101
|
Wong YC, Tay SS, McCaughan GW, Bowen DG, Bertolino P. Immune outcomes in the liver: Is CD8 T cell fate determined by the environment? J Hepatol 2015; 63:1005-14. [PMID: 26103545 DOI: 10.1016/j.jhep.2015.05.033] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 05/22/2015] [Accepted: 05/26/2015] [Indexed: 02/07/2023]
Abstract
The liver is known for its tolerogenic properties. This unique characteristic is associated with persistent infection of the liver by the hepatitis B and C viruses. Improper activation of cellular adaptive immune responses within the liver and immune exhaustion over time both contribute to ineffective cytotoxic T cell responses to liver-expressed antigens in animal models, and likely play a role in incomplete clearance of chronic hepatitis virus infections in humans. However, under some conditions, functional immune responses can be elicited against hepatic antigens, resulting in control of hepatotropic infections. In order to develop improved therapeutics in immune-mediated chronic liver diseases, including viral hepatitis, it is essential to understand how intrahepatic immunity is regulated. This review focuses on CD8 T cell immunity directed towards foreign antigens expressed in the liver, and explores how the liver environment dictates the outcome of intrahepatic CD8 T cell responses. Potential strategies to rescue unresponsive CD8 T cells in the liver are also discussed.
Collapse
Affiliation(s)
- Yik Chun Wong
- Liver Immunology Group, Centenary Institute and AW Morrow Gastroenterology and Liver Centre, University of Sydney and Royal Prince Alfred Hospital, Sydney, NSW, Australia.
| | - Szun Szun Tay
- Liver Immunology Group, Centenary Institute and AW Morrow Gastroenterology and Liver Centre, University of Sydney and Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Geoffrey W McCaughan
- Liver Cancer and Injury Group, Centenary Institute and AW Morrow Gastroenterology and Liver Centre, University of Sydney and Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - David G Bowen
- Liver Immunology Group, Centenary Institute and AW Morrow Gastroenterology and Liver Centre, University of Sydney and Royal Prince Alfred Hospital, Sydney, NSW, Australia
| | - Patrick Bertolino
- Liver Immunology Group, Centenary Institute and AW Morrow Gastroenterology and Liver Centre, University of Sydney and Royal Prince Alfred Hospital, Sydney, NSW, Australia.
| |
Collapse
|
102
|
Sørensen KK, Simon‐Santamaria J, McCuskey RS, Smedsrød B. Liver Sinusoidal Endothelial Cells. Compr Physiol 2015; 5:1751-74. [DOI: 10.1002/cphy.c140078] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
103
|
Kim KS, Hyun H, Yang JA, Lee MY, Kim H, Yun SH, Choi HS, Hahn SK. Bioimaging of Hyaluronate-Interferon α Conjugates Using a Non-Interfering Zwitterionic Fluorophore. Biomacromolecules 2015; 16:3054-61. [PMID: 26258264 DOI: 10.1021/acs.biomac.5b00933] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We conducted real-time bioimaging of the hyaluronate-interferon α (HA-IFNα) conjugate using a biologically inert zwitterionic fluorophore of ZW800-1 for the treatment of hepatitis C virus (HCV) infection. ZW800-1 was labeled on the IFNα molecule of the HA-IFNα conjugate to investigate its biodistribution and clearance without altering its physicochemical and targeting characteristics. Confocal microscopy clearly visualized the effective in vitro cellular uptake of the HA-IFNα conjugate to HepG2 cells. After verifying the biological activity in Daudi cells, we conducted the pharmacokinetic analysis of the HA-IFNα conjugate, which confirmed its target-specific delivery to the liver with a prolonged residence time longer than that of PEGylated IFNα. In vivo and ex vivo bioimaging of the ZW800-1-labeled HA-IFNα conjugate directly showed real-time biodistribution and clearance of the conjugate that are consistent with the biological behaviors analyzed by an enzyme-linked immunosorbent assay. Furthermore, the elevated level of OAS1 mRNA in the liver confirmed in vivo antiviral activity of HA-IFNα conjugates. With the data taken together, we could confirm the feasibility of ZW800-1 as a biologically inert fluorophore and target-specific HA-IFNα conjugate for the treatment of HCV infection.
Collapse
Affiliation(s)
- Ki Su Kim
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School , 65 Landsdowne Street, Cambridge, Massachusetts 02139, United States
| | - Hoon Hyun
- Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School , 330 Brookline Avenue, Boston, Massachusetts 02215, United States.,Department of Biomedical Science, Chonnam National University Medical School , 160 Baekseo-ro, Dong-gu, Gwangju 501-746, Korea
| | - Jeong-A Yang
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH) , 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk 790-784, Korea
| | - Min Young Lee
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH) , 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk 790-784, Korea
| | - Hyemin Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH) , 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk 790-784, Korea
| | - Seok-Hyun Yun
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School , 65 Landsdowne Street, Cambridge, Massachusetts 02139, United States
| | - Hak Soo Choi
- Division of Hematology/Oncology, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School , 330 Brookline Avenue, Boston, Massachusetts 02215, United States
| | - Sei Kwang Hahn
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School , 65 Landsdowne Street, Cambridge, Massachusetts 02139, United States.,Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH) , 77 Cheongam-ro, Nam-gu, Pohang, Kyungbuk 790-784, Korea
| |
Collapse
|
104
|
Inverso D, Iannacone M. Spatiotemporal dynamics of effector CD8+ T cell responses within the liver. J Leukoc Biol 2015; 99:51-5. [PMID: 26188075 DOI: 10.1189/jlb.4mr0415-150r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/26/2015] [Indexed: 01/12/2023] Open
Abstract
CD8(+) T cells play a critical role in controlling hepatotropic viral infections, such as those caused by hepatitis B and hepatitis C viruses. The capacity of these cells to protect against such pathogens is mediated by antigen-experienced effector cells and relies on their ability to home to the liver, recognize pathogen-derived antigens, and deploy effector functions. Here, we review how dynamic imaging of hepatic effector CD8(+) T cell migration and function in mouse models of hepatitis B virus pathogenesis has recently revealed a unique and novel mode of adaptive immune surveillance. Circulating effector CD8(+) T cells initially arrest within liver sinusoids by docking onto adherent platelets and then actively crawl along the liver vasculature, probing hepatocytes for the presence of antigens by extending protrusions through the fenestrated sinusoidal endothelial cells. Hepatocellular antigen recognition and effector functions occur while CD8(+) T cells are still confined to the intravascular space and are inhibited by the pathologic processes that characterize liver fibrosis. A detailed understanding of the spatiotemporal dynamics of effector CD8(+) T cells within the liver is important for the rational design of targeted immunotherapeutic approaches for chronic liver infections.
Collapse
Affiliation(s)
- Donato Inverso
- Division of Immunology, Transplantation and Infectious Diseases, and Experimental Imaging Center, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy
| | - Matteo Iannacone
- Division of Immunology, Transplantation and Infectious Diseases, and Experimental Imaging Center, Istituto di Ricovero e Cura a Carattere Scientifico San Raffaele Scientific Institute and Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
105
|
Frevert U, Krzych U. Plasmodium cellular effector mechanisms and the hepatic microenvironment. Front Microbiol 2015; 6:482. [PMID: 26074888 PMCID: PMC4445044 DOI: 10.3389/fmicb.2015.00482] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/01/2015] [Indexed: 12/23/2022] Open
Abstract
Plasmodium falciparum malaria remains one of the most serious health problems globally. Immunization with attenuated parasites elicits multiple cellular effector mechanisms capable of eliminating Plasmodium liver stages. However, malaria liver stage (LS) immunity is complex and the mechanisms effector T cells use to locate the few infected hepatocytes in the large liver in order to kill the intracellular LS parasites remain a mystery to date. Here, we review our current knowledge on the behavior of CD8 effector T cells in the hepatic microvasculature, in malaria and other hepatic infections. Taking into account the unique immunological and lymphogenic properties of the liver, we discuss whether classical granule-mediated cytotoxicity might eliminate infected hepatocytes via direct cell contact or whether cytokines might operate without cell–cell contact and kill Plasmodium LSs at a distance. A thorough understanding of the cellular effector mechanisms that lead to parasite death hence sterile protection is a prerequisite for the development of a successful malaria vaccine to protect the 40% of the world’s population currently at risk of Plasmodium infection.
Collapse
Affiliation(s)
- Ute Frevert
- Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine , New York, NY, USA
| | - Urszula Krzych
- Division of Malaria Vaccine Development, Department of Cellular Immunology, Walter Reed Army Institute of Research , Silver Spring, MD, USA
| |
Collapse
|
106
|
Abstract
PURPOSE OF REVIEW Aging is a condition in which a person gradually loses the ability to maintain homeostasis, due to structural alteration or dysfunction. Aging is a major risk factor for most chronic diseases. As the liver has a remarkable ability to regenerate, this review assessed the effect of aging on clinical liver disease with references to preclinical models when relevant to pathogenesis. RECENT FINDINGS Aging has been shown to not only enhance vulnerability to acute liver injury but also increase susceptibility of the fibrotic response. Aging is associated with the severity and poor prognosis of various liver diseases including nonalcoholic fatty liver disease, alcoholic liver disease, hepatitis C, and liver transplantation. SUMMARY Treatment of older patients with liver disease may require different or longer interventions. Transplantation of an older liver will be less tolerant of subsequent injury. Future studies are needed to understand more about the molecular mechanism of aging and contribute to the development of a noble treatment strategy that can block the progression of aging-induced liver diseases.
