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Umeshappa CS, Solé P, Surewaard BGJ, Yamanouchi J, Mohapatra S, Uddin MM, Clarke R, Ortega M, Singha S, Mondal D, Yang Y, Vignali DAA, Serra P, Kubes P, Santamaria P. Liver-specific T regulatory type-1 cells program local neutrophils to suppress hepatic autoimmunity via CRAMP. Cell Rep 2021; 34:108919. [PMID: 33789099 DOI: 10.1016/j.celrep.2021.108919] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/17/2020] [Accepted: 03/08/2021] [Indexed: 12/17/2022] Open
Abstract
Neutrophils with immunoregulatory properties, also referred to as type-2 neutrophils (N2), myeloid-derived suppressor cells (MDSCs), or tumor-associated neutrophils (TANs), comprise a heterogeneous subset of cells that arise from unknown precursors in response to poorly understood cues. Here, we find that, in several models of liver autoimmunity, pharmacologically induced, autoantigen-specific T regulatory type-1 (TR1) cells and TR1-cell-induced B regulatory (Breg) cells use five immunoregulatory cytokines to coordinately recruit neutrophils into the liver and program their transcriptome to generate regulatory neutrophils. The liver-associated neutrophils from the treated mice, unlike their circulating counterparts or the liver neutrophils of sick mice lacking antigen-specific TR1 cells, are proliferative, can transfer disease protection to immunocompromised hosts engrafted with pathogenic effectors, and blunt antigen-presentation and local autoimmune responses via cathelin-related anti-microbial peptide (CRAMP), a cathelicidin, in a CRAMP-receptor-dependent manner. These results, thus, identify antigen-specific regulatory T cells as drivers of tissue-restricted regulatory neutrophil formation and CRAMP as an effector of regulatory neutrophil-mediated immunoregulation.
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Affiliation(s)
- Channakeshava Sokke Umeshappa
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Patricia Solé
- Institut D'Investigacions Biomèdiques August Pi i Sunyer, Barcelona 08036, Spain
| | - Bas G J Surewaard
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Jun Yamanouchi
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Saswat Mohapatra
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Muhammad Myn Uddin
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Robert Clarke
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Mireia Ortega
- Institut D'Investigacions Biomèdiques August Pi i Sunyer, Barcelona 08036, Spain
| | - Santiswarup Singha
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Debajyoti Mondal
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Yang Yang
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada; Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Dario A A Vignali
- Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Pau Serra
- Institut D'Investigacions Biomèdiques August Pi i Sunyer, Barcelona 08036, Spain
| | - Paul Kubes
- Department of Physiology and Pharmacology, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada
| | - Pere Santamaria
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, AB T2N 4N1, Canada; Institut D'Investigacions Biomèdiques August Pi i Sunyer, Barcelona 08036, Spain.
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Sutti S, Rigamonti C, Vidali M, Albano E. CYP2E1 autoantibodies in liver diseases. Redox Biol 2014; 3:72-8. [PMID: 25462068 PMCID: PMC4297929 DOI: 10.1016/j.redox.2014.11.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 11/10/2014] [Accepted: 11/11/2014] [Indexed: 12/11/2022] Open
Abstract
Autoimmune reactions involving cytochrome P4502E1 (CYP2E1) are a feature of idiosyncratic liver injury induced by halogenated hydrocarbons and isoniazid, but are also detectable in about one third of the patients with advanced alcoholic liver disease (ALD) and chronic hepatitis C (CHC). In these latter the presence of anti-CYP2E1 auto-antibodies is an independent predictor of extensive necro-inflammation and fibrosis and worsens the recurrence of hepatitis following liver transplantation, indicating that CYP2E1-directed autoimmunity can contribute to hepatic injury. The molecular characterization of the antigens recognized by anti-CYP2E1 auto-antibodies in ALD and CHC has shown that the targeted conformational epitopes are located in close proximity on the molecular surface. Furthermore, these epitopes can be recognized on CYP2E1 expressed on hepatocyte plasma membranes where they can trigger antibody-mediated cytotoxicity. This does not exclude that T cell-mediated responses against CYP2E1 might also be involved in causing hepatocyte damage. CYP2E1 structural modifications by reactive metabolites and molecular mimicry represent important factors in the breaking of self-tolerance against CYP2E1 in, respectively, ALD and CHC. However, genetic or acquired interferences with the mechanisms controlling the homeostasis of the immune system are also likely to contribute. More studies are needed to better characterize the impact of anti-CYP2E1 autoimmunity in liver diseases particularly in relation to the fact that common metabolic alterations such as obesity and diabetes stimulates hepatic CYP2E1 expression. CYP2E1 is a frequent autoimmune target in alcoholic liver disease and hepatitis C. Anti-CYP2E1 auto-antibodies mainly target conformational epitopes. Molecular mimicry contribute to anti-CYP2E1 autoimmunity during HCV infection. Anti-CYP2E1 autoimmunity contributes to the evolution of liver damage.
