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Chalise JP, Ehsani A, Lemecha M, Hung YW, Zhang G, Larson GP, Itakura K. ARID5B regulates fatty acid metabolism and proliferation at the Pre-B cell stage during B cell development. Front Immunol 2023; 14:1170475. [PMID: 37483604 PMCID: PMC10360657 DOI: 10.3389/fimmu.2023.1170475] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 06/15/2023] [Indexed: 07/25/2023] Open
Abstract
During B cell development in bone marrow, large precursor B cells (large Pre-B cells) proliferate rapidly, exit the cell cycle, and differentiate into non-proliferative (quiescent) small Pre-B cells. Dysregulation of this process may result in the failure to produce functional B cells and pose a risk of leukemic transformation. Here, we report that AT rich interacting domain 5B (ARID5B), a B cell acute lymphoblastic leukemia (B-ALL) risk gene, regulates B cell development at the Pre-B stage. In both mice and humans, we observed a significant upregulation of ARID5B expression that initiates at the Pre-B stage and is maintained throughout later stages of B cell development. In mice, deletion of Arid5b in vivo and ex vivo exhibited a significant reduction in the proportion of immature B cells but an increase in large and small Pre-B cells. Arid5b inhibition ex vivo also led to an increase in proliferation of both Pre-B cell populations. Metabolic studies in mouse and human bone marrow revealed that fatty acid uptake peaked in proliferative B cells then decreased during non-proliferative stages. We showed that Arid5b ablation enhanced fatty acid uptake and oxidation in Pre-B cells. Furthermore, decreased ARID5B expression was observed in tumor cells from B-ALL patients when compared to B cells from non-leukemic individuals. In B-ALL patients, ARID5B expression below the median was associated with decreased survival particularly in subtypes originating from Pre-B cells. Collectively, our data indicated that Arid5b regulates fatty acid metabolism and proliferation of Pre-B cells in mice, and reduced expression of ARID5B in humans is a risk factor for B cell leukemia.
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Affiliation(s)
- Jaya Prakash Chalise
- Center for RNA Biology and Therapeutics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Ali Ehsani
- Center for RNA Biology and Therapeutics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Mengistu Lemecha
- Center for RNA Biology and Therapeutics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Yu-Wen Hung
- Immunology and Theranostics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Guoxiang Zhang
- Center for RNA Biology and Therapeutics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Garrett P. Larson
- Center for RNA Biology and Therapeutics, Beckman Research Institute, City of Hope, Duarte, CA, United States
| | - Keiichi Itakura
- Center for RNA Biology and Therapeutics, Beckman Research Institute, City of Hope, Duarte, CA, United States
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2
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OBF1 and Oct factors control the germinal center transcriptional program. Blood 2021; 137:2920-2934. [PMID: 33512466 DOI: 10.1182/blood.2020010175] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 12/29/2020] [Indexed: 12/12/2022] Open
Abstract
OBF1 is a specific coactivator of the POU family transcription factors OCT1 and OCT2. OBF1 and OCT2 are B cell-specific and indispensable for germinal center (GC) formation, but their mechanism of action is unclear. Here, we show by chromatin immunoprecipitation-sequencing that OBF1 extensively colocalizes with OCT1 and OCT2. We found that these factors also often colocalize with transcription factors of the ETS family. Furthermore, we showed that OBF1, OCT2, and OCT1 bind widely to the promoters or enhancers of genes involved in GC formation in mouse and human GC B cells. Short hairpin RNA knockdown experiments demonstrated that OCT1, OCT2, and OBF1 regulate each other and are essential for proliferation of GC-derived lymphoma cell lines. OBF1 downregulation disrupts the GC transcriptional program: genes involved in GC maintenance, such as BCL6, are downregulated, whereas genes related to exit from the GC program, such as IRF4, are upregulated. Ectopic expression of BCL6 does not restore the proliferation of GC-derived lymphoma cells depleted of OBF1 unless IRF4 is also depleted, indicating that OBF1 controls an essential regulatory node in GC differentiation.
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3
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Lipid Metabolism in Tumor-Associated B Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1316:133-147. [PMID: 33740248 DOI: 10.1007/978-981-33-6785-2_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Breakthroughs have been made in the cancer immunotherapy field focusing on utilizing T cells' antitumor immunity, and the lipid metabolism of tumor-associated B cells is not well studied compared to T cells. Accumulating evidence suggested that B cells also play important roles in tumor biology and antitumor immunity, especially the germinal center B cells that present in the tumor-related tertiary lymphoid structures. Due to scarce studies on lipid metabolisms of tumor-associated B cells, this chapter mainly summarized findings on B cell lipid metabolism and discussed B cell development and major transcription factors, tumor-associated B cell populations and their potential functions in antitumor immunity, fatty acid oxidation in germinal center B cells, and tumor microenvironment factors that potentially affect B cell lipid metabolism, focusing on hypoxia and nutrients competition, as well as lipid metabolites that affect B cell function, including cholesterol, geranylgeranyl pyrophosphate, oxysterols, and short-chain fatty acids.
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4
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Javed A, Mattar P, Lu S, Kruczek K, Kloc M, Gonzalez-Cordero A, Bremner R, Ali RR, Cayouette M. Pou2f1 and Pou2f2 cooperate to control the timing of cone photoreceptor production in the developing mouse retina. Development 2020; 147:dev.188730. [DOI: 10.1242/dev.188730] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 08/19/2020] [Indexed: 12/27/2022]
Abstract
Multipotent retinal progenitor cells (RPCs) generate various cell types in a precise chronological order, but how exactly cone photoreceptor production is restricted to early stages remains unclear. Here, we show that the POU-homeodomain factors Pou2f1/Pou2f2, the homologs of Drosophila temporal identity factors nub/pdm2, regulate the timely production of cones in mice. Forcing sustained expression of Pou2f1 or Pou2f2 in RPCs expands the period of cone production, whereas misexpression in late-stage RPCs triggers ectopic cone production at the expense of late-born fates. Mechanistically, we report that Pou2f1 induces Pou2f2 expression, which binds to a POU motif in the promoter of the rod-inducing factor Nrl to repress its expression. Conversely, conditional inactivation of Pou2f2 in RPCs increases Nrl expression and reduces cone production. Finally, we provide evidence that Pou2f1 is part of a cross-regulatory cascade with the other temporal identity factors Ikzf1 and Casz1. These results uncover Pou2f1/2 as regulators of the temporal window for cone genesis and, given their widespread expression in the nervous system, raise the possibility of a general role in temporal patterning.
