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Greene TT, Jo Y, Macal M, Fang Z, Khatri FS, Codrington AL, Kazane KR, Chiale C, Akbulut E, Swaminathan S, Fujita Y, Fitzgerald-Bocarsly P, Cordes T, Metallo C, Scott DA, Zuniga EI. Metabolic Deficiencies Underlie Plasmacytoid Dendritic Cell Exhaustion After Viral Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582551. [PMID: 38464328 PMCID: PMC10925345 DOI: 10.1101/2024.02.28.582551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Type I Interferons (IFN-I) are central to host protection against viral infections 1 . While any cell can produce IFN-I, Plasmacytoid Dendritic Cells (pDCs) make greater quantities and more varieties of these cytokines than any other cell type 2 . However, following an initial burst of IFN- I, pDCs lose their exceptional IFN-I production capacity and become "exhausted", a phenotype that associates with enhanced susceptibility to secondary infections 3-5 . Despite this apparent cost for the host, pDC exhaustion is conserved across multiple species and viral infections, but the underlying mechanisms and the potential evolutionary advantages are not well understood. Here we characterize pDC exhaustion and demonstrate that it is associated with a reduced capacity of pDCs to engage both oxidative and glycolytic metabolism. Mechanistically, we identify lactate dehydrogenase B (LDHB) as a novel positive regulator of pDC IFN-I production in mice and humans, show that LDHB deficiency is associated with suppressed IFN-I production, pDC metabolic capacity, and viral control following a viral infection, and demonstrate that preservation of LDHB expression is sufficient to partially restore exhausted pDC function in vitro and in vivo . Furthermore, restoring LDHB in vivo in exhausted pDCs increased IFNAR dependent infection- associated pathology. Therefore, our work identifies a novel and conserved mechanism for balancing immunity and pathology during viral infections, while also providing insight into the highly preserved but previously unexplained phenomenon of pDC exhaustion.
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2
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Bozward A, Ce M, Dell'oro L, Oo YH, Ronca V. Breakdown in hepatic tolerance and its relation to autoimmune liver diseases. Minerva Gastroenterol (Torino) 2023; 69:10-22. [PMID: 33793157 DOI: 10.23736/s2724-5985.21.02853-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The liver is a complex immunological organ. It has both immunogenic and tolerogenic capacity. Tolerogenic potential of human liver with its protective firewalls is required to guard the body against the continuous influx of microbial product from the gut via the sinusoids and biliary tree. Immunotolerance and anergic state is maintained by a combined effort of both immune cells, parenchyma cells, epithelial and endothelial cells. Despite this, an unknown trigger can ignite the pathway towards breakdown in hepatic tolerance leading to autoimmune liver diseases. Understanding the initial stimulus which causes the hepatic immune system to switch from the regulatory arm towards self-reactive effector arm remains challenging. Dissecting this pathology using the current technological advances is crucial to develop curative immune based therapy in autoimmune liver diseases. We discuss the hepatic immune cells and non-immune cells which maintain liver tolerance and the evidence of immune system barrier breach which leads to autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis.
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Affiliation(s)
- Amber Bozward
- Center for Liver and Gastro Research and NIHR Biomedical Research Center, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.,Center for Rare Diseases, European Reference Network Centre - Rare Liver, Birmingham, UK
| | - Maurizio Ce
- Department of Health Sciences, University of Milan, Milan, Italy
| | | | - Ye H Oo
- Center for Liver and Gastro Research and NIHR Biomedical Research Center, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK.,Center for Rare Diseases, European Reference Network Centre - Rare Liver, Birmingham, UK.,Liver Transplant and Hepatobiliary Unit, University Hospital of Birmingham NHS Foundation Trust, Birmingham, UK
| | - Vincenzo Ronca
- Center for Liver and Gastro Research and NIHR Biomedical Research Center, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK - .,Center for Rare Diseases, European Reference Network Centre - Rare Liver, Birmingham, UK.,Liver Transplant and Hepatobiliary Unit, University Hospital of Birmingham NHS Foundation Trust, Birmingham, UK
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3
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Riaz F, Wei P, Pan F. Fine-tuning of regulatory T cells is indispensable for the metabolic steatosis-related hepatocellular carcinoma: A review. Front Cell Dev Biol 2022; 10:949603. [PMID: 35912096 PMCID: PMC9337771 DOI: 10.3389/fcell.2022.949603] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 06/28/2022] [Indexed: 12/12/2022] Open
Abstract
The majority of chronic hepatic diseases are caused by nutritional imbalance. These nutritional inequities include excessive intake of alcohol and fat, which causes alcoholic liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD), respectively. The pathogenesis of hepatic diseases is mainly dependent on oxidative stress, autophagy, DNA damage, and gut microbiota and their metabolites. These factors influence the normal physiology of the liver and impact the hepatic microenvironment. The hepatic microenvironment contains several immune cells and inflammatory cytokines which interact with each other and contribute to the progression of chronic hepatic diseases. Among these immune cells, Foxp3+ CD4+ regulatory T cells (Tregs) are the crucial subset of CD4+ T cells that create an immunosuppressive environment. This review emphasizes the function of Tregs in the pathogenesis of ALD and NAFLD and their role in the progression of NAFLD-associated hepatocellular carcinoma (HCC). Briefly, Tregs establish an immunosuppressive landscape in the liver by interacting with the innate immune cells and gut microbiota and their metabolites. Meanwhile, with the advancement of steatosis, these Tregs inhibit the proliferation, activation and functions of other cytotoxic T cells and support the progression of simple steatosis to HCC. Briefly, it can be suggested that targeting Tregs can act as a favourable prognostic indicator by modulating steatosis and insulin resistance during the pathogenesis of hepatic steatosis and NAFLD-associated HCC.
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Affiliation(s)
- Farooq Riaz
- Center for Cancer Immunology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Ping Wei
- Center for Cancer Immunology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- Chongqing Key Laboratory of Pediatrics, Department of otolaryngology, Children’s Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China
| | - Fan Pan
- Center for Cancer Immunology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- *Correspondence: Fan Pan,
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4
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Greene TT, Zuniga EI. Type I Interferon Induction and Exhaustion during Viral Infection: Plasmacytoid Dendritic Cells and Emerging COVID-19 Findings. Viruses 2021; 13:1839. [PMID: 34578420 PMCID: PMC8472174 DOI: 10.3390/v13091839] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 01/12/2023] Open
Abstract
Type I Interferons (IFN-I) are a family of potent antiviral cytokines that act through the direct restriction of viral replication and by enhancing antiviral immunity. However, these powerful cytokines are a caged lion, as excessive and sustained IFN-I production can drive immunopathology during infection, and aberrant IFN-I production is a feature of several types of autoimmunity. As specialized producers of IFN-I plasmacytoid (p), dendritic cells (DCs) can secrete superb quantities and a wide breadth of IFN-I isoforms immediately after infection or stimulation, and are the focus of this review. Notably, a few days after viral infection pDCs tune down their capacity for IFN-I production, producing less cytokines in response to both the ongoing infection and unrelated secondary stimulations. This process, hereby referred to as "pDC exhaustion", favors viral persistence and associates with reduced innate responses and increased susceptibility to secondary opportunistic infections. On the other hand, pDC exhaustion may be a compromise to avoid IFN-I driven immunopathology. In this review we reflect on the mechanisms that initially induce IFN-I and subsequently silence their production by pDCs during a viral infection. While these processes have been long studied across numerous viral infection models, the 2019 coronavirus disease (COVID-19) pandemic has brought their discussion back to the fore, and so we also discuss emerging results related to pDC-IFN-I production in the context of COVID-19.
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Affiliation(s)
| | - Elina I. Zuniga
- Division of Biological Sciences, University of California, San Diego, CA 92093, USA;
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5
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Méndez-Sánchez N, Córdova-Gallardo J, Barranco-Fragoso B, Eslam M. Hepatic Dendritic Cells in the Development and Progression of Metabolic Steatohepatitis. Front Immunol 2021; 12:641240. [PMID: 33833761 PMCID: PMC8021782 DOI: 10.3389/fimmu.2021.641240] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/08/2021] [Indexed: 12/11/2022] Open
Abstract
Metabolic Associated Fatty liver disease (MAFLD) is a global health problem and represents the most common cause of chronic liver disease in the world. MAFLD spectrum goes from simple steatosis to cirrhosis, in between metabolic steatohepatitis with progressive fibrosis, which pathogenesis is not completely understood. Hence, the role of the immune system has become an important fact in the trigger of inflammatory cascades in metabolic steatohepatitis and in the activation of hepatic stellate cells (HSCs). Among, the more studied immune cells in the pathogenesis of MAFLD are macrophages, T cells, natural killer and dendritic cells. In particular, hepatic dendritic cells had recently attracted a special attention, with a dual role in the pathogenesis of MAFLD. These cells have the capacity to switch from a tolerant state to active state inducing an inflammatory cascade. Furthermore, these cells play a role in the lipid storage within the liver, having, thus providing a crucial nexus between inflammation and lipid metabolism. In this review, we will discuss the current knowledge on the dual role of dendritic cells in lipid accumulation, as wells as in the triggering of hepatic inflammation and hepatocytes cell death in metabolic steatohepatitis.
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Affiliation(s)
- Nahum Méndez-Sánchez
- Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.,Liver Research Unit, Medica Sur Clinic & Foundation, Mexico City, Mexico
| | - Jacqueline Córdova-Gallardo
- Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico.,Department of Hepatology, Service of Surgery and Obesity Clinic, General Hospital "Dr. Manuel Gea González", Mexico City, Mexico
| | | | - Mohammed Eslam
- Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Sydney, NSW, Australia
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6
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Lutckii A, Strunz B, Zhirkov A, Filipovich O, Rukoiatkina E, Gusev D, Lobzin Y, Fischler B, Aleman S, Sällberg M, Björkström NK. Evidence for B cell maturation but not trained immunity in uninfected infants exposed to hepatitis C virus. Gut 2020; 69:2203-2213. [PMID: 32341018 DOI: 10.1136/gutjnl-2019-320269] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 03/11/2020] [Accepted: 04/03/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVES Vertical transmission of hepatitis C virus (HCV) is rare compared with other chronic viral infections, despite that newborns have an immature, and possibly more susceptible, immune system. It further remains unclear to what extent prenatal and perinatal exposure to HCV affects immune system development in neonates. DESIGN To address this, we studied B cells, innate immune cells and soluble factors in a cohort of 62 children that were either unexposed, exposed uninfected or infected with HCV. Forty of these infants were followed longitudinally from birth up until 18 months of age. RESULTS As expected, evidence for B cell maturation was observed with increased age in children, whereas few age-related changes were noticed among innate immune cells. HCV-infected children had a high frequency of HCV-specific IgG-secreting B cells. Such a response was also detected in some exposed but uninfected children but not in uninfected controls. Consistent with this, both HCV-exposed uninfected and HCV-infected infants had evidence of early B cell immune maturation with an increased proportion of IgA-positive plasma cells and upregulated CD40 expression. In contrast, actual HCV viraemia, but not mere exposure, led to alterations within myeloid immune cell populations, natural killer (NK) cells and a distinct soluble factor profile with increased levels of inflammatory cytokines and chemokines. CONCLUSION Our data reveal that exposure to, and infection with, HCV causes disparate effects on adaptive B cells and innate immune cell such as myeloid cells and NK cells in infants.
