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Richardson B. Epigenetically Altered T Cells Contribute to Lupus Flares. Cells 2019; 8:cells8020127. [PMID: 30764520 PMCID: PMC6406295 DOI: 10.3390/cells8020127] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/26/2019] [Accepted: 02/02/2019] [Indexed: 12/17/2022] Open
Abstract
Lupus flares when genetically predisposed people encounter exogenous agents such as infections and sun exposure and drugs such as procainamide and hydralazine, but the mechanisms by which these agents trigger the flares has been unclear. Current evidence indicates that procainamide and hydralazine, as well as inflammation caused by the environmental agents, can cause overexpression of genes normally silenced by DNA methylation in CD4⁺ T cells, converting them into autoreactive, proinflammatory cytotoxic cells that are sufficient to cause lupus in mice, and similar cells are found in patients with active lupus. More recent studies demonstrate that these cells comprise a distinct CD4⁺ T cell subset, making it a therapeutic target for the treatment of lupus flares. Transcriptional analyses of this subset reveal proteins uniquely expressed by this subset, which may serve as therapeutic to deplete these cells, treating lupus flares.
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Affiliation(s)
- Bruce Richardson
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48103-2200, USA.
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2
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Wu G, Wu N, Li T, Lu W, Yu G. Total glucosides of peony ameliorates Sjögren's syndrome by affecting Th1/Th2 cytokine balance. Exp Ther Med 2016; 11:1135-1141. [PMID: 26998049 DOI: 10.3892/etm.2016.3016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 11/25/2015] [Indexed: 11/05/2022] Open
Abstract
The present study aimed to investigate the molecular mechanisms underlying the effects of total glucosides of peony (TGP) in the treatment of Sjögren's syndrome (SS). A total of 40 mice with SS were evenly assigned into four groups, including: Control group; TGP group, receiving 1 mg TGP daily; hydroxychloroquine (HCQ) group, receiving 0.25 mg HCQ daily; and a combined group, receiving 1 mg TGP and 0.25 mg HCQ daily. After 8 weeks, quantitative polymerase chain reaction and an enzyme-linked immunosorbent assay were used to detect the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), Fas and FasL in each group of mice. In addition, immunohistochemical analysis was used to determine the expression levels of IFN-γ and IL-4. IFN-γ, IL-4, Fas and FasL levels were significantly increased in the control group compared with the other three groups (P<0.05). Furthermore, the expression levels of these factors were reduced in the combined group in comparison with the HCQ group (P<0.05). The ratios of IFN-γ to IL-4 were decreased in the TGP and combined groups compared with the control group (P<0.05). The present results indicate that TGP ameliorates SS by affecting the Th1/Th2 cytokine balance and decreasing the expression levels of IFN-γ, IL-4, Fas and FasL. Therefore, TGP may represent a potential novel therapeutic agent for the treatment of SS.
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Affiliation(s)
- Guolin Wu
- Department of Chinese Traditional Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Nayuan Wu
- Department of Chinese Traditional Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Tianyi Li
- Function Institute of Basic Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Wenwen Lu
- Department of Chinese Traditional Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
| | - Guoyou Yu
- Department of Chinese Traditional Medicine, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310003, P.R. China
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3
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Richardson B, Sawalha AH, Ray D, Yung R. Murine models of lupus induced by hypomethylated T cells (DNA hypomethylation and lupus…). Methods Mol Biol 2012; 900:169-80. [PMID: 22933069 DOI: 10.1007/978-1-60761-720-4_8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
CD4+ T cell DNA hypomethylation may contribute to the development of drug induced and idiopathic human lupus. Inhibiting DNA methylation in mature CD4+ T cells causes MHC-specific autoreactivity in vitro. The lupus-inducing drugs hydralazine and procainamide also inhibit T cell DNA methylation and induce autoreactivity, and T cells from patients with active lupus have hypomethylated DNA and a similarly autoreactive T cell subset. Further, T cells treated with DNA methylation inhibitors demethylate the same sequences that demethylate in T cells from patients with active lupus. The pathologic significance of the autoreactivity induced by inhibiting T cell DNA methylation has been tested by treating murine T cells in vitro with drugs which modify DNA methylation, then injecting the cells into syngeneic female mice. Mice receiving CD4+ T cells demethylated by a variety of agents including procainamide and hydralazine develop a lupus-like disease. Further, transgenic mice with an inducible T cell DNA methylation defect also develop lupus-like autoimmunity. This chapter describes the protocols for inducing autoreactivity in murine T cells in vitro and for inducing autoimmunity in vivo using an adoptive transfer approach or transgenic animal models.