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Affiliation(s)
- Awais Javed
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montreal (IRCM), Canada
- Molecular Biology Program, Université de Montréal, Canada
| | - Pierre Mattar
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montreal (IRCM), Canada
| | - Suying Lu
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada. Department of Ophthalmology and Vision Science, Department of Lab Medicine and Pathobiology, University of Toronto
| | | | | | | | - Rod Bremner
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada. Department of Ophthalmology and Vision Science, Department of Lab Medicine and Pathobiology, University of Toronto
| | - Robin R. Ali
- UCL Institute of Ophthalmology, London, UK
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Michel Cayouette
- Cellular Neurobiology Research Unit, Institut de recherches cliniques de Montreal (IRCM), Canada
- Molecular Biology Program, Université de Montréal, Canada
- Department of Medicine, Université de Montréal, Canada
- Department of Anatomy and Cell Biology; Division of Experimental Medicine, McGill University, Canada
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5
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Masgutova G, Harris A, Jacob B, Corcoran LM, Clotman F. Pou2f2 Regulates the Distribution of Dorsal Interneurons in the Mouse Developing Spinal Cord. Front Mol Neurosci 2019; 12:263. [PMID: 31787878 PMCID: PMC6853997 DOI: 10.3389/fnmol.2019.00263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 10/16/2019] [Indexed: 12/20/2022] Open
Abstract
Spinal dorsal interneurons, which are generated during embryonic development, relay and process sensory inputs from the periphery to the central nervous system. Proper integration of these cells into neuronal circuitry depends on their correct positioning within the spinal parenchyma. Molecular cues that control neuronal migration have been extensively characterized but the genetic programs that regulate their production remain poorly investigated. Onecut (OC) transcription factors have been shown to control the migration of the dorsal interneurons (dINs) during spinal cord development. Here, we report that the OC factors moderate the expression of Pou2f2, a transcription factor essential for B-cell differentiation, in spinal dINs. Overexpression or inactivation of Pou2f2 leads to alterations in the differentiation of dI2, dI3 and Phox2a-positive dI5 populations and to defects in the distribution of dI2-dI6 interneurons. Thus, an OC-Pou2f2 genetic cascade regulates adequate diversification and distribution of dINs during embryonic development.
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Affiliation(s)
- Gauhar Masgutova
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium
| | - Audrey Harris
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium
| | - Benvenuto Jacob
- Université catholique de Louvain, Institute of Neuroscience, System and Cognition Division, Brussels, Belgium
| | - Lynn M Corcoran
- Molecular Immunology Division and Immunology Division, The Walter and Eliza Hall Institute, Parkville, VIC, Australia
| | - Frédéric Clotman
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium
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6
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Harris A, Masgutova G, Collin A, Toch M, Hidalgo-Figueroa M, Jacob B, Corcoran LM, Francius C, Clotman F. Onecut Factors and Pou2f2 Regulate the Distribution of V2 Interneurons in the Mouse Developing Spinal Cord. Front Cell Neurosci 2019; 13:184. [PMID: 31231191 PMCID: PMC6561314 DOI: 10.3389/fncel.2019.00184] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/12/2019] [Indexed: 11/21/2022] Open
Abstract
Acquisition of proper neuronal identity and position is critical for the formation of neural circuits. In the embryonic spinal cord, cardinal populations of interneurons diversify into specialized subsets and migrate to defined locations within the spinal parenchyma. However, the factors that control interneuron diversification and migration remain poorly characterized. Here, we show that the Onecut transcription factors are necessary for proper diversification and distribution of the V2 interneurons in the developing spinal cord. Furthermore, we uncover that these proteins restrict and moderate the expression of spinal isoforms of Pou2f2, a transcription factor known to regulate B-cell differentiation. By gain- or loss-of-function experiments, we show that Pou2f2 contribute to regulate the position of V2 populations in the developing spinal cord. Thus, we uncovered a genetic pathway that regulates the diversification and the distribution of V2 interneurons during embryonic development.
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Affiliation(s)
- Audrey Harris
- Laboratory of Neural Differentiation, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Gauhar Masgutova
- Laboratory of Neural Differentiation, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Amandine Collin
- Laboratory of Neural Differentiation, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Mathilde Toch
- Laboratory of Neural Differentiation, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Maria Hidalgo-Figueroa
- Laboratory of Neural Differentiation, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Benvenuto Jacob
- Institute of Neuroscience, System and Cognition Division, Université catholique de Louvain, Brussels, Belgium
| | - Lynn M. Corcoran
- Molecular Immunology Division and Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Cédric Francius
- Laboratory of Neural Differentiation, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
| | - Frédéric Clotman
- Laboratory of Neural Differentiation, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
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7
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Zou F, Wang X, Han X, Rothschild G, Zheng SG, Basu U, Sun J. Expression and Function of Tetraspanins and Their Interacting Partners in B Cells. Front Immunol 2018; 9:1606. [PMID: 30072987 PMCID: PMC6058033 DOI: 10.3389/fimmu.2018.01606] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 06/27/2018] [Indexed: 01/26/2023] Open
Abstract
Tetraspanins are transmembrane proteins that modulate multiple diverse biological processes, including signal transduction, cell–cell communication, immunoregulation, tumorigenesis, cell adhesion, migration, and growth and differentiation. Here, we provide a systematic review of the involvement of tetraspanins and their partners in the regulation and function of B cells, including mechanisms associated with antigen presentation, antibody production, cytokine secretion, co-stimulator expression, and immunosuppression. Finally, we direct our focus to the signaling mechanisms, evolutionary conservation aspects, expression, and potential therapeutic strategies that could be based on tetraspanins and their interacting partners.