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Affiliation(s)
- Anton Lutckii
- Department of Laboratory Medicine, Karolinska institutet, Stockholm, Sweden.,Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russian Federation
| | - Benedikt Strunz
- Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Anton Zhirkov
- Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russian Federation
| | - Olga Filipovich
- North-Western State Medical University named after I.I.Mechnikov, Saint Petersburg, Russian Federation
| | - Elena Rukoiatkina
- Maternity Hospital No 16, Saint Petersburg, Russian Federation.,Department of Pediatrics, Gynecology and Female Reproductology, Saint Petersburg State Pediatric Medical University, Saint Petersburg, Russian Federation
| | - Denis Gusev
- Center for Prevention and Control of AIDS and Infectious Diseases, Saint Petersburg, Russian Federation
| | - Yuriy Lobzin
- Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russian Federation
| | - Björn Fischler
- Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm, Sweden.,Department of Pediatrics, Karolinska University Hospital, Stockholm, Sweden
| | - Soo Aleman
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Matti Sällberg
- Department of Laboratory Medicine, Karolinska institutet, Stockholm, Sweden
| | - Niklas K Björkström
- Center for Infectious Medicine, Department of Medicine Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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7
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Lurje I, Hammerich L, Tacke F. Dendritic Cell and T Cell Crosstalk in Liver Fibrogenesis and Hepatocarcinogenesis: Implications for Prevention and Therapy of Liver Cancer. Int J Mol Sci 2020; 21:ijms21197378. [PMID: 33036244 PMCID: PMC7583774 DOI: 10.3390/ijms21197378] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/01/2020] [Accepted: 10/04/2020] [Indexed: 02/06/2023] Open
Abstract
Liver fibrosis is a chronic, highly prevalent disease that may progress to cirrhosis and substantially increases the risk for development of hepatocellular carcinoma (HCC). Fibrotic livers are characterized by an inflammatory microenvironment that is composed of various immunologically active cells, including liver-resident populations (e.g., Kupffer cells, hepatic stellate cells and sinusoidal endothelium) and infiltrating leukocytes (e.g., monocytes, monocyte-derived macrophages, neutrophils and lymphocytes). While inflammatory injury drives both fibrogenesis and carcinogenesis, the tolerogenic microenvironment of the liver conveys immunosuppressive effects that encourage tumor growth. An insufficient crosstalk between dendritic cells (DCs), the professional antigen presenting cells, and T cells, the efficient anti-tumor effector cells, is one of the main mechanisms of HCC tumor tolerance. The meticulous analysis of patient samples and mouse models of fibrosis-HCC provided in-depth insights into molecular mechanisms of immune interactions in liver cancer. The therapeutic modulation of this multifaceted immunological response, e.g., by inhibiting immune checkpoint molecules, in situ vaccination, oncolytic viruses or combinations thereof, is a rapidly evolving field that holds the potential to improve the outcome of patients with HCC. This review aims to highlight the current understanding of DC–T cell interactions in fibrogenesis and hepatocarcinogenesis and to illustrate the potentials and pitfalls of therapeutic clinical translation.
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8
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Greene TT, Jo YR, Zuniga EI. Infection and cancer suppress pDC derived IFN-I. Curr Opin Immunol 2020; 66:114-122. [PMID: 32947131 PMCID: PMC8526282 DOI: 10.1016/j.coi.2020.08.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 08/03/2020] [Accepted: 08/04/2020] [Indexed: 12/12/2022]
Abstract
Plasmacytoid dendritic cells (pDCs) are specialized producers of Type I interferon (IFN-I) that promote anti-viral and anti-tumor immunity. However, chronic infections and cancer inhibit pDC-derived IFN-I. While the mechanisms of this inhibition are multifarious they can be classified broadly into two categories: i) reduction or ablation of pDC IFN-I-production capacity (functional exhaustion) and/or ii) decrease in pDC numbers (altered population dynamics). Recent work has identified many processes that contribute to suppression of pDC-derived IFN-I during chronic infections and cancer, including sustained stimulation through Toll Like Receptors (TLRs), inhibitory microenvironments, inhibitory receptor ligation, and reduced development from bone marrow progenitors and apoptosis. Emerging success leveraging pDCs in treatment of disease through TLR activation illustrates the therapeutic potential of targeting pDCs. Deeper understanding of the systems that limit pDC-derived IFN-I has the potential to improve these emerging therapies as well as help devising new approaches that harness the outstanding IFN-I-production capacity of pDCs.
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Affiliation(s)
- Trever T Greene
- University of California San Diego, Department of Biological Sciences, San Diego, United States
| | - Yea-Ra Jo
- University of California San Diego, Department of Biological Sciences, San Diego, United States
| | - Elina I Zuniga
- University of California San Diego, Department of Biological Sciences, San Diego, United States.
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9
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Wang H, Lu CH, Ho PC. Metabolic adaptation orchestrates tissue context-dependent behavior in regulatory T cells. Immunol Rev 2020; 295:126-139. [PMID: 32147869 DOI: 10.1111/imr.12844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 02/19/2020] [Indexed: 02/07/2023]
Abstract
The diverse distribution and functions of regulatory T cells (Tregs) ensure tissue and immune homeostasis; however, it remains unclear which factors can guide distribution, local differentiation, and tissue context-specific behavior in Tregs. Although the emerging concept that Tregs could re-adjust their transcriptome based on their habitations is supported by recent findings, the underlying mechanisms that reprogram transcriptome in Tregs are unknown. In the past decade, metabolic machineries have been revealed as a new regulatory circuit, known as immunometabolic regulation, to orchestrate activation, differentiation, and functions in a variety of immune cells, including Tregs. Given that systemic and local alterations of nutrient availability and metabolite profile associate with perturbation of Treg abundance and functions, it highlights that immunometabolic regulation may be one of the mechanisms that orchestrate tissue context-specific regulation in Tregs. The understanding on how metabolic program instructs Tregs in peripheral tissues not only represents a critical opportunity to delineate a new avenue in Treg biology but also provides a unique window to harness Treg-targeting approaches for treating cancer and autoimmunity with minimizing side effects. This review will highlight the metabolic features on guiding Treg formation and function in a disease-oriented perspective and aim to pave the foundation for future studies.
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Affiliation(s)
- Haiping Wang
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
| | - Chun-Hao Lu
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
| | - Ping-Chih Ho
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
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10
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Weston CJ, Zimmermann HW, Adams DH. The Role of Myeloid-Derived Cells in the Progression of Liver Disease. Front Immunol 2019; 10:893. [PMID: 31068952 PMCID: PMC6491757 DOI: 10.3389/fimmu.2019.00893] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 04/08/2019] [Indexed: 12/12/2022] Open
Abstract
Control of homeostasis and rapid response to tissue damage in the liver is orchestrated by crosstalk between resident and infiltrating inflammatory cells. A crucial role for myeloid cells during hepatic injury and repair has emerged where resident Kupffer cells, circulating monocytes, macrophages, dendritic cells and neutrophils control local tissue inflammation and regenerative function to maintain tissue architecture. Studies in humans and rodents have revealed a heterogeneous population of myeloid cells that respond to the local environment by either promoting regeneration or driving the inflammatory processes that can lead to hepatitis, fibrogenesis, and the development of cirrhosis and malignancy. Such plasticity of myeloid cell responses presents unique challenges for therapeutic intervention strategies and a greater understanding of the underlying mechanisms is needed. Here we review the role of myeloid cells in the establishment and progression of liver disease and highlight key pathways that have become the focus for current and future therapeutic strategies.
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Affiliation(s)
- Chris John Weston
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham, United Kingdom.,NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, United Kingdom
| | | | - David H Adams
- Centre for Liver and Gastrointestinal Research, Institute of Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham, United Kingdom.,NIHR Birmingham Biomedical Research Centre, University Hospitals Birmingham NHS Foundation Trust and University of Birmingham, Birmingham, United Kingdom
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11
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Yang Y, Tu ZK, Liu XK, Zhang P. Mononuclear phagocyte system in hepatitis C virus infection. World J Gastroenterol 2018; 24:4962-4973. [PMID: 30510371 PMCID: PMC6262249 DOI: 10.3748/wjg.v24.i44.4962] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/30/2018] [Accepted: 11/08/2018] [Indexed: 02/06/2023] Open
Abstract
The mononuclear phagocyte system (MPS), which consists of monocytes, dendritic cells (DCs), and macrophages, plays a vital role in the innate immune defense against pathogens. Hepatitis C virus (HCV) is efficient in evading the host immunity, thereby facilitating its development into chronic infection. Chronic HCV infection is the leading cause of end-stage liver diseases, liver cirrhosis, and hepatocellular carcinoma. Acquired immune response was regarded as the key factor to eradicate HCV. However, innate immunity can regulate the acquired immune response. Innate immunity-derived cytokines shape the adaptive immunity by regulating T-cell differentiation, which determines the outcome of acute HCV infection. Inhibition of HCV-specific T-cell responses is one of the most important strategies for immune system evasion. It is meaningful to illustrate the role of innate immune response in HCV infection. With the MPS being the important factor in innate immunity, therefore, understanding the role of the MPS in HCV infection will shed light on the pathophysiology of chronic HCV infection. In this review, we outline the impact of HCV infection on the MPS and cytokine production. We discuss how HCV is detected by the MPS and describe the function and impairment of MPS components in HCV infection.
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Affiliation(s)
- Yu Yang
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun 130021, Jilin Province, China
| | - Zheng-Kun Tu
- Institute of Translational Medicine, The First Hospital of Jilin University, Changchun 130061, Jilin Province, China
| | - Xing-Kai Liu
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun 130021, Jilin Province, China
| | - Ping Zhang
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun 130021, Jilin Province, China
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12
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Dustin LB. Innate and Adaptive Immune Responses in Chronic HCV Infection. Curr Drug Targets 2018; 18:826-843. [PMID: 26302811 DOI: 10.2174/1389450116666150825110532] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/25/2015] [Accepted: 07/27/2015] [Indexed: 12/14/2022]
Abstract
Hepatitis C virus (HCV) remains a public health problem of global importance, even in the era of potent directly-acting antiviral drugs. In this chapter, I discuss immune responses to acute and chronic HCV infection. The outcome of HCV infection is influenced by viral strategies that limit or delay the initiation of innate antiviral responses. This delay may enable HCV to establish widespread infection long before the host mounts effective T and B cell responses. HCV's genetic agility, resulting from its high rate of replication and its error prone replication mechanism, enables it to evade immune recognition. Adaptive immune responses fail to keep up with changing viral epitopes. Neutralizing antibody epitopes may be hidden by decoy structures, glycans, and lipoproteins. T cell responses fail due to changing epitope sequences and due to exhaustion, a phenomenon that may have evolved to limit immune-mediated pathology. Despite these difficulties, innate and adaptive immune mechanisms do impact HCV replication. Immune-mediated clearance of infection is possible, occurring in 20-50% of people who contract the disease. New developments raise hopes for effective immunological interventions to prevent or treat HCV infection.