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Affiliation(s)
- Bruce Richardson
- University of Michigan and the Ann Arbor Veteran's Affairs Hospital, Ann Arbor, MI, USA.
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4
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Cooper G, Gilbert K, Greidinger E, James J, Pfau J, Reinlib L, Richardson B, Rose N. Recent advances and opportunities in research on lupus: environmental influences and mechanisms of disease. CIENCIA & SAUDE COLETIVA 2010; 14:1865-76. [PMID: 19851599 DOI: 10.1590/s1413-81232009000500028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 03/05/2008] [Indexed: 12/14/2022] Open
Abstract
We summarize research on mechanisms through which environmental agents may affect the pathogenesis of lupus, discuss three exposures that have been the focus of research in this area, and propose recommendations for new research initiatives. We examined studies pertaining to key mechanistic events and specific exposures. Apoptosis leading to increased production or decreased clearance of immunogenic intracellular self-antigens and defective apoptosis of autoreactive immune cells both have been implicated in the loss of self-tolerance. The adjuvant or bystander effect is also needed to produce a sustained autoimmune response. Activation of toll-like receptors is one mechanism through which these effects may occur. Abnormal DNA methylation may contribute to the pathogenesis of lupus. Each of the specific exposures has been shown, in humans or in mice, to act upon one or more of these pathogenic steps. Specific recommendations for the continued advancement of our understanding of environmental influences on lupus and other autoimmune diseases include the development and use of mouse models with varying degrees of penetrance and manifestations of disease, identification of molecular or physiologic targets of specific exposures, development and use of improved exposure assessment methodologies, and multisite collaborations designed to examine understudied environmental exposures in humans.
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Affiliation(s)
- Glinda Cooper
- National Center for Environmental Assessment, U.S. EnvironmentalProtection Agency, Washington, DC 20460 USA.
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5
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Sawalha AH, Harley JB, Scofield RH. Autoimmunity and Klinefelter's syndrome: when men have two X chromosomes. J Autoimmun 2009; 33:31-4. [PMID: 19464849 DOI: 10.1016/j.jaut.2009.03.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Accepted: 03/03/2009] [Indexed: 11/19/2022]
Abstract
Similar to other autoimmune diseases, systemic lupus erythematosus (SLE) predominately affects women. Recent reports demonstrate excess Klinefelter's among men with SLE and a possible under-representation of Turner's syndrome among women with SLE as well as a case report of a 46,XX boy with SLE. These data suggest that risk of SLE is related to a gene dose effect for the X chromosome. Such an effect could be mediated by abnormal inactivation of genes on the X chromosome as has been demonstrated for CD40L, or by genetic polymorphism as has been demonstrated for Xq28. On the other hand, a gene dose effect could also be mediated by a gene without an SLE-associated polymorphism in that a gene that avoids X inactivation will have a higher level of expression in persons with two X chromosomes.
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Affiliation(s)
- Amr H Sawalha
- Arthritis and Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
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6
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Defective T-cell ERK signaling induces interferon-regulated gene expression and overexpression of methylation-sensitive genes similar to lupus patients. Genes Immun 2008; 9:368-78. [PMID: 18523434 DOI: 10.1038/gene.2008.29] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies against a host of nuclear antigens. The pathogenesis of lupus is incompletely understood. Environmental factors may play a role via altering DNA methylation, a mechanism regulating gene expression. In lupus, genes including CD11a and CD70 are overexpressed in T cells as a result of promoter hypomethylation. T-cell DNA methyltransferase expression is regulated in part by the extracellular signal-regulated kinase (ERK) signaling pathway. In this study, we investigate the effects of decreased ERK pathway signaling in T cells using transgenic animals. We generated a transgenic mouse that inducibly expresses a dominant-negative MEK in T cells in the presence of doxycycline. We show that decreased ERK pathway signaling in T cells results in decreased expression of DNA methyltransferase 1 and overexpression of the methylation-sensitive genes CD11a and CD70, similar to T cells in human lupus. Our transgenic animal model also develops anti-dsDNA antibodies. Interestingly, microarray expression assays revealed overexpression of several interferon-regulated genes in the spleen similar to peripheral blood cells of lupus patients. This model supports the contention that ERK pathway signaling defects in T cells contribute to the development of autoimmunity.
