
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Affiliation(s)
- Julian Schulze zur Wiesch
- Partners AIDS Research Center and Infectious Disease Division, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02129, USA
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Abstract
The hepatitis C virus (HCV) persists in the majority of infected individuals and is a significant cause of human illness and death globally. Recent studies have yielded important insights into immunity to HCV, in particular revealing the central role of T cells in viral control and clearance. Other key features of adaptive immune responses remain obscure, including mechanisms by which T cells control HCV replication, the role of antibodies in conferring protection and how cellular and humoral immunity are subverted in persistent infection.
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Affiliation(s)
- David G Bowen
- Center for Vaccines and Immunity, Columbus Children's Research Institute, Columbus, Ohio OH 43205, USA
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Tedaldi EM, Chen L, Markowitz N, Kelly L, Abrams D. Effect of IL-2 on hepatitis C virus RNA levels in patients co-infected with human immunodeficiency virus receiving HAART. J Viral Hepat 2005; 12:414-20. [PMID: 15985013 DOI: 10.1111/j.1365-2893.2005.00610.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The effect of interleukin-2 (IL-2) on the plasma levels of hepatitis C RNA (HCV-RNA) has varied in published reports. We measured the impact of IL-2 on plasma HCV RNA levels in 54 human immunodeficiency virus (HIV)/HCV coinfected patients enrolled in a randomized trial of 512 participants designed to compare the virologic and immunologic effects of cycled IL-2 plus antiretroviral therapy (ART) vs ART alone in the treatment of HIV in patients with CD4 cell counts > or =300 cells/mm(3). The mean decreases in average HCV RNA levels (copies/mL, log (10)) were 0.28 log in the IL-2 group (n = 26) and 0.04 log in the ART alone group (n = 28) at 12 months (P = 0.18). The changes in HCV RNA level were not associated with baseline or nadir CD4 cell counts, baseline aspartate aminotransferanse, CD4 cell response to IL-2, or changes in plasma HIV RNA values. Compared with those participants who only had HIV, the HIV/HCV co-infected patients did not have a significantly different CD4 cell response to IL-2 therapy. Intermittent IL-2 therapy does not produce a significant sustained decrease in plasma HCV RNA levels among patients co-infected with HIV/HCV who are on highly active ART.
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Affiliation(s)
- E M Tedaldi
- University School of Medicine, Temple General Internal Medicine, 1316 W. Ontario Street, Philadelphia, PA 19140, USA
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Zhong J, Gastaminza P, Cheng G, Kapadia S, Kato T, Burton DR, Wieland SF, Uprichard SL, Wakita T, Chisari FV. Robust hepatitis C virus infection in vitro. Proc Natl Acad Sci U S A 2005; 102:9294-9. [PMID: 15939869 PMCID: PMC1166622 DOI: 10.1073/pnas.0503596102] [Citation(s) in RCA: 1464] [Impact Index Per Article: 73.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The absence of a robust cell culture model of hepatitis C virus (HCV) infection has severely limited analysis of the HCV life cycle and the development of effective antivirals and vaccines. Here we report the establishment of a simple yet robust HCV cell culture infection system based on the HCV JFH-1 molecular clone and Huh-7-derived cell lines that allows the production of virus that can be efficiently propagated in tissue culture. This system provides a powerful tool for the analysis of host-virus interactions that should facilitate the discovery of antiviral drugs and vaccines for this important human pathogen.
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Affiliation(s)
- Jin Zhong
- Departments of Molecular and Experimental Medicine and Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
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Abstract
The absence of a robust cell culture model of hepatitis C virus (HCV) infection has severely limited analysis of the HCV life cycle and the development of effective antivirals and vaccines. Here we report the establishment of a simple yet robust HCV cell culture infection system based on the HCV JFH-1 molecular clone and Huh-7-derived cell lines that allows the production of virus that can be efficiently propagated in tissue culture. This system provides a powerful tool for the analysis of host-virus interactions that should facilitate the discovery of antiviral drugs and vaccines for this important human pathogen.