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Affiliation(s)
- Lynn B Dustin
- University of Oxford, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Kennedy Institute of Rheumatology, Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom
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13
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Wawman RE, Bartlett H, Oo YH. Regulatory T Cell Metabolism in the Hepatic Microenvironment. Front Immunol 2018; 8:1889. [PMID: 29358934 PMCID: PMC5766647 DOI: 10.3389/fimmu.2017.01889] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 12/11/2017] [Indexed: 12/19/2022] Open
Abstract
Thymic-derived naturally occurring regulatory T cells (tTreg) are crucial for maintaining peripheral immune homeostasis. They play a crucial role in preventing autoimmunity and maintaining organ transplant without requiring immunosuppression. Cellular metabolism has recently emerged as an important regulator of adaptive immune cell balance between Treg and effector T cells. While the metabolic requirements of conventional T cells are increasingly understood, the role of Treg cellular metabolism is less clear. The continuous exposure of metabolites and nutrients to the human liver via the portal blood flow influences the lineage fitness, function, proliferation, migration, and survival of Treg cells. As cellular metabolism has an impact on its function, it is crucial to understand the metabolic pathways wiring in regulatory T cells. Currently, there are ongoing early phase clinical trials with polyclonal and antigen-specific good manufacturing practice (GMP) Treg therapy to treat autoimmune diseases and organ transplantation. Thus, enhancing immunometabolic pathways of Treg by translational approach with existing or new drugs would utilize Treg cells to their full potential for effective cellular therapy.
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Affiliation(s)
- Rebecca Ellen Wawman
- Centre for Liver Research, National Institute of Health Research Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.,Faculty of Health and Life Sciences, School of Life Sciences, Coventry University, Coventry, United Kingdom
| | - Helen Bartlett
- Centre for Liver Research, National Institute of Health Research Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Ye Htun Oo
- Centre for Liver Research, National Institute of Health Research Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom.,University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
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14
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Audiger C, Rahman MJ, Yun TJ, Tarbell KV, Lesage S. The Importance of Dendritic Cells in Maintaining Immune Tolerance. THE JOURNAL OF IMMUNOLOGY 2017; 198:2223-2231. [PMID: 28264998 DOI: 10.4049/jimmunol.1601629] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/11/2016] [Indexed: 12/30/2022]
Abstract
Immune tolerance is necessary to prevent the immune system from reacting against self, and thus to avoid the development of autoimmune diseases. In this review, we discuss key findings that position dendritic cells (DCs) as critical modulators of both thymic and peripheral immune tolerance. Although DCs are important for inducing both immunity and tolerance, increased autoimmunity associated with decreased DCs suggests their nonredundant role in tolerance induction. DC-mediated T cell immune tolerance is an active process that is influenced by genetic variants, environmental signals, as well as the nature of the specific DC subset presenting Ag to T cells. Answering the many open questions with regard to the role of DCs in immune tolerance could lead to the development of novel therapies for the prevention of autoimmune diseases.
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Affiliation(s)
- Cindy Audiger
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montreal, Quebec H1T 2M4, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
| | - M Jubayer Rahman
- Immune Tolerance Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Tae Jin Yun
- Laboratory of Cellular Physiology and Immunology, Clinical Research Institute of Montreal, Montreal, Quebec H2W 1R7, Canada; and.,Division of Experimental Medicine, Department of Medicine, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Kristin V Tarbell
- Immune Tolerance Section, Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Sylvie Lesage
- Department of Immunology-Oncology, Maisonneuve-Rosemont Hospital, Montreal, Quebec H1T 2M4, Canada; .,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
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15
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Resheq YJ, Menzner AK, Bosch J, Tickle J, Li KK, Wilhelm A, Hepburn E, Murihead G, Ward ST, Curbishley SM, Zimmermann HW, Bruns T, Gilbert DF, Tripal P, Mackensen A, Adams DH, Weston CJ. Impaired Transmigration of Myeloid-Derived Suppressor Cells across Human Sinusoidal Endothelium Is Associated with Decreased Expression of CD13. THE JOURNAL OF IMMUNOLOGY 2017; 199:1672-1681. [PMID: 28739875 DOI: 10.4049/jimmunol.1600466] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/22/2017] [Indexed: 12/14/2022]
Abstract
Human monocytic myeloid-derived suppressor cells (MO-MDSCs) within the hepatic compartment suppress inflammation and impair immune surveillance in liver cancer. It is currently not known whether recruitment of MO-MDSCs from blood via hepatic sinusoidal endothelium (HSEC) contributes to their enrichment within the hepatic compartment. We compared the transmigratory potential of MO-MDSCs and monocytes after adhesion to hepatic endothelial monolayers in flow-based assays that mimic in vivo shear stress in the sinusoids. Despite comparable binding to HSEC monolayers, proportionally fewer MO-MDSCs underwent transendothelial migration, indicating that the final steps of extravasation, where actin polymerization plays an important role, are impaired in MO-MDSCs. In this article, we found reduced levels of CD13 on MO-MDSCs, which has recently been reported to control cell motility in monocytes, alongside reduced VLA-4 expression, an integrin predominantly involved in adherence to the apical side of the endothelium. CD13 and VLA-4 blocking and activating Abs were used in flow-based adhesion assays, live-cell imaging of motility, and actin polymerization studies to confirm a role for CD13 in impaired MO-MDSC transmigration. These findings indicate that CD13 significantly contributes to tissue infiltration by MO-MDSCs and monocytes, thereby contributing to the pathogenesis of hepatic inflammation.
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Affiliation(s)
- Yazid J Resheq
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom; .,Department of Internal Medicine 5, Hematology/Oncology, University of Erlangen-Nuremberg, Erlangen 91054, Germany
| | - Ann-Katrin Menzner
- Department of Internal Medicine 5, Hematology/Oncology, University of Erlangen-Nuremberg, Erlangen 91054, Germany
| | - Jacobus Bosch
- Department of Internal Medicine 5, Hematology/Oncology, University of Erlangen-Nuremberg, Erlangen 91054, Germany
| | - Joseph Tickle
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Ka-Kit Li
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Annika Wilhelm
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.,Division of Digestive Diseases, Department of Surgery and Cancer, Imperial College London, London W2 1NY, United Kingdom
| | - Elizabeth Hepburn
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Gillian Murihead
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Stephen T Ward
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Stuart M Curbishley
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Henning W Zimmermann
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.,Department of Medicine III, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Tony Bruns
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.,Department of Medicine IV, University of Jena, 07743 Jena, Germany
| | - Daniel F Gilbert
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nuremberg, 91052 Erlangen, Germany; and
| | - Philipp Tripal
- Optical Imaging Centre Erlangen, Friedrich-Alexander-University Erlangen-Nuremberg, 91052 Erlangen, Germany
| | - Andreas Mackensen
- Department of Internal Medicine 5, Hematology/Oncology, University of Erlangen-Nuremberg, Erlangen 91054, Germany
| | - David H Adams
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Chris J Weston
- Institute of Immunology and Immunotherapy, Centre for Liver Research and National Institute for Health Research Birmingham Liver Biomedical Research Centre, College of Medicine and Dentistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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16
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Hepatitis C virus drives increased type I interferon-associated impairments associated with fibrosis severity in antiretroviral treatment-treated HIV-1-hepatitis C virus-coinfected individuals. AIDS 2017; 31:1223-1234. [PMID: 28492391 DOI: 10.1097/qad.0000000000001455] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Viral coinfections might contribute to the increased immune activation and inflammation that persist in antiretroviral treatment (ART)-treated HIV-1 patients. We investigated whether the hepatitis C virus (HCV) coinfection contributes to such alterations by impairing the plasmacytoid dendritic cell (pDC) IFNα/TLR7 pathway in a highly homogeneous group of ART-treated HIV-1-HCV-coinfected patients. METHODS Twenty-nine HIV-1-infected patients with fully suppressive ART were included, 15 of whom being HCV-coinfected with mild-to-moderate fibrosis and matched for their HIV-1 disease, and 13 control healthy donors. Cellular activation, plasma levels of inflammatory cytokines and pDC transcriptome associated with IFNα/TLR7 pathway were characterized. RESULTS Higher plasma levels of type-I interferon (IFN)-associated cytokines [interferon gamma-induced protein 10 (IP-10), MIP-1β, IL-8 and IFN-inducible T-cell alpha chemoattractant) were observed in HIV-1-HCV-coinfected than in HIV-1-monoinfected patients (P = 0.0007, 0.028, 0.028 and 0.035, respectively). The pDCs and T cells displayed a more exhausted (LAG-3+ and CD57+, respectively) phenotype. The pDC IFNα pathway (defined by phosphorylated STAT1 expression) was constitutively activated in all patients, irrespective of HCV coinfection. Expression of interferon-stimulated genes (ISGs) EI2AK2, ISG15, Mx1 and IFI44 was increased in pDCs from HIV-1-HCV-coinfected individuals and was correlated with fibrosis score (Fibroscan, www.echosens.com, Paris, France and aspartate-aminotransferase/platelet-ratio index score, P = 0.026 and 0.019, respectively). Plasma levels of IP-10, STAT1 expression in pDCs and Mx1 mRNA levels in pDCs decreased after interferon-free anti-HCV treatment. CONCLUSION HCV replication appears to drive increases in type-I IFN-associated inflammation and ISGs expression in pDCs, in association with fibrosis severity in ART-treated HIV-1-infected patients with mild-to-moderate fibrosis. Preliminary results indicate reduction of these alterations with earlier interferon-free anti-HCV treatment in those patients.
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17
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Demetris AJ, Bellamy COC, Gandhi CR, Prost S, Nakanuma Y, Stolz DB. Functional Immune Anatomy of the Liver-As an Allograft. Am J Transplant 2016; 16:1653-80. [PMID: 26848550 DOI: 10.1111/ajt.13749] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/26/2016] [Accepted: 01/28/2016] [Indexed: 01/25/2023]
Abstract
The liver is an immunoregulatory organ in which a tolerogenic microenvironment mitigates the relative "strength" of local immune responses. Paradoxically, necro-inflammatory diseases create the need for most liver transplants. Treatment of hepatitis B virus, hepatitis C virus, and acute T cell-mediated rejection have redirected focus on long-term allograft structural integrity. Understanding of insults should enable decades of morbidity-free survival after liver replacement because of these tolerogenic properties. Studies of long-term survivors show low-grade chronic inflammatory, fibrotic, and microvascular lesions, likely related to some combination of environment insults (i.e. abnormal physiology), donor-specific antibodies, and T cell-mediated immunity. The resultant conundrum is familiar in transplantation: adequate immunosuppression produces chronic toxicities, while lightened immunosuppression leads to sensitization, immunological injury, and structural deterioration. The "balance" is more favorable for liver than other solid organ allografts. This occurs because of unique hepatic immune physiology and provides unintended benefits for allografts by modulating various afferent and efferent limbs of allogenic immune responses. This review is intended to provide a better understanding of liver immune microanatomy and physiology and thereby (a) the potential structural consequences of low-level, including allo-antibody-mediated injury; and (b) how liver allografts modulate immune reactions. Special attention is given to the microvasculature and hepatic mononuclear phagocytic system.
