1
|
Guo CC, Xu HE, Ma X. ARID3a from the ARID family: structure, role in autoimmune diseases and drug discovery. Acta Pharmacol Sin 2023; 44:2139-2150. [PMID: 37488425 PMCID: PMC10618457 DOI: 10.1038/s41401-023-01134-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 07/09/2023] [Indexed: 07/26/2023] Open
Abstract
The AT-rich interaction domain (ARID) family of DNA-binding proteins is a group of transcription factors and chromatin regulators with a highly conserved ARID domain that recognizes specific AT-rich DNA sequences. Dysfunction of ARID family members has been implicated in various human diseases including cancers and intellectual disability. Among them, ARID3a has gained increasing attention due to its potential involvement in autoimmunity. In this article we provide an overview of the ARID family, focusing on the structure and biological functions of ARID3a. It explores the role of ARID3a in autoreactive B cells and its contribution to autoimmune diseases such as systemic lupus erythematosus and primary biliary cholangitis. Furthermore, we also discuss the potential for drug discovery targeting ARID3a and present a plan for future research in this field.
Collapse
Affiliation(s)
- Cheng-Cen Guo
- Department of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, 200001, China.
| | - H Eric Xu
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Xiong Ma
- Department of Gastroenterology and Hepatology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, Shanghai, 200001, China.
| |
Collapse
|
2
|
Neys SFH, Rip J, Hendriks RW, Corneth OBJ. Bruton's Tyrosine Kinase Inhibition as an Emerging Therapy in Systemic Autoimmune Disease. Drugs 2021; 81:1605-1626. [PMID: 34609725 PMCID: PMC8491186 DOI: 10.1007/s40265-021-01592-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 12/14/2022]
Abstract
Systemic autoimmune disorders are complex heterogeneous chronic diseases involving many different immune cells. A significant proportion of patients respond poorly to therapy. In addition, the high burden of adverse effects caused by "classical" anti-rheumatic or immune modulatory drugs provides a need to develop more specific therapies that are better tolerated. Bruton's tyrosine kinase (BTK) is a crucial signaling protein that directly links B-cell receptor (BCR) signals to B-cell activation, proliferation, and survival. BTK is not only expressed in B cells but also in myeloid cells, and is involved in many different signaling pathways that drive autoimmunity. This makes BTK an interesting therapeutic target in the treatment of autoimmune diseases. The past decade has seen the emergence of first-line BTK small-molecule inhibitors with great efficacy in the treatment of B-cell malignancies, but with unfavorable safety profiles for use in autoimmunity due to off-target effects. The development of second-generation BTK inhibitors with superior BTK specificity has facilitated the investigation of their efficacy in clinical trials with autoimmune patients. In this review, we discuss the role of BTK in key signaling pathways involved in autoimmunity and provide an overview of the different inhibitors that are currently being investigated in clinical trials of systemic autoimmune diseases, including rheumatoid arthritis and systemic lupus erythematosus, as well as available results from completed trials.
Collapse
Affiliation(s)
- Stefan F H Neys
- Department of Pulmonary Medicine, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
| | - Jasper Rip
- Department of Pulmonary Medicine, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
- Department of Immunology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands
| | - Rudi W Hendriks
- Department of Pulmonary Medicine, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
| | - Odilia B J Corneth
- Department of Pulmonary Medicine, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
| |
Collapse
|
3
|
Abstract
Systemic lupus erythematosus (SLE) is a devastating and heterogeneous autoimmune disease that affects multiple organs, and for which the underlying causes are unknown. The majority of SLE patients produce autoantibodies, have increased levels of type-I inflammatory cytokines, and can develop glomerulonephritis. Recent studies indicate an unexpected but strong association between increased disease activity in SLE patients and the expression of the DNA-binding protein ARID3a (A + T rich interaction domain protein 3a) in a number of peripheral blood cell types. ARID3a expression was first associated with autoantibody production in B cells; however, more recent findings also indicate associations with expression of the inflammatory cytokine interferon alpha in SLE plasmacytoid dendritic cells and low-density neutrophils. In addition, ARID3a is expressed in hematopoietic stem cells and some adult kidney progenitor cells. SLE cells expressing enhanced ARID3a levels show differential gene expression patterns compared with homologous healthy control cells, identifying new pathways potentially regulated by ARID3a. The associations of ARID3a expression with increased disease severity in SLE, suggest that it, or its downstream targets, may provide new therapeutic targets for SLE.
