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Naseem S, Manzoor S, Javed A, Abbas S. Interleukin-6 Rescues Lymphocyte from Apoptosis and Exhaustion Induced by Chronic Hepatitis C Virus Infection. Viral Immunol 2018; 31:624-631. [PMID: 30222516 DOI: 10.1089/vim.2018.0045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Chronic hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion and apoptosis to potentially assist viral persistence inside the host, eventually leading to exacerbated conditions of inflammation and hepatocarcinogenesis. Growing evidence suggests that spontaneous apoptosis of peripheral blood mononuclear cells (PBMCs) could be one of the potential immune impairment mechanisms in chronic viral infection. Interleukin-6 (IL-6) is a pleiotropic cytokine that plays an essential role in regulating immune and inflammatory responses. Owing to its known role in priming T cell growth, differentiation, and inhibition of lymphocyte apoptosis, we investigated the protective effect of IL-6 in rescuing lymphocytes from apoptosis and functional exhaustion in chronic HCV infection. The expression pattern of antiapoptotic (Mcl-1 and Bcl-2), proapoptotic (caspase-3 and Bim) genes along with interferon gamma (IFN-γ) and T cell inhibitory receptor (TIM-3) was analyzed before and after in vitro IL-6 treatment of patient-derived PBMCs. It was observed that the expression of antiapoptotic genes, Mcl-1 and Bcl-2 increased (threefolds and twofolds, respectively) and there was a considerable downregulation in T cell inhibitory receptor (TIM-3) and caspase-3. Similarly, the capacity of PBMCs to produce IFN-γ was also significantly increased (p < 0.001) depicting the promising nature of IL-6 in enhancing lymphocyte effector function. Summing it up, the study supports the positive role of IL-6 in rescuing PBMC population; however, the cytokine alone is not sufficient to sustain the adaptive immunity. It could be used as a potential candidate for combinational therapy along with other regulatory factors for ex vivo enhancement of lymphocyte and may help in moving one step toward adoptive T cell therapy in chronic HCV infection.
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Affiliation(s)
- Sidrah Naseem
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) , Islamabad, Pakistan
| | - Sobia Manzoor
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) , Islamabad, Pakistan
| | - Aneela Javed
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) , Islamabad, Pakistan
| | - Sadaf Abbas
- Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) , Islamabad, Pakistan
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Hoffmann M, Pantazis N, Martin GE, Hickling S, Hurst J, Meyerowitz J, Willberg CB, Robinson N, Brown H, Fisher M, Kinloch S, Babiker A, Weber J, Nwokolo N, Fox J, Fidler S, Phillips R, Frater J. Exhaustion of Activated CD8 T Cells Predicts Disease Progression in Primary HIV-1 Infection. PLoS Pathog 2016; 12:e1005661. [PMID: 27415828 PMCID: PMC4945085 DOI: 10.1371/journal.ppat.1005661] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/05/2016] [Indexed: 12/22/2022] Open
Abstract
The rate at which HIV-1 infected individuals progress to AIDS is highly variable and impacted by T cell immunity. CD8 T cell inhibitory molecules are up-regulated in HIV-1 infection and associate with immune dysfunction. We evaluated participants (n = 122) recruited to the SPARTAC randomised clinical trial to determine whether CD8 T cell exhaustion markers PD-1, Lag-3 and Tim-3 were associated with immune activation and disease progression. Expression of PD-1, Tim-3, Lag-3 and CD38 on CD8 T cells from the closest pre-therapy time-point to seroconversion was measured by flow cytometry, and correlated with surrogate markers of HIV-1 disease (HIV-1 plasma viral load (pVL) and CD4 T cell count) and the trial endpoint (time to CD4 count <350 cells/μl or initiation of antiretroviral therapy). To explore the functional significance of these markers, co-expression of Eomes, T-bet and CD39 was assessed. Expression of PD-1 on CD8 and CD38 CD8 T cells correlated with pVL and CD4 count at baseline, and predicted time to the trial endpoint. Lag-3 expression was associated with pVL but not CD4 count. For all exhaustion markers, expression of CD38 on CD8 T cells increased the strength of associations. In Cox models, progression to the trial endpoint was most marked for PD-1/CD38 co-expressing cells, with evidence for a stronger effect within 12 weeks from confirmed diagnosis of PHI. The effect of PD-1 and Lag-3 expression on CD8 T cells retained statistical significance in Cox proportional hazards models including antiretroviral therapy and CD4 count, but not pVL as co-variants. Expression of 'exhaustion' or 'immune checkpoint' markers in early HIV-1 infection is associated with clinical progression and is impacted by immune activation and the duration of infection. New markers to identify exhausted T cells and novel interventions to reverse exhaustion may inform the development of novel immunotherapeutic approaches.