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Affiliation(s)
- A J Demetris
- Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - C O C Bellamy
- Department of Pathology, University of Edinburgh, Edinburgh, Scotland, UK
| | - C R Gandhi
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center and Department of Surgery, University of Cincinnati, Cincinnati, OH
| | - S Prost
- Department of Pathology, University of Edinburgh, Edinburgh, Scotland, UK
| | - Y Nakanuma
- Department of Diagnostic Pathology, Shizuoka Cancer Center, Shizuoka, Japan
| | - D B Stolz
- Center for Biologic Imaging, Cell Biology, University of Pittsburgh, Pittsburgh, PA
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18
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Crosignani A, Riva A, Della Bella S. Analysis of peripheral blood dendritic cells as a non-invasive tool in the follow-up of patients with chronic hepatitis C. World J Gastroenterol 2016; 22:1393-1404. [PMID: 26819508 PMCID: PMC4721974 DOI: 10.3748/wjg.v22.i4.1393] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 09/11/2015] [Accepted: 11/13/2015] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) has a high propensity to establish chronic infections. Failure of HCV-infected individuals to activate effective antiviral immune responses is at least in part related to HCV-induced impairment of dendritic cells (DCs) that play a central role in activating T cell responses. Although the impact of HCV on DC phenotype and function is likely to be more prominent in the liver, major HCV-induced alterations are detectable in peripheral blood DCs (pbDCs) that represent the most accessible source of DCs. These alterations include numerical reduction, impaired production of inflammatory cytokines and increased production of immunosuppressive IL10. These changes in DCs are relevant to our understanding the immune mechanisms underlying the propensity of HCV to establish persistent infection. Importantly, the non-invasive accessibility of pbDCs renders the analysis of these cells a convenient procedure that can be serially repeated in patient follow-up. Accordingly, the study of pbDCs in HCV-infected patients during conventional treatment with pegylated interferon and ribavirin indicated that restoration of normal plasmacytoid DC count may represent an additional mechanism contributing to the efficacy of the dual therapy. It also identified the pre-treatment levels of plasmacytoid DCs and IL10 as putative predictors of response to therapy. Treatment of chronic HCV infection is changing, as new generation direct-acting antiviral agents will soon be available for use in interferon-free therapeutic strategies. The phenotypic and functional analysis of pbDCs in this novel therapeutic setting will provide a valuable tool for investigating mechanisms underlying treatment efficacy and for identifying predictors of treatment response.
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19
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Leone P, Di Tacchio M, Berardi S, Santantonio T, Fasano M, Ferrone S, Vacca A, Dammacco F, Racanelli V. Dendritic cell maturation in HCV infection: altered regulation of MHC class I antigen processing-presenting machinery. J Hepatol 2014; 61:242-51. [PMID: 24732300 PMCID: PMC8759579 DOI: 10.1016/j.jhep.2014.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 03/04/2014] [Accepted: 04/06/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND & AIMS Modulation of dendritic cell (DC) function has been theorized as one of the mechanisms used by hepatitis C virus (HCV) to evade the host immune response and cause persistent infection. METHODS We used a range of cell and molecular biology techniques to study DC subsets from uninfected and HCV-infected individuals. RESULTS We found that patients with persistent HCV infection have lower numbers of circulating myeloid DC and plasmacytoid DC than healthy controls or patients who spontaneously recovered from HCV infection. Nonetheless, DC from patients with persistent HCV infection display normal phagocytic activity, typical expression of the class I and II HLA and co-stimulatory molecules, and conventional cytokine production when stimulated to mature in vitro. In contrast, they do not display the strong switch from immunoproteasome to standard proteasome subunit expression and the upregulation of the transporter-associated proteins following stimulation, which were instead observed in DC from uninfected individuals. This different modulation of components of the HLA class I antigen processing-presenting machinery results in a differential ability to present a CD8(+) T cell epitope whose generation is dependent on the LMP7 immunoproteasome subunit. CONCLUSIONS Overall, these findings establish that under conditions of persistent HCV antigenemia, HLA class I antigen processing and presentation are distinctively regulated during DC maturation.
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Affiliation(s)
- Patrizia Leone
- Department of Internal Medicine and Clinical Oncology, University of Bari Medical School, Bari, Italy
| | - Mariangela Di Tacchio
- Department of Internal Medicine and Clinical Oncology, University of Bari Medical School, Bari, Italy
| | - Simona Berardi
- Department of Internal Medicine and Clinical Oncology, University of Bari Medical School, Bari, Italy
| | | | - Massimo Fasano
- Department of Infectious Diseases, University of Foggia, Foggia, Italy
| | - Soldano Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Angelo Vacca
- Department of Internal Medicine and Clinical Oncology, University of Bari Medical School, Bari, Italy
| | - Franco Dammacco
- Department of Internal Medicine and Clinical Oncology, University of Bari Medical School, Bari, Italy
| | - Vito Racanelli
- Department of Internal Medicine and Clinical Oncology, University of Bari Medical School, Bari, Italy.
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20
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Bekeredjian-Ding I, Greil J, Ammann S, Parcina M. Plasmacytoid Dendritic Cells: Neglected Regulators of the Immune Response to Staphylococcus aureus. Front Immunol 2014; 5:238. [PMID: 24904586 PMCID: PMC4033153 DOI: 10.3389/fimmu.2014.00238] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 05/08/2014] [Indexed: 12/18/2022] Open
Abstract
Plasmacytoid dendritic cells (pDC) are a rare subset of leukocytes equipped with Fcγ and Fcε receptors, which exert contrary effects on sensing of microbial nucleic acids by endosomal Toll-like receptors. In this article, we explain how pDC contribute to the immune response to Staphylococcus aureus. Under normal circumstances the pDC participates in the memory response to the pathogen: pDC activation is initiated by uptake of staphylococcal immune complexes with IgG or IgE. However, protein A-expressing S. aureus strains additionally trigger pDC activation in the absence of immunoglobulin. In this context, staphylococci exploit the pDC to induce antigen-independent differentiation of IL-10 producing plasmablasts, an elegant means to propagate immune evasion. We further discuss the role of type I interferons in infection with S. aureus and the implications of these findings for the development of immune based therapies and vaccination.
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Affiliation(s)
| | - Johann Greil
- Institute for Microbiology, Immunology and Parasitology, University Hospital Bonn , Bonn , Germany ; Department of Pediatrics, University Hospital Heidelberg , Heidelberg , Germany
| | - Sandra Ammann
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University Hospital Heidelberg , Heidelberg , Germany
| | - Marijo Parcina
- Institute for Microbiology, Immunology and Parasitology, University Hospital Bonn , Bonn , Germany
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21
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Fénéant L, Levy S, Cocquerel L. CD81 and hepatitis C virus (HCV) infection. Viruses 2014; 6:535-72. [PMID: 24509809 PMCID: PMC3939471 DOI: 10.3390/v6020535] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 01/29/2014] [Accepted: 02/02/2014] [Indexed: 12/16/2022] Open
Abstract
Hepatitis C Virus (HCV) infection is a global public health problem affecting over 160 million individuals worldwide. Its symptoms include chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped RNA virus mainly targeting liver cells and for which the initiation of infection occurs through a complex multistep process involving a series of specific cellular entry factors. This process is likely mediated through the formation of a tightly orchestrated complex of HCV entry factors at the plasma membrane. Among HCV entry factors, the tetraspanin CD81 is one of the best characterized and it is undoubtedly a key player in the HCV lifecycle. In this review, we detail the current knowledge on the involvement of CD81 in the HCV lifecycle, as well as in the immune response to HCV infection.
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Affiliation(s)
- Lucie Fénéant
- Center for Infection and Immunity of Lille, CNRS-UMR8204, Inserm-U1019, Institut Pasteur de Lille, Université Lille Nord de France, Institut de Biologie de Lille, 1 rue du Pr Calmette, CS50447, 59021 Lille Cedex, France.
| | - Shoshana Levy
- Department of Medicine, Division of Oncology, CCSR, Stanford University Medical Center, Stanford, CA 94305, USA.
| | - Laurence Cocquerel
- Center for Infection and Immunity of Lille, CNRS-UMR8204, Inserm-U1019, Institut Pasteur de Lille, Université Lille Nord de France, Institut de Biologie de Lille, 1 rue du Pr Calmette, CS50447, 59021 Lille Cedex, France.
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22
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Sehgal M, Zeremski M, Talal AH, Khan ZK, Capocasale R, Philip R, Jain P. Host Genetic Factors and Dendritic Cell Responses Associated with the Outcome of Interferon/Ribavirin Treatment in HIV-1/HCV Co-Infected Individuals. ACTA ACUST UNITED AC 2014; 5. [PMID: 25705565 PMCID: PMC4332701 DOI: 10.4172/2155-9899.1000271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
HIV-1/HCV co-infection is a significant health problem. Highly active antiretroviral treatment (HAART) against HIV-1 has proved to be fairly successful. On the other hand, direct acting antiviral drugs against HCV have improved cure rates but high cost and development of drug resistance are important concerns. Therefore PEGylated interferon (PEG-IFN) and ribavirin (RBV) still remain essential components of HCV treatment, and identification of host factors that predict IFN/RBV treatment response is necessary for effective clinical management of HCV infection. Impaired dendritic cell (DC) and T cell responses are associated with HCV persistence. It has been shown that IFN/RBV treatment enhances HCV-specific T cell functions and it is likely that functional restoration of DCs is the underlying cause. To test this hypothesis, we utilized an antibody cocktail (consisting of DC maturation, adhesion and other surface markers) to perform comprehensive phenotypic characterization of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in a cohort of HIV-1/HCV co-infected individuals undergoing IFN/RBV treatment. Our results show that pre-treatment frequencies of mDCs are lower in non-responders (NRs) compared to responders (SVRs) and healthy controls. Although, the treatment was able to restore the frequency of mDCs in NRs, it downregulated the frequency of CCR7+, CD54+ and CD62L+ mDCs. Pre-treatment frequencies of pDCs were lower in NRs and decreased further upon treatment. Compared to SVRs, NRs exhibited higher ratio of PD-L1+/CD86+ pDCs prior to treatment; and this ratio remained high even after treatment. These findings demonstrate that enumeration and phenotypic assessment of DCs before/during therapy can help predict the treatment outcome. We also show that before treatment, PBMCs from SVRs secrete higher amounts of IFN-γ compared to controls and NRs. Upon genotyping IFNL3 polymorphisms rs12979860, rs4803217 and ss469415590, we found rs12979860 to be a better predictor of treatment outcome. Collectively, our study led to identification of important correlates of IFN/RBV treatment response in HIV-1/HCV co-infected individuals.
