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Abstract
The three common themes that underlie the induction and perpetuation of autoimmunity are genetic predisposition, environmental factors, and immune regulation. Environmental factors have gained much attention for their role in triggering autoimmunity, with increasing evidence of their influence as demonstrated by epidemiological studies, laboratory research, and animal studies. Environmental factors known to trigger and perpetuate autoimmunity include infections, gut microbiota, as well as physical and environmental agents. To address these issues, we will review major potential mechanisms that underlie autoimmunity including molecular mimicry, epitope spreading, bystander activation, polyclonal activation of B and T cells, infections, and autoinflammatory activation of innate immunity. The association of the gut microbiota on autoimmunity will be particularly highlighted by their interaction with pharmaceutical agents that may lead to organ-specific autoimmunity. Nonetheless, and we will emphasize this point, the precise mechanism of environmental influence on disease pathogenesis remains elusive.
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Affiliation(s)
- Annarosa Floreani
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Via Giustiniani, 2, 35128, Padova, Italy.
| | - Patrick S C Leung
- Department of Surgery, Oncology and Gastroenterology, University of Padova, Via Giustiniani, 2, 35128, Padova, Italy
| | - M Eric Gershwin
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California Davis, Davis, CA, USA
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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.
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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
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Bianchi I, Lleo A, Bernuzzi F, Caliari L, Smyk DS, Invernizzi P. The X-factor in primary biliary cirrhosis: monosomy X and xenobiotics. AUTOIMMUNITY HIGHLIGHTS 2012; 3:127-32. [PMID: 26000136 PMCID: PMC4389075 DOI: 10.1007/s13317-012-0043-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 10/24/2012] [Indexed: 12/12/2022]
Abstract
Primary biliary cirrhosis (PBC) is a chronic, cholestatic, autoimmune liver disease characterised by the destruction of small- and medium-sized bile ducts. The serological hallmark of PBC includes antimitochondrial antibodies (AMA). The disease has a striking female predominance, and primarily affects women of middle-age. First-degree relatives, and in particular female relatives, are known to have an increased risk of developing the disease. Several studies have attempted to explain the female predominance of PBC, and autoimmune diseases in general. Two components that are of interest in PBC include monosomy X and xenobiotics. Monosomy X has been noted to be prevalent in the peripheral blood mononuclear cells of PBC patients. Xenobiotics, which are exogenous chemicals not normally found within the body, have been implicated in the modification of, and loss of, tolerance to AMA. Several cosmetics are known to contain these xenobiotics, which is of interest given the information provided in regards to known risk factors for PBC development. This review will focus on X monosomy and xenobiotics, which appear to constitute the X-factor of PBC.
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Affiliation(s)
- Ilaria Bianchi
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano (MI), Italy
| | - Ana Lleo
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano (MI), Italy
| | - Francesca Bernuzzi
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano (MI), Italy
| | - Lisa Caliari
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano (MI), Italy
| | - Dan S. Smyk
- Institute of Liver Transplantation, Division of Transplantation Immunology and Mucosal Biology, King’s College London School of Medicine at King’s College Hospital, London, SE5 9RJ UK
| | - Pietro Invernizzi
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Via Manzoni 56, 20089 Rozzano (MI), Italy
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, USA
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Milkiewicz M, Caballería L, Smyk DS, Milkiewicz P. Predicting and preventing autoimmunity: the case of anti-mitochondrial antibodies. AUTOIMMUNITY HIGHLIGHTS 2012; 3:105-12. [PMID: 26000133 PMCID: PMC4389078 DOI: 10.1007/s13317-012-0038-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 10/03/2012] [Indexed: 12/12/2022]
Abstract
To be able to predict who will develop autoimmune disease would allow for early treatment which may dramatically alter the course of the disease. In some cases, it may also lead to prevention of the disease development. The prediction of disease development is based on the analysis of risk factors which have been associated with the disease in question. These factors include genetic susceptibility, as well as immunological and environmental factors. One autoimmune disease that may serve as a model for disease prediction is primary biliary cirrhosis (PBC), an autoimmune liver disease affecting the small- and medium-sized bile ducts. PBC could be an ideal model due to recent advances in elucidating its genetic associations. As well, a variety of immunological and environmental risk factors have been well established. Indeed, the presence of PBC-specific antimitochondrial antibodies and/or antinuclear antibodies has been shown to be predictor of disease development and possibly prognosis. This review will examine the current evidence which suggests that we may potentially be able to predict the development of PBC in some individuals. These concepts may also be applied to autoimmune diseases in general.
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Affiliation(s)
| | | | - Daniel S Smyk
- Institute of Liver Studies, King's College London School of Medicine, London, UK
| | - Piotr Milkiewicz
- Liver Unit, Pomeranian Medical University, Al. Powstancow Wlkp. 72, 70-111 Szczecin, Poland
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Smyk D, Rigopoulou EI, Baum H, Burroughs AK, Vergani D, Bogdanos DP. Autoimmunity and environment: am I at risk? Clin Rev Allergy Immunol 2012; 42:199-212. [PMID: 21337133 DOI: 10.1007/s12016-011-8259-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The complex interplay between environmental factors and genetic susceptibility plays an essential role in disease pathogenesis. This is especially true for autoimmunity, where clinical reports, genomic and epidemiological studies, as well as animal models have identified several environmental and genetic risk factors associated with autoimmune disease. The complexity of this relationship is demonstrated by the vast array of environmental factors that have now been implicated in the induction, and possibly the maintenance of autoimmune disease. The multitude of environmental factors implicated includes both infectious and non-infectious agents. Here, we review one specific autoimmune disease, primary biliary cirrhosis (PBC), as a model for environmental risk factors acting in concert with genetic susceptibility in the disease pathogenesis. PBC is an ideal model, as both infectious and non-infectious environmental agents have been identified as risk factors, and their study provides clues for unravelling the pathogenesis of the disease.
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Affiliation(s)
- Daniel Smyk
- Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, London, UK.
