1
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Young GR, Ferron AKW, Panova V, Eksmond U, Oliver PL, Kassiotis G, Stoye JP. Gv1, a Zinc Finger Gene Controlling Endogenous MLV Expression. Mol Biol Evol 2021; 38:2468-2474. [PMID: 33560369 PMCID: PMC8136514 DOI: 10.1093/molbev/msab039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The genomes of inbred mice harbor around 50 endogenous murine leukemia virus (MLV) loci, although the specific complement varies greatly between strains. The Gv1 locus is known to control the transcription of endogenous MLVs and to be the dominant determinant of cell-surface presentation of MLV envelope, the GIX antigen. Here, we identify a single Krüppel-associated box zinc finger protein (ZFP) gene, Zfp998, as Gv1 and show it to be necessary and sufficient to determine the GIX+ phenotype. By long-read sequencing of bacterial artificial chromosome clones from 129 mice, the prototypic GIX+ strain, we reveal the source of sufficiency and deficiency as splice-acceptor variations and highlight the varying origins of the chromosomal region encompassing Gv1. Zfp998 becomes the second identified ZFP gene responsible for epigenetic suppression of endogenous MLVs in mice and further highlights the prominent role of this gene family in control of endogenous retroviruses.
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Affiliation(s)
- George R Young
- Retrovirus-host Interactions Laboratory, The Francis Crick Institute, London, UK
| | - Aaron K W Ferron
- Retrovirus-host Interactions Laboratory, The Francis Crick Institute, London, UK
| | - Veera Panova
- Retroviral Immunology, The Francis Crick Institute, London, UK
| | - Urszula Eksmond
- Retroviral Immunology, The Francis Crick Institute, London, UK
| | | | - George Kassiotis
- Retroviral Immunology, The Francis Crick Institute, London, UK.,Department of Infectious Disease, Imperial College London, London, UK
| | - Jonathan P Stoye
- Retrovirus-host Interactions Laboratory, The Francis Crick Institute, London, UK.,Department of Infectious Disease, Imperial College London, London, UK
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2
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Ito K, Baudino L, Kihara M, Leroy V, Vyse TJ, Evans LH, Izui S. Three Sgp loci act independently as well as synergistically to elevate the expression of specific endogenous retroviruses implicated in murine lupus. J Autoimmun 2013; 43:10-7. [PMID: 23465716 DOI: 10.1016/j.jaut.2013.01.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 01/28/2013] [Accepted: 01/31/2013] [Indexed: 01/06/2023]
Abstract
Endogenous retroviruses are implicated in murine lupus nephritis. They provide a source of nephritogenic retroviral gp70-anti-gp70 immune complexes through the production of serum gp70 protein and anti-gp70 autoantibodies as a result of the activation of TLR7. The Sgp (serum gp70 production) loci identified in lupus-prone mice play distinct roles for the expression of different classes of endogenous retroviruses, as Sgp3 regulates the transcription of xenotropic, polytropic and modified polytropic (mPT) viruses, and Sgp4 the transcription of only xenotropic viruses. In the present study, we extended these analyses to a third locus, Sgp5, using BALB/c mice congenic for the NZW-derived Sgp5 allele and also explored the possible interaction of Sgp3 and Sgp4 loci to promote the expression of endogenous retroviruses and serum gp70. The analysis of Sgp5 BALB/c congenic mice demonstrated that the Sgp5 locus enhanced the expression of xenotropic and mPT viruses, thereby upregulating the production of serum gp70. These data indicate a distinct action of the Sgp5 locus on the expression of endogenous retroviruses, as compared with two other Sgp loci. Moreover, comparative analysis of C57BL/6 double congenic mice for Sgp3 and Sgp4 loci with single congenic mice revealed that Sgp3 and Sgp4 acted synergistically to elevate the transcription of the potentially replication-competent Xmv18 provirus and the production of serum gp70. This indicates that the combined effect of three different Sgp loci markedly enhance the expression of endogenous retroviruses and their gene product, serum gp70, thereby contributing to the formation of nephritogenic gp70-anti-gp70 immune complexes in murine lupus.
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Affiliation(s)
- Kiyoaki Ito
- Department of Pathology and Immunology, University of Geneva, 1211 Geneva 4, Switzerland
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3
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Leroy V, Kihara M, Baudino L, Brighouse G, Evans LH, Izui S. Sgp3 and TLR7 stimulation differentially alter the expression profile of modified polytropic retroviruses implicated in murine systemic lupus. J Autoimmun 2012; 38:361-8. [PMID: 22503566 DOI: 10.1016/j.jaut.2012.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 02/27/2012] [Accepted: 03/07/2012] [Indexed: 12/24/2022]
Abstract
The envelope glycoprotein, gp70, of endogenous retroviruses represents one of the major nephritogenic autoantigens implicated in murine systemic lupus erythematosus. Among different endogenous retroviruses (ecotropic, xenotropic and polytropic), lupus-prone mice express remarkably high levels of modified polytropic (mPT) retroviruses, which are controlled by the Sgp3 (serum gp70 production) locus. To define the contribution of the Sgp3 locus derived from lupus-prone mice to the expression of the specific mPT proviruses, the genetic origin of different mPT viruses expressed in livers and thymi of wild-type and Sgp3 congenic C57BL/6 mice was determined through clonal analysis of their transcripts. Among 13 mPT proviruses present in the C57BL/6 genome, only 3 proviruses (Mpmv6, Mpmv10 and Mpmv13) were selectively but differentially expressed in livers and thymi. This was likely a result of co-regulated expression with host genes because of their integration in the same transcriptional direction. In contrast, Sgp3 induced the steady-state expression of an additional select group of mPT proviruses and, after stimulation of TLR7, the highly upregulated expression of a potentially replication-competent mPT virus Mpmv4. These results indicated that the expression of distinct subpopulations of mPT retroviruses was regulated by Sgp3- and TLR7-dependent mechanisms. The induction of potentially replication-competent mPT viruses and the upregulation of one such virus after stimulation with TLR7 in Sgp3 congenic mice further highlight the implication of Sgp3 in autoimmune responses against nephritogenic serum gp70 through the activation of TLR7.