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Affiliation(s)
- Fagui Zou
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xu Wang
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Xinxin Han
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
| | - Gerson Rothschild
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Song Guo Zheng
- Department of Medicine, Milton S. Hershey Medical Center at Penn State University, Pennsylvania, PA, United States.,Center for Clinic Immunology, Third Affiliated Hospital at Sun Yat-Sen University, Guangzhou, China
| | - Uttiya Basu
- Department of Microbiology and Immunology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Jianbo Sun
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, China
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8
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Minocycline decreases CD36 and increases CD44 in LPS-induced microglia. J Neuroimmunol 2018; 317:95-99. [PMID: 29395319 DOI: 10.1016/j.jneuroim.2018.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 12/18/2017] [Accepted: 01/16/2018] [Indexed: 12/31/2022]
Abstract
Microglia are the resident macrophages patrolling the central nervous system (CNS) to find dangerous signals and infectious agents mediating catastrophic cascades resulting in neuronal degeneration. Their morphological and biochemical properties made them enable to swift activation in response to neural insults and site-directed phagocytosis. Beside of beneficial roles in homeostasis of the brain and spinal cord, microglia can be participating in neuronal destruction and propagation of inflammation when they are unregulated or hyper-activated. A large body of research indicates that various cluster of differentiations (CDs) contribute to flame/quench the inflammatory processes occurred in immune system. In this study, we investigated the expression of CD36 and CD44 in LPS-activated primary rat microglia in response to treatment of minocycline at the levels of protein and gene using flow cytometry and real-time PCR, respectively. The results showed that minocycline decreased the expression of CD36 in cells treated with minocycline with respect to cells treated with LPS. Inversely, the expression of CD44 was increased in cells treated with minocycline in comparison to LPS-induced microglia. It seems that minocycline can modulate the expression of CDs involved in inflammatory reactions and enrich the armamentarium of therapeutic agents used for the treatment of neuroinflammatory and neurodegenerative disorders.
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9
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Corcoran L, Emslie D, Kratina T, Shi W, Hirsch S, Taubenheim N, Chevrier S. Oct2 and Obf1 as Facilitators of B:T Cell Collaboration during a Humoral Immune Response. Front Immunol 2014; 5:108. [PMID: 24688485 PMCID: PMC3960507 DOI: 10.3389/fimmu.2014.00108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/03/2014] [Indexed: 11/16/2022] Open
Abstract
The Oct2 protein, encoded by the Pou2f2 gene, was originally predicted to act as a DNA binding transcriptional activator of immunoglobulin (Ig) in B lineage cells. This prediction flowed from the earlier observation that an 8-bp sequence, the “octamer motif,” was a highly conserved component of most Ig gene promoters and enhancers, and evidence from over-expression and reporter assays confirmed Oct2-mediated, octamer-dependent gene expression. Complexity was added to the story when Oct1, an independently encoded protein, ubiquitously expressed from the Pou2f1 gene, was characterized and found to bind to the octamer motif with almost identical specificity, and later, when the co-activator Obf1 (OCA-B, Bob.1), encoded by the Pou2af1 gene, was cloned. Obf1 joins Oct2 (and Oct1) on the DNA of a subset of octamer motifs to enhance their transactivation strength. While these proteins variously carried the mantle of determinants of Ig gene expression in B cells for many years, such a role has not been borne out for them by characterization of mice lacking functional copies of the genes, either as single or as compound mutants. Instead, we and others have shown that Oct2 and Obf1 are required for B cells to mature fully in vivo, for B cells to respond to the T cell cytokines IL5 and IL4, and for B cells to produce IL6 normally during a T cell dependent immune response. We show here that Oct2 affects Syk gene expression, thus influencing B cell receptor signaling, and that Oct2 loss blocks Slamf1 expression in vivo as a result of incomplete B cell maturation. Upon IL4 signaling, Stat6 up-regulates Obf1, indirectly via Xbp1, to enable plasma cell differentiation. Thus, Oct2 and Obf1 enable B cells to respond normally to antigen receptor signals, to express surface receptors that mediate physical interaction with T cells, or to produce and respond to cytokines that are critical drivers of B cell and T cell differentiation during a humoral immune response.
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Affiliation(s)
- Lynn Corcoran
- Molecular Immunology Division, Walter and Eliza Hall Institute of Medical Research , Melbourne, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Melbourne, VIC , Australia
| | - Dianne Emslie
- Molecular Immunology Division, Walter and Eliza Hall Institute of Medical Research , Melbourne, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Melbourne, VIC , Australia
| | - Tobias Kratina
- Molecular Immunology Division, Walter and Eliza Hall Institute of Medical Research , Melbourne, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Melbourne, VIC , Australia
| | - Wei Shi
- Molecular Immunology Division, Walter and Eliza Hall Institute of Medical Research , Melbourne, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Melbourne, VIC , Australia
| | - Susanne Hirsch
- Molecular Immunology Division, Walter and Eliza Hall Institute of Medical Research , Melbourne, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Melbourne, VIC , Australia
| | - Nadine Taubenheim
- Molecular Immunology Division, Walter and Eliza Hall Institute of Medical Research , Melbourne, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Melbourne, VIC , Australia
| | - Stephane Chevrier
- Molecular Immunology Division, Walter and Eliza Hall Institute of Medical Research , Melbourne, VIC , Australia ; Department of Medical Biology, The University of Melbourne , Melbourne, VIC , Australia
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10
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Mueller K, Quandt J, Marienfeld RB, Weihrich P, Fiedler K, Claussnitzer M, Laumen H, Vaeth M, Berberich-Siebelt F, Serfling E, Wirth T, Brunner C. Octamer-dependent transcription in T cells is mediated by NFAT and NF-κB. Nucleic Acids Res 2013; 41:2138-54. [PMID: 23293002 PMCID: PMC3575799 DOI: 10.1093/nar/gks1349] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The transcriptional co-activator BOB.1/OBF.1 was originally identified in B cells and is constitutively expressed throughout B cell development. BOB.1/OBF.1 associates with the transcription factors Oct1 and Oct2, thereby enhancing octamer-dependent transcription. In contrast, in T cells, BOB.1/OBF.1 expression is inducible by treatment of cells with PMA/Ionomycin or by antigen receptor engagement, indicating a marked difference in the regulation of BOB.1/OBF.1 expression in B versus T cells. The molecular mechanisms underlying the differential expression of BOB.1/OBF.1 in T and B cells remain largely unknown. Therefore, the present study focuses on mechanisms controlling the transcriptional regulation of BOB.1/OBF.1 and Oct2 in T cells. We show that both calcineurin- and NF-κB-inhibitors efficiently attenuate the expression of BOB.1/OBF.1 and Oct2 in T cells. In silico analyses of the BOB.1/OBF.1 promoter revealed the presence of previously unappreciated combined NFAT/NF-κB sites. An array of genetic and biochemical analyses illustrates the involvement of the Ca2+/calmodulin-dependent phosphatase calcineurin as well as NFAT and NF-κB transcription factors in the transcriptional regulation of octamer-dependent transcription in T cells. Conclusively, impaired expression of BOB.1/OBF.1 and Oct2 and therefore a hampered octamer-dependent transcription may participate in T cell-mediated immunodeficiency caused by the deletion of NFAT or NF-κB transcription factors.