Collapse
|
107
|
Iannacone M. Hepatic effector CD8(+) T-cell dynamics. Cell Mol Immunol 2015; 12:269-72. [PMID: 25242274 PMCID: PMC4654318 DOI: 10.1038/cmi.2014.78] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 07/25/2014] [Accepted: 07/26/2014] [Indexed: 12/11/2022] Open
Abstract
CD8(+) T cells play a critical role in hepatitis B virus (HBV) pathogenesis. During acute, self-limited infections, these cells are instrumental to viral clearance; in chronic settings, they sustain repetitive cycles of hepatocellular necrosis that promote hepatocellular carcinoma development. Both CD8(+) T-cell defensive and destructive functions are mediated by antigen-experienced effector cells and depend on the ability of these cells to migrate to the liver, recognize hepatocellular antigens and perform effector functions. Understanding the signals that modulate the spatiotemporal dynamics of CD8(+) T cells in the liver, particularly in the context of antigen recognition, is therefore critical to gaining insight into the pathogenesis of acute and chronic HBV infection. Here, we highlight recent data on how effector CD8(+) T cells traffic within the liver, and we discuss the potential for novel imaging techniques to shed light on this important aspect of HBV pathogenesis.
Collapse
|
108
|
Guidotti LG, Inverso D, Sironi L, Di Lucia P, Fioravanti J, Ganzer L, Fiocchi A, Vacca M, Aiolfi R, Sammicheli S, Mainetti M, Cataudella T, Raimondi A, Gonzalez-Aseguinolaza G, Protzer U, Ruggeri ZM, Chisari FV, Isogawa M, Sitia G, Iannacone M. Immunosurveillance of the liver by intravascular effector CD8(+) T cells. Cell 2015; 161:486-500. [PMID: 25892224 DOI: 10.1016/j.cell.2015.03.005] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 12/18/2014] [Accepted: 02/24/2015] [Indexed: 02/06/2023]
Abstract
Effector CD8(+) T cells (CD8 TE) play a key role during hepatotropic viral infections. Here, we used advanced imaging in mouse models of hepatitis B virus (HBV) pathogenesis to understand the mechanisms whereby these cells home to the liver, recognize antigens, and deploy effector functions. We show that circulating CD8 TE arrest within liver sinusoids by docking onto platelets previously adhered to sinusoidal hyaluronan via CD44. After the initial arrest, CD8 TE actively crawl along liver sinusoids and probe sub-sinusoidal hepatocytes for the presence of antigens by extending cytoplasmic protrusions through endothelial fenestrae. Hepatocellular antigen recognition triggers effector functions in a diapedesis-independent manner and is inhibited by the processes of sinusoidal defenestration and capillarization that characterize liver fibrosis. These findings reveal the dynamic behavior whereby CD8 TE control hepatotropic pathogens and suggest how liver fibrosis might reduce CD8 TE immune surveillance toward infected or transformed hepatocytes.
Collapse
Affiliation(s)
- Luca G Guidotti
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Donato Inverso
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Laura Sironi
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; Department of Physics, University of Milano Bicocca, 20126 Milan, Italy
| | - Pietro Di Lucia
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Jessica Fioravanti
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Lucia Ganzer
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; Department of Physics, University of Milano Bicocca, 20126 Milan, Italy
| | - Amleto Fiocchi
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Maurizio Vacca
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Roberto Aiolfi
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; Vita-Salute San Raffaele University, 20132 Milan, Italy
| | - Stefano Sammicheli
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Marta Mainetti
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Tiziana Cataudella
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Andrea Raimondi
- Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | | | - Ulrike Protzer
- Institute of Virology, Technical University of Munich, 81675 Munich, Germany
| | - Zaverio M Ruggeri
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Francis V Chisari
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Masanori Isogawa
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Giovanni Sitia
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Matteo Iannacone
- Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; Vita-Salute San Raffaele University, 20132 Milan, Italy; Experimental Imaging Center, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy.
| |
Collapse
|
109
|
Restoration of responsiveness of phospholipase Cγ2-deficient platelets by enforced expression of phospholipase Cγ1. PLoS One 2015; 10:e0119739. [PMID: 25793864 PMCID: PMC4368822 DOI: 10.1371/journal.pone.0119739] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 01/15/2015] [Indexed: 01/21/2023] Open
Abstract
Receptor-mediated platelet activation requires phospholipase C (PLC) activity to elevate intracellular calcium and induce actin cytoskeleton reorganization. PLCs are classified into structurally distinct β, γ, δ, ε, ζ, and η isoforms. There are two PLCγ isoforms (PLCγ1, PLCγ2), which are critical for activation by tyrosine kinase-dependent receptors. Platelets express both PLCγ1 and PLCγ2. Although PLCγ2 has been shown to play a dominant role in platelet activation, the extent to which PLCγ1 contributes has not been evaluated. To ascertain the relative contributions of PLCγ1 and PLCγ2 to platelet activation, we generated conditionally PLCγ1-deficient, wild-type (WT), PLCγ2-deficient, and PLCγ1/PLCγ2 double-deficient mice and measured the ability of platelets to respond to different agonists. We found that PLCγ2 deficiency abrogated αIIbβ3-dependent platelet spreading, GPVI-dependent platelet aggregation, and thrombus formation on collagen-coated surfaces under shear conditions, which is dependent on both GPVI and αIIbβ3. Addition of exogenous ADP overcame defective spreading of PLCγ2-deficient platelets on immobilized fibrinogen, suggesting that PLCγ2 is required for granule secretion in response to αIIbβ3 ligation. Consistently, αIIbβ3-mediated release of granule contents was impaired in the absence of PLCγ2. In contrast, PLCγ1-deficient platelets spread and released granule contents normally on fibrinogen, exhibited normal levels of GPVI-dependent aggregation, and formed thrombi normally on collagen-coated surfaces. Interestingly, enforced expression of PLCγ1 fully restored GPVI-dependent aggregation and αIIbβ3-dependent spreading of PLCγ2-deficient platelets. We conclude that platelet activation through GPVI and αIIbβ3 utilizes PLCγ2 because PLCγ1 levels are insufficient to support responsiveness, but that PLCγ1 can restore responsiveness if expressed at levels normally achieved by PLCγ2.
Collapse
|
110
|
Bertolino P, Bowen DG. Malaria and the liver: immunological hide-and-seek or subversion of immunity from within? Front Microbiol 2015; 6:41. [PMID: 25741320 PMCID: PMC4332352 DOI: 10.3389/fmicb.2015.00041] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/12/2015] [Indexed: 12/28/2022] Open
Abstract
During the pre-erythrocytic asymptomatic phase of malarial infection, sporozoites develop transiently inside less than 100 hepatocytes that subsequently release thousands of merozoites. Killing of these hepatocytes by cytotoxic T cells (CTLs) confers protection to subsequent malarial infection, suggesting that this bottleneck phase in the parasite life cycle can be targeted by vaccination. During natural transmission, although some CTLs are generated in the skin draining lymph nodes, they are unable to eliminate the parasite, suggesting that the liver is important for the sporozoite to escape immune surveillance. The contribution of the organ to this process is unclear. Based on the known ability of several hepatic antigen-presenting cells (APCs) to induce primary activation of CD8 T cells and tolerance, malarial antigens presented by both infected hepatocytes and/or hepatic cross-presenting APCs should result in tolerance. However, our latest model predicts that due to the low frequency of infected hepatocytes, some T cells recognizing sporozoite epitopes with high affinity should differentiate into CTLs. In this review, we discuss two possible models to explain why CTLs generated in the liver and skin draining lymph nodes are unable to eliminate the parasite: (1) sporozoites harness the tolerogenic property of the liver; (2) CTLs are not tolerized but fail to detect infected cells due to sparse infection of hepatocytes and the very short liver stage. We propose that while malaria sporozoites might use the ability of the liver to tolerize both naive and effector cells, they have also developed strategies to decrease the probability of encounter between CTLs and infected liver cells. Thus, we predict that to achieve protection, vaccination strategies should aim to boost intrahepatic activation and/or increase the chance of encounter between sporozoite-specific CTLs and infected hepatocytes.
Collapse
Affiliation(s)
- Patrick Bertolino
- Liver Immunology Group, Centenary Institute and AW Morrow Gastroenterology and Liver Centre, University of Sydney and Royal Prince Alfred Hospital Sydney, NSW, Australia
| | - David G Bowen
- Liver Immunology Group, Centenary Institute and AW Morrow Gastroenterology and Liver Centre, University of Sydney and Royal Prince Alfred Hospital Sydney, NSW, Australia
| |
Collapse
|
111
|
Salvadori M, Bertoni E. What's new in clinical solid organ transplantation by 2013. World J Transplant 2014; 4:243-66. [PMID: 25540734 PMCID: PMC4274595 DOI: 10.5500/wjt.v4.i4.243] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 07/11/2014] [Accepted: 07/27/2014] [Indexed: 02/05/2023] Open
Abstract
Innovative and exciting advances in the clinical science in solid organ transplantation continuously realize as the results of studies, clinical trials, international conferences, consensus conferences, new technologies and discoveries. This review will address to the full spectrum of news in transplantation, that verified by 2013. The key areas covered are the transplantation activity, with particular regards to the donors, the news for solid organs such as kidney, pancreas, liver, heart and lung, the news in immunosuppressive therapies, the news in the field of tolerance and some of the main complications following transplantation as infections and cancers. The period of time covered by the study starts from the international meetings held in 2012, whose results were published in 2013, up to the 2013 meetings, conferences and consensus published in the first months of 2014. In particular for every organ, the trends in numbers and survival have been reviewed as well as the most relevant problems such as organ preservation, ischemia reperfusion injuries, and rejections with particular regards to the antibody mediated rejection that involves all solid organs. The new drugs and strategies applied in organ transplantation have been divided into new way of using old drugs or strategies and drugs new not yet on the market, but on phase Ito III of clinical studies and trials.