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Affiliation(s)
- Salvatore Sutti
- Department of Health Sciences, University "Amedeo Avogadro" of East Piedmont and Interdepartmental Research Centre for Autoimmune Diseases (IRCAD), Novara, Italy
| | | | - Matteo Vidali
- Azienda Ospedaliero-Universitaria Maggiore della Carità, Novara, Italy
| | - Emanuele Albano
- Department of Health Sciences, University "Amedeo Avogadro" of East Piedmont and Interdepartmental Research Centre for Autoimmune Diseases (IRCAD), Novara, Italy.
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3
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Selmi C, Gershwin ME. The role of environmental factors in primary biliary cirrhosis. Trends Immunol 2009; 30:415-20. [PMID: 19643668 DOI: 10.1016/j.it.2009.05.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 05/06/2009] [Accepted: 05/07/2009] [Indexed: 01/12/2023]
Abstract
The etiology of primary biliary cirrhosis (PBC) is enigmatic, although it is clearly related to a combination of genetic predisposition and environmental stimulation. PBC is a chronic autoimmune cholestatic liver disease that occurs throughout the world with a reported latitudinal gradient in prevalence and incidence. PBC is also characterized by a 60% concordance in monozygotic twins and is considered a model autoimmune disease because of several features common to other conditions and the relatively homogeneous serological and biochemical features. Several risk factors have been suggested to be associated with PBC, including exposure to infectious agents and chemical xenobiotics. This review will attempt to place such factors in perspective.
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Affiliation(s)
- Carlo Selmi
- Department of Internal Medicine, IRCCS Istituto Clinico Humanitas, University of Milan, Rozzano, Milan 20089, Italy
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4
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Walden HR, Kirby JA, Yeaman SJ, Gray J, Jones DE, Palmer JM. Xenobiotic incorporation into pyruvate dehydrogenase complex can occur via the exogenous lipoylation pathway. Hepatology 2008; 48:1874-84. [PMID: 19003917 DOI: 10.1002/hep.22540] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
UNLABELLED Lipoylated enzymes such as the E2 component of pyruvate dehydrogenase complex (PDC-E2) are targets for autoreactive immune responses in primary biliary cirrhosis, with lipoic acid itself forming a component of the dominant auto-epitopes. A candidate mechanism for the initiation of tolerance breakdown in this disease is immune recognition of neo-antigens formed by xenobiotic substitution of normal proteins. Importantly, sensitization with proteins artificially substituted with the lipoic acid analogue xenobiotic 6-bromohexanoic acid (6BH) can induce an immune response that cross-reacts with PDC-E2. This study investigated the potential of recombinant lipoylation enzymes lipoate activating enzyme and lipoyl-AMP(GMP):N-lysine lipoyl transferase to aberrantly incorporate xenobiotics into PDC-E2. It was found that these enzymes could incorporate lipoic acid analogues including octanoic and hexanoic acids and the xenobiotic 6BH into PDC-E2. The efficiency of incorporation of these analogues showed a variable dependence on activation by adenosine triphosphate (ATP) or guanosine triphosphate (GTP), with ATP favoring the incorporation of hexanoic acid and 6BH whereas GTP enhanced substitution by octanoic acid. Importantly, competition studies showed that the relative incorporation of both 6BH and lipoic acid could be regulated by the balance between ATP and GTP, with the formation of 6BH-substituted PDC-E2 predominating in an ATP-rich environment. CONCLUSION Using a well-defined system in vitro we have shown that an important xenobiotic can be incorporated into PDC in place of lipoic acid by the exogenous lipoylation system; the relative levels of lipoic acid and xenobiotic incorporation may be determined by the balance between ATP and GTP. These observations suggest a clear mechanism for the generation of an auto-immunogenic neo-antigen of relevance for the pathogenesis of primary biliary cirrhosis.