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7
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Cooper GS, Gilbert KM, Greidinger EL, James JA, Pfau JC, Reinlib L, Richardson BC, Rose NR. Recent advances and opportunities in research on lupus: environmental influences and mechanisms of disease. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:695-702. [PMID: 18560522 PMCID: PMC2430222 DOI: 10.1289/ehp.11092] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 03/05/2008] [Indexed: 05/26/2023]
Abstract
OBJECTIVES In this review we summarize research on mechanisms through which environmental agents may affect the pathogenesis of lupus, discuss three exposures that have been the focus of research in this area, and propose recommendations for new research initiatives. DATA SOURCES AND SYNTHESIS We examined studies pertaining to key mechanistic events and specific exposures. Apoptosis leading to increased production or decreased clearance of immunogenic intracellular self-antigens and defective apoptosis of autoreactive immune cells both have been implicated in the loss of self-tolerance. The adjuvant or bystander effect is also needed to produce a sustained autoimmune response. Activation of toll-like receptors is one mechanism through which these effects may occur. Abnormal DNA methylation may also contribute to the pathogenesis of lupus. Each of the specific exposures we examined--Epstein-Barr virus, silica, and trichloroethylene--has been shown, in humans or in mice, to act upon one or more of these pathogenic steps. Specific recommendations for the continued advancement of our understanding of environmental influences on lupus and other autoimmune diseases include the development and use of mouse models with varying degrees of penetrance and manifestations of disease, identification of molecular or physiologic targets of specific exposures, development and use of improved exposure assessment methodologies, and multisite collaborations designed to examine understudied environmental exposures in humans. CONCLUSIONS The advances made in the past decade concerning our understanding of mechanisms involved in the development of lupus and the influence of environmental agents on this process provide a strong foundation for further developments in this field.
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Affiliation(s)
- Glinda S Cooper
- National Center for Environmental Assessment, US Environmental Protection Agency, Washington, DC 20460, USA.
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8
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Zhou Y, Lu Q. DNA methylation in T cells from idiopathic lupus and drug-induced lupus patients. Autoimmun Rev 2008; 7:376-83. [DOI: 10.1016/j.autrev.2008.03.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2008] [Accepted: 03/03/2008] [Indexed: 10/22/2022]
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9
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Denny MF, Chandaroy P, Killen PD, Caricchio R, Lewis EE, Richardson BC, Lee KD, Gavalchin J, Kaplan MJ. Accelerated macrophage apoptosis induces autoantibody formation and organ damage in systemic lupus erythematosus. THE JOURNAL OF IMMUNOLOGY 2006; 176:2095-104. [PMID: 16455965 DOI: 10.4049/jimmunol.176.4.2095] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Increased monocyte/macrophage (Mphi) apoptosis occurs in patients with systemic lupus erythematosus (SLE) and is mediated, at least in part, by an autoreactive CD4(+) T cell subset. Furthermore, autoreactive murine CD4(+) T cells that kill syngeneic Mphi in vitro induce a lupus-like disease in vivo. However, it is unclear whether increased Mphi apoptosis in SLE per se is sufficient to accelerate/promote autoimmunity. We have investigated whether increased Mphi apoptosis in vivo, induced by the administration of clodronate liposomes, can exacerbate the autoimmune phenotype in NZB x SWR (SNF(1)) lupus-prone mice, and induce autoantibody production in haplotype-matched BALB/c x DBA1 (DBF(1)) non-lupus-prone mice. Lupus-prone mice SNF(1) mice that were treated with clodronate liposomes, but not mice treated with vehicle, developed significant increases in autoantibodies to dsDNA, nucleosomes, and the idiotypically related family of nephritic Abs Id(LN)F(1), when compared with untreated SNF(1) mice. Furthermore, clodronate treatment hastened the onset of proteinuria and worsened SNF(1) lupus nephritis. When compared with vehicle-treated controls, clodronate-treated non-lupus-prone DBF(1) mice developed significantly higher levels of anti-nucleosome and Id(LN)F(1) Abs but did not develop lupus nephritis. We propose that Mphi apoptosis contributes to the pathogenesis of autoantibody formation and organ damage through both an increase in the apoptotic load and impairment in the clearance of apoptotic material. This study suggests that mechanisms that induce scavenger cell apoptosis, such as death induced by autoreactive cytotoxic T cells observed in SLE, could play a pathogenic role and contribute to the severity of the disease.