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Affiliation(s)
- Kerstin Mueller
- Institute of Physiological Chemistry, University Ulm, D-89081 Ulm, Germany, Institute of Pathology, University Ulm, D-89081 Ulm, Germany
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11
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Karnowski A, Chevrier S, Belz GT, Mount A, Emslie D, D'Costa K, Tarlinton DM, Kallies A, Corcoran LM. B and T cells collaborate in antiviral responses via IL-6, IL-21, and transcriptional activator and coactivator, Oct2 and OBF-1. ACTA ACUST UNITED AC 2012; 209:2049-64. [PMID: 23045607 PMCID: PMC3478936 DOI: 10.1084/jem.20111504] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Transcriptional activator Oct2 and cofactor OBF-1 regulate B cell IL-6 to induce T cell production of IL-21, to support Tfh cell development in antiviral immunity. A strong humoral response to infection requires the collaboration of several hematopoietic cell types that communicate via antigen presentation, surface coreceptors and their ligands, and secreted factors. The proinflammatory cytokine IL-6 has been shown to promote the differentiation of activated CD4+ T cells into T follicular helper cells (TFH cells) during an immune response. TFH cells collaborate with B cells in the formation of germinal centers (GCs) during T cell–dependent antibody responses, in part through secretion of critical cytokines such as IL-21. In this study, we demonstrate that loss of either IL-6 or IL-21 has marginal effects on the generation of TFH cells and on the formation of GCs during the response to acute viral infection. However, mice lacking both IL-6 and IL-21 were unable to generate a robust TFH cell–dependent immune response. We found that IL-6 production in follicular B cells in the draining lymph node was an important early event during the antiviral response and that B cell–derived IL-6 was necessary and sufficient to induce IL-21 from CD4+ T cells in vitro and to support TFH cell development in vivo. Finally, the transcriptional activator Oct2 and its cofactor OBF-1 were identified as regulators of Il6 expression in B cells.
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Affiliation(s)
- Alex Karnowski
- Molecular Immunology Division and 2 Immunology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
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12
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Advani AS, Lim K, Gibson S, Shadman M, Jin T, Copelan E, Kalaycio M, Sekeres MA, Sobecks R, Hsi E. OCT-2 expression and OCT-2/BOB.1 co-expression predict prognosis in patients with newly diagnosed acute myeloid leukemia. Leuk Lymphoma 2010; 51:606-12. [PMID: 20141429 DOI: 10.3109/10428191003592735] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OCT-2 and its co-activator, BOB.1, are B-cell associated transcription factors expressed in a subset of patients with acute myeloid leukemia (AML). We evaluated OCT-2 and BOB.1 expression by immunohistochemistry in patients with newly diagnosed AML. The median overall survival (OS) for patients with varying levels of OCT-2 expression was statistically different (p = 0.03) (OCT-2 <10%: 21.7 months; OCT-2 10-50%: 18.4 months; OCT-2 >50%: 11.6 months). On multivariate analysis, co-expression of OCT-2/BOB.1 remained predictive for achievement of complete remission (HR 0.44, p = 0.010) and increased risk of relapse (HR 2.30, p = 0.047). OCT-2 (per 10% increase) was associated with a decreased progression-free survival (HR 1.10, p = 0.036) and a trend toward a worse OS (HR 1.10, p = 0.063). OCT-2 may act as a cell survival factor in AML by mediating expression of downstream targets, such as BCL-2. These results will need to be validated prospectively.
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Affiliation(s)
- Anjali S Advani
- Leukemia Program, Department of Hematologic Oncology and Blood Disorders, Cleveland Clinic Taussig Cancer Institute, Cleveland, OH 44195, USA.
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13
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14
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Emslie D, D'Costa K, Hasbold J, Metcalf D, Takatsu K, Hodgkin PO, Corcoran LM. Oct2 enhances antibody-secreting cell differentiation through regulation of IL-5 receptor alpha chain expression on activated B cells. ACTA ACUST UNITED AC 2008; 205:409-21. [PMID: 18250192 PMCID: PMC2271016 DOI: 10.1084/jem.20072049] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Mice lacking a functional gene for the Oct2 transcriptional activator display several developmental and functional deficiencies in the B lymphocyte lineage. These include defective B cell receptor (BCR) and Toll-like receptor 4 signaling, an absence of B-1 and marginal zone populations, and globally reduced levels of serum immunoglobulin (Ig) in naive and immunized animals. Oct2 was originally identified through its ability to bind to regulatory regions in the Ig loci, but genetic evidence has not supported an essential role for Oct2 in the expression of Ig genes. We describe a new Oct2-mediated role in B cells. Oct2 augments the ability of activated B cells to differentiate to antibody-secreting plasma cells (ASCs) under T cell-dependent conditions through direct regulation of the gene encoding the alpha chain of the interleukin (IL) 5 receptor. Ectopic expression of IL-5Ralpha in oct2-deficient B cells largely restores their ability to differentiate to functional ASCs in vitro but does not correct other phenotypic defects in the mutants, such as the maturation and specialization of peripheral B cells, which must therefore rely on distinct Oct2 target genes. IL-5 augments ASC differentiation in vitro, and we show that IL-5 directly activates the plasma cell differentiation program by enhancing blimp1 expression.