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Affiliation(s)
- Matthias Hoffmann
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
- Division of Infectious Diseases and Hospital Epidemiology, Kantonsspital, St. Gallen, Switzerland
| | - Nikos Pantazis
- Department of Hygiene, Epidemiology & Medical Statistics, Athens University Medical School, Athens, Greece
- MRC Clinical Trials Unit at UCL Institute of Clinical Trials & Methodology, London, United Kingdom
| | - Genevieve E. Martin
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
| | - Stephen Hickling
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
| | - Jacob Hurst
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
- The Oxford Martin School, Oxford, United Kingdom
| | - Jodi Meyerowitz
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
| | - Christian B. Willberg
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
- Oxford National Institute of Health Research Biomedical Research Centre, Oxford, United Kingdom
| | - Nicola Robinson
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
- Oxford National Institute of Health Research Biomedical Research Centre, Oxford, United Kingdom
| | - Helen Brown
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
- Oxford National Institute of Health Research Biomedical Research Centre, Oxford, United Kingdom
| | - Martin Fisher
- Brighton and Sussex University Hospitals, Brighton, United Kingdom
| | - Sabine Kinloch
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Abdel Babiker
- MRC Clinical Trials Unit at UCL Institute of Clinical Trials & Methodology, London, United Kingdom
| | - Jonathan Weber
- Division of Medicine, Wright Fleming Institute, Imperial College, London, United Kingdom
| | - Nneka Nwokolo
- Chelsea and Westminster Hospital, London, United Kingdom
| | - Julie Fox
- Department of Genitourinary Medicine and Infectious Disease, Guys and St Thomas' NHS Trust, London, United Kingdom
| | - Sarah Fidler
- Division of Medicine, Wright Fleming Institute, Imperial College, London, United Kingdom
| | - Rodney Phillips
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
- The Oxford Martin School, Oxford, United Kingdom
- Oxford National Institute of Health Research Biomedical Research Centre, Oxford, United Kingdom
| | - John Frater
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, Oxford, United Kingdom
- The Oxford Martin School, Oxford, United Kingdom
- Oxford National Institute of Health Research Biomedical Research Centre, Oxford, United Kingdom
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3
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Jabłońska J, Pawłowski T, Laskus T, Zalewska M, Inglot M, Osowska S, Perlejewski K, Bukowska-Ośko I, Cortes KC, Pawełczyk A, Ząbek P, Radkowski M. The correlation between pretreatment cytokine expression patterns in peripheral blood mononuclear cells with chronic hepatitis C outcome. BMC Infect Dis 2015; 15:556. [PMID: 26637466 PMCID: PMC4670510 DOI: 10.1186/s12879-015-1305-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 12/01/2015] [Indexed: 12/24/2022] Open
Abstract
Backgroud Cytokine response against hepatitis C virus (HCV) is likely to determine the natural course of infection as well as the outcome of antiviral treatment. However, the role of particular cytokines remains unclear. The current study analyzed activation of cytokine response in chronic hepatitis C patients undergoing standard antiviral treatment. Methods Twenty-two patients were treated with pegylated interferon and ribavirin. Twenty-six different cytokine transcripts were measured quantitatively in peripheral blood mononuclear cells (PBMC) before and after therapy and correlated with therapy outcome as well as with clinical and liver histological data. Results We found that patients who achieved sustained virological response (SVR) showed higher pretreatment cytokine response when compared to subjects in whom therapy was unsuccessful. The differentially expressed factors included IL-8, IL-16, TNF-α, GM-CSF, MCP-2, TGF-β, and IP-10. Serum ALT activity and/or histological grading also positively correlated with the expression of IL-1α, IL-4, IL-6, IL-10, IL-12, IL-15, GM-CSF, M-CSF, MCP-2 and TGF-β. Conclusion Pretreatment activation of the immune system, as reflected by cytokines transcripts upregulation, positively correlates with treatment outcome and closely reflects liver inflammatory activity.
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Affiliation(s)
- Joanna Jabłońska
- Department of Hepatology and Acquired Immunodeficiences, Medical University of Warsaw, Warsaw, Poland.
| | - Tomasz Pawłowski
- Division of Psychotherapy and Psychosomatic Medicine, Wrocław Medical University, Wrocław, Poland.
| | - Tomasz Laskus
- Department of Immunopathology of Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
| | - Małgorzata Zalewska
- Department of Infectious Diseases, Hepatology and Acquired Immune Deficiences, Wrocław Medical University, Wrocław, Poland.
| | - Małgorzata Inglot
- Department of Infectious Diseases, Hepatology and Acquired Immune Deficiences, Wrocław Medical University, Wrocław, Poland.
| | - Sylwia Osowska
- Department of General Surgery and Clinical Nutrition, Medical University of Warsaw, Warsaw, Poland.
| | - Karol Perlejewski
- Department of Immunopathology of Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
| | - Iwona Bukowska-Ośko
- Department of Immunopathology of Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
| | - Kamila Caraballo Cortes
- Department of Immunopathology of Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
| | - Agnieszka Pawełczyk
- Department of Immunopathology of Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
| | - Piotr Ząbek
- Municipal Hospital of Infectious Diseases, Warsaw, Poland.