Collapse
|
4
|
Human effector B lymphocytes express ARID3a and secrete interferon alpha. J Autoimmun 2016; 75:130-140. [PMID: 27522115 DOI: 10.1016/j.jaut.2016.08.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 07/28/2016] [Accepted: 08/03/2016] [Indexed: 12/31/2022]
Abstract
Previously, we determined that enhanced disease activity in patients with systemic lupus erythematosus (SLE) was associated with dramatic increases in numbers of B lymphocytes expressing the transcription factor ARID3a. Our data now indicate ARID3a is important for interferon alpha (IFNa) expression and show a strong association between ARID3a expression and transcription of genes associated with lupus IFN signatures. Furthermore, both ARID3a and IFNa production were elicited in healthy control B cells upon stimulation with the TLR 9 agonist, CpG. Importantly, secretion of IFNa from ARID3a+ healthy B lymphocytes stimulated increased IFNa production in plasmacytoid dendritic cells. These data identify ARID3a+ B cells as a novel type of effector B cell, and link ARID3a expression in B lymphocytes to IFN-associated inflammatory responses in SLE.
Collapse
|
5
|
Ratliff ML, Mishra M, Frank MB, Guthridge JM, Webb CF. The Transcription Factor ARID3a Is Important for In Vitro Differentiation of Human Hematopoietic Progenitors. THE JOURNAL OF IMMUNOLOGY 2015; 196:614-23. [PMID: 26685208 DOI: 10.4049/jimmunol.1500355] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 11/10/2015] [Indexed: 12/12/2022]
Abstract
We recently reported that the transcription factor ARID3a is expressed in a subset of human hematopoietic progenitor stem cells in both healthy individuals and in patients with systemic lupus erythematosus. Numbers of ARID3a(+) lupus hematopoietic stem progenitor cells were associated with increased production of autoreactive Abs when those cells were introduced into humanized mouse models. Although ARID3a/Bright knockout mice died in utero, they exhibited decreased numbers of hematopoietic stem cells and erythrocytes, indicating that ARID3a is functionally important for hematopoiesis in mice. To explore the requirement for ARID3a for normal human hematopoiesis, hematopoietic stem cell progenitors from human cord blood were subjected to both inhibition and overexpression of ARID3a in vitro. Inhibition of ARID3a resulted in decreased B lineage cell production accompanied by increases in cells with myeloid lineage markers. Overexpression of ARID3a inhibited both myeloid and erythroid differentiation. Additionally, inhibition of ARID3a in hematopoietic stem cells resulted in altered expression of transcription factors associated with hematopoietic lineage decisions. These results suggest that appropriate regulation of ARID3a is critical for normal development of both myeloid and B lineage pathways.
Collapse
Affiliation(s)
| | - Meenu Mishra
- Walter Reed Army Institute of Research, Silver Spring, MD 20910
| | - Mark B Frank
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | | | - Carol F Webb
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104; and Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| |
Collapse
|
6
|
Ward JM, James JA, Zhao YD, Webb CF. Antibody Reactivity of B Cells in Lupus Patients with Increased Disease Activity and ARID3a Expression. Antibodies (Basel) 2015; 4:354-368. [PMID: 28580178 PMCID: PMC5451160 DOI: 10.3390/antib4040354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Earlier studies showed that the DNA-binding protein, Bright/ARID3a bound to a subset of human and mouse immunoglobulin heavy chain promoters where it enhanced expression. Indeed, mice with transgenic expression of ARID3a in all B lymphocytes have expanded MZ B cells and produce anti-nuclear antibodies (ANAs). Consistent with our findings in mice, we observed that human systemic lupus erythematosus (SLE) patients had expanded numbers of peripheral blood ARID3a+ B cells that were associated with increased disease activity (p = 0.0038). We hypothesized that ARID3a+ naïve B cells would eventually produce autoantibodies, explaining associations between ARID3a expression and disease activity in lupus. Unlike healthy controls, ARID3a was expressed in the naïve B cell population in SLE patients, and we hypothesized that these might represent expansions of autoreactive cells. Therefore, monoclonal antibodies were generated from single-sorted naïve B cells derived from patients with normal (ARID3aN) and high (ARID3aH) numbers of ARID3a+ B cells. We found that ARID3a expression did not correlate with autoantibody expression. Furthermore, measures of antigen specificities of autoreactive antibodies did not reveal skewing toward particular proteins. These data suggest that the association of increased disease activity in SLE with numbers of ARID3a+ B lymphocytes may be mediated by an antibody-independent mechanism.