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Affiliation(s)
- Hannah R Walden
- Liver Research Group, Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, UK
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Jones DEJ, Palmer JM, Burt AD, Kirby JA. The specificity of liver inflammation in mouse models of primary biliary cirrhosis. Hepatology 2008; 48:1353-4; author reply 1354-5. [PMID: 18792128 DOI: 10.1002/hep.22522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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6
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Abstract
Primary biliary cirrhosis (PBC) is well known as a disease that predominantly affects women and has been hitherto only described in humans. The absence of an animal model has significantly impaired research into both etiology and treatment. However, in the past 2 years, several spontaneous and two induced models of PBC were described. This article reviews the data on these animal models and places it in the perspective of human PBC and generic autoimmunity.
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Affiliation(s)
- Ya-Hui Chuang
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan,
| | - William M. Ridgway
- Division of Rheumatology and Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15216,
| | - Yoshiyuki Ueno
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan, 980-8574,
| | - M. Eric Gershwin
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis School of Medicine, Davis, CA 95616,
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7
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Abstract
Liver damage leads to an inflammatory response and to the activation and proliferation of mesenchymal cell populations within the liver which remodel the extracellular matrix as part of an orchestrated wound-healing response. Chronic damage results in a progressive accumulation of scarring proteins (fibrosis) that, with increasing severity, alters tissue structure and function, leading to cirrhosis and liver failure. Efforts to modulate the fibrogenesis process have focused on understanding the biology of the heterogeneous liver fibroblast populations. The fibroblasts are derived from sources within and out with the liver. Fibroblasts expressing alpha-smooth muscle actin (myofibroblasts) may be derived from the transdifferentiation of quiescent hepatic stellate cells. Other fibroblasts emerge from the portal tracts within the liver. At least a proportion of these cells in diseased liver originate from the bone marrow. In addition, fibrogenic fibroblasts may also be generated through liver epithelial (hepatocyte and biliary epithelial cell)-mesenchymal transition. Whatever their origin, it is clear that fibrogenic fibroblast activity is sensitive to (and may be active in) the cytokine and chemokine profiles of liver-resident leucocytes such as macrophages. They may also be a component driving the regeneration of tissue. Understanding the complex intercellular interactions regulating liver fibrogenesis is of increasing importance in view of predicted increases in chronic liver disease and the current paucity of effective therapies.
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8
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Interplay between oxidative stress and immunity in the progression of alcohol-mediated liver injury. Trends Mol Med 2008; 14:63-71. [PMID: 18222109 DOI: 10.1016/j.molmed.2007.12.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2007] [Revised: 12/02/2007] [Accepted: 12/03/2007] [Indexed: 12/13/2022]
Abstract
Inflammation is recognized increasingly as having an important role in the pathogenesis of alcoholic liver disease (ALD). Nonetheless, the mechanisms by which alcohol maintains hepatic inflammation are still characterized incompletely. Several studies have demonstrated that ethanol-induced oxidative stress promotes immune responses in ALD by stimulating both humoral and cellular reactions against liver proteins adducted to hydroxyethyl free radicals and several lipid peroxidation products. Moreover, ALD patients have autoantibodies targeting cytochrome P4502E1 and oxidized phospholipids. In both chronic alcohol-fed rats and heavy drinkers, the elevation of IgG against lipid peroxidation-derived antigens is associated with tumor necrosis factor-alpha production and the severity of liver inflammation. On this basis, we propose that allo- and autoimmune reactions associated with oxidative stress might contribute to fueling hepatic inflammation in ALD.