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Affiliation(s)
- Dianne Emslie
- Immunology Division, The Walter and Eliza Hall Institute, Parkville, Victoria 3050, Australia
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15
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Won WJ, Bachmann MF, Kearney JF. CD36 Is Differentially Expressed on B Cell Subsets during Development and in Responses to Antigen. THE JOURNAL OF IMMUNOLOGY 2007; 180:230-7. [DOI: 10.4049/jimmunol.180.1.230] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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16
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Mummidi S, Adams LM, VanCompernolle SE, Kalkonde M, Camargo JF, Kulkarni H, Bellinger AS, Bonello G, Tagoh H, Ahuja SS, Unutmaz D, Ahuja SK. Production of specific mRNA transcripts, usage of an alternate promoter, and octamer-binding transcription factors influence the surface expression levels of the HIV coreceptor CCR5 on primary T cells. THE JOURNAL OF IMMUNOLOGY 2007; 178:5668-81. [PMID: 17442950 DOI: 10.4049/jimmunol.178.9.5668] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Surface levels of CCR5 on memory CD4(+) T cells influence HIV-1/AIDS susceptibility. Alternative promoter usage results in the generation of CCR5 mRNA isoforms that differ based on whether they contain or lack the untranslated exon 1. The impact of exon 1-containing transcripts on CCR5 surface expression is unknown. In this study, we show that the increased cell surface expression of CCR5 on primary T cells is associated with selective enrichment of exon 1-containing transcripts. The promoter that drives exon 1-containing transcripts is highly active in primary human T cells but not in transformed T cell lines. The transcription factors Oct-1 and -2 inhibit and enhance, respectively, the expression of exon 1-containing transcripts and CCR5 surface levels. However, polymorphisms at homologous octamer-binding sites in the CCR5 promoter of nonhuman primates abrogate the binding of these transcription factors. These results identify exon 1-containing transcripts, and the cis-trans factors that regulate the expression levels of these mRNA isoforms as key parameters that affect CCR5 surface expression levels, and by extension, susceptibility to HIV/AIDS among humans, and possibly, the observed interspecies differences in susceptibility to lentiviral infection.
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Affiliation(s)
- Srinivas Mummidi
- Veterans Administration Center for AIDS and HIV Infection, South Texas Veterans Healthcare System and Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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17
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Malfitano AM, Toruner GA, Gazzerro P, Laezza C, Husain S, Eletto D, Orlando P, De Petrocellis L, Terskiy A, Schwalb M, Vitale E, Bifulco M. Arvanil and anandamide up-regulate CD36 expression in human peripheral blood mononuclear cells. Immunol Lett 2007; 109:145-54. [PMID: 17360047 DOI: 10.1016/j.imlet.2007.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2006] [Revised: 02/05/2007] [Accepted: 02/05/2007] [Indexed: 11/26/2022]
Abstract
In this study we analysed the regulation of gene expression by arvanil and anandamide in human peripheral blood mononuclear cells (PBMCs) to clarify their immunosuppressive properties. PBMCs were activated, leading to CD36 down regulation, that was normalized by arvanil and anandamide. We used microarray technology to identify a regulatory pattern associated with cell proliferation in the presence of both substances. CD3-CD28 stimulated PBMCs showed a pattern of up-regulated and down-regulated genes after treatment with these substances. We selected and analysed several genes chosen by their function in the regulation of cell proliferation. We showed a transcriptional control of the CD36 gene by arvanil and anandamide associated with an increased protein expression, thus suggesting a possible role of CD36 in anandamide and arvanil anti-inflammatory pattern.
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Affiliation(s)
- Anna Maria Malfitano
- Dipartimento di Scienze Farmaceutiche, Università di Salerno, Fisciano (SA), Italy
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18
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Zhou L, Nazarian AA, Xu J, Tantin D, Corcoran LM, Smale ST. An inducible enhancer required for Il12b promoter activity in an insulated chromatin environment. Mol Cell Biol 2007; 27:2698-712. [PMID: 17242186 PMCID: PMC1899891 DOI: 10.1128/mcb.00788-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Interleukin-12 (IL-12) and IL-23 are heterodimeric cytokines that serve as critical regulators of T helper cell development. The Il12b gene, which encodes the p40 subunit of both IL-12 and IL-23, is expressed in macrophages and dendritic cells following induction by bacterial products. Although the Il12b promoter, like the promoters of most proinflammatory genes, can support transcriptional induction in typical transfection assays, we show that it is not sufficient for transcription in an insulated chromatin environment. Using a DNase I hypersensitivity assay, two potential distal control regions were identified. One region, DNase I-hypersensitive site 1 (HSS1), located 10 kb upstream of the transcription start site, exhibited hypersensitivity only in stimulated macrophages. In an insulated environment, a 105-bp fragment spanning HSS1 was sufficient for transcription when combined with the Il12b promoter. Although several elements are likely to contribute to activity of the endogenous HSS1 enhancer, including an evolutionarily conserved binding site for C/EBP proteins, the only element required for activity in transient- and stable-transfection assays bound Oct-1 and Oct-2, both of which are expressed constitutively in macrophages. Oct-1 and Oct-2 were recruited to the enhancer upon macrophage stimulation, and the Oct site appeared important for nucleosome remodeling at HSS1. These results suggest that the HSS1 enhancer and Oct proteins play central roles in Il12b induction upon macrophage activation.
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Affiliation(s)
- Liang Zhou
- Howard Hughes Medical Institute, University of California-Los Angeles, 675 Charles E. Young Drive South, Los Angeles, CA 90095-1662, USA
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19
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Kwon UK, Yen PH, Collins T, Wells RA. Differential lineage-specific regulation of murine CD45 transcription by Oct-1 and PU.1. Biochem Biophys Res Commun 2006; 344:146-54. [PMID: 16616894 DOI: 10.1016/j.bbrc.2006.03.119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Accepted: 03/20/2006] [Indexed: 10/24/2022]
Abstract
Although it has been established that CD45 expression is regulated at the transcriptional level, neither the regulatory elements that are responsible for its unique expression pattern nor the relevance of its three distinct transcriptional start sites (P1a, P1b, and P2) has been fully characterized. We studied the contribution of the three start sites to CD45 mRNA production in haematopoietic cell lines and primary haematopoietic cells. In myeloid and lymphoid cells and cell lines most CD45 transcripts originate from P1b with the exception of the thymoma-derived T cell line EL4, in which approximately 90% of CD45 transcripts originate from P1a. The degree of contribution of P1a is highest in lymphoid cells and increases in T cells following mitogen stimulation. In vitro evaluation of sequence upstream of the start sites shows that the P2 start site is sufficient for CD45 expression in lymphoid but not in myeloid cells, confirms the presence of a PU.1-binding site essential for myeloid expression of CD45, and reveals an Octamer-binding site that interacts with both Oct-1 and Oct-2 and activates CD45 transcription in lymphoid and myeloid cells. These findings are the first evidence that Octamer-binding factors are involved in the control of CD45 expression.