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Invernizzi P, Alessio MG, Smyk DS, Lleo A, Sonzogni A, Fabris L, Candusso M, Bogdanos DP, Iorio R, Torre G. Autoimmune hepatitis type 2 associated with an unexpected and transient presence of primary biliary cirrhosis-specific antimitochondrial antibodies: a case study and review of the literature. BMC Gastroenterol 2012; 12:92. [PMID: 22816667 PMCID: PMC3464927 DOI: 10.1186/1471-230x-12-92] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Accepted: 07/20/2012] [Indexed: 12/14/2022] Open
Abstract
Background Unlike other autoimmune liver diseases, primary biliary cirrhosis (PBC) has never been reported in early childhood, while type 2 autoimmune hepatitis (AIH) is eminently a paediatric disease. Case presentation We describe a case of type 2 AIH with serological positivity for PBC-specific anti-mitochondrial antibodies (AMA) in a 3-year old girl. We found this observation intriguing as AMA and indeed an overlap with PBC are virtually absent in Type 2 AIH, a pediatric form of AIH which is distinct precisely because it is characterized by pathognomonic anti-liver kidney microsomal type 1 (LKM-1) showing a remarkable antigen-specificity directed against cytochrome P4502D6. We also review the literature in relation to AMA positivity in paediatric age and adolescence. In our case, the presence of AIH-2-specific anti-LKM-1 and PBC-specific AMA was confirmed by indirect immunofluorescence (IIF), and immunoblotting and ELISA based on recombinant mitochondrial antigens. The clinical, laboratory and histological features of the child are given in detail. Interestingly the mother was AMA positive without other features of PBC. The child was successfully treated with immunosuppression and five years after the original diagnosis is on a low dose of prednisolone and azathioprine, with no signs of relapse. Anti-LKM-1 antibodies are still present in low titres. AMA were detectable for the first 4 years after the diagnosis and disappeared later. Conclusion This is the first case report in the literature of AIH type 2 with an unexpected PBC-specific AMA positivity in a young child. Response to immunosuppressive treatment was satisfactory and similar to that described in AIH. A review of published reports on AMA positivity in paediatric age shows that the antibody may arise in the context of immunodeficiency and is variably associated with liver damage.
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Affiliation(s)
- Pietro Invernizzi
- Center for Autoimmune Liver Diseases, Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano(MI), Italy.
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Sex differences associated with primary biliary cirrhosis. Clin Dev Immunol 2012; 2012:610504. [PMID: 22693524 PMCID: PMC3369468 DOI: 10.1155/2012/610504] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 02/27/2012] [Indexed: 12/14/2022]
Abstract
Primary biliary cirrhosis (PBC) is a cholestatic liver disease of autoimmune origin, characterised by the destruction of small intrahepatic bile ducts. The disease has an unpredictable clinical course but may progress to fibrosis and cirrhosis. The diagnostic hallmark of PBC is the presence of disease-specific antimitochondrial antibodies (AMA), which are pathognomonic for the development of PBC. The disease overwhelmingly affects females, with some cases of male PBC being reported. The reasons underlying the low incidence of males with PBC are largely unknown. Epidemiological studies estimate that approximately 7–11% of PBC patients are males. There does not appear to be any histological, serological, or biochemical differences between male and female PBC, although the symptomatology may differ, with males being at higher risk of life-threatening complications such as gastrointestinal bleeding and hepatoma. Studies on X chromosome and sex hormones are of interest when studying the low preponderance of PBC in males; however, these studies are far from conclusive. This paper will critically analyze the literature surrounding PBC in males.
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Smyk DS, Bogdanos DP, Kriese S, Billinis C, Burroughs AK, Rigopoulou EI. Urinary tract infection as a risk factor for autoimmune liver disease: from bench to bedside. Clin Res Hepatol Gastroenterol 2012; 36:110-21. [PMID: 21907008 DOI: 10.1016/j.clinre.2011.07.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 07/18/2011] [Accepted: 07/21/2011] [Indexed: 02/08/2023]
Abstract
Autoimmune liver diseases include autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), and primary sclerosing cholangitis. A variety of environmental and genetic risk factors have been associated with these conditions. Recurrent urinary tract infections (rUTI) have been strongly associated with PBC, and to a lesser extent with AIH. These observations were initially based on the observation of significant bacteriuria in female patients with PBC. Larger epidemiological studies demonstrated that there was indeed a strong correlation between recurrent UTI and PBC. AIH has not been linked to recurrent UTI in epidemiological studies; however treatment of UTI with nitrofurantoin can induce AIH. As Escherichia coli is the most prevalent organism isolated in women with UTI, it has been suggested that molecular mimicry between microbial and human PDC-E2 (the main autoantigenic target in PBC) epitopes may explain the link between UTI and PBC. Multiple studies have demonstrated molecular mimicry and immunological cross-reactivity involving microbial and self-antigen mimics. This review will examine the literature surrounding UTI and autoimmune liver disease. This will include case reports and epidemiological studies, as well as experimental data.
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Affiliation(s)
- Daniel S Smyk
- Liver Immunopathology, Institute of Liver Studies and Liver Unit, King's College London School of Medicine at King's College Hospital, Denmark Hill Campus, London SE5 9RS, UK
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Österreicher CH, Trauner M. Xenobiotic-induced liver injury and fibrosis. Expert Opin Drug Metab Toxicol 2012; 8:571-80. [PMID: 22452290 DOI: 10.1517/17425255.2012.674511] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Many different drugs and xenobiotics (chemical compounds foreign to an organism) can injure the bile duct epithelium and cause inflammatory bile duct diseases (cholangiopathies) ranging from transient cholestasis to vanishing bile duct syndrome, sclerosing cholangitis with development of biliary fibrosis and cirrhosis. Animal models of xenobiotic-induced liver injury have provided major mechanistic insights into the molecular mechanisms of xenobiotic-induced cholangiopathies and biliary fibrosis including primary biliary cirrhosis and primary sclerosing cholangitis. AREAS COVERED In this review, the authors discuss the basic principles of xenobiotic-induced liver and bile duct injury and biliary fibrosis with emphasis on animal models. A PubMed search was performed using the search terms "xenobiotic," "liver injury," "cholestasis," and "biliary fibrosis." Reference lists of retrieved articles were also searched for relevant literature. EXPERT OPINION Xenobiotic-induced cholangiopathies are underestimated and frequently overlooked medical conditions due to their often transient nature. However, biliary disease may progress to vanishing bile duct syndrome, biliary fibrosis, and cirrhosis. Moreover, xenobiotics may prime the liver for subsequent liver disease by other agents and may also contribute to the development of hepatobiliary cancer though interaction with resident stem cells.