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Leung PSC, Park O, Tsuneyama K, Kurth MJ, Lam KS, Ansari AA, Coppel RL, Gershwin ME. Induction of primary biliary cirrhosis in guinea pigs following chemical xenobiotic immunization. THE JOURNAL OF IMMUNOLOGY 2007; 179:2651-7. [PMID: 17675529 DOI: 10.4049/jimmunol.179.4.2651] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Although significant advances have been made in dissecting the effector mechanisms in autoimmunity, the major stumbling block remains defining the etiological events that precede disease. Primary biliary cirrhosis (PBC) illustrates this paradigm because of its high degree of heritability, its female predominance, and its extraordinarily specific and defined immune response and target destruction. In PBC, the major autoantigens belong to E2 components of the 2-oxo-acid dehydrogenase family of mitochondrially located enzymes that share a lipoylated peptide sequence that is the immunodominant target. Our previous work has demonstrated that synthetic mimics of the lipoate molecule such as 6-bromohexoanate demonstrate a high degree of reactivity with PBC sera prompted us to immunize groups of guinea pigs with 6-bromohexanoate conjugated to BSA. In this study, we provide serologic and immunohistochemical evidence that such immunized guinea pigs not only develop antimitochondrial autoantibody responses similar to human PBC, but also develop autoimmune cholangitis after 18 mo. Xenobiotic-immunized guinea pigs are the first induced model of PBC and suggest an etiology that has implications for the causation of other human autoimmune diseases. The data also reflect the likelihood that, in PBC, the multilineage antimitochondrial response is a pathogenic mechanism and that loss of tolerance and subsequent development of biliary lesions depends on either modification of the host mitochondrial Ag or a similar breakdown due to molecular mimicry.
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Affiliation(s)
- Patrick S C Leung
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California at Davis School of Medicine, Davis, CA 95616, USA.
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Cai P, König R, Khan MF, Kaphalia BS, Ansari GAS. Differential immune responses to albumin adducts of reactive intermediates of trichloroethene in MRL+/+ mice. Toxicol Appl Pharmacol 2007; 220:278-83. [PMID: 17376499 PMCID: PMC1959509 DOI: 10.1016/j.taap.2007.01.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 01/18/2007] [Accepted: 01/19/2007] [Indexed: 11/26/2022]
Abstract
Trichloroethene (TCE) is an industrial degreasing solvent and widespread environmental contaminant. Exposure to TCE is associated with autoimmunity. The mode of action of TCE is via its oxidative metabolism, and most likely, immunotoxicity is mediated via haptenization of macromolecules and subsequent induction of immune responses. To better understand the role of protein haptenization through TCE metabolism, we immunized MRL+/+ mice with albumin adducts of various TCE reactive intermediates. Serum immunoglobulins and cytokine levels were measured to determine immune responses against haptenized albumin. We found antigen-specific IgG responses of the IgG subtypes IgG(1), IgG(2a), and IgG(2b), with IgG(1) predominating. Serum levels of G-CSF were increased in immunized mice, suggesting macrophage activation. Liver histology revealed lymphocyte infiltration in the lobules and the portal area following immunization with formyl-albumin. Our findings suggest that proteins haptenized by metabolites of TCE may act as neo-antigens that can induce humoral immune responses and T cell-mediated hepatitis.
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Affiliation(s)
- Ping Cai
- Department of Pathology, University of Texas Medical Branch, Galveston TX 77555-0609, USA
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11
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Moritoki Y, Lian ZX, Wulff H, Yang GX, Chuang YH, Lan RY, Ueno Y, Ansari AA, Coppel RL, Mackay IR, Gershwin ME. AMA production in primary biliary cirrhosis is promoted by the TLR9 ligand CpG and suppressed by potassium channel blockers. Hepatology 2007; 45:314-22. [PMID: 17256753 DOI: 10.1002/hep.21522] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
UNLABELLED We previously reported that peripheral blood mononuclear cells (PBMCs) from patients with primary biliary cirrhosis (PBC) produce significantly higher levels of polyclonal IgM than controls after exposure to CpG. Furthermore, the prevalence and unusually high levels of antimitochondrial antibodies (AMAs) in patients with PBC suggest a profound loss ofB cell tolerance. We have addressed the issue of whether CpG will promote the production ofAMAs and whether new experimental agents that inhibit the lymphocyte potassium channels Kv1.3 and KCa3.1 can suppress CpG-mediated B cell activation and AMA production. PBMCs were stimulated with and without CpG and were subsequently analyzed for phenotype, including expression of TLR9, CD86, and KCa3.1 concurrent with measurements of AMA and responses to a control antigen, tetanus toxoid, in supernatants. Additionally, K+ channel expression on B cells from PBC patients and controls was studied using whole-cell patch-clamp technology. In patients with PBC, CpG induces secretion of AMAs in PBMCs andalso up-regulates B cell expression of TLR9, CD86, and KCa3.1. Additionally, K+ channel blockers suppress secretion of AMA without a reduction of CpG-B-enhanced IgM production. Furthermore, there is diminished up-regulation of TLR9 and CD86 without affecting proliferation of B cells, B cell apoptosis, or viability. CONCLUSION These data suggest that the hyperresponsiveness of B cells in PBC accelerates B cell-mediated autoimmunity.