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Affiliation(s)
- Valérie Leroy
- Department of Pathology and Immunology, University of Geneva, 1211 Geneva 4, Switzerland
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4
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Kihara M, Leroy V, Baudino L, Evans LH, Izui S. Sgp3 and Sgp4 control expression of distinct and restricted sets of xenotropic retroviruses encoding serum gp70 implicated in murine lupus nephritis. J Autoimmun 2011; 37:311-8. [PMID: 21982749 DOI: 10.1016/j.jaut.2011.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Revised: 09/02/2011] [Accepted: 09/05/2011] [Indexed: 12/23/2022]
Abstract
The envelope glycoprotein gp70 of endogenous retroviruses implicated in murine lupus nephritis is secreted by hepatocytes and its expression is controlled by Sgp3 (serum gp70 production 3) and Sgp4 loci derived from lupus-prone mice. Among three different endogenous retroviruses (ecotropic, xenotropic and polytropic), xenotropic viruses are considered to be the major source of serum gp70. Although the abundance of xenotropic viral gp70 RNA in livers was up-regulated by the presence of these two Sgp loci, it has not yet been clear whether Sgp3 and Sgp4 regulate the expression of a fraction or multiple xenotropic viruses present in mouse genome. To address this question, we determined the genetic origin of xenotropic viral sequences expressed in wild-type and two different Sgp congenic C57BL/6 mice. Among 14 xenotropic proviruses present in the C57BL/6 genome, only two proviruses (Xmv10 and Xmv14) were actively transcribed in wild-type C57BL/6 mice. In contrast, Sgp3 enhanced the transcription of Xmv10 and induced the transcription of three additional xenotropic viruses (Xmv15, Xmv17 and Xmv18), while Sgp4 induced the expression of a different xenotropic virus (Xmv13). Notably, stimulation of TLR7 in Sgp3 congenic C57BL/6 mice led to a highly enhanced expression of potentially replication-competent Xmv18. These results indicated that Sgp3 and Sgp4 independently regulated the transcription of distinct and restricted sets of xenotropic viruses in trans, thereby promoting the production of nephritogenic gp70 autoantigens. Furthermore, the induced expression of potentially replication-competent xenotropic viruses by Sgp3 may contribute to the development of autoimmune responses against gp70 through the activation of TLR7.
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Affiliation(s)
- Masao Kihara
- Department of Pathology and Immunology, University of Geneva, 1211 Geneve 4, Switzerland
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5
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Santiago-Raber ML, Baudino L, Alvarez M, van Rooijen N, Nimmerjahn F, Izui S. TLR7/9-mediated monocytosis and maturation of Gr-1(hi) inflammatory monocytes towards Gr-1(lo) resting monocytes implicated in murine lupus. J Autoimmun 2011; 37:171-9. [PMID: 21665436 DOI: 10.1016/j.jaut.2011.05.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 05/16/2011] [Accepted: 05/18/2011] [Indexed: 12/24/2022]
Abstract
Circulating monocytes are divided into two major, phenotypically and functionally distinct subsets: Gr-1(hi) "inflammatory" and Gr-1(lo) "resting" monocytes. One of the unique cellular abnormalities in lupus-prone mice is monocytosis, which is characterized by a selective expansion of Gr-1(lo) monocytes and dependent on the expression of stimulatory IgG Fc receptors (FcγR). We speculated that IgG immune complexes containing nuclear antigens could stimulate Gr-1(hi) monocytes through interaction with FcγRs and then TLR7 and TLR9, thereby promoting the maturation towards Gr-1(lo) monocytes. In the present study, we assessed this hypothesis by analyzing effects of TLR9 or TLR7 agonist on monocytes in vivo. The analysis of various surface markers differentially expressed on both subsets of monocytes in combination with selective depletion of either subset revealed that within 48 h after injection of the TLR9 agonist CpG, approximately one third of Gr-1(hi) monocytes became phenotypically identical to Gr-1(lo) monocytes. In addition, we observed approximately two-fold increases in the total monocyte population 8-24 h after injection of CpG. Moreover, the activation of TLR9 resulted in an increased expression of stimulatory FcγRIV relative to inhibitory FcγRIIB on monocytes, thereby enhancing their responsiveness to IgG immune complexes. Essentially identical results were obtained after stimulation of TLR7 with a synthetic agonist (1V136). Our results indicate that the activation of TLR7 and TLR9 not only induced the maturation of a fraction of Gr-1(hi) monocytes towards Gr-1(lo) monocytes but also promoted the overall generation of monocytes, thereby supporting the critical role of TLR7 and TLR9 for the development of monocytosis in lupus-prone mice.
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6
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Baudino L, Changolkar LN, Pehrson JR, Izui S. The Sgp3 locus derived from the 129 strain is responsible for enhanced endogenous retroviral expression in macroH2A1-deficient mice. J Autoimmun 2010; 35:398-403. [PMID: 20833509 PMCID: PMC2980350 DOI: 10.1016/j.jaut.2010.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 08/17/2010] [Accepted: 08/22/2010] [Indexed: 10/19/2022]
Abstract
The endogenous retroviral envelope glycoprotein, gp70, implicated in murine lupus nephritis is secreted by hepatocytes, and its expression is largely regulated by the Sgp3 (serum gp70 production 3) locus derived from lupus-prone mice. Because of the localization of the macroH2A1 gene encoding macroH2A histone variants within the Sgp3 interval and of an up-regulated transcription of endogenous retroviral sequences in macroH2A1-deficient C57BL/6 (B6) mice, we investigated whether macroH2A1 is a candidate gene for Sgp3. macroH2A1-deficient B6 mice carrying the 129-derived Sgp3 locus, which was co-transferred with the 129 macroH2A1 mutant gene, displayed increased levels of serum gp70 and hepatic retroviral gp70 RNAs comparable to those of B6.NZB-Sgp3 congenic mice bearing the Sgp3 locus of lupus-prone NZB mice. In contrast, the abundance of retroviral gp70 RNAs in macroH2A1-deficient 129 mice was not elevated at all as compared with wild-type 129 mice. Furthermore, Sgp3 subcongenic B6 mice devoid of the NZB-derived macroH2A1 gene displayed an Sgp3 phenotype identical to that of B6.NZB-Sgp3 congenic mice carrying the NZB-derived macroH2A1 gene, thus excluding macroH2A1 as a candidate Sgp3 gene. Collectively, our data indicate that enhanced transcription of endogenous retroviral sequences observed in macroH2A1-deficient B6 mice is not a result of the macroH2A1 mutation, but due to the presence of the 129-derived Sgp3 locus. In contrast, the effect of a macroH2A1 knockout mutation on the expression of several non-retroviral cellular genes was very similar on the B6 and 129 backgrounds, indicating that these effects were due to the macroH2A1 knockout.