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Affiliation(s)
- Christoph H Österreicher
- Medical University of Vienna, Institute of Pharmacology, Center for Physiology and Pharmacology, Vienna, Austria
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Abstract
Chemical compounds participate in all the processes of life. Understanding the complex interactions of small molecules such as metabolites and drugs and the biological macromolecules that consume and produce them is key to gaining a wider understanding in a systemic context. Chemical property databases collect information on the biological effects and physicochemical properties of chemical entities. Accessing and using such databases is key to understanding the chemistry of toxic molecules. In this chapter, we present methods to search, understand, download, and manipulate the wealth of information available in public chemical property databases, with particular focus on the database of Chemical Entities of Biological Interest (ChEBI).
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Immunopathogenesis of primary biliary cirrhosis: an old wives' tale. IMMUNITY & AGEING 2011; 8:12. [PMID: 22136162 PMCID: PMC3238302 DOI: 10.1186/1742-4933-8-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 12/02/2011] [Indexed: 12/15/2022]
Abstract
Primary biliary cirrhosis (PBC) is a cholestatic liver disease characterised by the autoimmune destruction of the small intrahepatic bile ducts. The disease has an unpredictable clinical course, but may progress to fibrosis and cirrhosis. Although medical treatment with urseodeoxycholic acid is largely successful, some patients may progress to liver failure requiring liver transplantation. PBC is characterised by the presence of disease specific anti-mitochondrial (AMA) antibodies, which are pathognomonic for PBC development. The disease demonstrates an overwhelming female preponderance and virtually all women with PBC present in middle age. The reasons for this are unknown; however several environmental and immunological factors may be involved. As the immune systems ages, it become less self tolerant, and mounts a weaker response to pathogens, possibly leading to cross reactivity or molecular mimicry. Some individuals display immunological changes which encourage the development of autoimmune disease. Risk factors implicated in PBC include recurrent urinary tract infection in females, as well as an increased prevalence of reproductive complications. These risk factors may work in concert with and possibly even accelerate, immune system ageing, contributing to PBC development. This review will examine the changes that occur in the immune system with ageing, paying particular attention to those changes which contribute to the development of autoimmune disease with increasing age. The review also discusses risk factors which may account for the increased female predominance of PBC, such as recurrent UTI and oestrogens.
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Naiyanetr P, Butler JD, Meng L, Pfeiff J, Kenny TP, Guggenheim KG, Reiger R, Lam K, Kurth MJ, Ansari AA, Coppel RL, López-Hoyos M, Gershwin ME, Leung PSC. Electrophile-modified lipoic derivatives of PDC-E2 elicits anti-mitochondrial antibody reactivity. J Autoimmun 2011; 37:209-16. [PMID: 21763105 DOI: 10.1016/j.jaut.2011.06.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 05/24/2011] [Accepted: 06/01/2011] [Indexed: 12/27/2022]
Abstract
Our laboratory has hypothesized that xenobiotic modification of the native lipoyl moiety of the major mitochondrial autoantigen, the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2), may lead to loss of self-tolerance in primary biliary cirrhosis (PBC). This thesis is based on the finding of readily detectable levels of immunoreactivity of PBC sera against extensive panels of protein microarrays containing mimics of the inner lipoyl domain of PDC-E2 and subsequent quantitative structure-activity relationships (QSARs). Importantly, we have demonstrated that murine immunization with one such mimic, 2-octynoic acid coupled to bovine serum albumin (BSA), induces anti-mitochondrial antibodies (AMAs) and cholangitis. Based upon these data, we have focused on covalent modifications of the lipoic acid disulfide ring and subsequent analysis of such xenobiotics coupled to a 15mer of PDC-E2 for immunoreactivity against a broad panel of sera from patients with PBC and controls. Our results demonstrate that AMA-positive PBC sera demonstrate marked reactivity against 6,8-bis(acetylthio)octanoic acid, implying that chemical modification of the lipoyl ring, i.e. disruption of the S-S disulfide, renders lipoic acid to its reduced form that will promote xenobiotic modification. This observation is particularly significant in light of the function of the lipoyl moiety in electron transport of which the catalytic disulfide constantly opens and closes and, thus, raises the intriguing thesis that common electrophilic agents, i.e. acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs), may lead to xenobiotic modification in genetically susceptible individuals that results in the generation of AMAs and ultimately clinical PBC.
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Affiliation(s)
- Phornnop Naiyanetr
- Division of Rheumatology, Allergy, and Clinical Immunology, Department of Internal Medicine, University of California, Davis, CA 95616, USA
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Smyk D, Cholongitas E, Kriese S, Rigopoulou EI, Bogdanos DP. Primary biliary cirrhosis: family stories. Autoimmune Dis 2011; 2011:189585. [PMID: 21687641 PMCID: PMC3112499 DOI: 10.4061/2011/189585] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 02/09/2011] [Accepted: 03/07/2011] [Indexed: 01/03/2023] Open
Abstract
Primary biliary cirrhosis (PBC) is a chronic immune-mediated cholestatic liver disease of unknown aetiology which affects mostly women in middle age. Familial PBC is when PBC affects more than one member of the same family, and data suggest that first-degree relatives of PBC patients have an increased risk of developing the disease. Most often, these familial clusters involve mother-daughter pairs, which is consistent with the female preponderance of the disease. These clusters provide evidence towards a genetic basis underlying PBC. However, clusters of nonrelated individuals have also been reported, giving strength to an environmental component. Twin studies have demonstrated a high concordance for PBC in monozygotic twins and a low concordance among dizygotic twins. In conclusion, studies of PBC in families clearly demonstrate that genetic, epigenetic, and environmental factors play a role in the development of the disease.