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Affiliation(s)
- Mohit Sehgal
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Marija Zeremski
- School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Andrew H Talal
- School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Zafar K Khan
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Renold Capocasale
- Flowmetric, Inc., Pennsylvania Biotechnology Center, Doylestown, PA, USA
| | - Ramila Philip
- Immunotope, Inc., Pennsylvania Biotechnology Center, Doylestown, PA, USA
| | - Pooja Jain
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
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23
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Cross-linking of CD81 by HCV-E2 protein inhibits human intrahepatic plasmacytoid dendritic cells response to CpG-ODN. Cell Immunol 2013; 284:98-103. [PMID: 23954883 DOI: 10.1016/j.cellimm.2013.07.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/18/2013] [Accepted: 07/23/2013] [Indexed: 12/17/2022]
Abstract
Plasmacytoid dendritic cells (pDCs) are reported to be defective in HCV-infected patients, the mechanisms of which remain poorly understood. We isolated liver derived mononuclear cells (LMNCs) and pDCs from normal liver tissues of benign tumor dissections and liver transplant donors. Isolated pDCs and LMNCs were cultured with precoated HCV envelop protein E2 (HCV-E2) or anti-CD81 mAb in the presence of CpG-ODN. Our results show that cross-linking of CD81 by either HCV-E2 or anti-CD81 mAb inhibits IFN-α secretion in CpG-induced pDCs; down-regulates HLA-DR, CD80 and CD86 expression in pDCs; and suppresses CpG-ODN induced proliferation and survival of pDCs. The blockade of CD81 by soluble anti-CD81 antibody restores pDCs response to CpG-ODN. These results suggest that HCV E2 protein interacts with CD81 to inhibit pDC maturation, activation, and IFN-α production, and may thereby contribute to the impaired innate anti-viral immune response in HCV infection.
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24
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Rollins-Raval MA, Marafioti T, Swerdlow SH, Roth CG. The number and growth pattern of plasmacytoid dendritic cells vary in different types of reactive lymph nodes: an immunohistochemical study. Hum Pathol 2013; 44:1003-10. [DOI: 10.1016/j.humpath.2012.08.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/24/2012] [Accepted: 08/29/2012] [Indexed: 10/27/2022]
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25
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Sehgal M, Khan ZK, Talal AH, Jain P. Dendritic Cells in HIV-1 and HCV Infection: Can They Help Win the Battle? Virology (Auckl) 2013; 4:1-25. [PMID: 25512691 PMCID: PMC4222345 DOI: 10.4137/vrt.s11046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Persistent infections with human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) are a major cause of morbidity and mortality worldwide. As sentinels of our immune system, dendritic cells (DCs) play a central role in initiating and regulating a potent antiviral immune response. Recent advances in our understanding of the role of DCs during HIV-1 and HCV infection have provided crucial insights into the mechanisms employed by these viruses to impair DC functions in order to evade an effective immune response against them. Modulation of the immunological synapse between DC and T-cell, as well as dysregulation of the crosstalk between DCs and natural killer (NK) cells, are emerging as two crucial mechanisms. This review focuses on understanding the interaction of HIV-1 and HCV with DCs not only to understand the immunopathogenesis of chronic HIV-1 and HCV infection, but also to explore the possibilities of DC-based immunotherapeutic approaches against them. Host genetic makeup is known to play major roles in infection outcome and rate of disease progression, as well as response to anti-viral therapy in both HIV-1 and HCV-infected individuals. Therefore, we highlight the genetic variations that can potentially affect DC functions, especially in the setting of chronic viral infection. Altogether, we address if DCs’ potential as critical effectors of antiviral immune response could indeed be utilized to combat chronic infection with HIV-1 and HCV.
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Affiliation(s)
- Mohit Sehgal
- Department of Microbiology and Immunology, and the Drexel Institute for Biotechnology and Virology Research, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Zafar K Khan
- Department of Microbiology and Immunology, and the Drexel Institute for Biotechnology and Virology Research, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Andrew H Talal
- Center for the Study of Hepatitis C, Weill Cornell Medical College, New York, NY
| | - Pooja Jain
- Department of Microbiology and Immunology, and the Drexel Institute for Biotechnology and Virology Research, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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26
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Zhou Y, Zhang Y, Yao Z, Moorman JP, Jia Z. Dendritic cell-based immunity and vaccination against hepatitis C virus infection. Immunology 2012; 136:385-96. [PMID: 22486354 DOI: 10.1111/j.1365-2567.2012.03590.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C virus (HCV) has chronically infected an estimated 170 million people worldwide. There are many impediments to the development of an effective vaccine for HCV infection. Dendritic cells (DC) remain the most important antigen-presenting cells for host immune responses, and are capable of either inducing productive immunity or maintaining the state of tolerance to self and non-self antigens. Researchers have recently explored the mechanisms by which DC function is regulated during HCV infection, leading to impaired antiviral T-cell responses and so to persistent viral infection. Recently, DC-based vaccines against HCV have been developed. This review summarizes the current understanding of DC function during HCV infection and explores the prospects of DC-based HCV vaccine. In particular, it describes the biology of DC, the phenotype of DC in HCV-infected patients, the effect of HCV on DC development and function, the studies on new DC-based vaccines against HCV infection, and strategies to improve the efficacy of DC-based vaccines.
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Affiliation(s)
- Yun Zhou
- Centre of Diagnosis and Treatment for Infectious Diseases of Chinese PLA, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China
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Schmidt SV, Nino-Castro AC, Schultze JL. Regulatory dendritic cells: there is more than just immune activation. Front Immunol 2012; 3:274. [PMID: 22969767 PMCID: PMC3432880 DOI: 10.3389/fimmu.2012.00274] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 08/10/2012] [Indexed: 12/11/2022] Open
Abstract
The immune system exists in a delicate equilibrium between inflammatory responses and tolerance. This unique feature allows the immune system to recognize and respond to potential threats in a controlled but normally limited fashion thereby preventing a destructive overreaction against healthy tissues. While the adaptive immune system was the major research focus concerning activation vs. tolerance in the immune system more recent findings suggest that cells of the innate immune system are important players in the decision between effective immunity and induction of tolerance or immune inhibition. Among immune cells of the innate immune system dendritic cells (DCs) have a special function linking innate immune functions with the induction of adaptive immunity. DCs are the primary professional antigen presenting cells (APCs) initiating adaptive immune responses. They belong to the hematopoietic system and arise from CD34(+) stem cells in the bone marrow. Particularly in the murine system two major subgroups of DCs, namely myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) can be distinguished. DCs are important mediators of innate and adaptive immunity mostly due to their remarkable capacity to present processed antigens via major histocompatibility complexes (MHC) to T cells and B cells in secondary lymphoid organs. A large body of literature has been accumulated during the last two decades describing which role DCs play during activation of T cell responses but also during the establishment and maintenance of central tolerance (Steinman et al., 2003). While the concept of peripheral tolerance has been clearly established during the last years, the role of different sets of DCs and their particular molecular mechanisms of immune deviation has not yet fully been appreciated. In this review we summarize accumulating evidence about the role of regulatory DCs in situations where the balance between tolerance and immunogenicity has been altered leading to pathologic conditions such as chronic inflammation or malignancies.
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Affiliation(s)
- Susanne V Schmidt
- Genomics and Immunoregulation, LIMES-Institute, University of Bonn Bonn, Germany
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Burlone ME, Minisini R, Pirisi M. Interferon-stimulated gene pathways in the treatment of viral hepatitis. Future Virol 2012. [DOI: 10.2217/fvl.12.21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Viral hepatitis has been treated empirically for more than 30 years with interferon (IFN)-based therapies, although in the early days of the IFN era, very little was known regarding the mechanisms of action through which IFN acts and the strategies that viruses deploy to escape the antiviral state induced by the activation of the IFN system. Over the years, we have learned how key effector molecules in this system are expressed and interact. On the verge of novel, IFN-free regimens for viral hepatitis, we can take advantage of this huge bulk of research data in order to gain better understanding of how resistance to IFN develops in our patients, to use IFN more effectively in conjunction with other drugs and to devise new treatments.
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Affiliation(s)
- Michela E Burlone
- Dipartimento di Medicina Traslazionale, Università del Piemonte Orientale ‘Amedeo Avogadro’, Novara, Italy
| | - Rosalba Minisini
- Dipartimento di Medicina Traslazionale, Università del Piemonte Orientale ‘Amedeo Avogadro’, Novara, Italy
| | - Mario Pirisi
- Dipartimento di Medicina Traslazionale, Università del Piemonte Orientale ‘Amedeo Avogadro’, Novara, Italy
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Demoulin S, Roncarati P, Delvenne P, Hubert P. Production of large numbers of plasmacytoid dendritic cells with functional activities from CD34(+) hematopoietic progenitor cells: use of interleukin-3. Exp Hematol 2012; 40:268-78. [PMID: 22245566 DOI: 10.1016/j.exphem.2012.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 12/20/2011] [Accepted: 01/03/2012] [Indexed: 12/14/2022]
Abstract
Plasmacytoid dendritic cells (pDC), a subset of dendritic cells characterized by a rapid and massive type-I interferon secretion through the Toll-like receptor pathway in response to viral infection, play important roles in the pathogenesis of several diseases, such as chronic viral infections (e.g., hepatitis C virus, human immunodeficiency virus), autoimmunity (e.g., psoriasis, systemic lupus erythematosus), and cancer. As pDC represent a rare cell type in the peripheral blood, the goal of this study was to develop a new method to efficiently generate large numbers of cells from a limited number of CD34(+) cord blood progenitors to provide a tool to resolve important questions about how pDC mediate tolerance, autoimmunity, and cancer. Human CD34(+) hematopoietic progenitor cells isolated from cord blood were cultured with a combination of Flt3-ligand (Flt3L), thrombopoietin (TPO), and one of the following cytokine: interleukin (IL)-3, interferon-β(IFN-β), or prostaglandin E2(PGE(2)). Cells obtained in the different culture conditions were analyzed for their phenotype and functional characteristics. The addition of IL-3 cooperates with Flt3L and TPO in the induction of pDC from CD34(+) hematopoietic progenitor cells. Indeed, Flt3L/TPO alone or supplemented with prostaglandin E2 or interferon-β produced smaller amounts of pDC from hematopoietic progenitor cells. In addition, pDC generated in Flt3L/TPO/IL-3 cultures exhibited morphological, immunohistochemical, and functional features of peripheral blood pDC. We showed that IL-3, in association with Flt3L and TPO, provides an advantageous tool for large-scale generation of pDC. This culture condition generated, starting from 2 × 10(5) CD34(+) cells, up to 2.6 × 10(6) pDC presenting features of blood pDC.
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Affiliation(s)
- Stéphanie Demoulin
- Laboratory of Experimental Pathology, GIGA-Cancer (Center for Experimental Cancer Research), University of Liege, Liege, Belgium.
