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Tipton CM, Hom JR, Fucile CF, Rosenberg AF, Sanz I. Understanding B-cell activation and autoantibody repertoire selection in systemic lupus erythematosus: A B-cell immunomics approach. Immunol Rev 2019; 284:120-131. [PMID: 29944759 DOI: 10.1111/imr.12660] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Understanding antibody repertoires and in particular, the properties and fates of B cells expressing potentially pathogenic antibodies is critical to define the mechanisms underlying multiple immunological diseases including autoimmune and allergic conditions as well as transplant rejection. Moreover, an integrated knowledge of the antibody repertoires expressed by B cells and plasma cells (PC) of different functional properties and longevity is essential to develop new therapeutic strategies, better biomarkers for disease segmentation, and new assays to measure restoration of B-cell tolerance or, at least, of normal B-cell homeostasis. Reaching these goals, however, will require a more precise phenotypic, functional and molecular definition of B-cell and PC populations, and a comprehensive analysis of the antigenic reactivity of the antibodies they express. While traditionally hampered by technical and ethical limitations in human experimentation, new technological advances currently enable investigators to address these questions in a comprehensive fashion. In this review, we shall discuss these concepts as they apply to the study of Systemic Lupus Erythematosus.
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Affiliation(s)
- Christopher M Tipton
- Lowance Center for Human Immunology, Division of Rheumatology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | - Jennifer R Hom
- Lowance Center for Human Immunology, Division of Rheumatology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
| | | | - Alexander F Rosenberg
- Informatics Institute, University of Alabama at Birmingham, Birmingham, AL.,Department of Microbiology, University of Alabama, Birmingham, AL
| | - Inaki Sanz
- Lowance Center for Human Immunology, Division of Rheumatology, Department of Medicine, Emory University School of Medicine, Atlanta, GA
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2
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Bendorius M, Neeli I, Wang F, Bonam SR, Dombi E, Buron N, Borgne-Sanchez A, Poulton J, Radic M, Muller S. The Mitochondrion-lysosome Axis in Adaptive and Innate Immunity: Effect of Lupus Regulator Peptide P140 on Mitochondria Autophagy and NETosis. Front Immunol 2018; 9:2158. [PMID: 30319621 PMCID: PMC6168670 DOI: 10.3389/fimmu.2018.02158] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 08/31/2018] [Indexed: 12/13/2022] Open
Abstract
Mitochondria deserve special attention as sensors of cellular energy homeostasis and metabolic state. Moreover, mitochondria integrate intra- and extra-cellular signals to determine appropriate cellular responses that range from proliferation to cell death. In autoimmunity, as in other inflammatory chronic disorders, the metabolism of immune cells may be extensively remodeled, perturbing sensitive tolerogenic mechanisms. Here, we examine the distribution and effects of the therapeutic 21-mer peptide called P140, which shows remarkable efficacy in modulating immune responses in inflammatory settings. We measured P140 and control peptide effects on isolated mitochondria, the distribution of peptides in live cells, and their influence on the levels of key autophagy regulators. Our data indicate that while P140 targets macro- and chaperone-mediated autophagy processes, it has little effect, if any, on mitochondrial autophagy. Remarkably, however, it suppresses NET release from neutrophils exposed to immobilized NET-anti-DNA IgG complexes. Together, our results suggest that in the mitochondrion-lysosome axis, a likely driver of NETosis and inflammation, the P140 peptide does not operate by affecting mitochondria directly.