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Affiliation(s)
- Daniel Smyk
- Institute of Liver Studies, King's College London School of Medicine at King's College Hospital, Denmark Hill Campus, London SE5 9RS, UK
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Overcoming a “Probable” Diagnosis in Antimitochondrial Antibody Negative Primary Biliary Cirrhosis: Study of 100 Sera and Review of the Literature. Clin Rev Allergy Immunol 2010; 42:288-97. [DOI: 10.1007/s12016-010-8234-y] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Abstract
Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease in which an immune-mediated injury targets the small intrahepatic bile ducts. PBC is further characterized by highly specific serum antimitochondrial autoantibodies (AMA) and autoreactive T cells, a striking female predominance, a strong genetic susceptibility, and a plethora of candidate environmental factors to trigger the disease onset. For these reasons PBC appears ideal to represent the developments of the clonal selection theory over the past decades. First, a sufficiently potent autoimmunogenic stimulus in PBC would require the coexistence of numerous pre-existing conditions (mostly genetic, as recently illustrated by genome-wide association studies and animal models) to perpetuate the destruction of the biliary epithelium by the immune system via the persistence of forbidden clones. Second, the proposed modifications of mitochondrial autoantigens caused by infectious agents and/or xenobiotics well illustrate the possibility that peculiar changes in the antigen structure and flexibility may contribute to tolerance breakdown. Third, the unique apoptotic features demonstrated for cholangiocytes are the ideal setting for the development of mitochondrial autoantigen presentation to the immune system through macrophages and AMA thus turning the non traditional mitochondrial antigen into a traditional one. This article will review the current knowledge on PBC etiology and pathogenesis in light of the clonal selection theory developments.
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Selmi C, Affronti A, Ferrari L, Invernizzi P. Immune-mediated bile duct injury: The case of primary biliary cirrhosis. World J Gastrointest Pathophysiol 2010; 1:118-28. [PMID: 21607152 PMCID: PMC3097954 DOI: 10.4291/wjgp.v1.i4.118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 08/08/2010] [Accepted: 08/15/2010] [Indexed: 02/07/2023] Open
Abstract
Autoimmune cholangitis would be the appropriate name to define the immune-mediated bile duct injury following the breakdown of tolerance to mitochondrial proteins and the appearance of serum autoantibodies and autoreactive T cells. Nevertheless, the condition is universally named primary biliary cirrhosis (PBC). The disease etiology and pathogenesis remain largely unknown despite the proposed lines of evidence. One twin study and numerous epidemiology reports suggest that both a susceptible genetic background and environmental factors determine disease onset while a recent genome-wide association study proposed highly significant associations with several common genetic polymorphisms in subgroups of patients. Specific infectious agents and chemicals may contribute to the disease onset and perpetuation in a genetically susceptible host, possibly through molecular mimicry. Importantly, several murine models have been proposed and include strains in which PBC is genetically determined or induced by immunization with chemicals and bacteria. From a pathogenetic standpoint, new exciting data have demonstrated the unique apoptotic features of bile duct cells that allow the mitochondrial autoantigens to be taken up in their intact form within apoptotic blebs. We are convinced that the application of the most recent molecular techniques will soon provide developments in PBC etiology and pathogenesis with likely implications in diagnostics and therapeutics.
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Selmi C, Diana A, Cocchi CA, Zuin M, Gershwin ME. Environmental factors and the induction of autoimmunity in primary biliary cirrhosis. Expert Rev Clin Immunol 2010; 4:239-45. [PMID: 20477053 DOI: 10.1586/1744666x.4.2.239] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Primary biliary cirrhosis (PBC) is a chronic cholestatic disease with an autoimmune pathogenesis and an unknown etiology, predominantly affecting postmenopausal women. The term PBC is a misnomer since most cases currently diagnosed have limited probability to develop cirrhosis. Antimitochondrial autoantibodies, elevated IgM and selective destruction of the intrahepatic bile ducts are the hallmarks of PBC. A permissive genetic background is critical in producing susceptibility despite limited associations with alleles within the MHC. The disease has incomplete concordance in monozygotic twins and its geoepidemiology suggests a role for environmental factors in the induction of PBC. This hypothesis is further supported by clinical (risk factors) and experimental evidence. Some of the factors incriminated model molecular mimicry by infectious agents and xenobiotic chemicals. Additional candidates are being proposed through large screening; all proposed associations ultimately require confirmation in animal models and clinical practice.
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Affiliation(s)
- Carlo Selmi
- University of Milan, Internal Medicine and Liver Unit, DIMCO San Paolo Hospital School of Medicine, Italy
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Invernizzi P, Selmi C, Gershwin ME. Update on primary biliary cirrhosis. Dig Liver Dis 2010; 42:401-8. [PMID: 20359968 PMCID: PMC2871061 DOI: 10.1016/j.dld.2010.02.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 02/24/2010] [Indexed: 12/11/2022]
Abstract
Primary biliary cirrhosis is an autoimmune chronic liver disease characterized by progressive bile duct destruction eventually leading to cirrhosis, liver failure, and death. The autoimmune pathogenesis is supported by a plethora of experimental and clinical data, such as the presence of autoreactive T cells and serum autoantibodies. The aetiology remains unknown, although evidence suggests a role for both genetic susceptibility and environmental factors that remain to be determined. In fact, a number of chemicals and infectious agents have been proposed to induce the disease in predisposed individuals. The recent availability of several murine models will significantly help in understanding pathophysiology mechanisms. In this review, we critically summarize the most recent data on the aetiopathogenesis of primary biliary cirrhosis, discuss the latest theories and developments, and suggest directions for future research.
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Affiliation(s)
- Pietro Invernizzi
- Division of Internal Medicine and Hepatobiliary Immunopathology Unit, IRCCS Istituto Clinico Humanitas, Rozzano, Italy, Division of Rheumatology, Allergy, and Clinical Immunology, University of California at Davis, Davis, CA
| | - Carlo Selmi
- Division of Internal Medicine and Hepatobiliary Immunopathology Unit, IRCCS Istituto Clinico Humanitas, Rozzano, Italy, Division of Rheumatology, Allergy, and Clinical Immunology, University of California at Davis, Davis, CA, Department of Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - M. Eric Gershwin
- Division of Rheumatology, Allergy, and Clinical Immunology, University of California at Davis, Davis, CA
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Abstract
PURPOSE OF REVIEW Primary biliary cirrhosis (PBC) is a human autoimmune liver disease whose molecular pathogenesis is poorly understood because of the difficulty in accessing human tissue and the absence of appropriate animal models. Recently, several unique murine models of human PBC have been discovered. These models have great potential for illustrating the cause and the cellular events that lead to biliary-specific damage. The purpose of this review is to summarize recent progress in these models. RECENT FINDINGS The murine models of autoimmune cholangitis include the transforming growth factor beta receptor II (TGF-betaRII) dominant-negative (dnTGF-betaRII), IL-2 receptor alpha deleted (IL-2Ralpha-/-), scurfy, nonobese diabetic (NOD) c3c4, and Ae2 gene-disrupted (Ae2a,b-/-) mice. Recently, we have also established a successful murine model following the immunization with a chemical mimicry of the lipoyl-lysine residue of the E2 component of PDC-E2. SUMMARY These emerging murine models have greatly enabled researchers to address the pathogenesis of human PBC and to elucidate pathogenic factors. These models will ultimately lead to new therapeutic options for human PBC.