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Affiliation(s)
- Yuki Moritoki
- Division of Rheumatology, Allergy, and Clinical Immunology and the University of California at Davis, Davis, CA 95616, USA
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12
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Abstract
BACKGROUND Autoantibody responses reactive with the E2 and E3BP components of pyruvate dehydrogenase complex (PDC), which characterise primary biliary cirrhosis (PBC) crossreact, precluding the identification, from serological studies, of the antigen to which the principal breakdown of tolerance occurs. Although autoreactive T-cell responses to PDC-E2 have been well characterised it is, at present, unclear whether T-cell tolerance breakdown also occurs to PDC-E3BP. The aims of this study were to characterise autoreactive T-cell responses to PDC-E3BP in PBC and potential factors regulating their expression. METHODS Peripheral blood T-cell proliferative responses to purified recombinant human PDC-E2 and PDC-E3BP at a range of concentrations were characterised in PBC patients and control subjects. RESULTS T-cell proliferative responses to both E2 and E3BP were absent from control subjects (median peak stimulation index (SI) to PDC-E2 1.2 [range 0.3-1.9], 0/10 positive (SI>2.32), median peak SI to PDC-E3BP 1.1 [0.7-2.1]], 0/10 positive). Significant responses to PDC-E2 were seen in the majority of patients (median peak SI 11.4 [0.4-24.4], 17/20 (85%) positive) but to PDC-E3BP in only a minority (median peak SI 1-9 [0.6-9.95], 8/20 (40%) positive). Where responses to PDC-E3BP were seen they were universally secondary to responses to PDC-E2. CONCLUSIONS Despite the presence of antibodies reactive with PDC-E3BP in the majority of PBC patients this self-protein is not a dominant T-cell autoantigen in PBC.
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Affiliation(s)
- Anna McHugh
- Liver Research Group, University of Newcastle, Newcastle-upon-Tyne, UK
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13
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N/A, 夏 薇, 李 永. N/A. Shijie Huaren Xiaohua Zazhi 2006; 14:702-708. [DOI: 10.11569/wcjd.v14.i7.702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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14
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Sanderson JP, Naisbitt DJ, Park BK. Role of bioactivation in drug-induced hypersensitivity reactions. AAPS JOURNAL 2006; 8:E55-64. [PMID: 16584134 PMCID: PMC2751424 DOI: 10.1208/aapsj080107] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Drug-induced hypersensitivity reactions are a major problem in both clinical treatment and drug development. This review covers recent developments in our understanding of the pathogenic mechanisms involved, with special focus on the potential role of metabolism and bioactivation in generating a chemical signal for activation of the immune system. The possible role of haptenation and neoantigen formation is discussed, alongside recent findings that challenge this paradigm. Additionally, the essential role of costimulation is examined, as are the potential points whereby costimulation may be driven by reactive metabolites. The relevance of local generation of metabolites in determining the location and character of a reaction is also covered.