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Affiliation(s)
- Mykolas Bendorius
- Unit Biotechnology and Cell Signaling, Laboratory of Excellence Medalis, CNRS, Strasbourg University, Illkirch, France
| | - Indira Neeli
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Fengjuan Wang
- Unit Biotechnology and Cell Signaling, Laboratory of Excellence Medalis, CNRS, Strasbourg University, Illkirch, France
| | - Srinivasa Reddy Bonam
- Unit Biotechnology and Cell Signaling, Laboratory of Excellence Medalis, CNRS, Strasbourg University, Illkirch, France
| | - Eszter Dombi
- Nuffield Department of Women's and Reproductive Health, Women's Centre, Oxford, United Kingdom
| | | | | | - Joanna Poulton
- Nuffield Department of Women's and Reproductive Health, Women's Centre, Oxford, United Kingdom
| | - Marko Radic
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Sylviane Muller
- Unit Biotechnology and Cell Signaling, Laboratory of Excellence Medalis, CNRS, Strasbourg University, Illkirch, France.,Institute for Advanced Study, University of Strasbourg, Strasbourg, France
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3
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Gould TJ, Tóth K, Mücke N, Langowski J, Hakusui AS, Olins AL, Olins DE. Defining the epichromatin epitope. Nucleus 2017; 8:625-640. [PMID: 28960120 DOI: 10.1080/19491034.2017.1380141] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Epichromatin is identified by immunostaining fixed and permeabilized cells with particular bivalent anti-nucleosome antibodies (mAbs PL2-6 and 1H6). During interphase, epichromatin resides adjacent to the inner nuclear membrane; during mitosis, at the outer surface of mitotic chromosomes. By STED (stimulated emission depletion) microscopy, PL2-6 stained interphase epichromatin is ∼76 nm thick and quite uniform; mitotic epichromatin is more variable in thickness, exhibiting a "wrinkled" surface with an average thickness of ∼78 nm. Co-immunostaining with anti-Ki-67 demonstrates Ki-67 deposition between the PL2-6 "ridges" of mitotic epichromatin. Monovalent papain-derived Fab fragments of PL2-6 yield a strikingly different punctate "chromomeric" immunostaining pattern throughout interphase nuclei and along mitotic chromosome arms. Evidence from electrophoretic mobility shift assay (EMSA) and from analytical ultracentrifugation characterize the Fab/mononucleosome complex, supporting the concept that there are two binding sites per nucleosome. The peptide sequence of the Hv3 region (heavy chain variable region 3) of the PL2-6 antibody binding site strongly resembles other nucleosome acidic patch binding proteins (especially, LANA and CENPC), supporting that the nucleosome acidic patch is included within the epichromatin epitope. It is speculated that the interphase epichromatin epitope is "exposed" with favorable geometric arrangements for binding bivalent PL2-6 at the surface chromatin; whereas, the epitope is "hidden" within internal chromatin. Furthermore, it is suggested that the "exposed" nucleosome surface of mitotic epichromatin may play a role in post-mitotic nuclear envelope reformation.
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Affiliation(s)
- Travis J Gould
- a Department of Physics & Astronomy , Bates College , Lewiston , ME , USA
| | - Katalin Tóth
- b Division of Biophysics of Macromolecules, German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - Norbert Mücke
- b Division of Biophysics of Macromolecules, German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | - Jörg Langowski
- b Division of Biophysics of Macromolecules, German Cancer Research Center (DKFZ) , Heidelberg , Germany
| | | | - Ada L Olins
- c Department of Pharmaceutical Sciences , College of Pharmacy, University of New England , Portland , ME , USA
| | - Donald E Olins
- c Department of Pharmaceutical Sciences , College of Pharmacy, University of New England , Portland , ME , USA
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Soni C, Wong EB, Domeier PP, Khan TN, Satoh T, Akira S, Rahman ZSM. B cell-intrinsic TLR7 signaling is essential for the development of spontaneous germinal centers. THE JOURNAL OF IMMUNOLOGY 2014; 193:4400-14. [PMID: 25252960 DOI: 10.4049/jimmunol.1401720] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Spontaneous germinal center (Spt-GC) B cells and follicular helper T cells generate high-affinity autoantibodies that are involved in the development of systemic lupus erythematosus. TLRs play a pivotal role in systemic lupus erythematosus pathogenesis. Although previous studies focused on the B cell-intrinsic role of TLR-MyD88 signaling on immune activation, autoantibody repertoire, and systemic inflammation, the mechanisms by which TLRs control the formation of Spt-GCs remain unclear. Using nonautoimmune C57BL/6 (B6) mice deficient in MyD88, TLR2, TLR3, TLR4, TLR7, or TLR9, we identified B cell-intrinsic TLR7 signaling as a prerequisite to Spt-GC formation without the confounding effects of autoimmune susceptibility genes and the overexpression of TLRs. TLR7 deficiency also rendered autoimmune B6.Sle1b mice unable to form Spt-GCs, leading to markedly decreased autoantibodies. Conversely, B6.yaa and B6.Sle1b.yaa mice expressing an extra copy of TLR7 and B6.Sle1b mice treated with a TLR7 agonist had increased Spt-GCs and follicular helper T cells. Further, TLR7/MyD88 deficiency led to compromised B cell proliferation and survival after B cell stimulation both in vitro and in vivo. In contrast, TLR9 inhibited Spt-GC development. Our findings demonstrate an absolute requirement for TLR7 and a negative regulatory function for TLR9 in Spt-GC formation under nonautoimmune and autoimmune conditions. Our data suggest that, under nonautoimmune conditions, Spt-GCs initiated by TLR7 produce protective Abs. However, in the presence of autoimmune susceptibility genes, TLR7-dependent Spt-GCs produce pathogenic autoantibodies. Thus, a single copy of TLR7 in B cells is the minimal requirement for breaking the GC-tolerance checkpoint.