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Selmi C, Meda F, Kasangian A, Invernizzi P, Tian Z, Lian Z, Podda M, Gershwin ME. Experimental evidence on the immunopathogenesis of primary biliary cirrhosis. Cell Mol Immunol 2009; 7:1-10. [PMID: 20029462 DOI: 10.1038/cmi.2009.104] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease for which an autoimmune pathogenesis is supported by clinical and experimental data, including the presence of autoantibodies and autoreactive T cells. The etiology remains to be determined, yet data suggest that both a susceptible genetic background and unknown environmental factors determine disease onset. Multiple infectious and chemical candidates have been proposed to trigger the disease in a genetically susceptible host, mostly by molecular mimicry. Most recently, several murine models have been reported, including genetically determined models as well as models induced by immunization with xenobiotics and bacteria.
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Affiliation(s)
- Carlo Selmi
- Department of Translational Medicine, Università degli Studi di Milano, Milan, Italy.
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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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Wakabayashi K, Yoshida K, Leung PSC, Moritoki Y, Yang GX, Tsuneyama K, Lian ZX, Hibi T, Ansari AA, Wicker LS, Ridgway WM, Coppel RL, Mackay IR, Gershwin ME. Induction of autoimmune cholangitis in non-obese diabetic (NOD).1101 mice following a chemical xenobiotic immunization. Clin Exp Immunol 2009; 155:577-86. [PMID: 19094117 PMCID: PMC2669535 DOI: 10.1111/j.1365-2249.2008.03837.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/27/2008] [Indexed: 01/03/2023] Open
Abstract
Our laboratory has suggested that loss of tolerance to pyruvate dehydrogenase (PDC-E2) leads to an anti-mitochondrial antibody response and autoimmune cholangitis, similar to human primary biliary cirrhosis (PBC). We have suggested that this loss of tolerance can be induced either via chemical xenobiotic immunization or exposure to select bacteria. Our work has also highlighted the importance of genetic susceptibility. Using the non-obese diabetic (NOD) congenic strain 1101 (hereafter referred to as NOD.1101 mice), which has chromosome 3 regions from B6 introgressed onto a NOD background, we exposed animals to 2-octynoic acid (2OA) coupled to bovine serum albumin (BSA). 2OA has been demonstrated previously by a quantitative structural activity relationship to react as well as or better than lipoic acid to anti-mitochondrial antibodies. We demonstrate herein that NOD.1101 mice immunized with 2OA-BSA, but not with BSA alone, develop high titre anti-mitochondrial antibodies and histological features, including portal infiltrates enriched in CD8(+) cells and liver granulomas, similar to human PBC. We believe this model will allow the rigorous dissection of early immunogenetic cause of biliary damage.
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Affiliation(s)
- K Wakabayashi
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis School of Medicine, Davis, CA 95616, USA
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24
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Wakabayashi K, Lian ZX, Leung PSC, Moritoki Y, Tsuneyama K, Kurth MJ, Lam KS, Yoshida K, Yang GX, Hibi T, Ansari AA, Ridgway WM, Coppel RL, Mackay IR, Gershwin ME. Loss of tolerance in C57BL/6 mice to the autoantigen E2 subunit of pyruvate dehydrogenase by a xenobiotic with ensuing biliary ductular disease. Hepatology 2008; 48:531-40. [PMID: 18563844 PMCID: PMC3753011 DOI: 10.1002/hep.22390] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
UNLABELLED There have been important advances in defining effector mechanisms for several human autoimmune diseases. However, for most human autoimmune diseases, the induction stage is less well defined and there are very few clues on etiology. Our laboratory has focused on defining the molecular basis of autoantibody recognition and epitope modification in primary biliary cirrhosis (PBC). Our work has demonstrated that antibodies to mitochondria, the hallmark of disease, are directed against a very conserved site of pyruvate dehydrogenase, the E2 subunit of pyruvate dehydrogenase (PDC-E2). We have also demonstrated that several chemical xenobiotics, chosen based on quantitative structural activity relationship analysis and rigorous epitope analysis, when coupled to the lysine residue that normally binds the lipoic acid cofactor of PDC-E2, reacts as well or better to PBC sera than native autoantigen. In the present studies, we immunized C57BL/6 mice with one such xenobiotic, 2-octynoic acid, coupled to bovine serum albumin and we followed the mice for 24 weeks. Animals were studied for appearance of histologic lesions as well as appearance of antibodies to PDC-E2, serum levels of tumor necrosis factor-alpha and interferon-gamma, and splenic and liver lymphoid phenotyping by flow cytometry. Mice immunized with 2-octynoic acid manifest autoimmune cholangitis, typical mitochondrial autoantibodies, increased liver lymphoid cell numbers, an increase in CD8(+) liver infiltrating cells, particularly CD8(+) T cells that coexpress CD44, and finally an elevation of serum tumor necrosis factor-alpha and interferon-gamma. CONCLUSION these data provide a persuasive argument in favor of an environmental origin for human PBC.
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Affiliation(s)
- Kanji Wakabayashi
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA 95616, USA
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25
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Selmi C, Cocchi CA, Zuin M, Gershwin ME. The Chemical Pathway to Primary Biliary Cirrhosis. Clin Rev Allergy Immunol 2008; 36:23-9. [DOI: 10.1007/s12016-008-8089-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Abstract
The recent development in the authors' laboratory of a sensitive bead assay able to detect AMA in 20% of otherwise AMA-negative sera seems to support the hypothesis that many AMA-negative cases of primary biliary cirrhosis (PCB) are secondary to limits in the methods used and do not represent an independent clinical entity. Clinical data demonstrate that patients without detectable serum AMA do not differ in their natural history from their seropositive counterparts. Anti-nuclear antibodies have been associated repeatedly with more severe disease and are helpful tools in the management of patients who have PBC, particularly those lacking AMA.