| | - Marek Radkowski
- Department of Immunopathology of Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
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Abstract
Introduction With 3 – 4 million new infections occurring annually, hepatitis C virus (HCV) is a major global health problem. There is increasing evidence to suggest that HCV will be highly amenable to a vaccine approach, and despite advances in treatment, a vaccine remains the most cost-effective and realistic means to significantly reduce the worldwide mortality and morbidity associated with persistent HCV infection. Areas covered In this review we discuss immune responses to HCV during natural infection, and describe how they may inform vaccine design. We introduce the current candidate vaccines for HCV and compare how these fare against the expected requirements of an effective prophylactic HCV vaccine in relation to the breadth, functionality, magnitude and phenotype of the vaccine-induced immune response. Expert opinion Although the correlates of immune protection against HCV are not completely defined, we now have vaccine technologies capable of inducing HCV-specific adaptive immune responses to an order of magnitude that are associated with protection during natural infection. The challenge next is to i) establish well-characterised cohorts of people at risk of HCV infection for vaccine efficacy testing and ii) to better understand the correlates of protection in natural history studies. If these can be achieved, a vaccine against HCV appears a realistic goal.
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Affiliation(s)
- Leo Swadling
- University of Oxford, NDM and Jenner Institute, Peter Medawar Building, South Parks Road, Oxford, OX1 3SY, UK
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5
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Salem ML, El-Demellawy M, El-Azm ARA. The potential use of Toll-like receptor agonists to restore the dysfunctional immunity induced by hepatitis C virus. Cell Immunol 2010; 262:96-104. [PMID: 20338549 DOI: 10.1016/j.cellimm.2010.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Accepted: 03/02/2010] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus (HCV) infection is a major public health concern with approximately 3% of the world's population is infected, posing social, economical and health burden. Less than 20% of the infected individuals clear the virus during the acute infection, while the rest develop chronic infection. The treatment of choice for HCV infection is pegylated interferon-alpha (IFN-alpha) in combination with ribavarin. Despite the cost and side effects of this treatment regimen, many patients fail this therapy and develop persistent HCV infection, leading to cirrhosis and hepatocellular carcinoma. Although the mechanisms underlying the failure to resolve HCV infection are poorly understood, the incapability of patients to develop effective anti-HCV immunity is a potential cause. We hypothesize that the dysfunctional anti-HCV immunity is due to the emergence of immunosuppressive cells coinciding with a decrease in the stimulatory dendritic cells (DCs) and natural killer (NK) cells. We further hypothesize that applying agents that can correct the imbalance between the immunosuppressive cells and stimulatory cells can results in resolution of chronic HCV. In this review article, we will discuss potential approaches, focusing on the use of Toll-like receptor agonists, to block the suppressive effects of the regulatory cells and restore the stimulatory effects of DCs and NK cells.
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MESH Headings
- Adjuvants, Immunologic/therapeutic use
- Antiviral Agents/therapeutic use
- Dendritic Cells/immunology
- Enzyme Inhibitors/therapeutic use
- Hepacivirus/immunology
- Hepatitis C, Chronic/drug therapy
- Hepatitis C, Chronic/epidemiology
- Hepatitis C, Chronic/immunology
- Hepatitis C, Chronic/virology
- Humans
- Immunity, Innate
- Indoleamine-Pyrrole 2,3,-Dioxygenase/antagonists & inhibitors
- Interferon-alpha/therapeutic use
- Killer Cells, Natural/immunology
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Ribavirin/therapeutic use
- T-Lymphocytes, Regulatory/immunology
- Toll-Like Receptors/agonists
- Toll-Like Receptors/immunology
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Affiliation(s)
- Mohamed L Salem
- Surgery Department and Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
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6
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Wang Z, Liu X. A chronic viral infection model with immune impairment. J Theor Biol 2007; 249:532-42. [PMID: 17900625 DOI: 10.1016/j.jtbi.2007.08.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Revised: 07/08/2007] [Accepted: 08/15/2007] [Indexed: 11/22/2022]
Abstract
In this paper, a chronic viral infection model with cell-mediated immunity and immune impairment is proposed and studied, under the assumption that the presence of the antigen can both stimulate and impair immunity. It is shown that the virus persists in the host if the basic reproductive ratio of the virus is greater than 1. The immune cells persist when there is only one positive equilibrium. The system can exhibit two positive equilibria if the basic reproductive ratio of the virus is above a threshold. This allows a bistable behavior, and the immune cells persist or die out, i.e., infection will result in disease or immune control outcome, depending on the initial conditions. By theoretical analysis and numerical simulations, we show that therapy could shift the patient from a disease progression to an immune control outcome, despite that the therapy is not necessarily lifelong. This would allow the immune response to control the virus in the long term even in the absence of continued therapy.
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Affiliation(s)
- Zhiping Wang
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Mathematics and Statistics, Southwest University, Chongqing 400715, China
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7
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Abstract
Experimental immunology has given rise to detailed insights into how immune cells react to infectious agents and fight pathogens. At the same time, however, the interplay between infectious agents and immune responses can be viewed as an ecological system in vivo. This is characterized by complex interactions between species of immune cells and populations of pathogens. This review discusses how an understanding of the immune system can be aided by the application of ecological and evolutionary principles: competition, predation, and the evolution of viruses in vivo. These concepts can shed light onto important immunological concepts such as the correlates of efficient virus control, immunodominance, the relationship between viral evolution and the development of pathology, as well as the ability of the immune system to control immunosuppressive infections.