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Affiliation(s)
- Chetna Soni
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Eric B Wong
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Phillip P Domeier
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, PA 17033
| | - Tahsin N Khan
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, PA 17033; Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR 97239; and
| | - Takashi Satoh
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Shizuo Akira
- Department of Host Defense, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Ziaur S M Rahman
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, Hershey, PA 17033;
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5
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Ullal AJ, Marion TN, Pisetsky DS. The role of antigen specificity in the binding of murine monoclonal anti-DNA antibodies to microparticles from apoptotic cells. Clin Immunol 2014; 154:178-87. [PMID: 24873886 DOI: 10.1016/j.clim.2014.05.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 05/15/2014] [Indexed: 10/25/2022]
Abstract
Antibodies to DNA (anti-DNA) are the serological hallmark of systemic lupus erythematosus and markers of underlying immune system disturbances. These antibodies bind to both single-stranded and double-stranded DNA, mediating pathogenesis by forming immune complexes. As shown recently, DNA in blood exists in both free and particulate forms, with DNA representing an important component of microparticles. Microparticles are membrane-bound vesicles containing nuclear molecules, released by membrane blebbing during cell death and activation. A panel of monoclonal NZB/NZW F1 anti-DNA antibodies was tested for binding to microparticles generated from apoptotic THP-1 and Jurkat cells. These studies showed that only certain anti-DNA antibodies in the panel, specific for double-stranded DNA, bound to microparticles. Binding to particles was reduced by soluble DNA or DNase treatment. Together, these results indicate that particle binding is a feature of only certain anti-DNA antibodies, reflecting immunochemical properties of the antibodies and the nature of the exposed DNA antigens.
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Affiliation(s)
- Anirudh J Ullal
- Duke University Medical Center, Department of Medicine, Durham, NC 27710, USA
| | - Tony N Marion
- Department of Microbiology, Immunology and Biochemistry, The University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - David S Pisetsky
- Duke University Medical Center, Department of Medicine, Durham, NC 27710, USA; Medical Research Service, Durham Veterans Administration Medical Center, Durham, NC 27705, USA.
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Jenks SA, Palmer E, Marin E, Hartson L, Chida AS, Richardson C, Sanz I. 9G4+ autoantibodies are an important source of apoptotic cell reactivity associated with high levels of disease activity in systemic lupus erythematosus. ARTHRITIS AND RHEUMATISM 2013; 65:3165-75. [PMID: 23983101 PMCID: PMC3981458 DOI: 10.1002/art.38138] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 08/13/2013] [Indexed: 01/23/2023]
Abstract
OBJECTIVE To determine the prevalence of anti-apoptotic cell (anti-AC) antibodies with the 9G4 idiotype (9G4+) and the relationship between this and other known 9G4+ specificities and disease activity in patients with systemic lupus erythematosus (SLE). METHODS Serum samples from 60 SLE patients and 40 healthy donors were incubated with apoptotic Jurkat cells and assayed by flow cytometry for the binding of 9G4+ antibodies. The samples were also tested for 9G4+ reactivity against naive B cells and total IgG and IgM anti-AC antibody reactivity. RESULTS The 9G4+ antibodies bound late ACs in sera from a majority of the SLE patients (60%) but in sera from only 2 healthy control subjects. Among samples with global IgM or IgG anti-AC antibodies, those with 9G4+ anti-AC antibodies predominated. Patients with high levels of 9G4+ anti-AC antibodies were more likely to have active disease. This was the case even in patients with IgG anti-AC antibodies or anti-double-stranded DNA antibodies. Patients with lupus nephritis were also more likely to have 9G4+ anti-AC antibodies. While 9G4+ reactivity to ACs often coincided with anti-B cell reactivity, some samples had distinct anti-AC or anti-B cell reactivity. CONCLUSION The 9G4+ antibody represents a major species of anti-AC antibody in SLE serum, and this autoreactivity is associated with disease activity. The anti-AC reactivity of 9G4+ antibodies can be separated from the germline VH4-34-encoded anti-B cell autoreactivity. Our results indicate that ACs are an important antigenic source in SLE that positively selects B cells with intrinsic autoreactivity against other self antigens. This selection of 9G4+ B cells by ACs may represent an important step in disease progression.