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Kawano A, Shimoda S, Kamihira T, Ishikawa F, Niiro H, Soejima Y, Taketomi A, Maehara Y, Nakamura M, Komori A, Migita K, Ishibashi H, Azuma M, Gershwin ME, Harada M. Peripheral tolerance and the qualitative characteristics of autoreactive T cell clones in primary biliary cirrhosis. THE JOURNAL OF IMMUNOLOGY 2007; 179:3315-24. [PMID: 17709548 DOI: 10.4049/jimmunol.179.5.3315] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Primary biliary cirrhosis is characterized by autoreactive T cells specific for the mitochondrial Ag PDC-E2(163-176). We studied the ability of eight T cell clones (TCC) specific for PDC-E2(163-176) to proliferate or become anergic in the presence of costimulation signals. TCC were stimulated with either human PDC-E2(163-176), an Escherichia coli 2-oxoglutarate dehydrogenase mimic (OGDC-E2(34-47)), or analogs with amino acid substitutions using HLA-matched allogeneic PBMC or mouse L-DR53 fibroblasts as APC. Based on their differential responses to these peptides (human PDC-E2(163-176), E. coli OGDC-E2(34-47)) in the different APC systems, TCC were classified as costimulation dependent or independent. Only costimulation-dependent TCC could become anergic. TCC with costimulation-dependent responses to OGDC-E2 become anergic to PDC-E2 when preincubated with mimic, even if costimulation is independent for PDC-E2(163-176). Anergic TCC produced IL-10. One selected TCC could not become anergic after preincubation with PDC-E2(163-176)-pulsed L-DR53 but became anergic using L-DR53 pulsed with PDC-E2 peptide analogs with a substitution at a critical TCR binding site. TCC that only respond to peptide-pulsed PBMC, but not L-DR53, proliferate with peptide-pulsed CD80/CD86-transfected L-DR53; however, anergy was not induced with peptide-pulsed L-DR53 transfected with only CD80 or CD86. These data highlight that costimulation plays a dominant role in maintaining peripheral tolerance to PBC-specific Ags. They further suggest that, under specific circumstances, molecular mimicry of an autoantigen may restore rather than break peripheral tolerance.
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Affiliation(s)
- Akira Kawano
- Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
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Leung PS, Rossaro L, Davis PA, Park O, Tanaka A, Kikuchi K, Miyakawa H, Norman GL, Lee W, Gershwin ME. Antimitochondrial antibodies in acute liver failure: implications for primary biliary cirrhosis. Hepatology 2007; 46:1436-42. [PMID: 17657817 PMCID: PMC3731127 DOI: 10.1002/hep.21828] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UNLABELLED In our previous work, including analysis of more than 10,000 sera from control patients and patients with a variety of liver diseases, we have demonstrated that with the use of recombinant autoantigens, antimitochondrial autoantibodies (AMAs) are only found in primary biliary cirrhosis (PBC) and that a positive AMA is virtually pathognomonic of either PBC or future development of PBC. Although the mechanisms leading to the generation of AMA are enigmatic, we have postulated that xenobiotic-induced and/or oxidative modification of mitochondrial autoantigens is a critical step leading to loss of tolerance. This thesis suggests that a severe liver oxidant injury would lead to AMA production. We analyzed 217 serum samples from 69 patients with acute liver failure (ALF) collected up to 24 months post-ALF, compared with controls, for titer and reactivity with the E2 subunits of pyruvate dehydrogenase, branched chain 2-oxo-acid dehydrogenase, and 2-oxo-glutarate dehydrogenase. AMAs were detected in 28/69 (40.6%) ALF patients with reactivity found against all of the major mitochondrial autoantigens. In addition, and as further controls, sera were analyzed for autoantibodies to gp210, Sp100, centromere, chromatin, soluble liver antigen, tissue transglutaminase, and deaminated gliadin peptides; the most frequently detected nonmitochondrial autoantibody was against tissue transglutaminase (57.1% of ALF patients). CONCLUSION The strikingly high frequency of AMAs in ALF supports the thesis that oxidative stress-induced liver damage may lead to AMA induction. The rapid disappearance of AMAs in these patients provides further support for the contention that PBC pathogenesis requires additional factors, including genetic susceptibility.
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Affiliation(s)
- Patrick S.C. Leung
- Division of Rheumatology/Allergy, University of California, Davis, CA 95616
| | - Lorenzo Rossaro
- Division of Gastroenterology and Hepatology, University of California, Davis Medical Center, Sacramento, CA 95817
| | - Paul A. Davis
- Division of Rheumatology/Allergy, University of California, Davis, CA 95616
| | - Ogyi Park
- Division of Rheumatology/Allergy, University of California, Davis, CA 95616
| | - Atsushi Tanaka
- Department of Medicine, Teikyo University, School of Medicine, Tokyo, 173-8605, Japan
| | - Kentaro Kikuchi
- Fourth Department of Internal Medicine, Teikyo University School of Medicine, Kanagawa, 213-8507, Japan
| | - Hiroshi Miyakawa
- Fourth Department of Internal Medicine, Teikyo University School of Medicine, Kanagawa, 213-8507, Japan
| | | | - William Lee
- Clinical Center for Liver Disease, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - M. Eric Gershwin
- Division of Rheumatology/Allergy, University of California, Davis, CA 95616
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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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30
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Abstract
Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease more commonly found in women (with most cases being diagnosed in the fourth to fifth decades of life) that share peculiar features. Among these, serum antimitochondrial autoantibodies (AMA), serum hyper-immunoglobulin M, and progressive destruction of intrahepatic bile ducts are the most common clinical findings. The pathogenesis of the selective destruction of small-duct biliary epithelial cells is still unknown, although an autoimmune mechanism appears likely due to the detection of autoreactive T and B cells. Genetic background is critical in determining susceptibility to the disease, despite the limited associations with alleles within the major histocompatibility complex. However, among other observations, incomplete concordance of the disease in monozygotic twins and epidemiology strongly support a role for environmental factors in PBC onset. Molecular mimicry by either infectious agents or chemicals has been proposed to induce breakdown of immune tolerance in genetically predisposed individuals. This hypothesis is further supported by clinical (risk factors) and experimental evidence obtained also in animal models.