Collapse
|
112
|
Apicobasal polarity controls lymphocyte adhesion to hepatic epithelial cells. Cell Rep 2014; 8:1879-1893. [PMID: 25242329 DOI: 10.1016/j.celrep.2014.08.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 06/25/2014] [Accepted: 08/04/2014] [Indexed: 02/08/2023] Open
Abstract
Loss of apicobasal polarity is a hallmark of epithelial pathologies. Leukocyte infiltration and crosstalk with dysfunctional epithelial barriers are crucial for the inflammatory response. Here, we show that apicobasal architecture regulates the adhesion between hepatic epithelial cells and lymphocytes. Polarized hepatocytes and epithelium from bile ducts segregate the intercellular adhesion molecule 1 (ICAM-1) adhesion receptor onto their apical, microvilli-rich membranes, which are less accessible by circulating immune cells. Upon cell depolarization, hepatic ICAM-1 becomes exposed and increases lymphocyte binding. Polarized hepatic cells prevent ICAM-1 exposure to lymphocytes by redirecting basolateral ICAM-1 to apical domains. Loss of ICAM-1 polarity occurs in human inflammatory liver diseases and can be induced by the inflammatory cytokine tumor necrosis factor alpha (TNF-α). We propose that adhesion receptor polarization is a parenchymal immune checkpoint that allows functional epithelium to hamper leukocyte binding. This contributes to the haptotactic guidance of leukocytes toward neighboring damaged or chronically inflamed epithelial cells that expose their adhesion machinery.
Collapse
|
113
|
Smith CJ, Turula H, Snyder CM. Systemic hematogenous maintenance of memory inflation by MCMV infection. PLoS Pathog 2014; 10:e1004233. [PMID: 24992722 PMCID: PMC4081724 DOI: 10.1371/journal.ppat.1004233] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 05/20/2014] [Indexed: 12/02/2022] Open
Abstract
Several low-grade persistent viral infections induce and sustain very large numbers of virus-specific effector T cells. This was first described as a response to cytomegalovirus (CMV), a herpesvirus that establishes a life-long persistent/latent infection, and sustains the largest known effector T cell populations in healthy people. These T cells remain functional and traffic systemically, which has led to the recent exploration of CMV as a persistent vaccine vector. However, the maintenance of this remarkable response is not understood. Current models propose that reservoirs of viral antigen and/or latently infected cells in lymph nodes stimulate T cell proliferation and effector differentiation, followed by migration of progeny to non-lymphoid tissues where they control CMV reactivation. We tested this model using murine CMV (MCMV), a natural mouse pathogen and homologue of human CMV (HCMV). While T cells within draining lymph nodes divided at a higher rate than cells elsewhere, antigen-dependent proliferation of MCMV-specific effector T cells was observed systemically. Strikingly, inhibition of T cell egress from lymph nodes failed to eliminate systemic T cell division, and did not prevent the maintenance of the inflationary populations. In fact, we found that the vast majority of inflationary cells, including most cells undergoing antigen-driven division, had not migrated into the parenchyma of non-lymphoid tissues but were instead exposed to the blood supply. Indeed, the immunodominance and effector phenotype of inflationary cells, both of which are primary hallmarks of memory inflation, were largely confined to blood-localized T cells. Together these results support a new model of MCMV-driven memory inflation in which most immune surveillance occurs in circulation, and in which most inflationary effector T cells are produced in response to viral antigen presented by cells that are accessible to the blood supply. Herpesviruses persist for the life of the host and must be continuously controlled by a robust immune surveillance effort. In the case of the cytomegalovirus (CMV), this ongoing immune surveillance promotes the accumulation of CMV-specific T cells in a process known as “memory inflation”. We and others have proposed that the ability to induce memory inflation may be an important benefit of CMV-based vaccine vectors that persist within the host and continuously boost the immune response. However, it has been difficult to determine where T cells are encountering CMV in the body, leading to many unanswered questions about the maintenance of this remarkable response. Previous models proposed that T cells encountered viral antigen within lymph nodes and then migrated to other tissues to prevent CMV reactivation. However, we found that the majority of T cells stimulated by CMV were present in circulation, where they could be sustained without the input from T cells localized to lymph nodes. In fact, two of the defining features of memory inflation - inflated numbers and an effector phenotype - were restricted to cells that were exposed to the blood. Thus, we propose that memory inflation during CMV infection is largely the result of immune surveillance that occurs in circulation.
Collapse
Affiliation(s)
- Corinne J. Smith
- Department of Microbiology and Immunology, Jefferson Medical College, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Holly Turula
- Department of Microbiology and Immunology, Jefferson Medical College, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
| | - Christopher M. Snyder
- Department of Microbiology and Immunology, Jefferson Medical College, Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
114
|
Burghardt S, Claass B, Erhardt A, Karimi K, Tiegs G. Hepatocytes induce Foxp3⁺ regulatory T cells by Notch signaling. J Leukoc Biol 2014; 96:571-7. [PMID: 24970859 DOI: 10.1189/jlb.2ab0613-342rr] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The liver plays a pivotal role in maintaining immunological tolerance, although the exact molecular mechanism is still largely unknown. The induction of systemic tolerance by liver resident APCs has been attributed to peripheral deletion and to the induction of Tregs. HCs, the parenchymal cells in the liver, could function as nonprofessional APCs and interact and establish cell-cell contact with T lymphocytes. We hypothesized that HCs from healthy or regenerated livers may contribute to induction of functional Tregs. Here, we show that murine HCs induced Foxp3(+) Tregs within CD4(+) T cells in vitro, which increased in the presence of TGF-β. Interestingly, a further Foxp3(+) Treg expansion was observed if HCs were isolated from regenerated livers. Additionally, the induction of Foxp3(+) Tregs was associated with the Notch signaling pathway, as the ability of HCs to enhance Foxp3 was abolished by γ-secretase inhibition. Furthermore, HC-iTregs showed ability to suppress the proliferative response of CD4(+) T cells to anti-CD3 stimulation in vitro. Thus, HCs may play a pivotal role in the induction of tolerance via Notch-mediated conversion of CD4(+) T cells into Foxp3(+) Tregs upon TCR stimulation.
Collapse
Affiliation(s)
- Sven Burghardt
- Institute of Experimental Immunology and Hepatology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Benjamin Claass
- Institute of Experimental Immunology and Hepatology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Annette Erhardt
- Institute of Experimental Immunology and Hepatology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Khalil Karimi
- Institute of Experimental Immunology and Hepatology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Gisa Tiegs
- Institute of Experimental Immunology and Hepatology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| |
Collapse
|
115
|
Frevert U, Nacer A. Immunobiology of Plasmodium in liver and brain. Parasite Immunol 2014; 35:267-82. [PMID: 23631610 DOI: 10.1111/pim.12039] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Accepted: 04/17/2013] [Indexed: 12/11/2022]
Abstract
Malaria remains one of the most serious health problems globally, but our understanding of the biology of the parasite and the pathogenesis of severe disease is still limited. Multiple cellular effector mechanisms that mediate parasite elimination from the liver have been described, but how effector cells use classical granule-mediated cytotoxicity to attack infected hepatocytes and how cytokines and chemokines spread via the unique fluid pathways of the liver to reach the parasites over considerable distances remains unknown. Similarly, a wealth of information on cerebral malaria (CM), one of the most severe manifestations of the disease, was gained from post-mortem analyses of human brain and murine disease models, but the cellular processes that ultimately cause disease are not fully understood. Here, we discuss how imaging of the local dynamics of parasite infection and host response as well as consideration of anatomical and physiological features of liver and brain can provide a better understanding of the initial asymptomatic hepatic phase of the infection and the cascade of events leading to CM. Given the increasing drug resistance of both parasite and vector and the unavailability of a protective vaccine, the urgency to reduce the tremendous morbidity and mortality associated with severe malaria is obvious.
Collapse
Affiliation(s)
- U Frevert
- Division of Medical Parasitology, Department of Microbiology, New York University School of Medicine, New York, NY 10010, USA.
| | | |
Collapse
|
116
|
Abstract
The liver is the largest organ in the body and is generally regarded by nonimmunologists as having little or no lymphoid function. However, such is far from accurate. This review highlights the importance of the liver as a lymphoid organ. Firstly, we discuss experimental data surrounding the role of liver as a lymphoid organ. The liver facilitates tolerance rather than immunoreactivity, which protects the host from antigenic overload of dietary components and drugs derived from the gut and it is instrumental to fetal immune tolerance. Loss of liver tolerance leads to autoaggressive phenomena, which if not controlled by regulatory lymphoid populations, may lead to the induction of autoimmune liver diseases. Liver-related lymphoid subpopulations also act as critical antigen-presenting cells. The study of the immunological properties of liver and delineation of the microenvironment of the intrahepatic milieu in normal and diseased livers provides a platform to understand the hierarchy of a series of detrimental events that lead to immune-mediated destruction of the liver and the rejection of liver allografts. The majority of emphasis within this review will be on the normal mononuclear cell composition of the liver. However, within this context, we will discuss selected, but not all, immune-mediated liver disease and attempt to place these data in the context of human autoimmunity.
Collapse
Affiliation(s)
- Dimitrios P Bogdanos
- Institute of Liver Studies, Transplantation Immunology and Mucosal Biology, King's College London School of Medicine at King's College Hospital, London, UK
| | | | | |
Collapse
|
117
|
Burghardt S, Erhardt A, Claass B, Huber S, Adler G, Jacobs T, Chalaris A, Schmidt-Arras D, Rose-John S, Karimi K, Tiegs G. Hepatocytes contribute to immune regulation in the liver by activation of the Notch signaling pathway in T cells. THE JOURNAL OF IMMUNOLOGY 2013; 191:5574-82. [PMID: 24140644 DOI: 10.4049/jimmunol.1300826] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The "liver tolerance effect" has been attributed to a unique potential of liver-resident nonprofessional APCs including hepatocytes (HCs) to suppress T cell responses. The exact molecular mechanism of T cell suppression by liver APCs is still largely unknown. In mice, IL-10-dependent T cell suppression is observed after Th1-mediated hepatitis induced by Con A. In this study, we show that HCs, particularly those from regenerating livers of Con A-pretreated mice, induced a regulatory phenotype in naive CD4(+) T cells in vitro. Using reporter mice, we observed that these T regulatory cells released substantial amounts of IL-10, produced IFN-γ, failed to express Foxp3, but suppressed proliferation of responder T cells upon restimulation with anti-CD3 mAb. Hence, these regulatory cells feature a similar phenotype as the recently described IL-10-producing Th1 cells, which are generated upon activation of Notch signaling. Indeed, inhibition of γ-secretase and a disintegrin and metalloproteinase 17 but not a disintegrin and metalloproteinase 10, respectively, which blocked Notch activation, prevented IL-10 secretion. HCs from Con A-pretreated mice showed enhanced expression of the Notch ligand Jagged1 and significantly increased receptor density of Notch1 on CD4(+) T cells. However, HCs from Con A-pretreated IFN regulatory factor 1(-/-) mice, which cannot respond to IFN-γ, as well as those from IFN-γ(-/-) mice failed to augment IL-10 production by CD4(+) T cells. In conclusion, it seems that HCs fine-tune liver inflammation by upregulation of Jagged1 and activation of Notch signaling in Th1 cells. This mechanism might be of particular importance in the regenerating liver subsequent to Th1-mediated hepatitis.