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Affiliation(s)
- Scott A. Jenks
- Division of Allergy, Immunology and Rheumatology, University of Rochester School of Medicine
| | - Elise Palmer
- Division of Allergy, Immunology and Rheumatology, University of Rochester School of Medicine
| | - Elides Marin
- Division of Allergy, Immunology and Rheumatology, University of Rochester School of Medicine
| | | | - Asiya Seema Chida
- Division of Allergy, Immunology and Rheumatology, University of Rochester School of Medicine
| | - Christopher Richardson
- Division of Allergy, Immunology and Rheumatology, University of Rochester School of Medicine
- Medical Scientist Training Program (MSTP)
| | - Ignacio Sanz
- Division of Allergy, Immunology and Rheumatology, University of Rochester School of Medicine
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7
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Maranhão AQ, Costa MBW, Guedes L, Moraes-Vieira PM, Raiol T, Brigido MM. A mouse variable gene fragment binds to DNA independently of the BCR context: a possible role for immature B-cell repertoire establishment. PLoS One 2013; 8:e72625. [PMID: 24023756 PMCID: PMC3759382 DOI: 10.1371/journal.pone.0072625] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/11/2013] [Indexed: 01/13/2023] Open
Abstract
B-cell maturation occurs in several steps and requires constant stimulus for its continuing development. From the emergence of the pre-B-cell receptor, signal transduction stimulates and supports B-cell development. Current viewpoints indicate that both positive selection pressure for autoantigens and tonic signaling constitutively stimulate B-cell maturation. In this work, we tested for the presence of a putative DNA binding site in a variable gene segment in a germline configuration, independently of VDJ recombination. After a survey of the public antibody databases, we chose a single mouse heavy variable gene segment that is highly represented in anti-nucleic acid antibodies and tested it for ssDNA binding. A phage display approach was used to search for intrinsic binding to oligo deoxythymidine. The results revealed that binding to an antigen can be influenced by the use of a specific DNA binding V[Formula: see text] gene segment. Our data support the idea that some variable genes have intrinsic reactivity towards specific types of endogenous autoantigens, and this property may contribute to the establishment of the immature B-cell repertoire.
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Affiliation(s)
- Andrea Queiroz Maranhão
- Laboratório de Biologia Molecular, Instituto de Biologia, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Maria Beatriz Walter Costa
- Laboratório de Bioinformática, Instituto de Biologia, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Leonardo Guedes
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pedro Manoel Moraes-Vieira
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Tainá Raiol
- Laboratório de Bioinformática, Instituto de Biologia, Universidade de Brasília, Brasília, Distrito Federal, Brazil
| | - Marcelo Macedo Brigido
- Laboratório de Biologia Molecular, Instituto de Biologia, Universidade de Brasília, Brasília, Distrito Federal, Brazil
- Laboratório de Bioinformática, Instituto de Biologia, Universidade de Brasília, Brasília, Distrito Federal, Brazil
- * E-mail:
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8
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Mannoor K, Xu Y, Chen C. Natural autoantibodies and associated B cells in immunity and autoimmunity. Autoimmunity 2013. [DOI: 10.3109/08916934.2012.748753] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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9
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Doyle HA, Aswad DW, Mamula MJ. Autoimmunity to isomerized histone H2B in systemic lupus erythematosus. Autoimmunity 2012; 46:6-13. [PMID: 22967069 DOI: 10.3109/08916934.2012.710859] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Histone H2B is a common target of autoantibodies in both spontaneous and drug-induced systemic lupus erythematosus (SLE). Recent studies demonstrate that Asp(25) of histone H2B (H2B) spontaneously converts to an isoaspartic acid (isoAsp) in vivo. Our laboratory has demonstrated that the posttranslational modification of an aspartic acid to an isoaspartic acid within self-peptides renders otherwise ignored peptides immunogenic. Analysis of serum from lupus-prone mice and histone antibody positive SLE patients revealed antibodies specific to the Asp and isoAsp H2B(21-35) peptide, and that the expression of these antibodies is dependent on TLR9. IsoAsp H2B(21-35) is immunogenic in non-autoimmune prone mice and mice lacking the ability to repair isoAsp have significantly reduced levels of antibodies to H2B. Asp H2B(21-35) incubated at physiological temperatures and pH acquires the isoAsp modification, demonstrating that H2B(21-35) is prone to spontaneous isoAsp formation in vivo. Autoimmunity to isoAsp H2B suggests that this form of the autoantigen may be critical in the induction of anti-histone autoantibodies in human SLE and in murine models of disease.