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Affiliation(s)
- Lucie Baudino
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Lakshmi N. Changolkar
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - John R. Pehrson
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Shozo Izui
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
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7
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Baudino L, Yoshinobu K, Dunand-Sauthier I, Evans LH, Izui S. TLR-mediated up-regulation of serum retroviral gp70 is controlled by the Sgp loci of lupus-prone mice. J Autoimmun 2010; 35:153-9. [PMID: 20619604 PMCID: PMC2926185 DOI: 10.1016/j.jaut.2010.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 06/08/2010] [Accepted: 06/13/2010] [Indexed: 12/29/2022]
Abstract
The endogenous retroviral envelope glycoprotein, gp70, implicated in murine systemic lupus erythematosus (SLE), has been considered to be a product of xenotropic, polytropic (PT) and modified PT (mPT) endogenous retroviruses. It is secreted by hepatocytes like an acute phase protein, but its response is under a genetic control. Given critical roles of TLR7 and TLR9 in the pathogenesis of SLE, we assessed their contribution to the acute phase expression of serum gp70, and defined a pivotal role of the Sgp3 (serum gp70 production 3) and Sgp4 loci in this response. Our results demonstrated that serum levels of gp70 were up-regulated in lupus-prone NZB mice injected with TLR7 or TLR9 agonist at levels comparable to those induced by injection of IL-1, IL-6 or TNF. In addition, studies of C57BL/6 Sgp3 and/or Sgp4 congenic mice defined the major roles of these two loci in up-regulated production of serum gp70 during acute phase responses. Finally, the analysis of Sgp3 congenic mice strongly suggests the presence of at least two distinct genetic factors in the Sgp3 interval, one of which controlled the basal-level expression of xenotropic, PT and mPT gp70 and the other which controlled the up-regulated production of xenotropic and mPT gp70 during acute phase responses. Our results uncovered an additional pathogenic role of TLR7 and TLR9 in murine lupus nephritis by promoting the expression of nephritogenic gp70 autoantigen. Furthermore, they revealed the involvement of multiple regulatory genes for the expression of gp70 autoantigen under steady-state and inflammatory conditions in lupus-prone mice.
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MESH Headings
- Acute-Phase Proteins/biosynthesis
- Acute-Phase Proteins/genetics
- Acute-Phase Proteins/immunology
- Acute-Phase Reaction/blood
- Acute-Phase Reaction/complications
- Acute-Phase Reaction/genetics
- Acute-Phase Reaction/immunology
- Acute-Phase Reaction/virology
- Animals
- Autoantigens/biosynthesis
- Autoantigens/blood
- Autoantigens/genetics
- Autoantigens/immunology
- Cytokines/administration & dosage
- Disease Models, Animal
- Endogenous Retroviruses/genetics
- Female
- Gene Expression Regulation, Viral
- Glycoproteins/biosynthesis
- Glycoproteins/blood
- Glycoproteins/genetics
- Glycoproteins/immunology
- Glycoproteins/metabolism
- Humans
- Lipopolysaccharides/administration & dosage
- Lupus Erythematosus, Systemic/blood
- Lupus Erythematosus, Systemic/complications
- Lupus Erythematosus, Systemic/genetics
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/virology
- Lupus Nephritis/etiology
- Membrane Glycoproteins/immunology
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Inbred NZB
- Mice, Transgenic
- Molecular Chaperones/genetics
- Molecular Chaperones/metabolism
- Oligodeoxyribonucleotides/administration & dosage
- Toll-Like Receptor 7/immunology
- Toll-Like Receptor 7/metabolism
- Toll-Like Receptor 9/immunology
- Toll-Like Receptor 9/metabolism
- Viral Proteins/biosynthesis
- Viral Proteins/blood
- Viral Proteins/genetics
- Viral Proteins/immunology
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Affiliation(s)
- Lucie Baudino
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Kumiko Yoshinobu
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | - Leonard H. Evans
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana 59840
| | - Shozo Izui
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
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8
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Baudino L, Yoshinobu K, Morito N, Santiago-Raber ML, Izui S. Role of endogenous retroviruses in murine SLE. Autoimmun Rev 2010; 10:27-34. [PMID: 20659589 DOI: 10.1016/j.autrev.2010.07.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 07/21/2010] [Indexed: 11/17/2022]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by B cell hyperactivity leading to the production of various autoantibodies and subsequent development of glomerulonephritis, i.e. lupus nephritis. Among the principal targets of the autoantibodies produced in murine SLE are nucleic acid-protein complexes and the envelope glycoprotein gp70 of endogenous retroviruses. Recent studies have revealed that the innate receptor TLR7 plays a pivotal role in the development of a wide variety of autoimmune responses against DNA- and RNA-containing nuclear antigens, while TLR9 rather plays a protective role. In addition, the regulation of autoimmune responses against endogenous retroviral gp70 by TLR7 suggests the implication of endogenous retroviruses in this autoimmune response. Moreover, the demonstration that TLR7 is involved in the acute phase expression of serum gp70 uncovers an additional pathogenic role of TLR7 in murine lupus nephritis by promoting the expression of nephritogenic gp70 autoantigen. Clearly, the eventual identification of endogenous retroviruses implicated in murine SLE and of mouse genes regulating their production could provide a clue for the potential role of endogenous retroviruses in human SLE.
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Affiliation(s)
- Lucie Baudino
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
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9
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Cheung YH, Loh C, Pau E, Kim J, Wither J. Insights into the genetic basis and immunopathogenesis of systemic lupus erythematosus from the study of mouse models. Semin Immunol 2009; 21:372-82. [DOI: 10.1016/j.smim.2009.10.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 10/23/2009] [Indexed: 01/15/2023]
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10
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Santiago-Raber ML, Baudino L, Izui S. Emerging roles of TLR7 and TLR9 in murine SLE. J Autoimmun 2009; 33:231-8. [PMID: 19846276 DOI: 10.1016/j.jaut.2009.10.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by B cell hyperactivity leading to the production of various autoantibodies and subsequent development of glomerulonephritis, i.e. lupus nephritis. Among the principal targets of autoantibodies produced in murine SLE are nucleic acid-protein complexes, such as chromatin and ribonucleoproteins, and the envelope glycoprotein gp70 of endogenous retroviruses. The preferential production of these autoantibodies is apparently promoted by the presence of genetic abnormalities leading to defects in the elimination of apoptotic cells and to an enhanced expression of endogenous retroviruses. Moreover, recent studies revealed that the innate receptors TLR7 and TLR9 are critically involved in the activation of dendritic cells and autoreactive B cells through the recognition of endogenous DNA- or RNA-containing antigens and subsequent development of autoimmune responses against nuclear autoantigens. Furthermore, the regulation of autoimmune responses against endogenous retroviral gp70 by TLR7 suggested the implication of endogenous retroviruses in this autoimmune response. Clearly, further elucidation of the precise molecular role of TLR7 and TLR9 in the development of autoimmune responses will help to develop novel therapeutic strategies and targets for SLE.