Collapse
Affiliation(s)
- Sven Burghardt
- Institute of Experimental Immunology and Hepatology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
118
|
Wu SL, Pan CE. Tolerance and chimerism and allogeneic bone marrow/stem cell transplantation in liver transplantation. World J Gastroenterol 2013; 19:5981-7. [PMID: 24106398 PMCID: PMC3785619 DOI: 10.3748/wjg.v19.i36.5981] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 06/05/2013] [Accepted: 07/18/2013] [Indexed: 02/06/2023] Open
Abstract
The liver has particular tolerogenic properties that allow its spontaneous acceptance in some animal species. Liver structure is considered to favor a tolerogenic environment. The peripheral tolerance mechanisms also play a role in spontaneous tolerance to liver graft. In a clinical setting, the main challenge nowadays facing liver transplantation is minimization of immunosuppression with the goal of donor-specific tolerance. Mechanisms involved in tolerance to transplanted organs are complex and partly unknown. A significant mechanism in tolerance induction is chimerism. Chimerism can be induced through transplantation of allogeneic donor bone marrow/stem cells under appropriate host conditioning. This review focuses on the tolerance mechanisms in liver transplantation and highlights the role of chimerism and allogeneic bone marrow/stem cell transplantation in tolerance development.
Collapse
|
119
|
Jenne CN, Kubes P. Immune surveillance by the liver. Nat Immunol 2013; 14:996-1006. [PMID: 24048121 DOI: 10.1038/ni.2691] [Citation(s) in RCA: 719] [Impact Index Per Article: 65.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/22/2013] [Indexed: 12/11/2022]
Abstract
Receiving both portal vein blood and arterial blood, the liver is an important and critical component in the defense against blood-borne infection. To accomplish this role, the liver contains numerous innate and adaptive immune cells that specialize in detection and capture of pathogens from the blood. Further, these immune cells participate in coordinated immune responses leading to pathogen clearance, leukocyte recruitment and antigen presentation to lymphocytes within the vasculature. Finally, this role in host defense must be tightly regulated to ensure that inappropriate immune responses are not raised against nonpathogenic exogenous blood-borne molecules, such as those derived from food. It is this balance between activation and tolerance that characterizes the liver as a frontline immunological organ.
Collapse
Affiliation(s)
- Craig N Jenne
- 1] Calvin, Phoebe & Joan Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, Canada. [2] Department of Critical Care Medicine, University of Calgary, Calgary, Alberta, Canada
| | | |
Collapse
|
120
|
Cogger VC, Roessner U, Warren A, Fraser R, Le Couteur DG. A Sieve-Raft Hypothesis for the regulation of endothelial fenestrations. Comput Struct Biotechnol J 2013; 8:e201308003. [PMID: 24688743 PMCID: PMC3962122 DOI: 10.5936/csbj.201308003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/31/2013] [Accepted: 08/11/2013] [Indexed: 01/13/2023] Open
Affiliation(s)
- Victoria C Cogger
- Centre for Education and Research on Ageing and ANZAC Research Institute, Concord Hospital and University of Sydney, Sydney NSW, Australia ; Charles Perkins Centre, University of Sydney NSW Australia
| | - Ute Roessner
- Metabolomics Australia and Australian Centre for Plant Functional Genomics, The University of Melbourne, 3010 Victoria, Australia
| | - Alessandra Warren
- Centre for Education and Research on Ageing and ANZAC Research Institute, Concord Hospital and University of Sydney, Sydney NSW, Australia ; Charles Perkins Centre, University of Sydney NSW Australia
| | - Robin Fraser
- Christchurch School of Medicine, University of Otago, Christchurch NZ
| | - David G Le Couteur
- Centre for Education and Research on Ageing and ANZAC Research Institute, Concord Hospital and University of Sydney, Sydney NSW, Australia ; Charles Perkins Centre, University of Sydney NSW Australia
| |
Collapse
|
121
|
Isogawa M, Chung J, Murata Y, Kakimi K, Chisari FV. CD40 activation rescues antiviral CD8⁺ T cells from PD-1-mediated exhaustion. PLoS Pathog 2013; 9:e1003490. [PMID: 23853599 PMCID: PMC3708877 DOI: 10.1371/journal.ppat.1003490] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/28/2013] [Indexed: 02/07/2023] Open
Abstract
The intrahepatic immune environment is normally biased towards tolerance. Nonetheless, effective antiviral immune responses can be induced against hepatotropic pathogens. To examine the immunological basis of this paradox we studied the ability of hepatocellularly expressed hepatitis B virus (HBV) to activate immunologically naïve HBV-specific CD8+ T cell receptor (TCR) transgenic T cells after adoptive transfer to HBV transgenic mice. Intrahepatic priming triggered vigorous in situ T cell proliferation but failed to induce interferon gamma production or cytolytic effector function. In contrast, the same T cells differentiated into cytolytic effector T cells in HBV transgenic mice if Programmed Death 1 (PD-1) expression was genetically ablated, suggesting that intrahepatic antigen presentation per se triggers negative regulatory signals that prevent the functional differentiation of naïve CD8+ T cells. Surprisingly, coadministration of an agonistic anti-CD40 antibody (αCD40) inhibited PD-1 induction and restored T cell effector function, thereby inhibiting viral gene expression and causing a necroinflammatory liver disease. Importantly, the depletion of myeloid dendritic cells (mDCs) strongly diminished the αCD40 mediated functional differentiation of HBV-specific CD8+ T cells, suggesting that activation of mDCs was responsible for the functional differentiation of HBV-specific CD8+ T cells in αCD40 treated animals. These results demonstrate that antigen-specific, PD-1-mediated CD8+ T cell exhaustion can be rescued by CD40-mediated mDC-activation. Hepatitis B virus (HBV) infection is responsible for more than 500,000 deaths annually as a result of the immune-mediated chronic liver damage it induces. The HBV specific CD8+ T cell response contributes to the pathogenesis of liver disease and viral clearance, and the failure to induce and/or sustain a vigorous CD8+ T cell response results in viral persistence and causes chronic necroinflammatory liver disease. To understand how the HBV-specific CD8+ T cell response is generated in response to intrahepatically expressed HBV, we generated T cell receptor transgenic mice whose CD8+ T cells are specific for HBV core or HBV envelope antigens. We find that these T cells are primed in the liver when they are adoptively transferred into HBV transgenic mouse recipients whose livers produce infectious virus particles, and that they proliferate vigorously in situ but do not differentiate into functional effector T cells after antigen recognition. Functional differentiation is suppressed by dominant negative regulatory signals, including PD-1, unless they are suppressed by anti-CD40 activation of myeloid dendritic cells.
Collapse
MESH Headings
- Adaptive Immunity
- Animals
- Antigen Presentation
- Antigens, Differentiation/genetics
- Antigens, Differentiation/metabolism
- Antigens, Viral/metabolism
- CD40 Antigens/agonists
- CD40 Antigens/genetics
- CD40 Antigens/metabolism
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/pathology
- CD8-Positive T-Lymphocytes/virology
- Cell Differentiation
- Cell Proliferation
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Dendritic Cells/pathology
- Dendritic Cells/virology
- Gene Expression Regulation, Viral
- Hepatitis B/immunology
- Hepatitis B/metabolism
- Hepatitis B/pathology
- Hepatitis B/virology
- Hepatitis B virus/immunology
- Hepatitis B virus/physiology
- Host-Pathogen Interactions
- Liver/immunology
- Liver/metabolism
- Liver/pathology
- Liver/virology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Programmed Cell Death 1 Receptor/genetics
- Programmed Cell Death 1 Receptor/metabolism
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
- T-Lymphocytes, Cytotoxic/pathology
- T-Lymphocytes, Cytotoxic/virology
Collapse
Affiliation(s)
- Masanori Isogawa
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, California, United States of America.
| | | | | | | | | |
Collapse
|
122
|
Meredith LW, Harris HJ, Wilson GK, Fletcher NF, Balfe P, McKeating JA. Early infection events highlight the limited transmissibility of hepatitis C virus in vitro. J Hepatol 2013; 58:1074-80. [PMID: 23353869 DOI: 10.1016/j.jhep.2013.01.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 12/10/2012] [Accepted: 01/09/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS Hepatitis C virus (HCV) poses a global health problem, with over 170 million chronically infected individuals at risk of developing progressive liver disease. The ability of a virus to spread within a host is a key determinant of its persistence and virulence. HCV can transmit in vitro by cell-free particle diffusion or via contact(s) between infected and naïve hepatocytes. However, limited information is available on the relative efficiency of these routes, our aim is to develop physiologically relevant assays to quantify these processes. METHODS We developed a single-cycle infection assay to measure HCV transmission rates. RESULTS We compared HCV spread in proliferating and arrested cell systems and demonstrated a significant reduction in cell-to-cell infection of arrested target cells. Comparison of cell-free and cell-to-cell virus spread demonstrated relatively poor transmission rates, with 10-50 infected producer cells required to infect a single naïve target cell. We found HCV strain J6/JFH to be 10-fold more efficient at spreading via the cell-to-cell route than cell-free, whereas SA13/JFH and HK6/JFH strains showed comparable rates of infection via both routes. Importantly, the level of infectious virus released from cells did not predict the ability of a virus to spread in vitro, highlighting the importance of studying cell-associated viruses. CONCLUSIONS These studies demonstrate the relatively poor infectivity of HCV and highlight differences between strains in their efficiency and preferred route of transmission that may inform future therapeutic strategies that target virus entry.