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Affiliation(s)
- Un K Kwon
- Molecular and Cellular Biology, Sunnybrook and Women's Research Institute, Department of Medical Oncology, Toronto Sunnybrook Regional Cancer Centre, Toronto, Ont., Canada M4N 2M5
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20
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Abstract
The developmental program that commits a hematopoietic stem cell to the B lymphocyte lineage employs transcriptional regulators to enable the assembly of an antigen receptor complex with a useful specificity and with signalling competence. Once a naive IgM+ B cell is generated, it must correctly integrate signals from the antigen receptor with those from cytokine receptors and co-receptors delivering T cell help. The B cell responds through the regulated expression of genes that implement specific cell expansion and differentiation, secretion of high levels of high-affinity antibody, and generation of long-term memory. The transcriptional regulators highlighted in this chapter are those for which genetic evidence of function in IgM+ B cells in vivo has been provided, often in the form of mutant mice generated by conventional or conditional gene targeting. A critical developmental step is the maturation of bone marrow emigrant "transitional" B cells into the mature, long-lived cells of the periphery, and a number of the transcription factors discussed here impact on this process, yielding B cells with poor mitogenic responses in vitro. For mature B cells, it is clear that not only the nature, but the duration and amplitude of an activating signal are major determinants of the transcription factor activities enlisted, and so the ultimate outcome. The current challenge is the identification of the target genes that are activated to implement the correct response, so that we may more precisely and safely manipulate B cell behavior to predictably and positively influence humoral immune responses.
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Affiliation(s)
- L M Corcoran
- The Walter and Eliza Hall Institute of Medical Research, Victoria, Australia.
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21
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Corcoran LM, Koentgen F, Dietrich W, Veale M, Humbert PO. All known in vivo functions of the Oct-2 transcription factor require the C-terminal protein domain. THE JOURNAL OF IMMUNOLOGY 2004; 172:2962-9. [PMID: 14978099 DOI: 10.4049/jimmunol.172.5.2962] [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
Oct-2, a transcription factor expressed in the B lymphocyte lineage and in the developing CNS, functions through of a number of discrete protein domains. These include a DNA-binding POU homeodomain flanked by two transcriptional activation domains. In vitro studies have shown that the C-terminal activation domain, a serine-, threonine- and proline-rich sequence, possesses unique qualities, including the ability to activate transcription from a distance in a B cell-specific manner. In this study, we describe mice in which the endogenous oct-2 gene has been modified through gene targeting to create a mutated allele, oct-2DeltaC, which encodes Oct-2 protein isoforms that lack all sequence C-terminal to the DNA-binding domain. Surprisingly, despite the retention of the DNA-binding domain and the glutamine-rich N-terminal activation domain, the truncated protein(s) encoded by the oct-2DeltaC allele are unable to rescue any of the previously described defects exhibited by oct-2 null mice. Homozygous oct-2DeltaC/DeltaC mice die shortly after birth, and B cell maturation, B-1 cell self renewal, serum Ig levels, and B lymphocyte responses to in vitro stimulation are all reduced or absent, to a degree equivalent to that seen in oct-2 null mice. We conclude that the C-terminal activation domain of Oct-2 is required to mediate the unique and indispensable functions of the Oct-2 transcription factor in vivo.
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Affiliation(s)
- Lynn M Corcoran
- The Walter and Eliza Hall Institute, Parkville, Victoria, Australia.
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22
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Wang VEH, Schmidt T, Chen J, Sharp PA, Tantin D. Embryonic lethality, decreased erythropoiesis, and defective octamer-dependent promoter activation in Oct-1-deficient mice. Mol Cell Biol 2004; 24:1022-32. [PMID: 14729950 PMCID: PMC321444 DOI: 10.1128/mcb.24.3.1022-1032.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oct-1 is a sequence-specific DNA binding transcription factor that is believed to regulate a large group of tissue-specific and ubiquitous genes. Both Oct-1 and the related but tissue-restricted Oct-2 protein bind to a DNA sequence termed the octamer motif (5'-ATGCAAAT-3') with equal affinity in vitro. To address the role of Oct-1 in vivo, an Oct-1-deficient mouse strain was generated by gene targeting. Oct-1-deficient embryos died during gestation, frequently appeared anemic, and suffered from a lack of Ter-119-positive erythroid precursor cells. This defect was cell intrinsic. Fibroblasts derived from these embryos displayed a dramatic decrease in Oct-1 DNA binding activity and a lack of octamer-dependent promoter activity in transient transfection assays. Interestingly, several endogenous genes thought to be regulated by Oct-1 showed no change in expression. When crossed to Oct-2(+/-) animals, transheterozygotes were recovered at a very low frequency. These findings suggest a critical role for Oct-1 during development and a stringent gene dosage effect with Oct-2 in mediating postnatal survival.
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Affiliation(s)
- Victoria E H Wang
- Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA
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23
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Wang VEH, Tantin D, Chen J, Sharp PA. B cell development and immunoglobulin transcription in Oct-1-deficient mice. Proc Natl Acad Sci U S A 2004; 101:2005-10. [PMID: 14762167 PMCID: PMC357042 DOI: 10.1073/pnas.0307304101] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The POU domain transcription factors Oct-1 and Oct-2 interact with the octamer element, a motif conserved within Ig promoters and enhancers, and mediate transcription from the Ig loci. Inactivation of Oct-2 by gene targeting results in normal B cell development and Ig transcription. To study the role of Oct-1 in these processes, the lymphoid compartment of RAG-1(-/-) animals was reconstituted with Oct-1-deficient fetal liver hematopoietic cells. Recipient mice develop B cells with levels of surface Ig expression comparable with wild type, although at slightly reduced numbers. These B cells transcribe Ig normally, respond to antigenic stimulation, undergo class switching, and use a normal repertoire of light chain variable segments. However, recipient mice show slight reductions in serum IgM and IgA. Thus, the Oct-1 protein is dispensable for B cell development and Ig transcription.