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Affiliation(s)
- Dominik Wodarz
- Department of Ecology and Evolutionary Biology, 321 Steinhaus Hall, University of California, Irvine, CA 92697, USA.
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8
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Nattermann J, Feldmann G, Ahlenstiel G, Langhans B, Sauerbruch T, Spengler U. Surface expression and cytolytic function of natural killer cell receptors is altered in chronic hepatitis C. Gut 2006; 55:869-77. [PMID: 16322112 PMCID: PMC1856237 DOI: 10.1136/gut.2005.076463] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Impaired activity of natural killer (NK) cells has been proposed as a mechanism contributing to viral persistence in hepatitis C virus (HCV) infection. As the function of NK cells is primarily regulated by NK cell receptors (NKR), we analysed whether decreased NK cell function in hepatitis C may be related to dysregulated NKR expression. PATIENTS AND METHODS Expression of NK cell was analysed by flow cytometry on lymphocytes from HCV(+) subjects (n = 30), patients who became HCV(-) after antiviral therapy (n = 10), healthy individuals (n = 10), and hepatitis B virus (HBV) infected patients (n = 9). Cytolytic function of lymphocytes was studied in a redirected lysis assay and in a standard 51chromium release cytotoxicity assay, respectively. RESULTS In patients with chronic hepatitis C, we found a significantly reduced proportion of NKp46 and NKp30 expressing NK cells compared with healthy and HBV infected subjects. Low expression of natural cytotoxicity receptor (NCR) was also confirmed in in vitro activated NK cell populations derived from HCV patients compared with uninfected donors. In contrast, patients who cleared HCV under antiviral therapy showed normal expression of NKp44, NKp30, and NKp46. Reduced NCR expression in chronic hepatitis C was associated with a parallel decrease in NCR mediated target cell killing. Furthermore, we found a significantly increased proportion of NKG2A expressing NK cells and CD8+ T cells in HCV positive patients, resulting in a reduced cytolytic activity against cells incubated with the HLA-E stabilising peptide HCV core35-44. CONCLUSION The present study indicates that defective expression of NKR represents a novel mechanism contributing to impaired function of NK cells and CD8+ T cells in chronic hepatitis C.
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Affiliation(s)
- J Nattermann
- Department of Internal Medicine I, Rheinische Friedrich-Wilhelms-Universitaet, Germany.
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9
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Golden-Mason L, Rosen HR. Natural killer cells: primary target for hepatitis C virus immune evasion strategies? Liver Transpl 2006; 12:363-72. [PMID: 16498647 DOI: 10.1002/lt.20708] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Liver cirrhosis and hepatocellular carcinoma secondary to chronic hepatitis C virus (HCV) infection requiring transplantation represents a significant public health problem. The most remarkable feature of hepatitis C virus is the ability to establish chronic infection in the vast majority of cases. Efforts to define clinical correlates of HCV persistence have focused primarily on CD4 and CD8 T cell responses. Until recently, the role of innate immunity in determining the outcome of HCV infection had received relatively little attention. Natural killer (NK) cells are an important antiviral effector population eliminating virus through direct killing and cytokine production. Recent studies highlighting the cross-talk between NK cells, dendritic cells (DCs) and T cells have prompted reevaluation of the important role NK cells play in regulating and maintaining specific immune responses. Like many other viruses, HCV has evolved strategies to evade detection and elimination by NK cells. T cell defects observed in HCV infection may be a consequence of inhibition of NK:DC interactions. We propose a theoretical model for HCV persistence that places the NK cell at the center of HCV immune evasion strategies. While this model is only theoretical, it provides a plausible interpretation of many published observations and a useful working model to test the role of NK cells in HCV persistence. In conclusion, the role of innate immune cells and their regulation of antigen-specific responses by the initial innate response to the virus, in particular NK cells, may prove to be an informative and clinically relevant avenue of investigation.
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Komatsu H, Lauer G, Pybus OG, Ouchi K, Wong D, Ward S, Walker B, Klenerman P. Do antiviral CD8+ T cells select hepatitis C virus escape mutants? Analysis in diverse epitopes targeted by human intrahepatic CD8+ T lymphocytes. J Viral Hepat 2006; 13:121-30. [PMID: 16436130 DOI: 10.1111/j.1365-2893.2005.00676.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Hepatitis C virus (HCV) is a variable RNA virus that can readily establish persistent infection. Cellular immune responses are important in the early control of the virus. Evidence from animal models suggests that mutation in epitopes recognized by CD8+ T lymphocytes may play an important role in the establishment of persistence but in human persistent infection, equivalent evidence is lacking. We investigated this by analysing a unique resource: viruses from a set of chronically HCV-infected individuals in whom the CD8+ T-cell responses in liver had previously been accurately mapped. Virus was sequenced in seven individuals at 10 epitopes restricted by 10 human leucocyte antigen (HLA) molecules. Two main patterns emerged: in the majority of epitopes sequenced, no variation was seen. In three epitopes, mutations were identified which were compatible with immune escape as assessed using phylogenetic and/or functional studies. These data suggest that - even where specific intrahepatic T cells are detectable - many epitopes do not undergo mutation in chronic human infection. On the contrary, virus may escape from intrahepatic CD8+ T-cell responses in a 'patchy' manner in certain specific epitopes. Furthermore, longitudinal studies to identify the differences between 'selecting' and 'nonselecting' intrahepatic CD8+ T-cell responses are needed in HCV infection.