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Elkington R, Shoukry NH, Walker S, Crough T, Fazou C, Kaur A, Walker CM, Khanna R. Cross-reactive recognition of human and primate cytomegalovirus sequences by human CD4 cytotoxic T lymphocytes specific for glycoprotein B and H. Eur J Immunol 2004; 34:3216-26. [PMID: 15368271 DOI: 10.1002/eji.200425203] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Although the importance of CD4+ T cell responses to human cytomegalovirus (HCMV) has recently been recognized in transplant and immunosuppressed patients, the precise specificity and nature of this response has remained largely unresolved. In the present study we have isolated CD4+ CTL which recognize epitopes from HCMV glycoproteins gB and gH in association with two different HLA-DR antigens, DRA1*0101/DRB1*0701 (DR7) and DRA1*0101/DRB1*1101 (DR11). Comparison of amino acid sequences of HCMV isolates revealed that the gB and gH epitope sequences recognized by human CD4+ T cells were not only conserved in clinical isolates from HCMV but also in CMV isolates from higher primates (chimpanzee, rhesus and baboon). Interestingly, these epitope sequences from chimpanzee, rhesus and baboon CMV are efficiently recognized by human CD4+ CTL. More importantly, we show that gB-specific T cells from humans can also efficiently lyse peptide-sensitized Patr-DR7+ cells from chimpanzees. These findings suggest that conserved gB and gH epitopes should be considered while designing a prophylactic vaccine against HCMV. In addition, they also provide a functional basis for the conservation of MHC class II lineages between humans and Old World primates and open the possibility for the use of such primate models in vaccine development against HCMV.
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Affiliation(s)
- Rebecca Elkington
- Division of Infectious Diseases and Immunology, Queensland Institute of Medical Research, Department of Molecular and Cellular Pathology, University of Queensland, Brisbane, Australia
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Frazer I. Is vaccine therapy the future in cancer prevention? Expert Opin Pharmacother 2004; 5:2427-34. [PMID: 15571460 DOI: 10.1517/14656566.5.12.2427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
One vaccine designed to prevent cancer by preventing a precursor infection is already in common use, and at least one more is in the latter stages of clinical development. These vaccines are part of a new era of cancer immunoprophylaxis. Several further vaccines are in preclinical and clinical development, targeted at preventing cancer precursor infections, and these should add to our ability to prevent this common human disorder. However, vaccines to prevent cancers not triggered by infection are a more remote prospect, for a variety of reasons.
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Abstract
The hepatitis C virus (HCV) infects approximately three percent of the world's population. Some individuals resolve the infection spontaneously, but the majority develop persistent viremia that often causes progressive liver disease. There is an emerging consensus that cellular immune responses are essential for spontaneous resolution of acute hepatitis C and long-term protection from persistent infection. This review focuses on the recent advances in understanding mechanisms of protective immunity and why they fail in most infected individuals. The distinct yet complementary role of CD4+ and CD8+ T lymphocytes in this process is highlighted.
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Affiliation(s)
- Naglaa H Shoukry
- Center for Vaccines and Immunity, Columbus Children's Research Institute, Columbus, Ohio 43205, USA.
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Abstract
Chimpanzees remain the only recognized animal model for the study of hepatitis C virus (HCV). Studies performed in chimpanzees played a critical role in the discovery of HCV and are continuing to play an essential role in defining the natural history of this important human pathogen. In the absence of a reproducible cell culture system, the infectivity titer of HCV challenge pools can be determined only in chimpanzees. Recent studies in chimpanzees have provided new insight into the nature of host immune responses-particularly the intrahepatic responses-following primary and secondary experimental HCV infections. The immunogenicity and efficacy of vaccine candidates against HCV can be tested only in chimpanzees. Finally, it would not have been possible to demonstrate the infectivity of infectious clones of HCV without chimpanzees. Chimpanzees became infected when RNA transcripts from molecular clones were inoculated directly into the liver. The infection generated by such transfection did not differ significantly from that observed in animals infected intravenously with wild-type HCV. The RNA inoculated into chimpanzees originated from a single sequence, and the animals therefore had a monoclonal HCV infection. Monoclonal infection simplifies studies of HCV, because virus interaction with the host is not confounded by the quasispecies invariably present in a natural infection. It furthermore permits true homologous challenge in studies of protective immunity and in testing the efficacy of vaccine candidates. Finally, this in vivo transfection system has made it possible to test for the first time the importance of genetic elements for HCV infectivity.
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Affiliation(s)
- Jens Bukh
- Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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