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Affiliation(s)
- Michael F Denny
- Department of Internal Medicine, University of Michigan, Ann Arbor, 48109, USA
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10
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Mo R, Chen J, Grolleau-Julius A, Murphy HS, Richardson BC, Yung RL. Estrogen regulates CCR gene expression and function in T lymphocytes. THE JOURNAL OF IMMUNOLOGY 2005; 174:6023-9. [PMID: 15879095 DOI: 10.4049/jimmunol.174.10.6023] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Estrogen has been implicated in the observed female bias in autoimmune diseases. However, the mechanisms behind this gender dimorphism are poorly defined. We have previously reported that in vivo T cell trafficking is gender- and estrogen-dependent. Chemokine receptors are critical determinants of T cell homing and immune response. In this study, we show that the female gender is associated with increased CD4(+) T cell CCR1-CCR5 gene and protein expression in mice. The increased CCR expression correlates with enhanced in vitro chemotaxis response to MIP-1beta (CCL4). In vivo treatment of young oophorectomized and postmenopausal female mice with 17beta-estradiol also increased CD4(+) T cell CCR expression. Finally, 17beta-estradiol enhances tyrosine phosphorylation in T cells stimulated with MIP-1alpha in a time-dependent manner. Our results indicate an important role of estrogen in determining T cell chemokine response that may help explain the increased susceptibility and severity of autoimmune diseases in females.
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MESH Headings
- Animals
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- Cell Line
- Chemokine CCL3
- Chemokine CCL4
- Chemokine CXCL12
- Chemokines, CC/metabolism
- Chemokines, CXC/pharmacology
- Chemotaxis, Leukocyte/immunology
- Estrogens/administration & dosage
- Estrogens/physiology
- Female
- Gene Expression Regulation/immunology
- Macrophage Inflammatory Proteins/pharmacology
- Male
- Mice
- Mice, Inbred AKR
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Ovariectomy
- Receptors, CCR4
- Receptors, CCR5/biosynthesis
- Receptors, CCR5/genetics
- Receptors, CCR5/physiology
- Receptors, Chemokine/biosynthesis
- Receptors, Chemokine/genetics
- Receptors, Chemokine/physiology
- Sex Characteristics
- Species Specificity
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
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Affiliation(s)
- RuRan Mo
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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11
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Oelke K, Richardson B. Decreased T cell ERK pathway signaling may contribute to the development of lupus through effects on DNA methylation and gene expression. Int Rev Immunol 2005; 23:315-31. [PMID: 15204091 DOI: 10.1080/08830180490452567] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
T cells from patients with active lupus have multiple biochemical abnormalities. One of these is DNA hypomethylation, which in model systems alters gene expression and induces lupus-like autoimmunity. Recent reports indicate that DNA methylation is regulated in part by the ERK pathway, and that ERK pathway signaling is diminished in lupus T cells. This suggests a model in which defective T cell ERK pathway signaling contributes to the development of autoimmunity by decreasing DNA methyltransferase expression, modifying DNA methylation patterns and altering gene expression. This mechanism could contribute to idiopathic and drug-induced lupus.
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Affiliation(s)
- Kurt Oelke
- Department of Medicine, University of Michigan, and the Ann Arbor Veterans Affairs Hospital, Ann Arbor, Michigan
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12
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Kaplan MJ. Apoptosis in systemic lupus erythematosus. Clin Immunol 2004; 112:210-8. [PMID: 15308111 DOI: 10.1016/j.clim.2004.04.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2004] [Accepted: 04/25/2004] [Indexed: 12/17/2022]
Affiliation(s)
- Mariana J Kaplan
- University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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13
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Richardson B, Sawalha AH, Ray D, Yung R. Murine models of lupus induced by hypomethylated T cells. METHODS IN MOLECULAR MEDICINE 2004; 102:285-94. [PMID: 15286391 PMCID: PMC4023250 DOI: 10.1385/1-59259-805-6:285] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CD4+ T-cell DNA hypomethylation may contribute to the development of drug-induced and idiopathic human lupus. Inhibiting DNA methylation in mature CD4+ T cells causes autoreactivity specific to the major histocompatibility complex in vitro. The lupus-inducing drugs hydralazine and procainamide also inhibit T-cell DNA methylation and induce autoreactivity, and T cells from patients with active lupus have hypomethylated DNA and a similarly autoreactive T-cell subset. Further, T cells treated with DNA methylation inhibitors demethylate the same sequences that demethylate in T cells from patients with active lupus. The pathological significance of the autoreactivity induced by inhibiting T-cell DNA methylation has been tested by treating murine T cells in vitro with drugs that modify DNA methylation, then injecting the cells into syngeneic female mice. Mice receiving CD4+ T cells demethylated by a variety of agents, including procainamide and hydralazine, develop a lupuslike disease. This chapter describes the protocols for inducing autoreactivity in murine T cells in vitro and using the cells to induce autoimmunity in vivo.