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Affiliation(s)
- H Komatsu
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
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11
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Pollack H, Hou Z, Hughes AL, Borkowsky W. Perinatal transmission and viral evolution of hepatitis C virus quasispecies in infants coinfected with HIV. J Acquir Immune Defic Syndr 2005; 36:890-9. [PMID: 15220695 DOI: 10.1097/00126334-200408010-00002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Three HIV/hepatitis C virus (HCV)-coinfected children and the mothers of 2 were studied to examine the nature of perinatal HCV infection in HIV-coinfected infants and to assess the evolution of viral quasispecies thereafter. Sequences of the hypervariable region in the N terminus of the E2/NS1 region (HVR-1) of the children and their mothers were compared. HCV quasispecies changes in the infants were tracked over several years. METHODS Sequence similarity comparisons and phylogenetic trees were derived from cDNA of plasma isolates. Quantitation of plasma HCV and HIV was performed in the children, as well as CD4 T-cell percentage and liver transaminases. RESULTS Phylogenetic analysis of the mother-child pairs suggested that transmission of multiple dominant and nondominant variants identified in the mother were seen. HCV diversification in the children was seen as early as 2 months of life. The child with the best immune status and HIV control demonstrated the most diversification throughout. CONCLUSION Multiples HCV variants transmitted from mother to child and their early changes in the child may be related to maternal antibody. Variation after the 1st year of life may reflect immunologic pressure from the child. There was no trend suggesting that the presence or absence of selective immunologic pressure affected HCV load or liver transaminase values.
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Affiliation(s)
- Henry Pollack
- Department of Pediatrics, The Saul Krugman Division of Infectious Diseases and Immunology, New York University School of Medicine, NY 10016, USA
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12
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Wodarz D. Hepatitis C virus dynamics and pathology: the role of CTL and antibody responses. J Gen Virol 2003; 84:1743-1750. [PMID: 12810868 DOI: 10.1099/vir.0.19118-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This paper investigates the role of CTL and antibody responses in hepatitis C virus (HCV) dynamics and pathology. Mathematical models suggest that a strong CTL response is required for resolution of HCV infection and that a weak CTL response can result in persistent infection. According to the model, establishment of persistent infection is accompanied mainly by an ongoing antibody response, while CTLs are not maintained at high levels. In the model, this outcome correlates with absence of pathology. Persistent infection in the face of an ongoing antibody response can result in evolution of antigenic escape. According to the model, evolution towards escape from antibodies can shift the balance of immune responses so that the weak CTL levels become increasingly more dominant relative to antibodies. This shift results in onset of liver pathology as the virus evolves towards increased levels of antigenic escape. Therefore, the relative balance of the immune response can be a decisive factor that determines whether patients are asymptomatic or whether pathology is observed. Virus evolution can shift this balance towards pathology over time. Theoretical results are discussed in the context of published data.
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Affiliation(s)
- Dominik Wodarz
- Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, MP-665, Seattle, WA 98109, USA
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13
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Henderson DK. Managing occupational risks for hepatitis C transmission in the health care setting. Clin Microbiol Rev 2003; 16:546-68. [PMID: 12857782 PMCID: PMC164218 DOI: 10.1128/cmr.16.3.546-568.2003] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hepatitis C virus (HCV) infection is a significant contemporary health problem in the United States and elsewhere. Because it is primarily transmitted via blood, hepatitis C infection presents risks for both nosocomial transmission to patients and occupational spread to health care workers. Recent insights into the pathogenesis, immunopathogenesis, natural history, and treatment of infection caused by this unique flavivirus provide a rationale for the use of new strategies for managing occupational hepatitis C infections when they occur. This article reviews this developing information. Recently published data demonstrate success rates in the treatment of "acute hepatitis C syndrome" that approach 100\%, and although these studies are not directly applicable to all occupational infections, they may provide important clues to optimal management strategies. In addition, the article delineates approaches to the prevention of occupational exposures and also addresses the difficult issue of managing HCV-infected health care providers. The article summarizes currently available data about the nosocomial epidemiology of HCV infection and the magnitude of risk and discusses several alternatives for managing exposure and infection. No evidence supports the use of immediate postexposure prophylaxis with immunoglobulin, immunomodulators, or antiviral agents. Based on the very limited data available, the watchful waiting and preemptive therapy strategies described in detail in this article represent reasonable interim approaches to the complex problem of managing occupational HCV infections, at least until more definitive data are obtained.