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Affiliation(s)
- Victoria E H Wang
- Department of Biology and Center for Cancer Research and McGovern Institute, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA
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24
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Brunner C, Laumen H, Nielsen PJ, Kraut N, Wirth T. Expression of the aldehyde dehydrogenase 2-like gene is controlled by BOB.1/OBF.1 in B lymphocytes. J Biol Chem 2003; 278:45231-9. [PMID: 12947107 DOI: 10.1074/jbc.m302539200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BOB.1/OBF.1 is a lymphocyte-restricted transcriptional coactivator. It binds to the Oct1 and Oct2 transcription factors and increases their transactivation potential. Targeted gene disruption experiments revealed that BOB.1/OBF.1 is critical at different stages of B cell development. A large number of genes expressed in B cells contain octamer motifs in their regulatory regions. However, only few genes have been described so far whose expression is dependent on BOB.1/OBF.1. To understand the molecular basis of BOB.1/OBF.1 function in B cell development, we searched for BOB.1/OBF.1 target genes by expression profiling. We have identified genes both induced and repressed by BOB.1/OBF.1. Using different genetic systems, we demonstrate regulation of a selection of these genes. Identified targets included genes encoding Ahd2-like, AKR1C13, Rbp1, Sdh, Idh2, protocadherin gamma, alpha-catenin, Ptprs, Id3, and Creg. Classification of BOB.1/OBF.1 target genes by function suggests that they affect various aspects of B cell physiology such as cellular metabolism, cell adhesion, and differentiation. To better understand the mechanism of BOB.1/OBF.1 action, we cloned the promoter of the gene encoding Ahd2-like, the gene showing the strongest regulation by BOB.1/OBF.1. This promoter indeed contains a perfect octamer motif. Furthermore, the motif was recognized by the Oct transcription factors as well as BOB.1/OBF.1 in vitro and in vivo, as shown by electromobility shift and chromatin immunoprecipitation assays. Transient transfections confirm that this promoter is activated by BOB.1/OBF.1. Our observations suggest that by regulating genes in different functional pathways, BOB.1/OBF.1 has a widespread effect on B cell development and function.
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Affiliation(s)
- Cornelia Brunner
- University of Ulm, Department of Physiological Chemistry, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
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25
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Feldhahn N, Schwering I, Lee S, Wartenberg M, Klein F, Wang H, Zhou G, Wang SM, Rowley JD, Hescheler J, Krönke M, Rajewsky K, Küppers R, Müschen M. Silencing of B cell receptor signals in human naive B cells. J Exp Med 2002; 196:1291-305. [PMID: 12438421 PMCID: PMC2193982 DOI: 10.1084/jem.20020881] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
To identify changes in the regulation of B cell receptor (BCR) signals during the development of human B cells, we generated genome-wide gene expression profiles using the serial analysis of gene expression (SAGE) technique for CD34(+) hematopoietic stem cells (HSCs), pre-B cells, naive, germinal center (GC), and memory B cells. Comparing these SAGE profiles, genes encoding positive regulators of BCR signaling were expressed at consistently lower levels in naive B cells than in all other B cell subsets. Conversely, a large group of inhibitory signaling molecules, mostly belonging to the immunoglobulin superfamily (IgSF), were specifically or predominantly expressed in naive B cells. The quantitative differences observed by SAGE were corroborated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry. In a functional assay, we show that down-regulation of inhibitory IgSF receptors and increased responsiveness to BCR stimulation in memory as compared with naive B cells at least partly results from interleukin (IL)-4 receptor signaling. Conversely, activation or impairment of the inhibitory IgSF receptor LIRB1 affected BCR-dependent Ca(2+) mobilization only in naive but not memory B cells. Thus, LIRB1 and IL-4 may represent components of two nonoverlapping gene expression programs in naive and memory B cells, respectively: in naive B cells, a large group of inhibitory IgSF receptors can elevate the BCR signaling threshold to prevent these cells from premature activation and clonal expansion before GC-dependent affinity maturation. In memory B cells, facilitated responsiveness upon reencounter of the immunizing antigen may result from amplification of BCR signals at virtually all levels of signal transduction.
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Affiliation(s)
- Niklas Feldhahn
- Institute for Medical Microbiology, Immunology and Hygiene, University of Cologne, 50931 Köln, Germany
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26
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Corcoran L, Vremec D, Febbraio M, Baldwin T, Handman E. Differential regulation of CD36 expression in antigen-presenting cells: Oct-2 dependence in B lymphocytes but not dendritic cells or macrophages. Int Immunol 2002; 14:1099-104. [PMID: 12356675 DOI: 10.1093/intimm/dxf075] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In mice, three antigen-presenting cell types [B lymphocytes, macrophages and dendritic cells (DC)] express the scavenger receptor CD36. This molecule has been implicated in many important functions, including DC maturation and antigen presentation. In murine B cells, the CD36 gene requires the Oct-2 transcription factor for its expression. We previously found that B cells from Oct-2-null mice display defects in maturation, survival and proliferation. Here we have looked for a possible role for CD36 in B cells, but found that CD36 is dispensable for all responses tested. Although loss of CD36 did not directly affect B cell function, it did modulate slightly the isotype and level of IgG produced in vivo in naive mice, and IgM in Leishmania-infected mice. We also show that in DC and macrophages, CD36 expression is independent of Oct-2. We conclude that CD36 does not play a major role in B cell function, but that CD36 may contribute indirectly to humoral immunity through cells of the innate immune system.
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Affiliation(s)
- Lynn Corcoran
- The Walter and Eliza Hall Institute of Medical Research, PO Royal Melbourne Hospital, Victoria 3050, Australia.