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Affiliation(s)
- Bruce Richardson
- University of Michigan, Ann Arbor MI
- Ann Arbor Veteran’s Affairs Hospital, Ann Arbor MI
| | - Amr H Sawalha
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK
- US Department of Veterans Affairs Medical Center, Oklahoma City, OK
- Oklahoma Medical Research Foundation, Oklahoma City, OK
| | - Donna Ray
- University of Michigan, Ann Arbor MI
| | - Raymond Yung
- University of Michigan, Ann Arbor MI
- Ann Arbor Veteran’s Affairs Hospital, Ann Arbor MI
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Oelke K, Lu Q, Richardson D, Wu A, Deng C, Hanash S, Richardson B. Overexpression of CD70 and overstimulation of IgG synthesis by lupus T cells and T cells treated with DNA methylation inhibitors. ACTA ACUST UNITED AC 2004; 50:1850-60. [PMID: 15188362 DOI: 10.1002/art.20255] [Citation(s) in RCA: 172] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Generalized DNA hypomethylation contributes to altered T cell function and gene expression in systemic lupus erythematosus (SLE). Some of the overexpressed genes participate in the disease process, but the full repertoire of genes affected is unknown. Methylation-sensitive T cell genes were identified by treating T cells with the DNA methyltransferase inhibitor 5-azacytidine and comparing gene expression with oligonucleotide arrays. CD70, a costimulatory ligand for B cell CD27, was one gene that reproducibly increased. We then determined whether CD70 is overexpressed on T cells treated with other DNA methylation inhibitors and on SLE T cells, and determined its functional significance. METHODS Oligonucleotide arrays, real-time reverse transcription-polymerase chain reaction, and flow cytometry were used to compare CD70 expression in T cells treated with 2 DNA methyltransferase inhibitors (5-azacytidine and procainamide) and 3 ERK pathway inhibitors known to decrease DNA methyltransferase expression (U0126, PD98059, and hydralazine). The consequences of CD70 overexpression were tested by coculture of autologous T and B cells with and without anti-CD70 and measuring IgG production by enzyme-linked immunosorbent assay. The results were compared with those of T cells from lupus patients. RESULTS SLE T cells and T cells treated with DNA methylation inhibitors overexpressed CD70 and overstimulated B cell IgG production. The increase in IgG synthesis was abrogated by anti-CD70. CONCLUSION SLE T cells and T cells treated with DNA methyltransferase inhibitors and ERK pathway inhibitors overexpress CD70. This increased B cell costimulation and subsequent immunoglobulin overproduction may contribute to drug-induced and idiopathic lupus.
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Affiliation(s)
- Kurt Oelke
- University of Michigan, Ann Arbor, 48109, USA
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15
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Abstract
DNA methylation plays an essential role in maintaining T-cell function. A growing body of literature indicates that failure to maintain DNA methylation levels and patterns in mature T cells can result in T-cell autoreactivity in vitro and autoimmunity in vivo. Defective maintenance of DNA methylation may be caused by drugs such as procainamide or hydralazine, or failure to activate the genes encoding maintenance DNA methyltransferases during mitosis, resulting in the development of a lupus-like disease or perhaps other autoimmune disorders. This paper reviews the evidence supporting a role for abnormal T-cell DNA methylation in causing autoimmunity in an animal model of drug-induced lupus, and discusses some of the mechanisms involved. T cells from patients with active lupus have evidence for most if not all of the same methylation abnormalities, suggesting that abnormal DNA methylation plays a role in idiopathic human lupus as well.