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Affiliation(s)
- Marie-Laure Santiago-Raber
- Department of Pathology and Immunology, Centre Medical Universitaire, University of Geneva, 1211 Geneva 4, Switzerland
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11
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Yoshinobu K, Baudino L, Santiago-Raber ML, Morito N, Dunand-Sauthier I, Morley BJ, Evans LH, Izui S. Selective up-regulation of intact, but not defective env RNAs of endogenous modified polytropic retrovirus by the Sgp3 locus of lupus-prone mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2009; 182:8094-103. [PMID: 19494335 PMCID: PMC2792900 DOI: 10.4049/jimmunol.0900263] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Endogenous retroviruses are implicated in the pathogenesis of systemic lupus erythematosus (SLE). Because four different classes of endogenous retroviruses, i.e., ecotropic, xenotropic, polytropic, or modified polytropic (mPT), are expressed in mice, we investigated the possibility that a particular class of endogenous retroviruses is associated with the development of murine SLE. We observed >15-fold increased expression of mPT env (envelope) RNA in livers of all four lupus-prone mice, as compared with those of nine nonautoimmune strains of mice. This was not the case for the three other classes of retroviruses. Furthermore, we found that in addition to intact mPT transcripts, many strains of mice expressed two defective mPT env transcripts which carry a deletion in the env sequence of the 3' portion of the gp70 surface protein and the 5' portion of the p15E transmembrane protein, respectively. Remarkably, in contrast to nonautoimmune strains of mice, all four lupus-prone mice expressed abundant levels of intact mPT env transcripts, but only low or nondetectable levels of the mutant env transcripts. The Sgp3 (serum gp70 production 3) locus derived from lupus-prone mice was responsible for the selective up-regulation of the intact mPT env RNA. Finally, we observed that single-stranded RNA-specific TLR7 played a critical role in the production of anti-gp70 autoantibodies. These data suggest that lupus-prone mice may possess a unique genetic mechanism responsible for the expression of mPT retroviruses, which could act as a triggering factor through activating TLR7 for the development of autoimmune responses in mice predisposed to SLE.
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Affiliation(s)
- Kumiko Yoshinobu
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Lucie Baudino
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | - Naoki Morito
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | | | - Bernard J. Morley
- Molecular Genetics and Rheumatology Section, Hammersmith Campus, Imperial College London, London, UK
| | - Leonard H. Evans
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana
| | - Shozo Izui
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
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12
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Martínez-Soria E, Santiago-Raber ML, Ho L, Moll T, Izui S. Protection of Murine Systemic Lupus by the Ea Transgene without Expression of I-E Heterodimers. THE JOURNAL OF IMMUNOLOGY 2008; 181:3651-7. [DOI: 10.4049/jimmunol.181.5.3651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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13
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Baudino L, Yoshinobu K, Morito N, Kikuchi S, Fossati-Jimack L, Morley BJ, Vyse TJ, Hirose S, Jørgensen TN, Tucker RM, Roark CL, Kotzin BL, Evans LH, Izui S. Dissection of genetic mechanisms governing the expression of serum retroviral gp70 implicated in murine lupus nephritis. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:2846-54. [PMID: 18684976 PMCID: PMC2587122 DOI: 10.4049/jimmunol.181.4.2846] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The endogenous retroviral envelope glycoprotein, gp70, implicated in murine lupus nephritis is secreted by hepatocytes as an acute phase protein, and it has been thought to be a product of an endogenous xenotropic virus, NZB-X1. However, since endogenous polytropic (PT) and modified polytropic (mPT) viruses encode gp70s that are closely related to xenotropic gp70, these viruses can be additional sources of serum gp70. To better understand the genetic basis of the expression of serum gp70, we analyzed the abundance of xenotropic, PT, or mPT gp70 RNAs in livers and the genomic composition of corresponding proviruses in various strains of mice, including two different Sgp (serum gp70 production) congenic mice. Our results demonstrated that the expression of different viral gp70 RNAs was remarkably heterogeneous among various mouse strains and that the level of serum gp70 production was regulated by multiple structural and regulatory genes. Additionally, a significant contribution of PT and mPT gp70s to serum gp70 was revealed by the detection of PT and mPT, but not xenotropic transcripts in 129 mice, and by a closer correlation of serum levels of gp70 with the abundance of PT and mPT gp70 RNAs than with that of xenotropic gp70 RNA in Sgp3 congenic mice. Furthermore, the injection of lipopolysaccharides selectively up-regulated the expression of xenotropic and mPT gp70 RNAs, but not PT gp70 RNA. Our data indicate that the genetic origin of serum gp70 is more heterogeneous than previously thought, and that distinct retroviral gp70s are differentially regulated in physiological vs inflammatory conditions.
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Affiliation(s)
- Lucie Baudino
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Kumiko Yoshinobu
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Naoki Morito
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Shuichi Kikuchi
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
| | - Liliane Fossati-Jimack
- Molecular Genetics and Rheumatology Section, Hammersmith Campus, Imperial College London, London, UK
| | - Bernard J. Morley
- Molecular Genetics and Rheumatology Section, Hammersmith Campus, Imperial College London, London, UK
| | - Timothy J. Vyse
- Molecular Genetics and Rheumatology Section, Hammersmith Campus, Imperial College London, London, UK
| | - Sachiko Hirose
- Department of Pathology, Juntendo University School of Medicine, Tokyo, Japan
| | - Trine N. Jørgensen
- Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado and
| | - Rebecca M. Tucker
- Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado and
| | - Christina L. Roark
- Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado and
| | - Brian L. Kotzin
- Integrated Department of Immunology, National Jewish Medical and Research Center, Denver, Colorado and
| | - Leonard H. Evans
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana
| | - Shozo Izui
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland
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14
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B cells in glomerulonephritis: focus on lupus nephritis. Semin Immunopathol 2007; 29:337-53. [PMID: 17943287 DOI: 10.1007/s00281-007-0092-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 09/28/2007] [Indexed: 01/10/2023]
Abstract
The production of pathogenic antibody has been traditionally viewed as the principle contribution of B cells to the pathogenesis of immune-mediated glomerulonephritis. However, it is increasingly appreciated that B cells play a much broader role in such diseases, functioning as antigen-presenting cells, regulators of T cells, dendritic cells, and macrophages and orchestrators of local lymphatic expansion. In this review, we provide an overview of basic B cell biology and consider the evidence implicating B cells in one of the archetypal immune-mediated glomerulonephritides, lupus nephritis.