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Abstract
The human immune system is under constant challenge from many viruses, some of which the body is successfully able to clear. Other viruses have evolved to escape the host immune responses and thus persist, leading to the development of chronic diseases. Dendritic cells are professional antigen-presenting cells that play a major role in both innate and adaptive immunity against different pathogens. This review focuses on the interaction of different chronic viruses with dendritic cells and the viruses' ability to exploit this critical cell type to their advantage so as to establish persistence within the host.
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Affiliation(s)
- Saifur Rahman
- Department of Microbiology and Immunology, Drexel Institute for Biotechnology and Virology Research, Drexel University College of Medicine, 3805 Old Easton Road, Doylestown, PA 18902, USA
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Kushwah R, Hu J. Complexity of dendritic cell subsets and their function in the host immune system. Immunology 2011; 133:409-19. [PMID: 21627652 DOI: 10.1111/j.1365-2567.2011.03457.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Dendritic cells (DCs) are professional antigen-presenting cells that are critical for induction of adaptive immunity and tolerance. Traditionally DCs have been divided into two discrete subtypes, which comprise conventional and non-conventional DCs. They are distributed across various organs in the body and comprise a heterogeneous population, which has been shown to display differences in terms of surface marker expression, function and origins. Recent studies have shed new light on the process of DC differentiation and distribution of DC subtypes in various organs. Although monocytes, macrophages and DCs share a common macrophage-DC progenitor, a common DC progenitor population has been identified that exclusively gives rise to DCs and not monocytes or macrophages. In this review, we discuss the recent advances in our understanding of DC differentiation and subtypes and provide a comprehensive overview of various DC subtypes with emphasis on their function and origins. Furthermore, in light of recent developments in the field of DC biology, we classify DCs based on the precursor populations from which the various DC subsets originate. We classify DCs derived from common DC progenitor and pre-DC populations as conventional DCs, which includes both migratory and lymphoid-resident DC subsets and classify monocyte-derived DCs and plasmacytoid DCs as non-conventional DCs.
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Affiliation(s)
- Rahul Kushwah
- Physiology and Experimental Medicine Research Program, Hospital for Sick Children, Toronto, ON, Canada
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Dolganiuc A, Szabo G. Dendritic cells in hepatitis C infection: can they (help) win the battle? J Gastroenterol 2011; 46:432-47. [PMID: 21327958 DOI: 10.1007/s00535-011-0377-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 12/13/2010] [Indexed: 02/04/2023]
Abstract
Infection with hepatitis C virus (HCV) is a public health problem; it establishes a chronic course in ~85% of infected patients and increases their risk for developing liver cirrhosis, hepatocellular carcinoma, and significant extrahepatic manifestations. The mechanisms of HCV persistence remain elusive and are largely related to inefficient clearance of the virus by the host immune system. Dendritic cells (DCs) are the most efficient inducers of immune responses; they are capable of triggering productive immunity and maintaining the state of tolerance to self- and non-self antigens. During the past decade, multiple research groups have focused on DCs, in hopes of unraveling an HCV-specific DC signature or DC-dependent mechanisms of antiviral immunity which would lead to a successful HCV elimination strategy. This review incorporates the latest update in the current status of knowledge on the role of DCs in anti-HCV immunity as it relates to several challenging questions: (a) the phenotype and function of diverse DC subsets in HCV-infected patients; (b) the characteristics of non-human HCV infection models from the DCs' point of view; (c) how can in vitro systems, ranging from HCV protein- or peptide-exposed DC to HCV protein-expressing DCs, and in vivo systems, ranging from HCV protein-expressing transgenic mice to HCV-infected non-human primates, be employed to dissect the role of DCs in triggering/maintaining a robust antiviral response; and (d) the prospect of DC-based strategy for managing and finding a cure for HCV infection.
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Affiliation(s)
- Angela Dolganiuc
- Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, LRB-270-H, Worcester, MA 01605, USA.
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Jo J, Lohmann V, Bartenschlager R, Thimme R. Experimental models to study the immunobiology of hepatitis C virus. J Gen Virol 2010; 92:477-93. [PMID: 21148278 DOI: 10.1099/vir.0.027987-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Effective host immune responses are essential for the control of hepatitis C virus (HCV) infection and persistence of HCV has indeed been attributed to their failure. In recent years, several in vitro and in vivo experimental models have allowed studies of host immune responses against HCV. Numerous observations derived from these models have improved our understanding of the mechanisms responsible for the host's ability to clear the virus as well as of the mechanisms responsible for the host's failure to control HCV replication. Importantly, several findings obtained with these model systems have been confirmed in studies of acutely or chronically HCV-infected individuals. Collectively, several mechanisms are used by HCV to escape host immune responses, such as poor induction of the innate immune response and escaping/impairing adaptive immunity. In this review, we summarize current findings from experimental models available for studies of the immune response targeting HCV and discuss the relevance of these findings for the in vivo situation in HCV-infected humans.
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Affiliation(s)
- Juandy Jo
- Department of Medicine II, University Medical Center Freiburg, Germany
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34
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Abstract
The demands that are imposed on the liver as a result of its function as a metabolic organ that extracts nutrients and clears gut-derived microbial products from the blood are met by a unique microanatomical and immunological environment. The inherent tolerogenicity of the liver and its role in the regulation of innate and adaptive immunity are mediated by parenchymal and non-parenchymal antigen-presenting cells (APCs), cell-autonomous molecular pathways and locally produced factors. Here, we review the central role of liver APCs in the regulation of hepatic immune function and also consider how recent insights may be applied in strategies to target liver tolerance for disease therapy.
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Deal EM, Jaimes MC, Crawford SE, Estes MK, Greenberg HB. Rotavirus structural proteins and dsRNA are required for the human primary plasmacytoid dendritic cell IFNalpha response. PLoS Pathog 2010; 6:e1000931. [PMID: 20532161 PMCID: PMC2880586 DOI: 10.1371/journal.ppat.1000931] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 04/28/2010] [Indexed: 12/29/2022] Open
Abstract
Rotaviruses are the leading cause of severe dehydrating diarrhea in children worldwide. Rotavirus-induced immune responses, especially the T and B cell responses, have been extensively characterized; however, little is known about innate immune mechanisms involved in the control of rotavirus infection. Although increased levels of systemic type I interferon (IFNalpha and beta) correlate with accelerated resolution of rotavirus disease, multiple rotavirus strains, including rhesus rotavirus (RRV), have been demonstrated to antagonize type I IFN production in a variety of epithelial and fibroblast cell types through several mechanisms, including degradation of multiple interferon regulatory factors by a viral nonstructural protein. This report demonstrates that stimulation of highly purified primary human peripheral plasmacytoid dendritic cells (pDCs) with either live or inactivated RRV induces substantial IFNalpha production by a subset of pDCs in which RRV does not replicate. Characterization of pDC responses to viral stimulus by flow cytometry and Luminex revealed that RRV replicates in a small subset of human primary pDCs and, in this RRV-permissive small subset, IFNalpha production is diminished. pDC activation and maturation were observed independently of viral replication and were enhanced in cells in which virus replicates. Production of IFNalpha by pDCs following RRV exposure required viral dsRNA and surface proteins, but neither viral replication nor activation by trypsin cleavage of VP4. These results demonstrate that a minor subset of purified primary human peripheral pDCs are permissive to RRV infection, and that pDCs retain functionality following RRV stimulus. Additionally, this study demonstrates trypsin-independent infection of primary peripheral cells by rotavirus, which may allow for the establishment of extraintestinal viremia and antigenemia. Importantly, these data provide the first evidence of IFNalpha induction in primary human pDCs by a dsRNA virus, while simultaneously demonstrating impaired IFNalpha production in primary human cells in which RRV replicates. Rotavirus infection of primary human pDCs provides a powerful experimental system for the study of mechanisms underlying pDC-mediated innate immunity to viral infection and reveals a potentially novel dsRNA-dependent pathway of IFNalpha induction.
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Affiliation(s)
- Emily M. Deal
- Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, United States of America
| | - Maria C. Jaimes
- BD Biosciences, San Jose, California, United States of America
| | - Sue E. Crawford
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Mary K. Estes
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Harry B. Greenberg
- Department of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Medicine, Stanford University School of Medicine, Stanford, California, United States of America
- Veterans Affairs (VA) Palo Alto Health Care System, Palo Alto, California, United States of America
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Aspinall AI, Curbishley SM, Lalor PF, Weston CJ, Blahova M, Liaskou E, Adams RM, Holt AP, Adams DH. CX(3)CR1 and vascular adhesion protein-1-dependent recruitment of CD16(+) monocytes across human liver sinusoidal endothelium. Hepatology 2010; 51:2030-9. [PMID: 20512991 PMCID: PMC2919204 DOI: 10.1002/hep.23591] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
UNLABELLED The liver contains macrophages and myeloid dendritic cells (mDCs) that are critical for the regulation of hepatic inflammation. Most hepatic macrophages and mDCs are derived from monocytes recruited from the blood through poorly understood interactions with hepatic sinusoidal endothelial cells (HSECs). Human CD16(+) monocytes are thought to contain the precursor populations for tissue macrophages and mDCs. We report that CD16(+) cells localize to areas of active inflammation and fibrosis in chronic inflammatory liver disease and that a unique combination of cell surface receptors promotes the transendothelial migration of CD16(+) monocytes through human HSECs under physiological flow. CX(3)CR1 activation was the dominant pertussis-sensitive mechanism controlling transendothelial migration under flow, and expression of the CX(3)CR1 ligand CX(3)CL1 is increased on hepatic sinusoids in chronic inflammatory liver disease. Exposure of CD16(+) monocytes to immobilized purified CX(3)CL1 triggered beta1-integrin-mediated adhesion to vascular cell adhesion molecule-1 and induced the development of a migratory phenotype. Following transmigration or exposure to soluble CX(3)CL1, CD16(+) monocytes rapidly but transiently lost expression of CX(3)CR1. Adhesion and transmigration across HSECs under flow was also dependent on vascular adhesion protein-1 (VAP-1) on the HSECs. CONCLUSION Our data suggest that CD16(+) monocytes are recruited by a combination of adhesive signals involving VAP-1 and CX(3)CR1 mediated integrin-activation. Thus a novel combination of surface molecules, including VAP-1 and CX(3)CL1 promotes the recruitment of CD16(+) monocytes to the liver, allowing them to localize at sites of chronic inflammation and fibrosis.