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Affiliation(s)
- Carlo Selmi
- Division of Internal Medicine, "Luigi Sacco" Department of Clinical Sciences, University of Milan, Milan, Italy and Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, California, USA
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31
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Abstract
Primary biliary cirrhosis (PBC) is an organ-specific autoimmune disease that predominantly affects women and is characterized by chronic, progressive destruction of small intrahepatic bile ducts with portal inflammation and ultimately fibrosis, leading to liver failure in the absence of treatment. Little is known about the etiology of PBC. PBC is characterized by anti-mitochondrial antibodies and destruction of intra-hepatic bile ducts. The serologic hallmark of PBC is the presence of auto-antibodies to mitochondria, especially to the E2 component of the pyruvate dehydrogenase complex (PDC). Current theories on the pathogenesis of PBC favor the hypothesis that the disease develops as a result of an inappropriate immune response following stimulation by an environmental or infectious agent. Some reports suggest that xenobiotics and viral infections may induce PBC. The pathogenetic mechanism is believed to be caused by a defect in immunologic tolerance, resulting in the activation and expansion of self-antigen specific T and B lymphocyte clones and the production of circulating autoantibodies in addition to a myriad of cytokines and other inflammatory mediators. This leads to ductulopenia and persistent cholestasis, by developing end-stage hepatic-cell failure. In this review are given our own and literary data about mechanisms of development of intrahepatic cholestasis and possible ways of its correction.
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32
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Oh SJ, Hong BJ, Choi KY, Park JW. Surface Modification for DNA and Protein Microarrays. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2006; 10:327-43. [PMID: 17069511 DOI: 10.1089/omi.2006.10.327] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Microarrays of biomolecules are emerging as powerful tools for genomics, proteomics, and clinical assays, since they make it possible to screen biologically important binding events in a parallel and high throughput fashion. Because the microarrays are fabricated on a solid support, coating of the surface and immobilization strategy of the biomolecules are major issues for successful microarray fabrication. This review deals with both DNA microarrays and protein microarrays, and focuses on the various modification approaches for the two-dimensional surface materials and three-dimensional ones. In addition, the immobilization strategies including adsorption, covalent attachment, physical entrapment, and affinity attachment of the biomolecules are summarized, and advantage and limitation of representative efforts are discussed.
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Affiliation(s)
- Soon Jin Oh
- Department of Biomedical Science and Technology, Institute of Biomedical Science and Technology, Konkuk University, Seoul, Korea.
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33
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He XS, Ansari AA, Ridgway WM, Coppel RL, Gershwin ME. New insights to the immunopathology and autoimmune responses in primary biliary cirrhosis. Cell Immunol 2006; 239:1-13. [PMID: 16765923 DOI: 10.1016/j.cellimm.2006.04.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 04/19/2006] [Accepted: 04/20/2006] [Indexed: 01/07/2023]
Abstract
Primary biliary cirrhosis (PBC) is an autoimmune liver disease with profound changes in different compartments of the immune system, including those involved in innate, and adaptive immunity. New data from epidemiological studies of PBC have reinforced the thesis that the cause for this relatively uncommon disease is likely to be a combination of both environmental factors and a susceptible genetic predisposition. Recent findings of abnormalities of the innate immune system in PBC suggest that they may serve as links between the environmental factors and the early events in PBC development. Viral and bacterial infections as well as xenobiotics are some of the potential environmental factors that have been implicated in this complex process. Identification of the etiological factors for PBC will point to new preventive or therapeutic treatments.
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Affiliation(s)
- Xiao-Song He
- Division of Rheumatology, Allergy and Clinical Immunology, School of Medicine, University of California, Davis, USA
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34
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Rieger R, Leung PSC, Jeddeloh MR, Kurth MJ, Nantz MH, Lam KS, Barsky D, Ansari AA, Coppel RL, Mackay IR, Gershwin ME. Identification of 2-nonynoic acid, a cosmetic component, as a potential trigger of primary biliary cirrhosis. J Autoimmun 2006; 27:7-16. [PMID: 16876981 DOI: 10.1016/j.jaut.2006.06.002] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 06/20/2006] [Accepted: 06/23/2006] [Indexed: 01/03/2023]
Abstract
Antimitochondrial antibodies (AMA) are unique among autoimmune serologic reactants because of their extremely high association with the index disease primary biliary cirrhosis (PBC). This autoantibody response is specifically directed only to the lipoyl domain of the mitochondrial 2-oxo-acid dehydrogenase complexes, which prompted us to search for environmental mimotopes in the form of xenobiotics and led to our identification of 2-octynoic acid as a high-affinity reactant for AMA. To focus on the chemical characteristics requisite for binding of AMA to the xenobiotic-modified self-peptide, quantitative structure-activity relationship (QSAR) studies were performed using a panel of alkynoic compounds, including examination of the length of the carbon chain and the location of the triple bond in the identified mimotope. Analyses of octynamides that varied in the position of the triple bond demonstrated that only the 2-octynamide reacted strongly with PBC sera. Furthermore, among 2-alkynamides with varying carbon chain length, 2-octyn-, 2-nonyn- (particularly) and 2-decynamide exhibited the highest reactivity. Thus, an optimal chemical structure of the xenobiotically modified epitope recognized by AMA-positive PBC sera is provided by 2-nonynoic acid. The methyl ester of this compound is ranked 2,324th out of 12,945 compounds to which there is occupational exposure, with an 80% female prevalence due to its use in cosmetic products. Our findings illustrate an unusual polyreactivity of anti-PDC-E2 and support the idea of epitope mimicry in the genesis of this autoantibody and perhaps of PBC itself.