Collapse
Affiliation(s)
- Luke W Meredith
- Institute for Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, UK
| | | | | | | | | | | |
Collapse
|
123
|
McVicker BL, Thiele GM, Casey CA, Osna NA, Tuma DJ. Susceptibility to T cell-mediated liver injury is enhanced in asialoglycoprotein receptor-deficient mice. Int Immunopharmacol 2013; 16:17-26. [PMID: 23538026 DOI: 10.1016/j.intimp.2013.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 02/05/2013] [Accepted: 03/13/2013] [Indexed: 02/05/2023]
Abstract
T cell activation and associated pro-inflammatory cytokine production is a pathological feature of inflammatory liver disease. It is also known that liver injury is associated with marked impairments in the function of many hepatic proteins including a hepatocyte-specific binding protein, the asialoglycoprotein receptor (ASGPR). Recently, it has been suggested that hepatic ASGPRs may play an important role in the physiological regulation of T lymphocytes, leading to our hypothesis that ASGPR defects correlate with inflammatory-mediated events in liver diseases. Therefore, in this study we investigated whether changes in hepatocellular ASGPR expression were related to the dysregulation of intrahepatic T lymphocytes and correlate with the development of T-cell mediated hepatitis. Mice lacking functional ASGPRs (receptor-deficient, RD), and wild-type (WT) controls were intravenously injected with T-cell mitogens, Concanavalin A (Con A) or anti-CD3 antibody. As a result of T cell mitogen treatment, RD mice lacking hepatic ASGPRs displayed enhancements in liver pathology, transaminase activities, proinflammatory cytokine expression, and caspase activation compared to that observed in normal WT mice. Furthermore, FACS analysis demonstrated that T-cell mitogen administration resulted in a significant rise in the percentage of CD8+ lymphocytes present in the livers of RD animals versus WT mice. Since these two mouse strains differ only in whether they express the hepatic ASGPR, it can be concluded that proper ASGPR function exerts a protective effect against T cell mediated hepatitis and that impairments to this hepatic receptor could be related to the accumulation of cytotoxic T cells that are observed in inflammatory liver diseases.
Collapse
Affiliation(s)
- Benita L McVicker
- Research Service (151), VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105, United States.
| | | | | | | | | |
Collapse
|
124
|
Li F, Tian Z. The liver works as a school to educate regulatory immune cells. Cell Mol Immunol 2013; 10:292-302. [PMID: 23604044 DOI: 10.1038/cmi.2013.7] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 02/21/2013] [Indexed: 12/24/2022] Open
Abstract
Because of its unique blood supply, the liver maintains a special local immune tolerogenic microenvironment. Moreover, the liver can impart this immune tolerogenic effect on other organs, thus inducing systemic immune tolerance. The network of hepatic regulatory cells is an important mechanism underlying liver tolerance. Many types of liver-resident antigen-presenting cells (APCs) have immune regulatory function, and more importantly, they can also induce the differentiation of circulating immune cells into regulatory cells to further extend systemic tolerance. Thus, the liver can be seen as a type of 'school', where liver APCs function as 'teachers' and circulating immune cells function as 'students.'
Collapse
Affiliation(s)
- Fenglei Li
- Hefei National Laboratory for Physical Sciences at Microscale, Hefei, China
| | | |
Collapse
|
125
|
Annoni A, Goudy K, Akbarpour M, Naldini L, Roncarolo MG. Immune responses in liver-directed lentiviral gene therapy. Transl Res 2013; 161:230-40. [PMID: 23360745 DOI: 10.1016/j.trsl.2012.12.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 12/13/2012] [Accepted: 12/17/2012] [Indexed: 01/13/2023]
Abstract
The use of lentiviral vectors (LV)s for in vivo gene therapy is an ideal platform for treating many types of disease. Since LVs can transduce a wide array of cells, support long-term gene expression, and be modified to enhance cell targeting, LVs are a powerful modality to deliver life-long therapeutic proteins. A major limitation facing the use of LVs for in vivo gene therapy is the induction of immune responses, which can reduce the transduction efficiency of LV, eliminate the transduced cells, and inhibit the effect of the therapeutic protein. LV strategies designed to restrict transgene expression to the liver to exploit its naturally tolerogenic properties have proven to significantly reduce the induction of pathogenic immune responses and increase therapeutic efficacy. In this review, we outline the immunological hurdles facing in vivo LV gene therapy and highlight the advantages and limitations of using liver-directed LV gene therapy.
Collapse
Affiliation(s)
- Andrea Annoni
- San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET), Division of Regenerative Medicine, Stem Cells and Gene Therapy, San Raffaele Scientific Institute, Milan, Italy
| | | | | | | | | |
Collapse
|
126
|
Jain R, Weninger W. Shedding light on cutaneous innate immune responses: the intravital microscopy approach. Immunol Cell Biol 2013; 91:263-70. [PMID: 23459295 DOI: 10.1038/icb.2012.76] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The skin is under constant assault by environmental factors and microbes. Innate immune cells in epidermis and dermis regulate immune responses against pathogens while maintaining tolerance against commensal bacteria and autoantigens. The introduction of intravital imaging approaches, in particular multiphoton microscopy, has enabled studying the cellular and molecular regulation of cutaneous immunity in real time within intact skin. Here, we discuss recent advances in our understanding of innate immune cell behaviour in the skin, as unravelled by intravital microscopy, with emphasis on the function of myeloid cells, including dendritic cells, neutrophils and monocytes.
Collapse
Affiliation(s)
- Rohit Jain
- Immune Imaging Program, The Centenary Institute, Newtown, New South Wales, Australia
| | | |
Collapse
|
127
|
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.
Collapse
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
| |
Collapse
|
128
|
Tateno C, Miya F, Wake K, Kataoka M, Ishida Y, Yamasaki C, Yanagi A, Kakuni M, Wisse E, Verheyen F, Inoue K, Sato K, Kudo A, Arii S, Itamoto T, Asahara T, Tsunoda T, Yoshizato K. Morphological and microarray analyses of human hepatocytes from xenogeneic host livers. J Transl Med 2013; 93:54-71. [PMID: 23147226 DOI: 10.1038/labinvest.2012.158] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We previously produced mice with human hepatocyte (h-hep) chimeric livers by transplanting h-heps into albumin enhancer/promoter-driven urokinase-type plasminogen activator-transgenic severe combined immunodeficient (SCID) mice with liver disease. The chimeric livers were constructed with h-heps, mouse hepatocytes, and mouse hepatic sinusoidal cells (m-HSCs). Here, we investigated the morphological features of the chimeric livers and the h-hep gene expression profiles in the xenogeneic animal body. To do so, we performed immunohistochemistry, morphometric analyses, and electron microscopic observations on chimeric mouse livers, and used microarray analyses to compare gene expression patterns in hepatocytes derived from chimeric mouse hepatocytes (c-heps) and h-heps. Morphometric analysis revealed that the ratio of hepatocytes to m-HSCs in the chimeric mouse livers were twofold higher than those in the SCID mouse livers, corresponding to twin-cell plates in the chimeric mouse liver. The h-heps in the chimeric mouse did not show hypoxia even in the twin-cell plate structure, probably because of low oxygen consumption by the h-heps relative to the mouse hepatocytes (m-heps). Immunohistochemical and electron microscopic examinations revealed that the sinusoids in the chimeric mouse livers were normally constructed with h-heps and m-HSCs. However, a number of microvilli projected into the intercellular clefts on the lateral aspects of the hepatocytes, features typical of a growth phase. Microarray profiles indicated that ∼82% of 16 605 probes were within a twofold range difference between h-heps and c-heps. Cluster and principal component analyses showed that the gene expression patterns of c-heps were extremely similar to those of h-heps. In conclusion, the chimeric mouse livers were normally reconstructed with h-heps and m-HSCs, and expressed most human genes at levels similar to those in human livers, although the chimeric livers showed morphological characteristics typical of growth.
Collapse
|
129
|
Seyed-Razavi Y, Hickey MJ, Kuffová L, McMenamin PG, Chinnery HR. Membrane nanotubes in myeloid cells in the adult mouse cornea represent a novel mode of immune cell interaction. Immunol Cell Biol 2012; 91:89-95. [PMID: 23146944 DOI: 10.1038/icb.2012.52] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Membrane nanotubes (MNTs) are newly discovered cellular extensions that are either blind-ended or can connect widely separated cells. They have predominantly been investigated in cultured isolated cells, however, previously we were the first group to demonstrate the existence of these structures in vivo in intact mammalian tissues. We previously demonstrated the frequency of both cell-cell or bridging MNTs and blind-ended MNTs was greatest between major histocompatibility complex (MHC) class II(+) cells during corneal injury or TLR ligand-mediated inflammation. The present study aimed to further explore the dynamics of MNT formation and their size, presence in another tissue, the dura mater, and response to stress factors and an active local viral infection of the murine cornea. Confocal live cell imaging of myeloid-derived cells in inflamed corneal explants from Cx(3)cr1(GFP) and CD11c(eYFP) transgenic mice revealed that MNTs form de novo at a rate of 15.5 μm/min. This observation contrasts with previous studies that demonstrated that in vitro these structures originate from cell-cell contacts. Conditions that promote formation of MNTs include inflammation in vivo and cell stress due to serum starvation ex vivo. Herpes simplex virus-1 infection did not cause a significant increase in MNT numbers in myeloid cells in the cornea above that observed in injury controls, confirming that corneal epithelium injury alone elicits MNT formation in vivo. These novel observations extend the currently limited understanding of MNTs in live mammalian tissues.