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Affiliation(s)
- David K Henderson
- Warren G. Magnuson Clinical Center, National Institutes of Health, U.S. Department of Health and Human Services, Bethesda, Maryland 20892, USA.
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14
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Komarova NL, Barnes E, Klenerman P, Wodarz D. Boosting immunity by antiviral drug therapy: a simple relationship among timing, efficacy, and success. Proc Natl Acad Sci U S A 2003; 100:1855-60. [PMID: 12574516 PMCID: PMC149923 DOI: 10.1073/pnas.0337483100] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Drug therapies against persistent human infections such as hepatitis C virus, hepatitis B virus, and HIV fail to consistently eradicate the infection from the host. Hence, recent emphasis has shifted to the study of antiviral therapy aimed at boosting specific immune responses. It was argued that structured therapy interruptions were required to achieve this, because such regimes have shown promising results in early HIV infection. Using mathematical models, we show that, contrary to this notion, a single phase of drug therapy can result in the establishment of sustained immunity. We present a simple relationship between timing of therapy and efficacy of the drugs required for success. In the presence of strong viral suppression, we show that therapy should be stopped relatively early, and that a longer duration of treatment leads to failure. On the other hand, in the presence of weaker viral suppression, stopping treatment too early is detrimental, and therapy has to be continued beyond a time threshold. We discuss our modeling results primarily in the context of HCV therapy during chronic infection. Although the therapy regimes explored here also have implications for HIV, virus-mediated destruction of specific immune cells renders success unlikely during the chronic phase of the infection.
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Kantzanou M, Lucas M, Barnes E, Komatsu H, Dusheiko G, Ward S, Harcourt G, Klenerman P. Viral escape and T cell exhaustion in hepatitis C virus infection analysed using Class I peptide tetramers. Immunol Lett 2003; 85:165-71. [PMID: 12527224 DOI: 10.1016/s0165-2478(02)00224-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Hepatitis C virus (HCV) has infected over 170 million people world wide, and in the majority sets up a chronic infection associated with hepatic inflammation. How it evades host immunity, particularly CD8+ T cells (CTL) is unclear, but two major factors are likely to operate, viral escape mutation and T cell exhaustion. We have investigated the role of CTL in control of infection during acute disease using Class I peptide tetramers. Although the immune response is quite diverse and numerous epitopes can be targeted, we observe that, especially during acute disease, one epitope (NS3 1073-81) is commonly recognised in HLA-A2 positive individuals. However, the levels of response to this epitope (and others) are very much lower if persistence is established. We examined in detail whether the cause of this low level of reactivity is due to mutation within the epitope. We find that, in fact this epitope is highly conserved during chronic infection, at a clonal level, between individuals, and over time. Thus, although variation within the epitope does occur, lack of reactivity in peripheral blood against this epitope in chronic disease, and loss of control of virus cannot be explained entirely by viral escape. Escape through mutation probably does play an important role in persistence of HCV, but we also discuss other mechanisms which lead to attenuation of T cell responses which may be important in determining the outcome.
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Affiliation(s)
- Maria Kantzanou
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, South Parks Road, Oxford OX1 3SY, UK
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16
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Saunier B, Triyatni M, Ulianich L, Maruvada P, Yen P, Kohn LD. Role of the asialoglycoprotein receptor in binding and entry of hepatitis C virus structural proteins in cultured human hepatocytes. J Virol 2003; 77:546-59. [PMID: 12477859 PMCID: PMC140572 DOI: 10.1128/jvi.77.1.546-559.2003] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We used a baculovirus-based system to prepare structural proteins of hepatitis C virus (HCV) genotype 1a. Binding of this preparation to cultured human hepatic cells was both dose dependent and saturable. This binding was decreased by calcium depletion and was partially prevented by ligands of the asialoglycoprotein receptor (ASGP-R), thyroglobulin, asialothyroglobulin, and antibody against a peptide in the carbohydrate recognition domain of ASGP-R but not preimmune antibody. Uptake by hepatocytes was observed with both radiolabeled and dye-labeled HCV structural proteins. With hepatocytes expressing the hH1 subunit of the ASGP-R fused to green fluorescent protein, we could show by confocal microscopy that dye stain cointernalized with the fusion protein in an area surrounding the nucleus. Internalization was more efficient with a preparation containing p7 than with one that did not. The two preparations bound to transfected 3T3-L1 cells expressing either both (hH1 and hH2) subunits of the ASGP-R (3T3-22Z cells) or both hH1 and a functionally defective variant of hH2 (3T3-24X cells) but not to parental cells. Additionally, uptake of dye-labeled preparation containing p7 was observed with 3T3-22Z cells but not with 3T3-L1 or 3T3-24X cells or with the preparation lacking p7, suggesting that p7 regulates the internalization properties of HCV structural proteins. Our observations suggest that HCV structural proteins bind to and cointernalize with the ASGP-R in cultured human hepatocytes.