Collapse
Affiliation(s)
- Julie M. Ward
- Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Judith A. James
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Departments of Medicine and Pathology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Yan D. Zhao
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Carol F. Webb
- Immunobiology and Cancer Research, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Author to whom correspondence should be addressed;
| |
Collapse
|
7
|
Ward JM, Rose K, Montgomery C, Adrianto I, James JA, Merrill JT, Webb CF. Disease activity in systemic lupus erythematosus correlates with expression of the transcription factor AT-rich-interactive domain 3A. Arthritis Rheumatol 2015; 66:3404-12. [PMID: 25185498 DOI: 10.1002/art.38857] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 08/19/2014] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Systemic lupus erythematosus (SLE) is a complex and multifactorial autoimmune disease with striking clinical, immunologic, and genetic heterogeneity, despite nearly ubiquitous antinuclear antibody (ANA) production. Multiple gene polymorphisms have been associated with the disease, but these individually account for only a very small percentage of overall SLE risk. In earlier studies, constitutive expression of the DNA-binding protein AT-rich-interactive domain 3A (ARID3a) in transgenic mouse B lymphocyte lineage cells led to spontaneous ANA production and preferential development of B cells associated with production of polyreactive antibodies. Therefore, we undertook this study to determine whether ARID3a was overexpressed in B lymphocytes of SLE patients and whether ARID3a expression was associated with disease severity. METHODS A cross-section of SLE patients, rheumatoid arthritis patients, and age- and sex-matched controls was analyzed longitudinally for lupus disease activity, numbers of ARID3a+ peripheral blood mononuclear B cells from multiple B cell subsets, and immunoglobulin and cytokine levels. RESULTS Fifty of 115 SLE patients (43%) had dramatically increased numbers of ARID3a+ B cells compared to healthy controls. ARID3a was not expressed in naive B cells of healthy controls, but was abundant in these precursors of antibody-secreting cells in SLE patients. Total numbers of ARID3a+ B cells correlated with increased disease activity as defined by SLE Disease Activity Index scores in individuals assessed at 3 time points. CONCLUSION These findings identify B cell anomalies in SLE that allow stratification of patient samples based on ARID3a expression and implicate ARID3a as a potential marker of CD19+ B lymphocytes correlated with disease activity.
Collapse
Affiliation(s)
- Julie M Ward
- Oklahoma Medical Research Foundation and Oklahoma University Health Sciences Center, Oklahoma City
| | | | | | | | | | | | | |
Collapse
|
8
|
Ratliff ML, Ward JM, Merrill JT, James JA, Webb CF. Differential expression of the transcription factor ARID3a in lupus patient hematopoietic progenitor cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:940-9. [PMID: 25535283 PMCID: PMC4297684 DOI: 10.4049/jimmunol.1401941] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Although hematopoietic stem/progenitor cells (HSPCs) are used for transplantation, characterization of the multiple subsets within this population in humans has lagged behind similar studies in mice. We found that expression of the DNA-binding protein, ARID3a, in mouse stem cells was important for normal development of hematopoietic lineages; however, progenitors expressing ARID3a in humans have not been defined. We previously showed increased numbers of ARID3a(+) B cells in nearly half of systemic lupus erythematosus (SLE) patients, and total numbers of ARID3a(+) B cells were associated with increased disease severity. Because expression of ARID3a in those SLE patients occurred throughout all B cell subsets, we hypothesized that ARID3a expression in patient HSPCs might also be increased relative to expression in healthy controls. Our data now show that ARID3a expression is not limited to any defined subset of HSPCs in either healthy controls or SLE patients. Numbers of ARID3a(+) HSPCs in SLE patients were increased over numbers of ARID3a(+) cells in healthy controls. Although all SLE-derived HSPCs exhibited poor colony formation in vitro compared with controls, SLE HSPCs with high numbers of ARID3a(+) cells yielded increased numbers of cells expressing the early progenitor marker, CD34. SLE HSPCs with high numbers of ARID3a(+) cells also more readily generated autoantibody-producing cells than HSPCs with lower levels of ARID3a in a humanized mouse model. These data reveal new functions for ARID3a in early hematopoiesis and suggest that knowledge regarding ARID3a levels in HSPCs could be informative for applications requiring transplantation of those cells.