Collapse
Affiliation(s)
- Yashar Seyed-Razavi
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
| | | | | | | | | |
Collapse
|
130
|
Guidotti LG, Iannacone M. Effector CD8 T cell trafficking within the liver. Mol Immunol 2012; 55:94-9. [PMID: 23149103 DOI: 10.1016/j.molimm.2012.10.032] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 10/17/2012] [Accepted: 10/22/2012] [Indexed: 01/06/2023]
Abstract
CD8 T cells play a critical role in several pathological conditions affecting the liver, most notably viral hepatitis. Accordingly, understanding the mechanisms that modulate the intrahepatic recruitment of CD8 T cells is of paramount importance. Some of the rules governing the behavior of these cells in the liver have been characterized at the population level, or have been inferred by studying the intrahepatic behavior of other leukocyte subpopulations. In contrast to most microvascular beds where leukocyte adhesion is restricted to the endothelium of post-capillary venules, it is now becoming clear that in the liver leukocytes, including CD8 T cells, can efficiently interact with the endothelium of hepatic capillaries (i.e. the sinusoids). While physical trapping has been proposed to play an important role in leukocyte adhesion to hepatic sinusoids, there is mounting evidence that T cell recruitment to the liver is highly regulated and depends on recruitment signals that are either constitutive or induced by inflammation. We review here several specific adhesive mechanisms that have been shown to regulate CD8 T cell trafficking within the liver, as well as highlight recent data that establish platelets as key cellular regulators of intrahepatic CD8 T cell accumulation.
Collapse
Affiliation(s)
- Luca G Guidotti
- Division of Immunology, Infectious Diseases and Transplantation, San Raffaele Scientific Institute, Milano, Italy
| | | |
Collapse
|
131
|
Role of resident liver cells in the pathogenesis of schistosomiasis. Trends Parasitol 2012; 28:572-9. [PMID: 23099112 DOI: 10.1016/j.pt.2012.09.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Revised: 09/14/2012] [Accepted: 09/21/2012] [Indexed: 12/12/2022]
Abstract
Pathology in schistosomiasis occurs as a result of eggs deposited in the liver by the schistosome parasite. A granulomatous reaction occurs, resulting in portal hypertension and hepatic fibrosis. Resident non-parenchymal cells within the liver take part in this process, including hepatic stellate cells, which are responsible for collagen production, and Kupffer cells, the liver macrophages involved in both host protection and in pathology. Other cells such as liver sinusoidal endothelial cells or portal fibroblasts may also be involved in this process. This review discusses the possible role of these resident liver cells in the pathology associated with schistosomiasis and provides information which may assist our understanding of the mechanisms associated with chronic liver disease in general.
Collapse
|
132
|
Naïve CD8 T cell activation by liver bone marrow-derived cells leads to a "neglected" IL-2low Bimhigh phenotype, poor CTL function and cell death. J Hepatol 2012; 57:830-6. [PMID: 22659099 DOI: 10.1016/j.jhep.2012.05.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 05/03/2012] [Accepted: 05/17/2012] [Indexed: 01/16/2023]
Abstract
BACKGROUND & AIMS The occurrence of primary CD8 T cell activation within the liver, unique among the non-lymphoid organs, is now well accepted. However, the outcome of intrahepatic T cell activation remains controversial. We have previously reported that activation initiated by hepatocytes results in a tolerogenic phenotype characterized by low expression of CD25 and IL-2, poor cytotoxic T lymphocyte (CTL) function, and excessive expression of the pro-apoptotic protein Bim. METHODS To investigate whether this phenotype was due to activation in the absence of co-stimulation, we generated bone marrow (bm) radiation chimeras in which adoptively transferred naïve transgenic CD8 T cells were activated in the presence of co-stimulation by liver bm-derived cells. RESULTS Despite expressing pro-inflammatory cytokines, high levels of CD25 and CD54, donor T cells activated by liver bm-derived cells did not produce detectable IL-2 and displayed poor CTL function, suggesting incomplete acquisition of effector function. Simultaneously, these cells expressed high levels of Bim and died by neglect. Transfer of Bim-deficient T cells resulted in increased T cell numbers. CONCLUSIONS These results imply that expression of CD25 and CD54 is co-stimulation dependent and distinguishes T cell activated by hepatocytes and liver bm-derived cells. In contrast, low expression of IL-2, poor CTL function and excess Bim production represent a more universal phenotype defining T cells undergoing primary activation by both types of hepatic antigen presenting cells (APC). These results have important implications for transplantation, in which all liver antigen presenting cells contribute to activation of T cells specific for the allograft.
Collapse
|
133
|
Svistounov D, Warren A, McNerney GP, Owen DM, Zencak D, Zykova SN, Crane H, Huser T, Quinn RJ, Smedsrød B, Le Couteur DG, Cogger VC. The Relationship between fenestrations, sieve plates and rafts in liver sinusoidal endothelial cells. PLoS One 2012; 7:e46134. [PMID: 23029409 PMCID: PMC3454341 DOI: 10.1371/journal.pone.0046134] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Accepted: 08/28/2012] [Indexed: 01/22/2023] Open
Abstract
Fenestrations are transcellular pores in endothelial cells that facilitate transfer of substrates between blood and the extravascular compartment. In order to understand the regulation and formation of fenestrations, the relationship between membrane rafts and fenestrations was investigated in liver sinusoidal endothelial cells where fenestrations are grouped into sieve plates. Three dimensional structured illumination microscopy, scanning electron microscopy, internal reflectance fluorescence microscopy and two-photon fluorescence microscopy were used to study liver sinusoidal endothelial cells isolated from mice. There was an inverse distribution between sieve plates and membrane rafts visualized by structured illumination microscopy and the fluorescent raft stain, Bodipy FL C5 ganglioside GM1. 7-ketocholesterol and/or cytochalasin D increased both fenestrations and lipid-disordered membrane, while Triton X-100 decreased both fenestrations and lipid-disordered membrane. The effects of cytochalasin D on fenestrations were abrogated by co-administration of Triton X-100, suggesting that actin disruption increases fenestrations by its effects on membrane rafts. Vascular endothelial growth factor (VEGF) depleted lipid-ordered membrane and increased fenestrations. The results are consistent with a sieve-raft interaction, where fenestrations form in non-raft lipid-disordered regions of endothelial cells once the membrane-stabilizing effects of actin cytoskeleton and membrane rafts are diminished.
Collapse
Affiliation(s)
- Dmitri Svistounov
- Centre for Education and Research on Ageing and ANZAC Medical Research Institute, University of Sydney and Concord Hospital, Sydney, Australia
| | - Alessandra Warren
- Centre for Education and Research on Ageing and ANZAC Medical Research Institute, University of Sydney and Concord Hospital, Sydney, Australia
| | - Gregory P. McNerney
- NSF Center for Biophotonics Science and Technology, University of California Davis, Sacramento, California, United States of America
| | - Dylan M. Owen
- Centre for Vascular Research, University of New South Wales, Sydney, Australia
| | - Dusan Zencak
- Eskitis Institute, Griffith University, Brisbane, Australia
| | - Svetlana N. Zykova
- Centre for Education and Research on Ageing and ANZAC Medical Research Institute, University of Sydney and Concord Hospital, Sydney, Australia
| | - Harry Crane
- Centre for Education and Research on Ageing and ANZAC Medical Research Institute, University of Sydney and Concord Hospital, Sydney, Australia
| | - Thomas Huser
- NSF Center for Biophotonics Science and Technology, University of California Davis, Sacramento, California, United States of America
| | | | - Bård Smedsrød
- Department of Medical Biology, University of Tromso, Tromso, Norway
| | - David G. Le Couteur
- Centre for Education and Research on Ageing and ANZAC Medical Research Institute, University of Sydney and Concord Hospital, Sydney, Australia
- * E-mail:
| | - Victoria C. Cogger
- Centre for Education and Research on Ageing and ANZAC Medical Research Institute, University of Sydney and Concord Hospital, Sydney, Australia
| |
Collapse
|
134
|
Adams WJ, García-Cardeña G. Novel stem cell-based drug discovery platforms for cardiovascular disease. ACTA ACUST UNITED AC 2012; 17:1117-27. [PMID: 22853930 DOI: 10.1177/1087057112454741] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The complexity and diversity of many human diseases pose significant hurdles to the development of novel therapeutics. New scientific and technological advances, such as pharmacogenetics, provide valuable frameworks for understanding genetic predisposition to disease and tools for diagnosis and drug development. However, another framework is emerging based on recent scientific advances, one we suggest to call pharmacoempirics. Pharmacoempirics takes advantage of merging two nascent fields: first, the generation of induced pluripotent stem cells, which are differentiated into mature cell types and represent patient-specific genetic backgrounds, and, second, bioengineering advances allowing sophisticated re-creation of human pathophysiology in laboratory settings. The combination of these two innovative technologies should allow new experimentation on disease biology and drug discovery, efficacy, and toxicology unencumbered by hypothesis generation and testing. In this review, we discuss the challenges and promises of this exciting new type of discovery platform and outline its implementation for cardiovascular drug discovery.
Collapse
Affiliation(s)
- William J Adams
- Program in Developmental and Regenerative Biology, Harvard Medical School, Boston, MA, USA.
| | | |
Collapse
|
135
|
Abstract
SUMMARY The 'liver sieve' is a term developed to describe the appearance and the role of fenestrations in the liver sinusoidal endothelial cell (LSEC). LSECs are gossamer-thin cells that line the hepatic sinusoid and they are perforated with pores called fenestrations clustered in sieve plates. There is growing evidence that fenestrations act like a permselective ultrafiltration system which is important for the hepatic uptake of many substrates, particularly chylomicron remnant lipoproteins. The liver sieve is a very efficient exchange system, however in conditions such as hepatic cirrhosis and fibrosis, diabetes mellitus and old age, there is defenestration of the liver sieve. Such defenestration has been shown to influence the hepatic uptake of various substrates including lipoproteins. In the future, pharmacological manipulation of the liver sieve may play a number of therapeutic roles including the management of dyslipidaemia; increasing the efficiency of liver-targeted gene therapy; and improving regeneration of old livers.