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Affiliation(s)
- Bertrand Saunier
- Edison Biotechnology Institute and College of Osteopathic Medicine, Ohio University, Athens 45701, USA.
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Barnes E, Harcourt G, Brown D, Lucas M, Phillips R, Dusheiko G, Klenerman P. The dynamics of T-lymphocyte responses during combination therapy for chronic hepatitis C virus infection. Hepatology 2002; 36:743-54. [PMID: 12198669 DOI: 10.1053/jhep.2002.35344] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hepatitis C virus (HCV) readily sets up a persistent infection and is a major cause of liver disease worldwide. Interferon alfa and ribavirin therapy lead to sustained clearance of virus in 31% to 64% of patients with type 1 and non-type 1 genotypes, respectively. It is not clear to what extent these drugs act directly to reduce HCV replication, or indirectly via host immune responses, and what evoked immune responses are associated with clinical outcome. We have examined prospectively 15 patients with chronic HCV infection before, during, and after combination therapy. Quantitative assays for HCV antigen-specific CD4+ and CD8+ T-cell responses, and flow cytometric assays for analysis of the phenotype of T cells, in addition to viral sequencing of core protein, were performed throughout the treatment and follow-up period over 18 months. We found enhancement of proliferative T-cell responses during therapy. Proliferative responses are strikingly heterogeneous in terms of specificity, kinetics, and magnitude. Proliferative responses are often not associated with interferon-gamma release. T-cell responses are rarely sustained irrespective of treatment outcome and this is not due to the evolution of new immune escape variants. T-cell responses tend to peak late in the course of treatment. In conclusion, combination therapy for HCV has a transient effect on host virus-specific T cells in the blood. Induction of sustained T-cell responses may require additional immune modulation later in therapy.
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Affiliation(s)
- Eleanor Barnes
- Centre for Hepatology, Royal Free Hospital, London; and the Nuffield Department of Medicine, Oxford University, Oxford, UK.
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18
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Kimball P, Verbeke S, Shiffman M. Proliferative suppression and class I insufficiency on peripheral blood cells from hepatitis C patients overcome by exogenous cytokines or high-dose mitogen. Clin Immunol 2002; 103:317-23. [PMID: 12173307 DOI: 10.1006/clim.2002.5217] [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: 11/22/2022]
Abstract
An abnormal T cell response to HCV viral infection is speculated to cause viral persistence, although the mechanism(s) is not understood. Using a classical in vitro test of T cell vigor, proliferative responses to PHA were determined in PBLs from 92 HCV+ individuals and 35 healthy noninfected controls. In addition, since HLA antigens modulate proliferation, surface HLA content was measured by quantitative flow cytometry. The proliferative response of cells from HCV+ individuals was lower than that of controls (SI of 91 +/- 70 vs 219 +/- 70, P < .0001). In addition, class I content was underexpressed on cells from HCV+ individuals (4540 +/- 1359 vs 13,180 +/- 5511 MESF units, P < .0001) after 5 days of PHA stimulation. Class II content was also lower than that of controls (89 +/- 17 vs 124 +/- 61 MESF units, P < .0001) after PHA stimulation. Treatment of cells from HCV+ individuals with a high dose of PHA corrected proliferative hyporesponsiveness (P < 0.01) and class I and II insufficiency (P = 0.02). Treatment with exogenous IL-2 or IFN-gamma corrected proliferative reduction (P < 0.01) but not HLA antigen content (P = ns). The results show a biochemical and functional abnormality in PBLs from HCV+ individuals, which may contribute to HCV chronicity.
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Affiliation(s)
- Pam Kimball
- Department of Surgery and Hepatology, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, Virginia, USA
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19
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Ward S, Lauer G, Isba R, Walker B, Klenerman P. Cellular immune responses against hepatitis C virus: the evidence base 2002. Clin Exp Immunol 2002; 128:195-203. [PMID: 11985510 PMCID: PMC1906407 DOI: 10.1046/j.1365-2249.2002.01840.x] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Hepatitis C virus (HCV) is an RNA virus which is estimated to persistently infect about 170 million people worldwide. After acute infection, there is an initial period during which long-term outcome is decided. There is strong evidence that the cellular immune responses, involving both CD4+ and CD8+ T lymphocytes, are involved at this stage and it is their effectiveness which determines outcome. What is not understood is what determines their effectiveness. The most important component of this is likely to be some aspect of epitope selection, itself dictated by host MHC. Thus, to understand host immunity to HCV, we need to have a detailed understanding of the peptides involved in T lymphocyte responses. In this review, we discuss the peptide epitopes that have been identified so far, and their potential significance. We relate this to a scheme of host defence which may be useful for understanding natural and vaccine-induced immunity.