Collapse
Affiliation(s)
- Michelle L Ratliff
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Julie M Ward
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104; Microbiology and Immunology Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Joan T Merrill
- Clinical Pharmacology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Judith A James
- Microbiology and Immunology Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104; Arthritis and Clinical Immunology Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104; Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104; and
| | - Carol F Webb
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104; Microbiology and Immunology Program, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| |
Collapse
|
9
|
Role of tissue-specific AT-rich DNA sequence-binding proteins in lymphocyte differentiation. Int J Hematol 2014; 100:238-45. [PMID: 24938377 DOI: 10.1007/s12185-014-1602-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 05/13/2014] [Accepted: 05/14/2014] [Indexed: 02/06/2023]
Abstract
A great many transcription factors, cytokines, and cytokine receptors have been identified as indispensable elements in lymphocyte differentiation, but the molecular mechanism that orchestrates the expression and function of these molecular factors is unknown. The process of lymphocyte differentiation involves both the simultaneous activation of lymphoid-related genes and the inactivation of non-lymphoid lineage-related genes, suggesting that there should be critical molecules that regulate such gene expression in both temporal and spatial dimensions. Recent studies of chromatin-remodeling proteins shed light on this complex process. In particular, special AT-rich sequence-binding protein 1 has been studied extensively. In this article, we review the wealth of information characterizing this protein.
Collapse
|
10
|
Ratliff ML, Templeton TD, Ward JM, Webb CF. The Bright Side of Hematopoiesis: Regulatory Roles of ARID3a/Bright in Human and Mouse Hematopoiesis. Front Immunol 2014; 5:113. [PMID: 24678314 PMCID: PMC3958700 DOI: 10.3389/fimmu.2014.00113] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 03/04/2014] [Indexed: 12/12/2022] Open
Abstract
ARID3a/Bright is a DNA-binding protein that was originally discovered for its ability to increase immunoglobulin transcription in antigen-activated B cells. It interacts with DNA as a dimer through its ARID, or A/T-rich interacting domain. In association with other proteins, ARID3a increased transcription of the immunoglobulin heavy chain and led to improved chromatin accessibility of the heavy chain enhancer. Constitutive expression of ARID3a in B lineage cells resulted in autoantibody production, suggesting its regulation is important. Abnormal ARID3a expression has also been associated with increased proliferative capacity and malignancy. Roles for ARID3a in addition to interactions with the immunoglobulin locus were suggested by transgenic and knockout mouse models. Over-expression of ARID3a resulted in skewing of mature B cell subsets and altered gene expression patterns of follicular B cells, whereas loss of function resulted in loss of B1 lineage B cells and defects in hematopoiesis. More recent studies showed that loss of ARID3a in adult somatic cells promoted developmental plasticity, alterations in gene expression patterns, and lineage fate decisions. Together, these data suggest new regulatory roles for ARID3a. The genes influenced by ARID3a are likely to play pivotal roles in lineage decisions, highlighting the importance of this understudied transcription factor.