Collapse
|
136
|
Yang D, Liu Q, Yang M, Wu H, Wang Q, Xiao J, Zhang Y. RNA-seq liver transcriptome analysis reveals an activated MHC-I pathway and an inhibited MHC-II pathway at the early stage of vaccine immunization in zebrafish. BMC Genomics 2012; 13:319. [PMID: 22805612 PMCID: PMC3583171 DOI: 10.1186/1471-2164-13-319] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/17/2012] [Indexed: 01/18/2023] Open
Abstract
Background Zebrafish (Danio rerio) is a prominent vertebrate model of human development and pathogenic disease and has recently been utilized to study teleost immune responses to infectious agents threatening the aquaculture industry. In this work, to clarify the host immune mechanisms underlying the protective effects of a putative vaccine and improve its immunogenicity in the future efforts, high-throughput RNA sequencing technology was used to investigate the immunization-related gene expression patterns of zebrafish immunized with Edwardsiella tarda live attenuated vaccine. Results Average reads of 18.13 million and 14.27 million were obtained from livers of zebrafish immunized with phosphate buffered saline (mock) and E. tarda vaccine (WED), respectively. The reads were annotated with the Ensembl zebrafish database before differential expressed genes sequencing (DESeq) comparative analysis, which identified 4565 significantly differentially expressed genes (2186 up-regulated and 2379 down-regulated in WED; p<0.05). Among those, functional classifications were found in the Gene Ontology database for 3891 and in the Kyoto Encyclopedia of Genes and Genomes database for 3467. Several pathways involved in acute phase response, complement activation, immune/defense response, and antigen processing and presentation were remarkably affected at the early stage of WED immunization. Further qPCR analysis confirmed that the genes encoding the factors involved in major histocompatibility complex (MHC)-I processing pathway were up-regulated, while those involved in MHC-II pathway were down-regulated. Conclusion These data provided insights into the molecular mechanisms underlying zebrafish immune response to WED immunization and might aid future studies to develop a highly immunogenic vaccine against gram-negative bacteria in teleosts.
Collapse
Affiliation(s)
- Dahai Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | | | | | | | | | | | | |
Collapse
|
137
|
Goudy KS, Annoni A, Naldini L, Roncarolo MG. Manipulating Immune Tolerance with Micro-RNA Regulated Gene Therapy. Front Microbiol 2011; 2:221. [PMID: 22144977 PMCID: PMC3229161 DOI: 10.3389/fmicb.2011.00221] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Accepted: 10/19/2011] [Indexed: 12/13/2022] Open
Abstract
The success of in vivo gene therapy greatly depends on the ability to control the immune response toward the therapeutic transgene. Over the last decade several vector-based and pharmacological approaches have been explored to control the immune-mediated clearance of transgene-expressing cells after viral delivery. One important outcome from these studies is the concept that expression of a transgene in tolerance-promoting organs, such as the liver and tolerogenic antigen-presenting cells, can help safeguard transgene-expressing cells from immune-mediated clearance. Gene therapists are now manipulating vectors to target naturally occurring tolerogenic properties of the body by: (i) incorporating tissue/cell specific promoters for targeted expression, (ii) using viral-capsid engineering to alter tropism and avoid pre-existing immunity, and (iii) regulating cell and activation dependent expression by including micro-RNA (miR) targets into expression cassettes. The combination of these three layers of vector regulation greatly enhances the targeting of tolerogenic cells and limits off-target expression of the transgene, which can lead to the induction of transgene-specific pathogenic effector T cells. In this review, we discuss the application of using miR transgene regulation to generate tolerogenic responses and speculate on possible mechanisms used by the liver to induce the transgene-specific regulatory T cells.
Collapse
Affiliation(s)
- Kevin Scott Goudy
- San Raffaele Telethon Institute for Gene Therapy, Department of Regenerative Medicine, Stem Cells and Gene Therapy, San Raffaele InstituteMilan, Italy
| | - Andrea Annoni
- San Raffaele Telethon Institute for Gene Therapy, Department of Regenerative Medicine, Stem Cells and Gene Therapy, San Raffaele InstituteMilan, Italy
| | - Luigi Naldini
- San Raffaele Telethon Institute for Gene Therapy, Department of Regenerative Medicine, Stem Cells and Gene Therapy, San Raffaele InstituteMilan, Italy
- Universitá Vita-Salute San RaffaeleMilan, Italy
| | - Maria-Grazia Roncarolo
- San Raffaele Telethon Institute for Gene Therapy, Department of Regenerative Medicine, Stem Cells and Gene Therapy, San Raffaele InstituteMilan, Italy
- Universitá Vita-Salute San RaffaeleMilan, Italy
| |
Collapse
|
138
|
Interleukin-10 is expressed in HepG2.2.15 cells and regulated by STAT1 pathway. ACTA ACUST UNITED AC 2011; 31:625. [DOI: 10.1007/s11596-011-0572-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Indexed: 01/07/2023]
|
139
|
Oteiza A, Li R, McCuskey RS, Smedsrød B, Sørensen KK. Effects of oxidized low-density lipoproteins on the hepatic microvasculature. Am J Physiol Gastrointest Liver Physiol 2011; 301:G684-93. [PMID: 21778464 DOI: 10.1152/ajpgi.00347.2010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Oxidized low-density lipoproteins (oxLDLs) are involved in proinflammatory and cytotoxic events in different microcirculatory systems. The liver is an important scavenger organ for circulating oxLDLs. However, the interaction of oxLDL with the hepatic microcirculation has been poorly investigated. The present study was conducted to examine the effects of differently modified oxLDLs on the hepatic microvasculature. C57Bl/6J mice were injected intravenously with low-density lipoprotein (LDL), or LDL oxidized for 3 h (oxLDL(3)) or 24 h (oxLDL(24)), at doses resembling oxLDL plasma levels in cardiovascular disease patients. Radioiodinated ligands were used to measure blood decay and organ distribution, and nonlabeled ligands to evaluate microcirculatory responses, examined by in vivo microscopy 30-60 min after ligand injection, immunohistochemistry, and scanning and transmission electron microscopy. Mildly oxLDL (oxLDL(3)) was cleared from blood at a markedly slower rate than heavily oxLDL (oxLDL(24)), but significantly faster than LDL (P < 0.01). Injected oxLDLs distributed to liver. OxLDL effects were most pronounced in central areas of the liver lobules where oxLDL(3) elicited a significant (P < 0.05) reduction in perfused sinusoids, and both oxLDL(3) and oxLDL(24) significantly increased the numbers of swollen endothelial cells and adherent leukocytes compared with LDL (P < 0.05). OxLDL-treated livers also exhibited increased intercellular adhesion molecule (ICAM)-1 centrilobular staining. Electron microscopy showed a 30% increased thickness of the liver sinusoidal endothelium in the oxLDL(3) group (P < 0.05) and a reduced sinusoidal fenestration in centrilobular areas with increased oxidation of LDL (P for linear trend <0.05). In conclusion, OxLDL induced several acute changes in the liver microvasculature, which may lead to sinusoidal endothelial dysfunction.
Collapse
Affiliation(s)
- Ana Oteiza
- Vascular Biology Research Group, Dept. of Medical Biology, Univ. of Tromsø, Norway.
| | | | | | | | | |
Collapse
|
140
|
Abstract
Although most self-reactive T cells are eliminated in the thymus, mechanisms to inactivate or control T cells specific for extrathymic antigens are required and exist in the periphery. By investigating the site in which autoreactive T cells are tolerized, we identify a unique mechanism of peripheral deletion in which naïve autoreactive CD8 T cells are rapidly eliminated in the liver after intrahepatic activation. T cells actively invade hepatocytes, enter endosomal/lysosomal compartments, and are degraded. Blockade of this process leads to accumulation of autoreactive CD8 T cells in the liver and breach of tolerance, with the development of autoimmune hepatitis. Cell into cell invasion, or emperipolesis, is a long-observed phenomenon for which a physiological role has not been previously demonstrated. We propose that this "suicidal emperipolesis" is a unique mechanism of autoreactive T-cell deletion, a process critical for the maintenance of tolerance.
Collapse
|
141
|
Guy CS, Rankin SL, Michalak TI. Hepatocyte cytotoxicity is facilitated by asialoglycoprotein receptor. Hepatology 2011; 54:1043-50. [PMID: 21656538 DOI: 10.1002/hep.24477] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 05/24/2011] [Indexed: 12/13/2022]
Abstract
UNLABELLED It has been recently identified that hepatocytes can act as cytotoxic effectors and can kill contacted cells by way of CD95 ligand-CD95 and perforin-dependent pathways. However, it remained unknown whether hepatocyte-mediated cell killing is indiscriminant or is directed toward targets with particular cell surface characteristics, as well as whether hepatocytes have the capacity to directly eliminate contacted lymphocytes. In this study, we found that desialylation of surface glycoproteins significantly augments cell susceptibility to hepatocyte-mediated killing. Using asialofetuin as a competitive ligand, and by silencing gene transcription with specific small interfering RNA, we found that the asialoglycoprotein receptor (ASGPR) is involved in hepatocyte recognition of cells predestined for killing, including activated autologous T lymphocytes. CONCLUSION Hepatocytes are constitutively equipped in the molecular machinery capable of eliminating cells brought into contact with their surface in a manner that is reliant, at least in part, upon the recognition of terminally desialylated glycoproteins by hepatocyte ASGPR. The study adds a new dimension to the physiological role of hepatic ASGPR and provides further evidence that hepatocytes can actively contribute to intrahepatic immune regulation and moderation of the local inflammatory response.