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Affiliation(s)
- Bruce Richardson
- Department of Medicine at the University of Michigan and the Ann Arbor VA Hospital, Ann Arbor, MI 48109-0940, USA.
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Yung RL, Ray D, Mo RR, Chen J. T Cell Integrin Overexpression as a Model of Murine Autoimmunity. Biol Proced Online 2003; 5:211-221. [PMID: 14615818 PMCID: PMC248482 DOI: 10.1251/bpo64] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2003] [Revised: 10/09/2003] [Accepted: 10/10/2003] [Indexed: 12/25/2022] Open
Abstract
Integrin adhesion molecules have important adhesion and signaling functions. They also play a central role in the pathogenesis of many autoimmune diseases. Over the past few years we have described a T cell adoptive transfer model to investigate the role of T cell integrin adhesion molecules in the development of autoimmunity. This report summarizes the methods we used in establishing this murine model. By treating murine CD4+ T cells with DNA hypomethylating agents and by transfection we were able to test the in vitro effects of integrin overexpression on T cell autoreactive proliferation, cytotoxicity, adhesion and trafficking. Furthermore, we showed that the ability to induce in vivo autoimmunity may be unique to the integrin lymphocyte function associated antigen-1 (LFA-1).
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Affiliation(s)
- Raymond L. Yung
- Divisions of Geriatrics and Rheumatology, Department of Internal Medicine, University of Michigan. 1500 East Medical Center Drive, Ann Arbor, MI 48109-0940. USA
| | - Donna Ray
- Department of Internal Medicine, University of Michigan. Ann Arbor, MI, 48109-0940. USA
| | - Ru Ran Mo
- Department of Internal Medicine, University of Michigan. Ann Arbor, MI, 48109-0940. USA
| | - Jun Chen
- Department of Internal Medicine, University of Michigan. Ann Arbor, MI, 48109-0940. USA
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17
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Mo RR, Eisenbraun JK, Sonstein J, Craig RA, Curtis JL, Stoolman LM, Chen J, Yung RL. CD49d overexpression and T cell autoimmunity. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:745-53. [PMID: 12847241 DOI: 10.4049/jimmunol.171.2.745] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
D10.G4.1 (D10) cells, a murine conalbumin-reactive Th2 cell line, made to overexpress the beta(2) integrin LFA-1 by pharmacological manipulation or by transfection become autoreactive and are capable of inducing in vivo autoimmunity. However, whether this is specific to LFA-1 and whether overexpression of other T cell integrin molecules has the same effect are unknown. We examined the functional consequences of T cell CD49d (alpha(4) integrin) overexpression by transfecting murine CD49d cDNA into D10 cells. Similar to the LFA-1-transfected cells, the CD49d-overexpressing T cells are autoreactive and proliferate in response to APCs in an MHC class II-dependent manner in the absence of nominal Ag. Additionally, CD49d overexpression is associated with increased in vitro adhesion to endothelial cells and increased in vivo splenic homing. However, in contrast to LFA-1 overexpression, increased T cell CD49d expression is not associated with autoreactive cytotoxicity or the ability to induce in vivo autoimmunity. In addition to the novel observation that CD49d overexpression is sufficient to induce T cell autoreactivity, our results also support the hypothesis that the ability to induce in vivo autoimmunity is related to T cell cytotoxicity and not to T cell proliferation function in the D10 murine adoptive transfer model of autoimmunity.