Collapse
Affiliation(s)
- Michelle L Ratliff
- Immunobiology and Cancer Research, Oklahoma Medical Research Foundation , Oklahoma City, OK , USA
| | - Troy D Templeton
- Department of Cell Biology, University of Oklahoma Health Sciences Center , Oklahoma City, OK , USA
| | - Julie M Ward
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center , Oklahoma City, OK , USA
| | - Carol F Webb
- Immunobiology and Cancer Research, Oklahoma Medical Research Foundation , Oklahoma City, OK , USA ; Department of Cell Biology, University of Oklahoma Health Sciences Center , Oklahoma City, OK , USA ; Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center , Oklahoma City, OK , USA
| |
Collapse
|
11
|
Lei F, Song J, Haque R, Xiong X, Fang D, Wu Y, Lens SMA, Croft M, Song J. Transgenic expression of survivin compensates for OX40-deficiency in driving Th2 development and allergic inflammation. Eur J Immunol 2013; 43:1914-24. [PMID: 23616302 DOI: 10.1002/eji.201243081] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 03/28/2013] [Accepted: 04/19/2013] [Indexed: 12/12/2022]
Abstract
Survivin, an inhibitor of apoptosis family molecule, has been proposed as a crucial intermediate in the signaling pathways leading to T-cell development, proliferation, and expansion. However, the importance of survivin to T-cell-driven inflammatory responses has not been demonstrated. Here, we show that survivin transgenic mice exhibit an increased antigen-driven Th2 lung inflammation and that constitutive expression of survivin reversed the defective lung inflammation even in the absence of OX40 costimulation. We found that OX40-deficient mice were compromised in generating Th2 cells, airway eosinophilia, and IgE responses. In contrast, OX40-deficient/survivin transgenic mice generated normal Th2 responses and exhibited strong lung inflammation. These results suggest that OX40 costimulation crucially engages survivin during antigen-mediated Th2 responses. These findings also promote the notion that OX40 costimulation regulates allergic responses or lung inflammation by targeting survivin thereby enhancing T-cell proliferation and resulting in more differentiated Th2 cells in the allergic inflammatory response.
Collapse
Affiliation(s)
- Fengyang Lei
- Department of Microbiology and Immunology, The Pennsylvania State University College of Medicine, Hershey, PA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Abstract
Mouse models of lupus have for many years provided accessible and reliable research systems for the pathogenesis and therapy of systemic autoimmune disease, spanning a spectrum of inbred strains that develop spontaneous disease to experimentally induced, sometimes genetically manipulated animals. Nearly all the models share in common the development of glomerulonephritis and autoantibodies, including antinuclear and DNA specificities, the most common endpoints examined in experimental studies, but exhibit specific differences in the incidence of other end-organ manifestations such as hemolytic anemia, arthritis, dermatitis, and vasculitis. This chapter contrasts the clinical characteristics of these various models, providing an outline for their use and analysis.
Collapse
Affiliation(s)
- Stanford L Peng
- Rheumatology Clinical Research Unit, Benaroya Research Institute at Virginia Mason, Seattle, WA, USA.
| |
Collapse
|
13
|
Oldham AL, Miner CA, Wang HC, Webb CF. The transcription factor Bright plays a role in marginal zone B lymphocyte development and autoantibody production. Mol Immunol 2011; 49:367-79. [PMID: 21963220 DOI: 10.1016/j.molimm.2011.09.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 09/07/2011] [Accepted: 09/12/2011] [Indexed: 10/17/2022]
Abstract
Previous data suggested that constitutive expression of the transcription factor Bright (B cell regulator of immunoglobulin heavy chain transcription), normally tightly regulated during B cell differentiation, was associated with autoantibody production. Here we show that constitutive Bright expression results in skewing of mature B lineage subpopulations toward marginal zone cells at the expense of the follicular subpopulation. C57Bl/6 transgenic mice constitutively expressing Bright in B lineage cells generated autoantibodies that were not the result of global increases in immunoglobulin or of breaches in key tolerance checkpoints typically defective in other autoimmune mouse models. Rather, autoimmunity correlated with increased numbers of marginal zone B cells and alterations in the phenotype and gene expression profiles of lymphocytes within the follicular B cell compartment. These data suggest a novel role for Bright in the normal development of mature B cell subsets and in autoantibody production.
Collapse
Affiliation(s)
- Athenia L Oldham
- Immunobiology and Cancer Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | | | | | | |
Collapse
|
14
|
The ARID family transcription factor bright is required for both hematopoietic stem cell and B lineage development. Mol Cell Biol 2011; 31:1041-53. [PMID: 21199920 DOI: 10.1128/mcb.01448-10] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Bright/Arid3a has been characterized both as an activator of immunoglobulin heavy-chain transcription and as a proto-oncogene. Although Bright expression is highly B lineage stage restricted in adult mice, its expression in the earliest identifiable hematopoietic stem cell (HSC) population suggests that Bright might have additional functions. We showed that >99% of Bright(-/-) embryos die at midgestation from failed hematopoiesis. Bright(-/-) embryonic day 12.5 (E12.5) fetal livers showed an increase in the expression of immature markers. Colony-forming assays indicated that the hematopoietic potential of Bright(-/-) mice is markedly reduced. Rare survivors of lethality, which were not compensated by the closely related paralogue Bright-derived protein (Bdp)/Arid3b, suffered HSC deficits in their bone marrow as well as B lineage-intrinsic developmental and functional deficiencies in their peripheries. These include a reduction in a natural antibody, B-1 responses to phosphocholine, and selective T-dependent impairment of IgG1 class switching. Our results place Bright/Arid3a on a select list of transcriptional regulators required to program both HSC and lineage-specific differentiation.