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Haywood MEK, Gabriel L, Rose SJ, Rogers NJ, Izui S, Morley BJ. BXSB/long-lived is a recombinant inbred strain containing powerful disease suppressor loci. THE JOURNAL OF IMMUNOLOGY 2007; 179:2428-34. [PMID: 17675504 DOI: 10.4049/jimmunol.179.4.2428] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The BXSB strain of recombinant inbred mice develops a spontaneous pathology that closely resembles the human disease systemic lupus erythematosus. Six non-MHC loci, Yaa, Bxs1-4, and Bxs6, have been linked to the development of aspects of the disease while a further locus, Bxs5, may be a BXSB-derived disease suppressor. Disease development is delayed in a substrain of BXSB, BXSB/MpJScr-long-lived (BXSB/ll). We compared the genetic derivation of BXSB/ll mice to the original strain, BXSB/MpJ, using microsatellite markers and single nucleotide polymorphisms across the genome. These differences were clustered and included two regions known to be important in the disease-susceptibility of these mice, Bxs5 and 6, as well as regions on chromosomes 5, 6, 9, 11, 12, and 13. We compared BXSB/ll to >20 strains including the BXSB parental SB/Le and C57BL/6 strains. This revealed that BXSB/ll is a separate recombinant inbred line derived from SB/Le and C57BL/6, but distinctly different from BXSB, that most likely arose due to residual heterozygosity in the BXSB stock. Despite the continued presence of the powerful disease-susceptibility locus Bxs3, BXSB/ll mice do not develop disease. We propose that the disappearance of the disease phenotype in the BXSB/ll mice is due to the inheritance of one or more suppressor loci in the differentially inherited intervals between the BXSB/ll and BXSB strains.
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Rankin J, Boyle JJ, Rose SJ, Gabriel L, Lewis M, Thiruudaian V, Rogers NJ, Izui S, Morley BJ. The Bxs6 locus of BXSB mice is sufficient for high-level expression of gp70 and the production of gp70 immune complexes. THE JOURNAL OF IMMUNOLOGY 2007; 178:4395-401. [PMID: 17371996 DOI: 10.4049/jimmunol.178.7.4395] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
High levels of the retroviral envelope protein gp70 and gp70 immune complexes have been linked to a single locus on chromosome 13 (Bxs6) in the BXSB model, to which linkage of nephritis was also seen. Congenic lines containing the BXSB Bxs6 interval on a non-autoimmune C57BL/10 background were bred in the presence or absence of the BXSB Y chromosome autoimmune accelerator gene (Yaa), which accelerates disease in male mice. In these mice, we have shown that Bxs6 is sufficient to cause high-level expression of gp70 and the production of gp70 autoantibodies, independently of Yaa, with gp70 immune complex levels enhanced by Yaa. In the presence of Yaa, Bxs6 also causes mild nephritis, and interestingly the sporadic production of high levels of anti-DNA Abs in some mice. Fine mapping using rare recombinant mice suggested that Bxs6 lies between 59.7 and 74.8 megabases (Mb), although the interval of 0.6 Mb between 73.6 and 78.6 Mb on chromosome 13 cannot be excluded in this study.
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Affiliation(s)
- Joanna Rankin
- Rheumatology Section, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London, UK
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17
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Haywood MEK, Rose SJ, Horswell S, Lees MJ, Fu G, Walport MJ, Morley BJ. Overlapping BXSB congenic intervals, in combination with microarray gene expression, reveal novel lupus candidate genes. Genes Immun 2007; 7:250-63. [PMID: 16541099 DOI: 10.1038/sj.gene.6364294] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The BXSB mouse strain is an important model of glomerulonephritis observed in systemic lupus erythematosus (SLE). Linkage studies have successfully identified disease-susceptibility intervals; however, extracting the identity of the susceptibility gene(s) in such regions is the crucial next step. Congenic mouse strains present a defined genetic resource that is highly amenable to microarray analysis. We have performed microarray analysis using a series of chromosome 1 BXSB congenic mice with partially overlapping disease-susceptibility intervals. Simultaneous comparison of the four congenic lines allowed the identification of expression differences associated with both the initiation and progression of disease. Thus, we have identified a number of novel SLE disease gene candidates and have confirmed the identity of Ifi202 as a disease candidate in the BXSB strain. Sequencing of the promoter regions of Gas5 has revealed polymorphisms in the BXSB strain, which may account for the differential expression profile. Furthermore, the combination of the microarray results with the different phenotypes of these mice has allowed the identification of a number of expression differences that do not necessarily map to the congenic interval, but may be implicated in disease pathways.
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Affiliation(s)
- M E K Haywood
- Rheumatology Section, Division of Medicine, Imperial College Faculty of Medicine, London, UK
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18
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Tucker AWD, Mellencamp MM, Donadeu M, Scobie L. Retroviremia in commercial pigs and its preliminary association with poor health. J Clin Microbiol 2006; 44:3846-7. [PMID: 17021127 PMCID: PMC1594782 DOI: 10.1128/jcm.01378-06] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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19
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Hamano Y, Tsukamoto K, Abe M, Sun GD, Zhang D, Fujii H, Matsuoka S, Tanaka M, Ishida-Okawara A, Tachikawa H, Nishimura H, Tokunaka K, Hirose S, Suzuki K. Genetic Dissection of Vasculitis, Myeloperoxidase-Specific Antineutrophil Cytoplasmic Autoantibody Production, and Related Traits in Spontaneous Crescentic Glomerulonephritis-Forming/Kinjoh Mice. THE JOURNAL OF IMMUNOLOGY 2006; 176:3662-73. [PMID: 16517735 DOI: 10.4049/jimmunol.176.6.3662] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The spontaneous crescentic glomerulonephritis-forming/Kinjoh (SCG/Kj) mouse is a model of human crescentic glomerulonephritis and vasculitis associated with the production of the myeloperoxidase (MPO)-specific antineutrophil cytoplasmic autoantibody (MPO-ANCA). Although the disease is mediated initially by mutation of the Fas gene (lpr), SCG/Kj mice also have non-Fas predisposing genetic factors. To define these factors, genome-wide quantitative trait locus (QTL) mapping was performed on female (B(6)x SCG/Kj) F(2) intercross mice. Fourteen non-Fas QTLs were identified. QTLs of glomerulonephritis were located on chromosomes 1, 10, 13, 16, and 17, vasculitis on chromosomes 1 and 17, splenomegaly on chromosome 1, hypergammaglobulinemia on chromosomes 1, 2, 4, 6, 7, 11, 13, and 17, antinuclear Ab on chromosomes 1, 8, 10, and 12, and MPO-ANCA production on chromosomes 1 and 10. Significant QTLs derived from SCG/Kj on chromosomes 1, 2, 7, and 13 were designated Scg-1 to Scg-5, respectively, and those derived from B(6) on chromosomes 4, 6, 17, and 10 were designated Sxb-1 to Sxb-4, respectively. Two loci linked to MPO-ANCA production on chromosomes 1 and 10 were designated Man-1 and Man-2 (for MPO-ANCA), respectively. Although both Scg-1 and Scg-2 were on chromosome 1 and shared several functions, it was of interest that aberrant MPO-ANCA production was exclusively controlled by Man-1, the centromeric half region of the Scg-2 chromosomal segment. We also examined the epistatic effects between the lpr mutation and non-Fas susceptibility genes. QTLs are discussed in relation to previously described loci, with emphasis on their candidate genes.