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Affiliation(s)
- S Ward
- Nuffield Department of Medicine, Oxford, UK
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20
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Abstract
Hepatitis C virus (HCV) readily causes a persistent infection, although some individuals spontaneously control infection. 'Successful' immune responses appear to be multi-specific and sustained-including a major role for CD4(+)T cells. Some antiviral CD8(+)T cells show reduced capacity to secrete antiviral cytokines either temporarily ('stunning') or in the long term ('stunting'). The co-ordination of multiple immune effector functions may be required to gain control of HCV.
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Affiliation(s)
- Paul Klenerman
- Nuffield Department of Medicine, University of Oxford, Peter Medawar Building, South Parks Road, Oxford OX1 3SY, UK.
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21
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Lucas M, Karrer U, Lucas A, Klenerman P. Viral escape mechanisms--escapology taught by viruses. Int J Exp Pathol 2001; 82:269-86. [PMID: 11703537 PMCID: PMC2517780 DOI: 10.1046/j.1365-2613.2001.00204.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2001] [Accepted: 07/24/2001] [Indexed: 01/12/2023] Open
Abstract
Viruses have 'studied' immunology over millions of years of coevolution with their hosts. During this ongoing education they have developed countless mechanisms to escape from the host's immune system. To illustrate the most common strategies of viral immune escape we have focused on two murine models of persistent infection, lymphocytic choriomeningitis virus (LCMV) and murine cytomegalovirus (MCMV). LCMV is a fast replicating small RNA virus with a genome prone to mutations. Therefore, LCMV escapes from the immune system mainly by two strategies: 'speed' and 'shape change'. At the opposite extreme, MCMV is a large, complex DNA virus with a more rigid genome and thus the strategies used by LCMV are no option. However, MCMV has the coding capacity for additional genes which interfere specifically with the immune response of the host. These escape strategies have been described as 'camouflage' and 'sabotage'. Using these simple concepts we describe the spectrum of viral escapology, giving credit not only to the researchers who uncovered this fascinating area of immunology but also to the viruses themselves, who still have a few lessons to teach.
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Affiliation(s)
- M Lucas
- Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, UK.
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22
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Sustained dysfunction of antiviral CD8+ T lymphocytes after infection with hepatitis C virus. J Virol 2001. [PMID: 11356962 DOI: 10.1128/jvi.75.12.5550-5558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Hepatitis C virus (HCV) sets up persistent infection in the majority of those exposed. It is likely that, as with other persistent viral infections, the efficacy of T-lymphocyte responses influences long-term outcome. However, little is known about the functional capacity of HCV-specific T-lymphocyte responses induced after acute infection. We investigated this by using major histocompatibility complex class I-peptide tetrameric complexes (tetramers), which allow direct detection of specific CD8+ T lymphocytes ex vivo, independently of function. Here we show that, early after infection, virus-specific CD8+ T lymphocytes detected with a panel of four such tetramers are abnormal in terms of their synthesis of antiviral cytokines and lytic activity. Furthermore, this phenotype is commonly maintained long term, since large sustained populations of HCV-specific CD8+ T lymphocytes were identified, which consistently had very poor antiviral cytokine responses as measured in vitro. Overall, HCV-specific CD8+ T lymphocytes show reduced synthesis of tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma) after stimulation with either mitogens or peptides, compared to responses to Epstein-Barr virus and/or cytomegalovirus. This behavior of antiviral CD8+ T lymphocytes induced after HCV infection may contribute to viral persistence through failure to effectively suppress viral replication.
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Gruener NH, Lechner F, Jung MC, Diepolder H, Gerlach T, Lauer G, Walker B, Sullivan J, Phillips R, Pape GR, Klenerman P. Sustained dysfunction of antiviral CD8+ T lymphocytes after infection with hepatitis C virus. J Virol 2001; 75:5550-8. [PMID: 11356962 PMCID: PMC114267 DOI: 10.1128/jvi.75.12.5550-5558.2001] [Citation(s) in RCA: 411] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2001] [Accepted: 03/12/2001] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus (HCV) sets up persistent infection in the majority of those exposed. It is likely that, as with other persistent viral infections, the efficacy of T-lymphocyte responses influences long-term outcome. However, little is known about the functional capacity of HCV-specific T-lymphocyte responses induced after acute infection. We investigated this by using major histocompatibility complex class I-peptide tetrameric complexes (tetramers), which allow direct detection of specific CD8+ T lymphocytes ex vivo, independently of function. Here we show that, early after infection, virus-specific CD8+ T lymphocytes detected with a panel of four such tetramers are abnormal in terms of their synthesis of antiviral cytokines and lytic activity. Furthermore, this phenotype is commonly maintained long term, since large sustained populations of HCV-specific CD8+ T lymphocytes were identified, which consistently had very poor antiviral cytokine responses as measured in vitro. Overall, HCV-specific CD8+ T lymphocytes show reduced synthesis of tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma) after stimulation with either mitogens or peptides, compared to responses to Epstein-Barr virus and/or cytomegalovirus. This behavior of antiviral CD8+ T lymphocytes induced after HCV infection may contribute to viral persistence through failure to effectively suppress viral replication.
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Affiliation(s)
- N H Gruener
- Institute for Immunology, D-80336 Munich, Germany
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