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Affiliation(s)
- Ru-Ran Mo
- Divisions of Geriatric Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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18
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Deng C, Lu Q, Zhang Z, Rao T, Attwood J, Yung R, Richardson B. Hydralazine may induce autoimmunity by inhibiting extracellular signal-regulated kinase pathway signaling. ARTHRITIS AND RHEUMATISM 2003; 48:746-56. [PMID: 12632429 DOI: 10.1002/art.10833] [Citation(s) in RCA: 191] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE To determine whether hydralazine might decrease DNA methyltransferase (DNMT) expression and induce autoimmunity by inhibiting extracellular signal-regulated kinase (ERK) pathway signaling. METHODS The effect of hydralazine on DNMT was tested in vitro using enzyme inhibition studies, and in vivo by measuring messenger RNA (mRNA) levels and enzyme activity. Effects on ERK, c-Jun N-terminal kinase, and p38 pathway signaling were tested using immunoblotting. Murine T cells treated with hydralazine or an ERK pathway inhibitor were injected into mice and anti-DNA antibodies were measured by enzyme-linked immunosorbent assay. RESULTS In vitro, hydralazine did not inhibit DNMT activity. Instead, hydralazine inhibited ERK pathway signaling, thereby decreasing DNMT1 and DNMT3a mRNA expression and DNMT enzyme activity similar to mitogen-activated protein kinase kinase (MEK) inhibitors. Inhibiting T cell ERK pathway signaling with an MEK inhibitor was sufficient to induce anti-double-stranded DNA antibodies in a murine model of drug-induced lupus, similar to the effect of hydralazine. CONCLUSION Hydralazine reproduces the lupus ERK pathway signaling abnormality and its effects on DNMT expression, and inhibiting this pathway induces autoimmunity. Hydralazine-induced lupus could be caused in part by inducing the same ERK pathway signaling defect that occurs in idiopathic lupus.
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Affiliation(s)
- Chun Deng
- Astrozeneca, Boston, Massachusetts, USA
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Kaplan MJ, Lewis EE, Shelden EA, Somers E, Pavlic R, McCune WJ, Richardson BC. The apoptotic ligands TRAIL, TWEAK, and Fas ligand mediate monocyte death induced by autologous lupus T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:6020-9. [PMID: 12421989 DOI: 10.4049/jimmunol.169.10.6020] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Individuals with systemic lupus erythematosus show evidence of a significant increase in monocyte apoptosis. This process is mediated, at least in part, by an autoreactive T cell subset that kills autologous monocytes in the absence of nominal Ag. We have investigated the apoptotic pathways involved in this T cell-mediated process. Expression of the apoptotic ligands TRAIL, TNF-like weak inducer of apoptosis (TWEAK), and Fas ligand on lupus T cells was determined, and the role of these molecules in the monocyte apoptotic response was examined. We report that these apoptotic ligands mediate the autologous monocyte death induced by lupus T cells and that this cytotoxicity is associated with increased expression of these molecules on activated T cells, rather than with an increased susceptibility of lupus monocytes to apoptosis induced by these ligands. These results define novel mechanisms that contribute to increased monocyte apoptosis characterizing patients with lupus. We propose that this mechanism could provide a source of potentially antigenic material for the autoimmune response and interfere with normal clearing mechanisms.
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Affiliation(s)
- Mariana J Kaplan
- Department of Internal Medicine, University of Michigan, 1150 West Medical Center Drive, 5220 Medical Science Research Building I, Ann Arbor, MI 48109, USA.
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Zhang Z, Deng C, Lu Q, Richardson B. Age-dependent DNA methylation changes in the ITGAL (CD11a) promoter. Mech Ageing Dev 2002; 123:1257-68. [PMID: 12020947 DOI: 10.1016/s0047-6374(02)00014-3] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
DNA methylation patterns change with age in a complex fashion, typically with an overall decrease in genomic deoxymethylcytosine (d(m)C) content, but with local increases in some promoters that contain GC-rich sequences known as CpG islands. While the consequences of age-dependent CpG island methylation have recently been studied in organs such as the colon, less is known about the functional significance of the progressive hypomethylation of promoters lacking CpG islands, and the significance of age-dependent changes in T cell DNA methylation is completely unexplored. We asked if age-dependent DNA hypomethylation might contribute to overexpression of the T cell ITGAL gene, which encodes CD11a, a subunit of LFA-1. CD11a mRNA increased with age as well as with experimentally induced DNA hypomethylation. This increase correlated with hypomethylation of sequences flanking the ITGAL promoter in vitro and in aging. 'Patch' methylation of the region suppressed promoter function. DNA methyltransferases 1 and 3a also decreased with aging. These results indicate that hypomethylation of regions flanking the ITGAL promoter may increase CD11a expression, and suggest that age-dependent hypomethylation of promoters lacking CpG islands, perhaps due to decreased DNA methyltransferase expression, may be one mechanism contributing to increased T cell gene expression with aging.
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Affiliation(s)
- Zhiyong Zhang
- Department of Medicine, Veterans Affairs Hospital, 5310 Cancer Center and Geriatrics Center Building, University of Michigan, Ann Arbor, MI 48109-0940, USA
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