Collapse
|
15
|
An G, Miner CA, Nixon JC, Kincade PW, Bryant J, Tucker PW, Webb CF. Loss of Bright/ARID3a function promotes developmental plasticity. Stem Cells 2010; 28:1560-7. [PMID: 20680960 DOI: 10.1002/stem.491] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
B-cell regulator of immunoglobulin heavy chain transcription (Bright)/ARID3a, an A+T-rich interaction domain protein, was originally discovered in B lymphocyte lineage cells. However, expression patterns and high lethality levels in knockout mice suggested that it had additional functions. Three independent lines of evidence show that functional inhibition of Bright results in increased developmental plasticity. Bright-deficient cells from two mouse models expressed a number of pluripotency-associated gene products, expanded indefinitely, and spontaneously differentiated into cells of multiple lineages. Furthermore, direct knockdown of human Bright resulted in colonies capable of expressing multiple lineage markers. These data suggest that repression of this single molecule confers adult somatic cells with new developmental options.
Collapse
Affiliation(s)
- Guangyu An
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | | | | | | | | | | | | |
Collapse
|
16
|
Signalling of the BCR is regulated by a lipid rafts-localised transcription factor, Bright. EMBO J 2009; 28:711-24. [PMID: 19214191 DOI: 10.1038/emboj.2009.20] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 01/09/2009] [Indexed: 02/06/2023] Open
Abstract
Regulation of BCR signalling strength is crucial for B-cell development and function. Bright is a B-cell-restricted factor that complexes with Bruton's tyrosine kinase (Btk) and its substrate, transcription initiation factor-I (TFII-I), to activate immunoglobulin heavy chain gene transcription in the nucleus. Here we show that a palmitoylated pool of Bright is diverted to lipid rafts of resting B cells where it associates with signalosome components. After BCR ligation, Bright transiently interacts with sumoylation enzymes, blocks calcium flux and phosphorylation of Btk and TFII-I and is then discharged from lipid rafts as a Sumo-I-modified form. The resulting lipid raft concentration of Bright contributes to the signalling threshold of B cells, as their sensitivity to BCR stimulation decreases as the levels of Bright increase. Bright regulates signalling independent of its role in IgH transcription, as shown by specific dominant-negative titration of rafts-specific forms. This study identifies a BCR tuning mechanism in lipid rafts that is regulated by differential post-translational modification of a transcription factor with implications for B-cell tolerance and autoimmunity.
Collapse
|
17
|
Nixon JC, Ferrell S, Miner C, Oldham AL, Hochgeschwender U, Webb CF. Transgenic mice expressing dominant-negative bright exhibit defects in B1 B cells. THE JOURNAL OF IMMUNOLOGY 2008; 181:6913-22. [PMID: 18981111 DOI: 10.4049/jimmunol.181.10.6913] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The transcription factor Bright up-regulates Ig H chain production from select V region promoters and requires Bright dimerization, Bruton's tyrosine kinase (Btk), and the Btk substrate, TFII-I, for this activity. Defects in Btk cause X-linked immunodeficiency disease in mice and humans. Btk-deficient mice exhibit decreased serum IgM production, B cell developmental blocks, absence of peritoneal B1 cells, and subnormal immune responses against Ags, including phosphorylcholine, which confer protection against Streptococcus pneumoniae. Transgenic mice expressing dominant-negative Bright share similarities with Btk-deficient mice, including decreased serum IgM, poor anti-phosphorylcholine responses, and slightly reduced numbers of mature B cells. Although dominant-negative Bright mice developed B1 B cells, these were functionally deficient in Ig secretion. These data suggest a mechanistic explanation for the abnormal responses to phosphorylcholine observed in Btk-deficient mice, and indicate that Bright functions in a subset of Btk-dependent pathways in vivo, particularly those responses dominated by B1 B cells.
Collapse
Affiliation(s)
- Jamee C Nixon
- Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | | | | | | | | | | |
Collapse
|