Collapse
Affiliation(s)
- Clifford S Guy
- Molecular Virology and Hepatology Research Group, Division of Biomedical Sciences, Faculty of Medicine, Health Sciences Centre, Memorial University, St. John's, Newfoundland, Canada
| | | | | |
Collapse
|
142
|
Abstract
In recent years, it has become increasingly apparent that the life span of transfused platelets in circulation is regulated, at least in part, by glycan-lectin mediated mechanisms. There is clear evidence that refrigerated platelets are cleared by glycan-lectin mediated clearance mechanisms. Acute platelet cooling clusters glycoprotein (GP) Ibα receptors bearing uncovered N-acetylglucosamine (GlcNAc), and α(M) β(2) integrins on hepatic macrophages recognise clustered GlcNAc to rapidly clear these platelets from circulation. With prolonged refrigeration GPIbα clustering bearing uncovered galactose increases, which mediates the removal of long-term refrigerated platelets via hepatic Ashwell-Morell receptors (AMR), originally named as asialoglycoprotein receptors. In contrast, little is known about the molecular mechanisms of transfused room temperature platelet clearance. This review examines the role of glycan-lectin mediated clearance of exogenous, that is transfused chilled platelet clearance and briefly addresses the current knowledge of stored platelet function, degradation and its relation to platelet clearance.
Collapse
Affiliation(s)
- K M Hoffmeister
- Division of Translational Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
143
|
Age-related changes in the hepatic pharmacology and toxicology of paracetamol. Curr Gerontol Geriatr Res 2011; 2011:624156. [PMID: 21765826 PMCID: PMC3135080 DOI: 10.1155/2011/624156] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 03/29/2011] [Indexed: 12/20/2022] Open
Abstract
Optimal pharmacotherapy is determined when the pharmacokinetics and pharmacodynamics of the drug are understood. However, the age-related changes in pharmacokinetics and pharmacodynamics, as well as the increased interindividual variation mean optimal dose selection are a challenge for prescribing in older adults. Poor understanding of how hepatic clearance and toxicity are different with age results in suboptimal dose selection, poor efficacy, and/or increased toxicity. Of particular concern is the analgesic paracetamol which has been in use for more than 50 years and is consumed by a large proportion of older adults. Paracetamol is considered to be a relatively safe drug; however, caution must be taken because of its potential for toxicity. Paracetamol-induced liver injury from accidental overdose accounts for up to 55% of cases in older adults. Better understanding of how age affects the hepatic clearance and toxicity of drugs will contribute to evidence-based prescribing for older people, leading to fewer adverse drug reactions without loss of benefit.
Collapse
|
144
|
Yan J, Jie Z, Hou L, Wanderley JL, Soong L, Gupta S, Qiu S, Chan T, Sun J. Parenchymal expression of CD40 exacerbates adenovirus-induced hepatitis in mice. Hepatology 2011; 53:1455-67. [PMID: 21360722 PMCID: PMC3082591 DOI: 10.1002/hep.24270] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
UNLABELLED The healthy adult human liver expresses low levels of major histocompatibility complex class II (MHC II) and undetectable levels of immune costimulatory molecules. However, high levels of MHC II, CD40, and B7 family molecules are expressed in the activated Kupffer cells and hepatocytes of patients with viral hepatitis. The precise role of these molecules in viral clearance and immune-mediated liver injury is not well understood. We hypothesized that parenchymal CD40 expression enhances T cell recruitment and effector functions, which may facilitate viral clearance and alleviate liver injury. To test this hypothesis, we generated novel liver-specific, conditional CD40 transgenic mice, and we challenged them intravenously with a recombinant replication-deficient adenovirus carrying Cre recombinase (AdCre). Wild-type mice infected with AdCre developed a relatively mild course of viral hepatitis and recovered spontaneously. CD40 expression in the livers of transgenic animals, however, resulted in CD80 and CD86 expression. The dysregulation of population dynamics and effector functions of intrahepatic lymphocytes (IHLs) resulted in severe lymphocytic infiltration, apoptosis, necroinflammation, and serum alanine aminotransferase elevations in a dose-dependent fashion. To our surprise, an early expansion and subsequent contraction of IHLs (especially CD8(+) and natural killer cells), accompanied by increased granzyme B and interferon-γ production, did not lead to faster viral clearance in CD40 transgenic mice. CONCLUSION Our results demonstrate that hepatic CD40 expression does not accelerate adenoviral clearance but rather exacerbates liver injury. This study unveils a previously unknown deleterious effect of hepatic CD40 on adenovirus-induced liver inflammation.
Collapse
Affiliation(s)
- Jiabin Yan
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| | - Zuliang Jie
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| | - Lifei Hou
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| | - Joao L. Wanderley
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA, Morphological Sciences Program, Federal University of Rio de Janeiro, RJ, Brazil
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA, Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| | - Shalini Gupta
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| | - Suimin Qiu
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| | - Tehsheng Chan
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas 77555-1019, USA
| |
Collapse
|
145
|
Pons JA, Revilla-Nuin B, Ramírez P, Baroja-Mazo A, Parrilla P. Desarrollo de inmunotolerancia en el trasplante hepático. GASTROENTEROLOGIA Y HEPATOLOGIA 2011; 34:155-69. [DOI: 10.1016/j.gastrohep.2010.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Accepted: 11/11/2010] [Indexed: 01/25/2023]
|
146
|
Abstract
The liver is an organ in which several major pathogens evade immune clearance and achieve chronicity. How do they do it? Recent research has documented multiple mechanisms by which immune responses in the liver are biased towards tolerance. In this review, the induction of local, intrahepatic tolerance is explored from the perspective of antigen presentation. Experiments support the role not only of liver dendritic cell subsets but also of diverse subsets of unconventional antigen-presenting cells in inducing immune suppression. The literature on this topic is controversial and sometimes contradictory, making it difficult to formulate a unified model of antigen handling and T cell priming in the liver. Here I offer a critical review of the state of the art in understanding antigen presentation in the liver.
Collapse
|
147
|
Warren A, Benseler V, Cogger VC, Bertolino P, Le Couteur DG. The impact of poloxamer 407 on the ultrastructure of the liver and evidence for clearance by extensive endothelial and kupffer cell endocytosis. Toxicol Pathol 2011; 39:390-7. [PMID: 21257999 DOI: 10.1177/0192623310394212] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Poloxamer 407 (P407) is a non-ionic detergent that is used widely in pharmaceutical formulations and personal care products. In animals, P407 causes hyperlipidaemia. P407 is taken up by the liver and causes loss of fenestrations in liver sinusoidal endothelial cells (LSEC), which contributes to the pathogenesis of hyperlipidaemia. Here the short-term (1-15 days) effects of P407 on all liver cells were investigated in mice using electron and light microscopy. As expected, P407 was associated with hyperlipidaemia. Kupffer cells became massively engorged with vacuoles and took on a marked honeycomb morphology. LSECs also became engorged with vacuoles and endocytosis was activated. The diameter of lipoproteins in the space of Disse was less than those in the lumen, consistent with a filtering effect of fenestrations. Defenestration of the LSEC was noted. Hepatocyte endocytosis of lipoproteins and P407 particles was also noted; however, hepatocyte steatosis was not evident. Hepatic stellate cells did not appear to be abnormal. In conclusion, P407 is taken up by the liver mostly through endocytosis by LSECs and Kupffer cells.
Collapse
Affiliation(s)
- Alessandra Warren
- Centre for Education and Research on Ageing and the ANZAC Research Institute, University of Sydney and Concord Hospital, Sydney, Australia
| | | | | | | | | |
Collapse
|
148
|
Abstract
In his clonal selection theory, Frank Macfarlane Burnet predicted that autoreactive lymphocytes are deleted to prevent autoimmunity. This and other principles of lymphocyte behavior outlined by Burnet guided many studies that lead to our current understanding of thymic selection. Thus, when the genetic mutation responsible for autoimmune polyglandular syndrome type 1 was mapped to the autoimmune regulator (AIRE) gene, and Aire was found to be highly expressed in thymic epithelium, studying the role of Aire in negative selection made sense in the context of modern models of thymic selection. We now know Aire is a transcription factor required for the expression of many tissue-specific antigens (TSAs) in the thymus. In the absence of functional Aire, human patients and mice develop multi-organ autoimmune disease because of a defect in thymic negative selection. In addition to its role in the thymus, recent work in our lab suggests that extrathymic Aire-expressing cells have an important role in the clonal deletion of autoreactive CD8+ T cells. In this review, we summarize the latest studies on thymic and peripheral Aire-expressing cells, as well as other TSA-expressing stromal cell populations in peripheral lymphoid organs. We also discuss theoretical differences in thymic and peripheral Aire function that warrant further studies.
Collapse
Affiliation(s)
- Ruth T Taniguchi
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143-0540, USA
| | | |
Collapse
|
149
|
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.
Collapse
|
150
|
Fromentin R, Tardif MR, Tremblay MJ. Inefficient fusion due to a lack of attachment receptor/co-receptor restricts productive human immunodeficiency virus type 1 infection in human hepatoma Huh7.5 cells. J Gen Virol 2010; 92:587-97. [PMID: 21123542 DOI: 10.1099/vir.0.028746-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Since the widespread use of the highly active antiretroviral therapy, the incidence of liver disease has increased to become a leading cause of death among human immunodeficiency virus type 1 (HIV-1)-infected individuals. It can be proposed that the ability of HIV-1 to infect hepatocytes could influence liver diseases. Although the presence of HIV-1 was identified in hepatocytes from HIV-1 seropositive patients, the susceptibility of hepatocytes to HIV-1 infection in vitro remains controversial. We present evidence here that human hepatoma cells are not productively infected with CD4-dependent HIV-1 strains because of inefficient fusion related to an absence of cell surface CD4 and CXCR4. However, these cells display an increased susceptibility to infection with a CD4-independent viral isolate through an interaction with galactosyl ceramide, an alternate receptor for HIV-1. This study provides further understanding of the susceptibility of human hepatocytes to HIV-1 infection. However, in vivo investigations are recommended to consolidate these data.
Collapse
Affiliation(s)
- Rémi Fromentin
- Centre de Recherche en Infectiologie, Université Laval, Québec, QC G1V 4G2, Canada
| | | | | |
Collapse
|