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Affiliation(s)
- Roman Rieger
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, GBSF 6510, 95616, USA
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35
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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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36
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Ala A, Stanca CM, Bu-Ghanim M, Ahmado I, Branch AD, Schiano TD, Odin JA, Bach N. Increased prevalence of primary biliary cirrhosis near Superfund toxic waste sites. Hepatology 2006; 43:525-31. [PMID: 16496326 DOI: 10.1002/hep.21076] [Citation(s) in RCA: 146] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are uncommon liver diseases of unknown etiology. Reported clustering of PBC cases may be due to environmental factors. Individuals with PBC have a high prevalence of thyroid disease and thyroid disease is reportedly more prevalent near Superfund toxic waste sites (SFS). The objective of this study was to examine the prevalence and potential clustering of individuals with PBC and PSC near SFS. De-identified clinical and demographic data were used to determine the observed prevalence for each New York City zip code (n = 174) and borough (n = 5) of patients with PBC (PBC-OLT) or PSC (PSC-OLT) who were listed for liver transplantation. The expected prevalence was calculated using Organ Procurement and Transfer Network (OPTN) and U.S. Census data. Both PBC-OLT patients and patients not listed for liver transplantation (PBC-MSSM) were included in the cluster analysis. Prevalence ratios of PBC-OLT and PSC-OLT cases were compared for each zip code and for each borough with regard to the proximity or density of SFS, respectively. SaTScan software was used to identify clusters of PBC-OLT cases and PBC-MSSM cases. Prevalence ratio of PBC-OLT, not PSC-OLT, was significantly higher in zip codes containing or adjacent to SFS (1.225 vs. 0.670, respectively, P = .025). The borough of Staten Island had the highest prevalence ratio of PBC-OLT cases and density of SFS. Significant clusters of both PBC-OLT and PBC-MSSM were identified surrounding SFS. In conclusion, toxin exposure may be a risk factor influencing the clustering of PBC cases.
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Affiliation(s)
- Aftab Ala
- Mount Sinai School of Medicine, New York, NY 10029, USA
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37
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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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38
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Affiliation(s)
- Marshall M Kaplan
- Division of Gastroenterology, Tufts-New England Medical Center, Boston, MA 02111, USA.
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39
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Amano K, Leung PSC, Rieger R, Quan C, Wang X, Marik J, Suen YF, Kurth MJ, Nantz MH, Ansari AA, Lam KS, Zeniya M, Matsuura E, Coppel RL, Gershwin ME. Chemical xenobiotics and mitochondrial autoantigens in primary biliary cirrhosis: identification of antibodies against a common environmental, cosmetic, and food additive, 2-octynoic acid. THE JOURNAL OF IMMUNOLOGY 2005; 174:5874-83. [PMID: 15845458 DOI: 10.4049/jimmunol.174.9.5874] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Emerging evidence has suggested environmental factors as causative agents in the pathogenesis of primary biliary cirrhosis (PBC). We have hypothesized that in PBC the lipoyl domain of the immunodominant E2 component of pyruvate dehydrogenase (PDC-E2) is replaced by a chemical xenobiotic mimic, which is sufficient to break self-tolerance. To address this hypothesis, based upon our quantitative structure-activity relationship data, a total of 107 potential xenobiotic mimics were coupled to the lysine residue of the immunodominant 15 amino acid peptide of the PDC-E2 inner lipoyl domain and spotted on microarray slides. Sera from patients with PBC (n = 47), primary sclerosing cholangitis (n = 15), and healthy volunteers (n = 20) were assayed for Ig reactivity. PBC sera were subsequently absorbed with native lipoylated PDC-E2 peptide or a xenobiotically modified PDC-E2 peptide, and the remaining reactivity analyzed. Of the 107 xenobiotics, 33 had a significantly higher IgG reactivity against PBC sera compared with control sera. In addition, 9 of those 33 compounds were more reactive than the native lipoylated peptide. Following absorption, 8 of the 9 compounds demonstrated cross-reactivity with lipoic acid. One compound, 2-octynoic acid, was unique in both its quantitative structure-activity relationship analysis and reactivity. PBC patient sera demonstrated high Ig reactivity against 2-octynoic acid-PDC-E2 peptide. Not only does 2-octynoic acid have the potential to modify PDC-E2 in vivo but importantly it was/is widely used in the environment including perfumes, lipstick, and many common food flavorings.
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Affiliation(s)
- Katsushi Amano
- Division of Rheumatology, Allergy and Clinical Immunology, Genomic and Biomedical Sciences Facility, University of California, Davis, CA 95616, USA
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Mao TK, Davis PA, Odin JA, Coppel RL, Gershwin ME. Sidechain biology and the immunogenicity of PDC-E2, the major autoantigen of primary biliary cirrhosis. Hepatology 2004; 40:1241-8. [PMID: 15558739 PMCID: PMC3140764 DOI: 10.1002/hep.20491] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The E2 component of mitochondrial pyruvate dehydrogenase complex (PDC-E2) is the immunodominant autoantigen of primary biliary cirrhosis. Whereas lipoylation of PDC-E2 is essential for enzymatic activity and predominates under normal conditions, other biochemical systems exist that also target the lysine residue, including acylation of fatty acids or xenobiotics and ubiquitinylation. More importantly, the immunogenicity can be affected by derivatization of the lysine residue, as the recognition of lipoylated PDC-E2 by patient autoantibodies is enhanced compared with octanoylated PDC-E2. Furthermore, our laboratory has shown that various xenobiotic modifications of a peptide representing the immunodominant region of PDC-E2 are immunoreactive against patient sera. The only purported regulatory system that prevents the accumulation of potentially autoreactive PDC-E2 is glutathionylation, in which the lysine-lipoic acid moiety is further modified with glutathione during apoptosis. Interestingly, this system is found in several cell lines, including HeLa, Jurkat, and Caco-2 cells, but not in cholangiocytes and salivary gland epithelial cells, both of which are targets for destruction in primary biliary cirrhosis. Hence, the failure of this or other regulatory system(s) may overwhelm the immune system with immunogenic PDC-E2 that can initiate the breakdown of tolerance in a genetically susceptible individual. In this review the authors survey the data available on the biochemical life of PDC-E2, with particular emphasis on the lysine residue and its known interactions with machinery involved in various posttranslational modifications.
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Affiliation(s)
- Tin K. Mao
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA
| | - Paul A. Davis
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA
| | - Joseph A. Odin
- Department of Hepatology, Mt. Sinai School of Medicine, New York, NY
| | - Ross L. Coppel
- Department of Microbiology, Monash University, Victoria, Australia
| | - M. Eric Gershwin
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA
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Affiliation(s)
- Konstantinos N Lazaridis
- Centr for Basic Research in Digestive Diseases, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
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