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Affiliation(s)
- Hester A Doyle
- Department of Rheumatology, Yale University School of Medicine, New Haven, Connecticut 06520-8031, USA
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10
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DeFranco AL, Rookhuizen DC, Hou B. Contribution of Toll-like receptor signaling to germinal center antibody responses. Immunol Rev 2012; 247:64-72. [PMID: 22500832 DOI: 10.1111/j.1600-065x.2012.01115.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Toll-like receptors (TLRs) have emerged as one of the most important families of innate immune receptors for initiating inflammation and also for promoting adaptive immune responses. Recent studies have examined the ability of TLRs to promote antibody responses, including T-cell-dependent antibody responses. Initial study suggested that TLR stimulation promotes primarily an extrafollicular antibody response, which rapidly produces moderate affinity antibodies made by short-lived plasma cells. Recent studies, however, have shown that TLRs can also enhance the germinal center response, which produces high affinity class-switched antibody made by long-lived plasma cells. TLR stimulation can increase the magnitude of the latter response and also enhance selection for high affinity IgG. This review summarizes recent advances in understanding the roles of TLRs in B cells and also in other cell types for enhancement of antibody responses, with an emphasis on T-cell-dependent and germinal center antibody responses.
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Affiliation(s)
- Anthony L DeFranco
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143-0414, USA.
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11
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Anti-DNA autoantibodies initiate experimental lupus nephritis by binding directly to the glomerular basement membrane in mice. Kidney Int 2012; 82:184-92. [PMID: 22297676 PMCID: PMC3343188 DOI: 10.1038/ki.2011.484] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The strongest serological correlate for lupus nephritis is antibody to double-stranded DNA although the mechanism by which anti-DNA antibodies initiate lupus nephritis is unresolved. Most recent reports indicate that anti-DNA must bind chromatin in the glomerular basement membrane or mesangial matrix to form glomerular deposits. Here we determined whether direct binding of anti-DNA antibody to glomerular basement membrane is critical to initiate glomerular binding of anti-DNA in experimental lupus nephritis. Mice were co-injected with IgG monoclonal antibodies or hybridomas with similar specificity for DNA and chromatin but different IgG subclass and different relative affinity for basement membrane. Only anti-DNA antibodies that bound basement membrane bound to glomeruli, activated complement, and induced proteinuria whether injected alone or co-injected with a non-basement membrane-binding anti-DNA antibody. Basement membrane-binding anti-DNA antibodies co-localized with heparan sulfate proteoglycan in glomerular basement membrane and mesangial matrix but not with chromatin. Thus, direct binding of anti-DNA antibody to antigens in the glomerular basement membrane or mesangial matrix may be critical to initiate glomerular inflammation. This may accelerate and exacerbate glomerular immune complex formation in human and murine lupus nephritis.
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Antoni A, Patel VA, Fan H, Lee DJ, Graham LH, Rosch CL, Spiegel DS, Rauch J, Levine JS. Macrophages from lupus-prone MRL mice have a conditional signaling abnormality that leads to dysregulated expression of numerous genes. Immunogenetics 2011; 63:291-308. [PMID: 21229240 PMCID: PMC3439499 DOI: 10.1007/s00251-010-0507-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 12/17/2010] [Indexed: 01/06/2023]
Abstract
Macrophages (mϕ) from pre-diseased mice of the major murine inbred models of spontaneous autoimmunity (AI), including multiple lupus-prone strains and the type I diabetes-prone NOD (non-obese diabetic) strain, have identical apoptotic target-dependent abnormalities. This characteristic feature of mϕ from AI-prone mice suggests that abnormal signaling events induced within mϕ following their interaction with apoptotic targets may predispose to AI. Such signaling abnormalities would affect predominantly the processing and presentation of self-antigen (i.e., derived from apoptotic targets), while sparing the processing and presentation of foreign antigen (i.e., derived from non-apoptotic sources). Here, we used DNA microarrays to test the hypothesis that mϕ from AI-prone mice (MRL/MpJ [MRL/+] or MRL/MpJ-Tnfrsf6 ( lpr ) [MRL/lpr]) differentially express multiple genes in comparison to non-AI mϕ (BALB/c), but do so in a largely apoptotic cell-dependent manner. Mϕ were stimulated with lipopolysaccharide, a potent innate stimulus, in the presence or absence of serum (an experimental surrogate for apoptotic targets). In accord with our hypothesis, the number of genes differentially expressed by MRL mϕ was significantly increased in the presence vs. the absence of serum, the apoptotic target surrogate (n = 401 vs. n = 201). Notably, for genes differentially expressed by MRL mϕ in the presence of serum, serum-free culture normalized their expression to a level statistically indistinguishable from that by non-AI mϕ. Comparisons of mϕ from AI-prone NOD and non-AI C57BL/6 mice corroborated these findings. Together, these data support the hypothesis that mϕ from MRL and other AI-prone mice are characterized by a conditional abnormality elicited by serum lipids or apoptotic targets.