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Affiliation(s)
- Yoshitomo Hamano
- Department of Pathology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
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20
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Wither JE, Loh C, Lajoie G, Heinrichs S, Cai YC, Bonventi G, MacLeod R. Colocalization of Expansion of the Splenic Marginal Zone Population with Abnormal B Cell Activation and Autoantibody Production in B6 Mice with an Introgressed New Zealand Black Chromosome 13 Interval. THE JOURNAL OF IMMUNOLOGY 2005; 175:4309-19. [PMID: 16177071 DOI: 10.4049/jimmunol.175.7.4309] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Polyclonal B cell activation is a prominent feature of the lupus-prone New Zealand Black (NZB) mouse strain. We have previously demonstrated linkage between a region on NZB chromosome 13 and increased costimulatory molecule expression on B cells. In this study we have produced C57BL/6 congenic mice with an introgressed homozygous NZB interval extending from approximately 24 to 73 cM on chromosome 13 (denoted B6.NZBc13). We show that B6.NZBc13 female mice not only have enhanced B cell activation but also share many other B cell phenotypic characteristics with NZB mice, including expansion of marginal zone and CD5+ B cell populations, increased numbers of IgM ELISPOTs, and increased serum levels of total IgM and IgM autoantibodies. In addition these mice have increased T cell activation, increased numbers of germinal centers, mild glomerulonephritis, and produce high-titer IgM and IgG anti-chromatin Abs. Male B6.NZBc13 mice have a less pronounced cellular phenotype, lacking expansion of the marginal zone B cell population and IgG anti-chromatin Ab production, indicating the presence of gender dimorphism for this locus. Thus, we have identified a genetic locus that recapitulates with fidelity the B cell phenotypic abnormalities in NZB mice, and we demonstrate that this locus is sufficient to induce an autoimmune phenotype. The data provide further support to the contention that immune abnormalities leading to altered B cell activation and selection contribute to the development of autoimmunity in NZB mice.
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Affiliation(s)
- Joan E Wither
- Arthritis Centre of Excellence, Toronto Western Research Institute, Toronto, Ontario, Canada.
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Jørgensen TN, Gubbels MR, Kotzin BL. New insights into disease pathogenesis from mouse lupus genetics. Curr Opin Immunol 2005; 16:787-93. [PMID: 15511674 DOI: 10.1016/j.coi.2004.09.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Full manifestation of mouse lupus, similar to the human disease in its severe form, is characterized by elevated antinuclear autoantibody levels and the development of kidney disease. Considerable evidence supports a genetic basis for lupus. The functional dissection of susceptibility loci in multigenic mouse models of lupus has provided insight into the immune abnormalities associated with autoantibody production and other processes critical for inflammation and damage in the kidney. The elucidation of models with single-gene manipulations has also identified immune mechanisms in the pathway to lupus. Recent advances have challenged previously accepted truths and new layers of complexity have become apparent.
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Affiliation(s)
- Trine N Jørgensen
- Amgen Inc., One Amgen Center Drive, Mail Stop 38-2-A, Thousand Oaks, California 91320-1799, USA
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Kikuchi S, Fossati-Jimack L, Moll T, Amano H, Amano E, Ida A, Ibnou-Zekri N, Laporte C, Santiago-Raber ML, Rozzo SJ, Kotzin BL, Izui S. Differential role of three major New Zealand Black-derived loci linked with Yaa-induced murine lupus nephritis. THE JOURNAL OF IMMUNOLOGY 2005; 174:1111-7. [PMID: 15634937 DOI: 10.4049/jimmunol.174.2.1111] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
By assessing the development of Y-linked autoimmune acceleration (Yaa) gene-induced systemic lupus erythematosus in C57BL/6 (B6) x (New Zealand Black (NZB) x B6.Yaa)F(1) backcross male mice, we mapped three major susceptibility loci derived from the NZB strain. These three quantitative trait loci (QTL) on NZB chromosomes 1, 7, and 13 differentially regulated three different autoimmune traits: anti-nuclear autoantibody production, gp70-anti-gp70 immune complex (gp70 IC) formation, and glomerulonephritis. Contributions to the disease traits were further confirmed by generating and analyzing three different B6.Yaa congenic mice, each carrying one individual NZB QTL. The chromosome 1 locus that overlapped with the previously identified Nba2 (NZB autoimmunity 2) locus regulated all three traits. A newly identified chromosome 7 locus, designated Nba5, selectively promoted anti-gp70 autoantibody production, hence the formation of gp70 IC and glomerulonephritis. B6.Yaa mice bearing the NZB chromosome 13 locus displayed increased serum gp70 production, but not gp70 IC formation and glomerulonephritis. This locus, called Sgp3 (serum gp70 production 3), selectively regulated the production of serum gp70, thereby contributing to the formation of nephritogenic gp70 IC and glomerulonephritis, in combination with Nba2 and Nba5 in NZB mice. Among these three loci, a major role of Nba2 was demonstrated, because B6.Yaa Nba2 congenic male mice developed the most severe disease. Finally, our analysis revealed the presence in B6 mice of an H2-linked QTL, which regulated autoantibody production. This locus had no apparent individual effect, but most likely modulated disease severity through interaction with NZB-derived susceptibility loci.