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Affiliation(s)
- Joseph P. Sanderson
- Department of Pharmacology and Therapeutics, University of Liverpool, Sherrington Buildings, Ashton Street, L69 3GE Liverpool, England
| | - Dean J. Naisbitt
- Department of Pharmacology and Therapeutics, University of Liverpool, Sherrington Buildings, Ashton Street, L69 3GE Liverpool, England
| | - B. Kevin Park
- Department of Pharmacology and Therapeutics, University of Liverpool, Sherrington Buildings, Ashton Street, L69 3GE Liverpool, England
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15
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Selmi C, Invernizzi P, Zuin M, Podda M, Seldin MF, Gershwin ME. Genes and (auto)immunity in primary biliary cirrhosis. Genes Immun 2005; 6:543-56. [PMID: 16034472 DOI: 10.1038/sj.gene.6364248] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Primary biliary cirrhosis (PBC) is a chronic autoimmune cholestatic liver disease most commonly encountered in postmenopausal women; it is characterized by high-titer serum autoantibodies to mitochondrial antigens, elevated serum IgM, progressive destruction of intrahepatic bile ducts, and ultimately liver cirrhosis and failure. The cytopathic mechanisms leading to the selective destruction of intrahepatic cholangiocytes are still largely unknown. The current theory on the pathogenesis of PBC indicated that environmental factors might trigger autoimmunity in genetically susceptible individuals. In fact, genetic predisposition is critical to disease onset and progression, yet peculiar among autoimmune diseases, as indicated by the lack of a strong association with major histocompatibility complex haplotypes. Further, the recently reported concordance rate among monozygotic twins strengthens the importance of genetic factors, while also indicating that additional factors, possibly infectious agents or xenobiotics, intervene to trigger the disease. In this review, the available data regarding the genetic factors associated with PBC susceptibility and progression, as well as the available evidence regarding the immunomediated pathogenesis of PBC, will be critically illustrated and discussed.
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Affiliation(s)
- C Selmi
- Division of Internal Medicine, San Paolo School of Medicine, University of Milan, Milan, Italy
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16
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Abstract
PURPOSE OF REVIEW This review highlights recent advances in understanding the regulation of bile acid transport in cholestasis and the pathogenesis and treatment of a variety of cholestatic conditions. RECENT FINDINGS Highlights include new understanding of the role of Mrp4 in bile acid homeostasis in cholestasis, new insights into the pathogenesis of specific cholestatic syndromes including primary biliary cirrhosis, primary sclerosing cholangitis, biliary atresia, and progressive familial intrahepatic cholestasis, and clinical trials of therapies for primary biliary cirrhosis, primary sclerosing cholangitis and intrahepatic cholestasis. SUMMARY Our understanding of the molecular mechanisms of cholestasis is advancing. These advances will hopefully lead to more effective therapies for specific cholestatic conditions.
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Affiliation(s)
- Daniel S Pratt
- Massachusetts General Hospital, Harvard Medical School, Boston, MA 02111, USA.
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17
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Robe AJ, Kirby JA, Jones DEJ, Palmer JM. A key role for autoreactive B cells in the breakdown of T-cell tolerance to pyruvate dehydrogenase complex in the mouse. Hepatology 2005; 41:1106-12. [PMID: 15830397 DOI: 10.1002/hep.20642] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The key immunological event in the pathogenesis of the autoimmune liver disease primary biliary cirrhosis is breakdown of T-cell self-tolerance to pyruvate dehydrogenase complex (PDC). The mechanism resulting in this breakdown of tolerance remains unclear. Mice exposed to self-PDC mount no immune response; however, animals coexposed to self-PDC and PDC of foreign origin (which in isolation induces a cross-reactive antibody but not an autoreactive T-cell response) show breakdown of T-cell as well as B-cell tolerance. This observation raises the possibility that a cross-reactive antibody response to self-PDC can promote breakdown of T-cell tolerance. The aim of this study was to address the hypothesis that breakdown of T-cell tolerance to PDC can be driven by the presence of B cells and/or antibodies cross-reactive with this self-antigen. Naive female SJL/J mice were exposed to self-PDC alone and in the presence of purified splenic B cells from animals primed with foreign PDC (or controls) or purified immunoglobulin (Ig) G from the same animals. Breakdown of T-cell tolerance was assessed by splenic T-cell proliferative response to antigen at 5 weeks. CD4(+) T-cell proliferative responses indicative of breakdown of T-cell tolerance to self-PDC were seen in the majority (7 of 9, 78%) of animals receiving self-PDC together with purified PDC-reactive B cells. Tolerance breakdown was not seen in animals receiving self-PDC with purified anti-PDC IgG or with B cells from animals sensitized with an irrelevant antigen. In conclusion, breakdown of T-cell tolerance to the highly conserved self-antigen PDC may be mediated by high-level presentation of self-derived epitopes by activated cross-reactive B cells.
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Affiliation(s)
- Amanda J Robe
- Liver Research Group, University of Newcastle, Newcastle-upon-Tyne, UK
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