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Affiliation(s)
| | - Stuart M. Curbishley
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT
| | - Patricia F. Lalor
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT
| | - Chris J. Weston
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT
| | - Miroslava Blahova
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT
| | - Evaggelia Liaskou
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT
| | - Rebecca M Adams
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT
| | - Andrew P. Holt
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT,The Liver Unit, Queen Elizabeth Hospital, Edgbaston, Birmingham, UK
| | - David H. Adams
- Centre for Liver Research and NIHR Biomedical Research Unit, College of Medicine and Dentistry, Division of Immunity and Infection, University of Birmingham, Edgbaston, Birmingham, UK. B15 2TT
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A look behind closed doors: interaction of persistent viruses with dendritic cells. Nat Rev Microbiol 2010; 8:350-60. [PMID: 20372157 DOI: 10.1038/nrmicro2332] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Persistent infections with HIV, hepatitis B virus and hepatitis C virus are major causes of morbidity and mortality worldwide. As sentinels of the immune system, dendritic cells (DCs) are crucial for the generation of protective antiviral immunity. Recent advances in our understanding of the role of DCs during infection with these viruses provide insights into the mechanisms used by these viruses to exploit DC function and evade innate and adaptive immunity. In this Review we highlight the current knowledge about the interaction between DCs and these viruses and the underlying mechanisms that might influence the outcome of viral infections.
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Oo YH, Weston CJ, Lalor PF, Curbishley SM, Withers DR, Reynolds GM, Shetty S, Harki J, Shaw JC, Eksteen B, Hubscher SG, Walker LSK, Adams DH. Distinct roles for CCR4 and CXCR3 in the recruitment and positioning of regulatory T cells in the inflamed human liver. THE JOURNAL OF IMMUNOLOGY 2010; 184:2886-98. [PMID: 20164417 DOI: 10.4049/jimmunol.0901216] [Citation(s) in RCA: 170] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Regulatory T cells (T(regs)) are found at sites of chronic inflammation where they mediate bystander and Ag-specific suppression of local immune responses. However, little is known about the molecular control of T(reg) recruitment into inflamed human tissues. We report that up to 18% of T cells in areas of inflammation in human liver disease are forkhead family transcriptional regulator box P3 (FoxP3)(+) T(regs). We isolated CD4(+)CD25(+)CD127(low)FoxP3(+) T(regs) from chronically inflamed human liver removed at transplantation; compared with blood-derived T(regs), liver-derived T(regs) express high levels of the chemokine receptors CXCR3 and CCR4. In flow-based adhesion assays using human hepatic sinusoidal endothelium, T(regs) used CXCR3 and alpha4beta1 to bind and transmigrate, whereas CCR4 played no role. The CCR4 ligands CCL17 and CCL22 were absent from healthy liver, but they were detected in chronically inflamed liver where their expression was restricted to dendritic cells (DCs) within inflammatory infiltrates. These DCs were closely associated with CD8 T cells and CCR4(+) T(regs) in the parenchyma and septal areas. Ex vivo, liver-derived T(regs) migrated to CCR4 ligands secreted by intrahepatic DCs. We propose that CXCR3 mediates the recruitment of T(regs) via hepatic sinusoidal endothelium and that CCR4 ligands secreted by DCs recruit T(regs) to sites of inflammation in patients with chronic hepatitis. Thus, different chemokine receptors play distinct roles in the recruitment and positioning of T(regs) at sites of hepatitis in chronic liver disease.
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Affiliation(s)
- Ye H Oo
- Centre for Liver Research, Institute of Biomedical Research, The University of Birmingham Medical School, Queen Elizabeth Hospital, Edgbaston, Birmingham, United Kingdom
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Lande R, Gilliet M. Plasmacytoid dendritic cells: key players in the initiation and regulation of immune responses. Ann N Y Acad Sci 2010; 1183:89-103. [DOI: 10.1111/j.1749-6632.2009.05152.x] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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40
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Abstract
Cytokines play an important role in the development of liver inflammatory injury. Various pro-inflammatory and anti-inflammatory cytokines constitute a cytokine network that mediates the development of various liver diseases. In recent years, numerous studies have been carried out on chronic liver diseases such as viral hepatitis, fatty liver, alcoholic liver disease and hepatic cirrhosis. Here, we will review the recent advances in research on the role of cytokines in chronic liver diseases and discuss future prospects in this field.
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Eksteen B, Mora JR, Haughton EL, Henderson NC, Lee–Turner L, Villablanca EJ, Curbishley SM, Aspinall AI, Von Andrian UH, Adams DH. Gut homing receptors on CD8 T cells are retinoic acid dependent and not maintained by liver dendritic or stellate cells. Gastroenterology 2009; 137:320-9. [PMID: 19233184 PMCID: PMC3201985 DOI: 10.1053/j.gastro.2009.02.046] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 01/15/2009] [Accepted: 02/11/2009] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS Lymphocytes primed by intestinal dendritic cells (DC) express the gut-homing receptors CCR9 and alpha4beta7, which recognize CCL25 and mucosal addressin cell-adhesion molecule-1 in the intestine promoting the development of regional immunity. In mice, imprinting of CCR9 and alpha4beta7 is dependent on retinoic acid during T-cell activation. Tissue specificity is lost in primary sclerosing cholangitis (PSC), an extraintestinal manifestation of inflammatory bowel disease, when ectopic expression of mucosal addressin cell-adhesion molecule-1 and CCL25 in the liver promotes recruitment of CCR9+alpha4beta7+ T cells to the liver. We investigated the processes that control enterohepatic T-cell migration and whether the ability to imprint CCR9 and alpha4beta7 is restricted to intestinal DCs or can under some circumstances be acquired by hepatic DCs in diseases such as PSC. METHODS Human and murine DCs from gut, liver, or portal lymph nodes and hepatic stellate cells were used to activate CD8 T cells. Imprinting of CCR9 and alpha4beta7 and functional migration responses were determined. Crossover activation protocols assessed plasticity of gut homing. RESULTS Activation by gut DCs imprinted high levels of functional CCR9 and alpha4beta7 on naïve CD8 T cells, whereas hepatic DCs and stellate cells proved inferior. Imprinting was RA dependent and demonstrated plasticity. CONCLUSIONS Imprinting and plasticity of gut-homing human CD8 T cells requires primary activation or reactivation by gut DCs and is retinoic acid dependent. The inability of liver DCs to imprint gut tropism implies that alpha4beta7+CCR9+ T cell that infiltrate the liver in PSC are primed in the gut.
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Affiliation(s)
- Bertus Eksteen
- Centre for Liver Research, MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Birmingham, United Kingdom
| | - J. Rodrigo Mora
- Gastrointestinal Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - Emma L. Haughton
- Centre for Liver Research, MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Neil C. Henderson
- Centre for Inflammation Research, Queens Medical Research Institute, University of Edinburgh, Edinburgh, Scotland
| | - Laura Lee–Turner
- Centre for Liver Research, MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Birmingham, United Kingdom
| | | | - Stuart M. Curbishley
- Centre for Liver Research, MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Alex I. Aspinall
- Foothills Hospital, University of Calgary, Calgary, Alberta, Canada
| | - Ulrich H. Von Andrian
- Department of Pathology and the Immune Disease Institute, Harvard Medical School, Boston, Massachusetts
| | - David H. Adams
- Centre for Liver Research, MRC Centre for Immune Regulation, Institute for Biomedical Research, Medical School, University of Birmingham, Birmingham, United Kingdom
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42
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Libri NA, Barker SJ, Rosenberg WMC, Semper AE. A class C CpG toll-like receptor 9 agonist successfully induces robust interferon-alpha production by plasmacytoid dendritic cells from patients chronically infected with hepatitis C. J Viral Hepat 2009; 16:315-24. [PMID: 19243499 PMCID: PMC2710800 DOI: 10.1111/j.1365-2893.2008.01011.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Immunomodulators that induce local endogenous interferon-alpha (IFN-alpha) production by plasmacytoid dendritic cells (pDCs) may offer new strategies for the treatment of patients chronically infected with the hepatitis C virus (HCV). However, such an approach may be compromised if reports are true that IFN-alpha production by pDCs from patients with chronic HCV (cHCV) is profoundly impaired. To address the question of pDC dysfunction in cHCV more definitively, in the present study a panel of four prototypic synthetic agonists of toll-like receptor 7 (TLR7) or TLR9 were administered in vitro to pDCs purified from cHCV patients and from normal uninfected donors and their responses compared in terms of not only IFN-alpha production but also the global expression of other cytokines and phenotypic maturation. Plasmacytoid DCs from uninfected donors produced substantial levels of IFN-alpha in response to three of the four agonists and yet only one TLR9 agonist, a class C CpG oligodeoxynucleotide (ODN), induced robust IFN-alpha production by pDCs from cHCV patients. Proinflammatory cytokine production and phenotypic maturation in response to all four agonists was equivalent in infected and uninfected pDCs. These data point to a profound but selective defect in IFN-alpha production by pDCs from cHCV donors. Nonetheless, a class C CpG ODN successfully induced robust IFN-alpha production, suggesting that this class of TLR9 agonist may have utility as a future immunotherapeutic for the treatment of chronic HCV infection.
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Affiliation(s)
- N A Libri
- iQur Ltd, Southampton General HospitalSouthampton, UK
| | - S J Barker
- iQur Ltd, Southampton General HospitalSouthampton, UK,Liver Group, Division of Infection Inflammation and Repair, University of Southampton, Southampton General HospitalSouthampton, UK
| | - W M C Rosenberg
- iQur Ltd, Southampton General HospitalSouthampton, UK,Liver Group, Division of Infection Inflammation and Repair, University of Southampton, Southampton General HospitalSouthampton, UK
| | - A E Semper
- iQur Ltd, Southampton General HospitalSouthampton, UK
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43
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Abstract
Chronic infection with the hepatitis C virus, a noncytopathic hepatotropic RNA virus, affects over 170 million people worldwide. In the majority of cases, neither the early innate immune response nor the later adaptive immune response succeeds in clearing the virus, and the infection becomes chronic. Furthermore, in many patients, the ineffective inflammatory response drives fibrogenesis and the development of cirrhosis. It is critical to understand this immune pathology if preventative and curative therapies are to be developed. Chemokines are a superfamily of small proteins that promote leukocyte migration and orchestrate the immune response to viruses, including hepatitis C virus. Chemokines are crucial for viral elimination, but inappropriate persistence of expression in chronic hepatitis C infection can drive tissue damage and inflammation. Here we review the role of chemokines and their receptors in hepatitis C virus infection.
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Affiliation(s)
- Mathis Heydtmann
- NIHR Biomedical Research Unit for Liver Disease, MRC Centre for Immune Regulation, Institute of Biomedical Research, University of Birmingham, Birmingham, United Kingdom
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44
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HCV and innate immunity. Uirusu 2009; 58:19-26. [PMID: 19122385 DOI: 10.2222/jsv.58.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Hepatitis C virus (HCV) is a single-strand, positive sense RNA virus belonging to the flaviviridae family. HCV develops persistent infection in >70% of infected patients, and eventually causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma in some patients. Once chronic infection is established in patients with HCV, spontaneous viral clearance fails, although how HCV remains persistently infecting the liver is largely unknown. Insufficient immune response, involving antiviral innate immune response including dendritic cells (DCs), has been focused. A number of controversial studies have been reported as to HCV genome replication and HCV-mediated immune responses in human DCs. A tantalizing point of these earlier studies is the lack of the system for viral propagation in HCV. Recently, an in vitro system was exploited to propagate HCV particles using the JFH1 strain. In this review, we review the previous reports about the subversion of innate immunity by HCV and show the innate response of monocyte-derived dendritic cells (MoDCs) against the JFH1 strain. We could not observe HCV direct interaction with MoDC maturation. MoDCs maturated by phagocytosing HCV-infected apoptotic cells containing virus-derived dsRNA, which interacted with TLR3 in the phagosomes. All of these data suggests the importance of TLR3 signal for the induction of anti-HCV innate immunity.