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Affiliation(s)
- Shuichi Kikuchi
- Department of Pathology and Immunology, Centre Médical Universitaire, Geneva, Switzerland
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Xie S, Li L, Chang S, Sharma R, Kaliyaperumal A, Datta SK, Mohan C. Genetic origin of lupus in NZB/SWR hybrids: Lessons from an intercross study. ACTA ACUST UNITED AC 2005; 52:659-67. [PMID: 15693014 DOI: 10.1002/art.20786] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE (SWR x NZB)F(1) (or SNF(1)) hybrid mice succumb to lupus nephritis. A previous analysis of SNF(1) x NZB backcross mice revealed the existence of 4 SWR loci (H2 on chromosome 17, Swrl-1 on chromosome 1, Swrl-2 on chromosome 14, and Swrl-3 on chromosome 18) and 2 NZB loci (Nba1 and Lbw2/Sbw2, both on chromosome 4). A second study focusing on SNF(1) x SWR backcross offspring uncovered 5 suggestive loci for antinuclear antibody formation, consisting of 3 dominant NZB contributions (Nba4 on chromosome 5, Lbw4 on chromosome 6, and Nba5 on chromosome 7) and 2 recessive SWR contributions (Swrl-1 on chromosome 1 and Swrl-4 on chromosome 10). The present intercross study was executed to replicate the earlier findings, using an independent panel of (SWR x NZB)F(2) offspring. METHODS A panel of (NZB x SWR)F(2) hybrids were phenotyped (for renal disease, early mortality, and a variety of autoantibodies) and genotyped (using 95 microsatellite primers positioned across all 19 autosomes and the X chromosome). Linkage analysis was conducted using the derived phenotype and genotype data, with the interval-mapping program MapManager. RESULTS Four suggestive loci were mapped: Swrl-5 on chromosome 1 (peak at 106 cM), linked to hypergammaglobulinemia; an NZB locus on chromosome 5 (Nba4; peak at 15 cM), linked to IgG anti-single-stranded DNA (anti-ssDNA) antibodies, IgG anti-doubled-stranded DNA (anti-dsDNA) antibodies, and glomerulonephritis; an NZB locus on chromosome 13 (Nba6; peak at 28 cM), linked to IgG anti-dsDNA antibodies; and an SWR locus on chromosome 14 (Swrl-2; peak at 30 cM), linked to IgG anti-ssDNA antibodies. Eight additional loci revealed linkage at P < 0.01, of which 7 co-mapped with lupus susceptibility loci previously identified in other models. CONCLUSION Considering all 3 mapping studies together, lupus in SWR/NZB hybrids appears to be the epistatic end product of several distinct loci, of which 3 SWR-derived loci (Swrl-1, Swrl-2, and Swrl-3) and 5 NZB-derived loci (Nba1, Nba3, Nba4, Nba5, and Lbw4) have been independently confirmed. The immunologic functions and molecular identities of these loci await elucidation.
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Affiliation(s)
- Shangkui Xie
- Simmons Arthritis Research Center, University of Texas Southwestern Medical School, Dallas 75390-8884, USA
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Haywood MEK, Rogers NJ, Rose SJ, Boyle J, McDermott A, Rankin JM, Thiruudaian V, Lewis MR, Fossati-Jimack L, Izui S, Walport MJ, Morley BJ. Dissection of BXSB lupus phenotype using mice congenic for chromosome 1 demonstrates that separate intervals direct different aspects of disease. THE JOURNAL OF IMMUNOLOGY 2004; 173:4277-85. [PMID: 15383556 DOI: 10.4049/jimmunol.173.7.4277] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To dissect the individual effects of the four non-MHC, autosomal loci (Bxs1 to Bxs4) that contribute to SLE susceptibility in BXSB mice, we generated congenic lines from chromosome 1 on a C57BL/10.Y(BXSB) (B10.Yaa) background for the intervals (values in megabases (Mb)) Bxs1 (46.3-89.2 Mb), Bxs1/4 (20.0-65.9 Mb), Bxs1/2 (64.4-159.0 Mb), and Bxs2/3 (105.4-189.0 Mb). Glomerulonephritis, qualitatively similar to that seen in the parental BXSB strain, developed in three of these congenic strains. Early onset, severe disease was observed in B10.Yaa.BXSB-Bxs2/3 congenic mice and caused 50% mortality by 12 mo. In B10.Yaa.BXSB-Bxs1/4 mice disease progressed more slowly, resulting in 13% mortality at 12 mo. The progression of renal disease in both of these strains was correlated with the level of anti-dsDNA Abs. B10.Yaa.BXSB-Bxs1 mice, despite their genetic similarity to B10.Yaa.BXSB-Bxs1/4 mice, developed a low-grade glomerulonephritis in the absence of anti-dsDNA Abs. Thus, Bxs4 directed an increase in titer and spectrum of autoantibodies, whereas Bxs1 promoted the development of nephritis. The Bxs2 interval was linked to the production of anti-dsDNA Abs without concomitant glomerulonephritis. In contrast, the Bxs3 interval was sufficient to generate classic lupus nephritis in a nonautoimmune-prone strain. Immune phenotype differed between controls and congenics with a significant increase in B220(+) cells in BXSB and B10.Yaa.BXSB-Bxs2/3, and an increase in CD4 to CD8 ratio in both BXSB and B10.Yaa.BXSB-Bxs1/4. Disease in the Bxs3 mice was delayed in comparison to the BXSB parental strain, emphasizing the necessity for multiple interactions in the production of the full BXSB phenotype.
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Affiliation(s)
- Michelle E K Haywood
- Rheumatology Section, Eric Bywaters Centre, Faculty of Medicine, Imperial College, London, UK
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Santiago-Raber ML, Laporte C, Reininger L, Izui S. Genetic basis of murine lupus. Autoimmun Rev 2004; 3:33-9. [PMID: 14871647 DOI: 10.1016/s1568-9972(03)00062-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/06/2003] [Indexed: 01/12/2023]
Abstract
Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by the formation of a variety of autoantibodies and subsequent development of severe glomerulonephritis. Etiology of SLE remains unknown even if it is now well established that SLE is under polygenic control as well as the contribution of hormonal and environmental factors. The availability of several murine strains that spontaneously develop an autoimmune syndrome resembling human SLE, such as New Zealand, MRL and BXSB mice has provided useful tools for the genetic dissection of susceptibility to SLE. Moreover, development of various transgenic and mutant mice has made it possible to identify a number of susceptibility genes such as those involved in the regulation of apoptosis or B cell receptor signaling that can trigger lupus-like phenotypes. Obviously, further identification of the genetic defects present in lupus-prone mice is of paramount importance for understanding the immunopathogenesis of SLE.