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Affiliation(s)
- Angelika Antoni
- Department of Biology, Kutztown University of Pennsylvania, Kutztown, PA 19530, USA
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13
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Vinuesa CG, Sanz I, Cook MC. Dysregulation of germinal centres in autoimmune disease. Nat Rev Immunol 2009; 9:845-57. [PMID: 19935804 DOI: 10.1038/nri2637] [Citation(s) in RCA: 336] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In germinal centres, somatic hypermutation and B cell selection increase antibody affinity and specificity for the immunizing antigen, but the generation of autoreactive B cells is an inevitable by-product of this process. Here, we review the evidence that aberrant selection of these autoreactive B cells can arise from abnormalities in each of the germinal centre cellular constituents--B cells, T follicular helper cells, follicular dendritic cells and tingible body macrophages--or in the supply of antigen. As the progeny of germinal centre B cells includes long-lived plasma cells, selection of autoreactive B cells can propagate long-lived autoantibody responses and cause autoimmune diseases. Elucidation of crucial molecular signals in germinal centres has led to the identification of novel therapeutic targets.
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Affiliation(s)
- Carola G Vinuesa
- John Curtin School of Medical Research, Australian National University, GPO Box 334, Canberra, ACT 2601, Australia.
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14
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Neeli I, Dwivedi N, Khan S, Radic M. Regulation of extracellular chromatin release from neutrophils. J Innate Immun 2009; 1:194-201. [PMID: 20375577 DOI: 10.1159/000206974] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2008] [Accepted: 11/05/2008] [Indexed: 01/13/2023] Open
Abstract
Neutrophils use intricate mechanisms for capturing and killing invading microorganisms. One mechanism entails the release of relaxed chromatin from the cell. Microbes are trapped by the extracellular chromatin and exposed to high local concentrations of bactericidal compounds. We examine the regulation of chromatin release by testing the contribution of microtubules and the actin cytoskeleton to the deployment of neutrophil extracellular traps (NETs). Incubation of human neutrophils with nocodazole, a tubulin polymerization inhibitor, or cytochalasin D, an inhibitor of actin filamentation, severely diminished the ability of neutrophils to respond to LPS by releasing chromatin from the cells. In addition, pretreatment of neutrophils with M1/70, a monoclonal antibody to the Mac-1 integrin adhesion receptor, drastically reduced the deployment of chromatin into NETs. Analysis of histone deimination, the conversion of arginine to citrulline in 3 of the 4 core histones by peptidylarginine deiminase 4, revealed that the treatments inhibiting NET formation also reduced histone deimination. Our data indicate that NET formation requires functional tubulin and actin filaments and responds to engagement of Mac-1 integrins. Because histone deimination coincides with the release of NETs, we propose that these events represent overlapping mechanisms of neutrophil responses to infections.
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Affiliation(s)
- Indira Neeli
- Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, Tenn. 38163, USA
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15
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Rich RL, Myszka DG. Survey of the year 2007 commercial optical biosensor literature. J Mol Recognit 2008; 21:355-400. [DOI: 10.1002/jmr.928] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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16
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Abstract
Tolerance to dsDNA is achieved through editing of Ig receptors that react with dsDNA. Nevertheless, some B cells with anti-dsDNA receptors escape editing and migrate to the spleen. Certain anti-dsDNA B cells that are recovered as hybridomas from the spleens of anti-dsDNA H chain transgenic mice also bind an additional, Golgi-associated antigen. B cells that bind this antigen accumulate intracellular IgM. The intracellular accumulation of IgM is incomplete, because IgM clusters are observed at the cell surface. In the spleen, B cells that express the heavy and light chains encoding this IgM are surface IgM-bright and acquire the CD21-high/CD23-low phenotype of marginal zone B cells. Our data imply that expression of an Ig that binds dsDNA and an additional antigen expressed in the secretory compartment renders B cells resistant to central tolerance. In the periphery, these B cells may be sequestered in the splenic marginal zone.
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