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Plasmacytoid dendritic cells move down on the list of suspects: in search of the immune pathogenesis of chronic hepatitis C. J Hepatol 2008; 49:1069-78. [PMID: 18929418 DOI: 10.1016/j.jhep.2008.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Chronic hepatitis C is a major public health problem. Despite numerous clinical studies in humans and experimental observations made in chimpanzees, hepatitis C pathogenesis remains poorly understood. Here, we review the clinical features of acute and chronic disease, and discuss the role of the immune system in the pathogenesis of disease. Many are aware of the dual role of T cells: responsibility for clearance of the virus during acute phase; and liver injury during chronic phase. Nonetheless, there is an emerging belief that failure to prime HCV-specific T cells is responsible for the failure to spontaneously clear the virus, and possibly, for the lack of response to pegylated-IFNalpha(2a)/ribavirin therapy. We have focused on the latest suspects, plasmacytoid dendritic cells (pDCs), considered to be the professional type I IFNs producing cells. We review the somewhat contradictory data regarding the functional capacity of pDCs in chronic HCV patients and argue that, while lower in relative concentration as compared to healthy individuals, they are not defective in their ability to initiate an innate inflammatory response. Thus, instead of being the culprit, pDCs may in fact represent a novel therapeutic target in order to improve upon existing therapies for treating HCV patients.
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Tokita D, Sumpter TL, Raimondi G, Zahorchak AF, Wang Z, Nakao A, Mazariegos GV, Abe M, Thomson AW. Poor allostimulatory function of liver plasmacytoid DC is associated with pro-apoptotic activity, dependent on regulatory T cells. J Hepatol 2008; 49:1008-18. [PMID: 18926588 PMCID: PMC2631180 DOI: 10.1016/j.jhep.2008.07.028] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 06/20/2008] [Accepted: 07/09/2008] [Indexed: 01/22/2023]
Abstract
BACKGROUND/AIMS The liver is comparatively rich in plasmacytoid (p) dendritic cells (DC), - innate immune effector cells that are also thought to play key roles in the induction and regulation of adaptive immunity. METHODS Liver and spleen pDC were purified from fms-like tyrosine kinase ligand-treated control or lipopolysaccharide-injected C57BL/10 mice. Flow cytometric and molecular biologic assays were used to characterize their function and interaction with naturally occurring regulatory T cells (Treg). RESULTS While IL-10 production was greater for freshly isolated liver compared with splenic pDC, the former produced less bioactive IL-12p70. Moreover, liver pDC expressed a low Delta4/Jagged1 Notch ligand ratio, skewed towards T helper 2 cell differentiation/cytokine production, and promoted allogeneic CD4(+)T cell apoptosis. T cell proliferation in response to liver pDC was, however, enhanced by blocking IL-10 function at the initiation of cultures. In the absence of naturally occurring CD4(+)CD25(+) regulatory T cells, similar levels of T cell proliferation were induced by liver and spleen pDC and the pro-apoptotic activity of liver pDC was reversed. CONCLUSIONS The inferior T cell allostimulatory activity of in vivo-stimulated liver pDC may depend on the presence and function of Treg, a property that may contribute to inherent liver tolerogenicity.
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Affiliation(s)
- Daisuke Tokita
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Tina L. Sumpter
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Giorgio Raimondi
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Alan F. Zahorchak
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Zhiliang Wang
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Atsunori Nakao
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - George V. Mazariegos
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Masanori Abe
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Angus W. Thomson
- Thomas E. Starzl Transplantation Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA,Corresponding author: Dr. Angus W. Thomson, Departments of Surgery and Immunology, University of Pittsburgh School of Medicine, Thomas E. Starzl Transplantation Institute, 200 Lothrop Street, Biomedical Science Tower, W1540, Pittsburgh, PA 15213, Office: (412) 624-6392, Fax: (412) 624-1172,
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Echeverría I, Zabaleta A, Silva L, Díaz-Valdés N, Riezu-Boj JI, Lasarte JJ, Borrás-Cuesta F, Civeira MP, Prieto J, Sarobe P. Monocyte-derived dendritic cells from HCV-infected patients transduced with an adenovirus expressing NS3 are functional when stimulated with the TLR3 ligand poly(I:C). J Viral Hepat 2008; 15:782-9. [PMID: 18637068 DOI: 10.1111/j.1365-2893.2008.01020.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Dendritic cells (DC) transfected with an adenovirus encoding hepatitis C virus (HCV) NS3 protein (AdNS3) induce potent antiviral immune responses when used to immunize mice. However, in HCV infected patients, controversial results have been reported regarding the functional properties of monocyte-derived DC (MoDC), a cell population commonly used in DC vaccination protocols. Thus, with the aim of future vaccination studies we decided to characterize MoDC from HCV patients transfected with AdNS3 and stimulated with the TLR3 ligand poly(I:C). Phenotypic and functional properties of these cells were compared with those from MoDC obtained from uninfected individuals. PCR analysis showed that HCV RNA was negative in MoDC from patients after the culture period. Also, phenotypic analysis of these cells showed lower expression of CD80, CD86, and CD40, but similar expression of HLA-DR molecules as compared to MoDC from uninfected individuals. Functional assays of MoDC obtained from patients and controls showed a similar ability to activate allogeneic lymphocytes or to produce IL-12 and IL-10, although lower IFN-alpha levels were produced by cells from HCV patients after poly(I:C) stimulation. Moreover, both groups of MoDC induced similar profiles of IFN-gamma and IL-5 after stimulation of allogeneic T-cells. Finally, migration assays did not reveal any difference in their ability to respond to CCL21 chemokine. In conclusion, MoDC from HCV patients are functional after transduction with AdNS3 and stimulation with poly(I:C). These findings suggest that these cells may be useful for therapeutic vaccination in chronic HCV infection.
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Affiliation(s)
- I Echeverría
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research (CIMA), Pamplona, Spain
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Abstract
Liver cirrhosis is caused by iterative cycles of tissue injury, inflammation, and repair. Although most causes of acute hepatitis resolve without scarring, chronic hepatitis is associated with persistent inflammation and matrix remodeling, which leads to fibrosis and, eventually, cirrhosis. The mechanisms that govern wound healing involve interactions between the innate and adaptive immune systems and stromal cells within a microenvironment composed of cytokines, growth factors, and modified matricellular proteins. The immune system plays a central role in the regulation of fibrosis, tissue repair, and recovery that is vital for the maintenance of tissue homeostasis. Chronic inflammation and fibrosis are inextricably linked and the cellular interactions between immune effector cells, local fibroblasts, and tissue macrophages at sites of scar formation determine the outcome of liver injury and the development of scarring.
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Affiliation(s)
- Andrew P Holt
- Honorary Clinical Fellow in Hepatology, Liver Research Group, MRC Centre for Immune Regulation, University of Birmingham, Birmingham. U.K
| | - Mike Salmon
- Professor of Experimental Rheumatology, MRC Centre for Immune Regulation, University of Birmingham, UK
| | - Christopher D Buckley
- ARC Professor of Rheumatology, MRC Centre for Immune Regulation, University of Birmingham, UK
| | - David H Adams
- Professor of Hepatology, Liver Research Group, MRC Centre for Immune Regulation, University of Birmingham, Birmingham. U.K
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Hepatitis C virus association with peripheral blood B lymphocytes potentiates viral infection of liver-derived hepatoma cells. Blood 2008; 113:585-93. [PMID: 18838615 DOI: 10.1182/blood-2008-05-158824] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hepatitis C virus (HCV) primarily replicates within the liver, leading to hepatitis, fibrosis, and hepatocellular carcinoma. Infection is also associated with B-cell abnormalities, suggesting an association of the virus with B cells. The infectious JFH-1 strain of HCV can bind primary and immortalized B cells but fails to establish productive infection. However, B cell-associated virus readily infects hepatoma cells, showing an enhanced infectivity compared with extracellular virus. B cells express the viral receptors CD81, SR-BI, and the C-type lectins DC-SIGN and L-SIGN. Antibodies specific for SR-BI and DC-SIGN/L-SIGN reduced B-cell transinfection, supporting a role for these molecules in B-cell association with HCV. Stimulation of B cells with CD40 ligand and interleukin-4 promoted their ability to transinfect hepatoma cells. B cell-associated virus is resistant to trypsin proteolysis and HCV-specific neutralizing antibodies, consistent with particle internalization. HCV promoted the adhesion of primary B cells to Huh-7 hepatomas, providing a mechanism for B-cell retention in the infected liver. In summary, B cells may provide a vehicle for HCV to persist and transmit to the liver.
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50
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Zhang Z, Zou ZS, Fu JL, Cai L, Jin L, Liu YJ, Wang FS. Severe dendritic cell perturbation is actively involved in the pathogenesis of acute-on-chronic hepatitis B liver failure. J Hepatol 2008; 49:396-406. [PMID: 18644645 DOI: 10.1016/j.jhep.2008.05.017] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 05/03/2008] [Accepted: 05/15/2008] [Indexed: 12/15/2022]
Abstract
BACKGROUND/AIMS Functionally impaired dendritic cells (DCs) play important roles in suppressing host immune responses and facilitating viral persistence in chronic hepatitis B virus (HBV) infection. However, little is known regarding the status of intrahepatic DCs in HBV infection. METHODS Based on availability, 11 recipient liver samples were obtained from acute-on-chronic hepatitis B liver failure (ACHBLF) patients who had undergone liver transplantation. The frequencies, phenotypes, and functions of intrahepatic DC subsets were analyzed. RESULTS Both plasmacytoid dendritic cells (pDCs) and myeloid dendritic cells (mDCs) extensively infiltrated the liver of the ACHBLF patients and expressed mature phenotypes therein. In particular, activated hepatic pDCs produced interferon (IFN)-alpha, which subsequently induced interleukin (IL)-12 and IL-10 production via toll-like receptor-9 ligation in liver-infiltrating lymphocytes cultured in vitro. However, blockade of IFN-alpha production significantly reduced the cytokine production of the LILs. Further, a significantly low frequency of peripheral pDCs and highly reduced IFN-alpha production were observed in a large cohort of the ACHBLF patients, particularly in the non-survivors. Moreover, a persistently upregulated expression of hepatic IFN-alpha-associated genes was observed in the ACHBLF patients during disease progression. CONCLUSIONS Activated pDCs accumulated in large numbers in the liver of the ACHBLF patients and regulated local immune responses in chronic HBV infection.
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Affiliation(s)
- Zheng Zhang
- Research Center for Biological Therapy, Beijing Institute of Infectious Diseases, Beijing 302 Hospital, Beijing 100039, China
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