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Tucker RM, Roark CL, Santiago-Raber ML, Izui S, Kotzin BL. Association between nuclear antigens and endogenous retrovirus in the generation of autoantibody responses in murine lupus. ACTA ACUST UNITED AC 2004; 50:3626-36. [PMID: 15529369 DOI: 10.1002/art.20623] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE (NZB x NZW)F(1) (NZB/NZW) mice and other strains of mice with experimental lupus frequently produce autoantibodies to both chromatin constituents and murine leukemia virus envelope gp70. These autoantibody responses are involved in the glomerulonephritis that develops in these mice. This study was undertaken to explore possible connections between these 2 antigen systems. METHODS We used monoclonal antibodies (mAb) derived from unmanipulated NZB/NZW mice to investigate the specificity of anti-gp70 and antichromatin autoantibodies for chromatin constituents, recombinant gp70, NZB retroviruses, and retrovirally infected cells. NZB mice were also immunized with retroviral particles and followed up for study of autoantibody responses. RESULTS Spontaneous autoantibody production in NZB/NZW mice reflects high-level autoimmune responses to nuclear antigens and gp70 that do not cross-react with the other antigen. However, both types of autoantibodies have the capability to bind to the endogenous xenotropic virions NZB-X1 or NZB-X2. The mAbs to recombinant gp70 cross-reacted only with the NZB-X2 virus, whereas the antichromatin mAb frequently bound to both retroviruses. The binding of antichromatin autoantibodies was mediated by nuclear material complexed to the retrovirus, and studies showed that this material can be acquired through the budding process. Immunization with NZB-X1 or NZB-X2 virions induced strong responses to gp70 and was much more effective than chromatin at inducing autoantibody responses to chromatin and double-stranded DNA in NZB mice. CONCLUSION These studies suggest that retroviral virions may harbor nuclear antigens and may link together the autoimmune responses to the disparate antigens, chromatin and gp70.
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Affiliation(s)
- Rebecca M Tucker
- University of Colorado Health Sciences Center and National Jewish Medical and Research Center, Denver, Colorado
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Rigby RJ, Rozzo SJ, Gill H, Fernandez-Hart T, Morley BJ, Izui S, Kotzin BL, Vyse TJ. A novel locus regulates both retroviral glycoprotein 70 and anti-glycoprotein 70 antibody production in New Zealand mice when crossed with BALB/c. THE JOURNAL OF IMMUNOLOGY 2004; 172:5078-85. [PMID: 15067091 DOI: 10.4049/jimmunol.172.8.5078] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Lupus-prone New Zealand Black and New Zealand White mice produce high serum levels of the endogenous retroviral envelope protein gp70 and develop an Ab response to this autoantigen as part of their autoimmune disease. Linkage analysis of two crosses involving New Zealand and BALB/c mice mapped these traits to a group of overlapping loci, including a novel locus on proximal chromosome 12. This locus was linked with serum gp70 and the autoimmune response against it. The linkage of serum gp70 levels to a previously described locus on distal chromosome 4 was also confirmed. Sequence analysis of a candidate gene on distal chromosome 4, Fv1, provided support that this gene may be associated with the control of serum gp70 levels in both New Zealand Black and New Zealand White mice. Linkage data and statistical analysis confirmed a close correlation between gp70 Ag and anti-gp70 Ab levels, and together gave support to the concept that a threshold level of gp70 is required for the production of anti-gp70 Abs. Serum levels of anti-gp70 Abs were closely correlated with the presence of renal disease, more so than anti-dsDNA Abs. Understanding the genetic basis of this complex autoantigen-autoantibody system will provide insight into the pathogenesis of lupus in mice, which may have implications for human disease.
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Affiliation(s)
- Robert J Rigby
- Rheumatology Section, Imperial College Faculty of Medicine, Hammersmith Campus, London, United Kingdom
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Laporte C, Ballester B, Mary C, Izui S, Reininger L. The Sgp3 locus on mouse chromosome 13 regulates nephritogenic gp70 autoantigen expression and predisposes to autoimmunity. THE JOURNAL OF IMMUNOLOGY 2004; 171:3872-7. [PMID: 14500689 DOI: 10.4049/jimmunol.171.7.3872] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
By interval mapping of a backcross progeny between New Zealand White (NZW) and C57BL/6 (B6) mice bearing the Y chromosome-linked autoimmune acceleration gene Yaa, we previously identified a genetic locus on mid-chromosome 13, here designated as Sgp3, showing a major effect on the expression of a nephritogenic autoantigen, gp70. In this study, the NZW-derived Sgp3 region was transferred by backcross procedure and marker-assisted selection on the B6 background to produce three independent congenic strains B6.NZW-Sgp3/1, -Sgp3/2, and -Sgp3/3. We show that NZW homozygosity at a single 3 centiMorgans ( approximately 12 megabases (Mb)) interval between markers D13Mit142 and D13Mit254 mediates increased basal serum levels of gp70 in B6.NZW-Sgp3/1 and B6.NZW-Sgp3/2 mice and with a higher degree in males ( approximately 15 micro g/ml) than in females ( approximately 9 micro g/ml) as compared with B6 ( approximately 2 micro g/ml), revealing a gender effect. However, their gp70 levels are still lower than that of NZW mice ( approximately 60 micro g/ml). In addition, B6.NZW-Sgp3/1 and B6.NZW-Sgp3/2 mice showed a moderate 2- to 3-fold increase in serum gp70 in response to LPS, which contrasted with over a 10-fold increase in NZW mice. Although both B6.NZW-Sgp3/1 and B6.NZW-Sgp3/2 mice failed to produce significant amounts of gp70 anti-gp70 immune complexes, unexpectedly, aged B6.NZW-Sgp3/2 congenic males bearing the Yaa gene developed increased titers of IgG autoantibodies to DNA and chromatin. Our data indicate that Sgp3 is involved in a complex process of gp70 production under polygenic control and may provide a significant contribution to lupus susceptibility not only through up-regulation of gp70 autoantigen production but also predisposition to autoimmunity.
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Affiliation(s)
- Catherine Laporte
- Institut National de la Santé et de la Recherche Médicale Unité 399, Faculté de Médecine, Marseille, France
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