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27
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Imai M, Tanaka T, Kintaka T, Ikemoto T, Shimizu A, Kitaura Y. Genomic heterogeneity of type II CD36 deficiency. Clin Chim Acta 2002; 321:97-106. [PMID: 12031598 DOI: 10.1016/s0009-8981(02)00102-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND CD36 deficiency has been classified in two types, i.e., type I and type II CD36 deficiency. Possible pathological involvement of CD36 deficiency has been suggested in humans, but is still confounding. Homozygous or compound heterozygous mutations (CD36(-/-)) were demonstrated in type I CD36 deficiency, while the genomic or molecular background of type II CD36 deficiency is still unclear, which may bring confounding interpretations of the cause-and-effect events in human CD36 deficiency. In this study, we analyzed the genotype and frequency of type II CD36 deficiency in Japanese populations, and its hereditary pattern in three families. METHODS Genotypes and protein expression levels of CD36 were examined in 238 Japanese subjects. Genotype was analyzed in the coding region of the CD36 gene. The expression level of CD36 protein was analyzed by flow cytometry after staining with monoclonal anti-CD36 antibody and assessed as mean fluorescence intensity (MFI). RESULTS Among 238 subjects, subjects for wild-type gene (WT), a single mutation (CD36(+/-)), and CD36(-/-) were 141, 44 and 53, respectively. Monocyte MFI (mean+/-SD) in subjects for WT, CD36(+/-), and CD36(-/-) were 35.7+/-8.5, 15.2+/-3.4, and 0.4+/-0.3, respectively (P<0.0001, between groups). Those of platelets in subjects for WT, CD36(+/-), and CD36(-/-) were 27.1+/-10.6, 11.5+/-6.3, and 0.5+/-0.3, respectively (P<0.0001, between groups). Subjects of both WT and CD36(+/-) were observed in type II CD36 deficiency. Monocyte and platelet MFI in family members of type II CD36 deficiency and 218 unrelated Japanese suggested that the expression level of CD36 protein in monocytes was directly dependent on genotypes. On the other hand, those in platelets were affected by additional heritable factor(s) in addition to the coding region genotype. CONCLUSIONS MFI in monocytes showed a strong gene-dosage-dependency. On the other hand, MFI in platelets was affected by heritable factor(s) in addition to the coding region genotype, which resulted in heterogeneity of type II CD36 deficiency.
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Affiliation(s)
- Makoto Imai
- Third Division, Department of Internal Medicine, Osaka Medical College, Takatsuki, Osaka 569-8686, Japan
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28
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Shore P, Dietrich W, Corcoran LM. Oct-2 regulates CD36 gene expression via a consensus octamer, which excludes the co-activator OBF-1. Nucleic Acids Res 2002; 30:1767-73. [PMID: 11937630 PMCID: PMC113195 DOI: 10.1093/nar/30.8.1767] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The POU domain transcription factor, Oct-2, is essential for the B cell-specific expression of CD36 in mouse B cells. In order to determine how Oct-2 mediates expression of CD36 in B cells, we cloned and analysed the mouse CD36 promoter. In contrast to the human CD36 promoter, the mouse promoter contains a consensus octamer element of the type ATGCTAAT. This octamer element can be bound by either Oct-1 or Oct-2 but requires the expression of Oct-2 to activate transcription in B cells. Mutation of the octamer element renders the CD36 promoter refractory to activation by Oct-2. Furthermore, we demonstrate that the CD36 octamer element does not support recruitment of the B cell-specific co-activator OBF-1 and that CD36 expression is unaffected in primary B cells derived from obf-1(-/-) mice. We conclude that Oct-2 activates CD36 gene expression in mouse B cells via the octamer element in the promoter. Our data also demonstrate that CD36 is the first example of an Oct-2-dependent gene whose expression in B cells is independent of OBF-1. These findings support the notion that Oct-2 regulates gene transcription by both OBF-1-dependent and -independent mechanisms.
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Affiliation(s)
- Paul Shore
- School of Biological Sciences, University of Manchester, 2.205, Stopford Building, Oxford Road, Manchester M13 9PT, UK.
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29
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Teboul L, Febbraio M, Gaillard D, Amri EZ, Silverstein R, Grimaldi PA. Structural and functional characterization of the mouse fatty acid translocase promoter: activation during adipose differentiation. Biochem J 2001; 360:305-12. [PMID: 11716758 PMCID: PMC1222230 DOI: 10.1042/0264-6021:3600305] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Fatty acid translocase (FAT/CD36) is a cell-surface glycoprotein that functions as a receptor/transporter for long-chain fatty acids (LCFAs), and interacts with other protein and lipid ligands. FAT/CD36 is expressed by various cell types, including platelets, monocytes/macrophages and endothelial cells, and tissues with an active LCFA metabolism, such as adipose, small intestine and heart. FAT/CD36 expression is induced during adipose cell differentiation and is transcriptionally up-regulated by LCFAs and thiazolidinediones in pre-adipocytes via a peroxisome-proliferator-activated receptor (PPAR)-mediated process. We isolated and analysed the murine FAT/CD36 promoter employing C(2)C(12)N cells directed to differentiate to either adipose or muscle. Transient transfection studies revealed that the 309 bp upstream from the start of exon 1 confer adipose specific activity. Sequence analysis of this DNA fragment revealed the presence of two imperfect direct repeat-1 elements. Electrophoretic mobility-shift assay demonstrated that these elements were peroxisome-proliferator-responsive elements (PPREs). Mutagenesis and transfection experiments indicated that both PPREs co-operate to drive strong promoter activity in adipose cells. We conclude that murine FAT/CD36 expression in adipose tissue is dependent upon transcriptional activation via PPARs through binding to two PPREs located at -245 to -233 bp and -120 to -108 bp from the transcription start site.
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Affiliation(s)
- L Teboul
- INSERM U470, Centre de Biochimie, Parc Valrose, UFR Sciences, Université de Nice-Sophia Antipolis, 06108 Nice, France.
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30
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Stein H, Marafioti T, Foss HD, Laumen H, Hummel M, Anagnostopoulos I, Wirth T, Demel G, Falini B. Down-regulation of BOB.1/OBF.1 and Oct2 in classical Hodgkin disease but not in lymphocyte predominant Hodgkin disease correlates with immunoglobulin transcription. Blood 2001; 97:496-501. [PMID: 11154228 DOI: 10.1182/blood.v97.2.496] [Citation(s) in RCA: 212] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In contrast to the tumor cells (L&H cells) of lymphocyte predominant Hodgkin disease (LPHD), Hodgkin and Reed-Sternberg (HRS) cells of classical Hodgkin disease (cHD) are unable to transcribe immunoglobulin, despite the presence of rearranged immunoglobulin genes. Although initial studies have suggested crippling immunoglobulin gene mutations to be the cause of absent immunoglobulin expression in cHD, recent work of our group has demonstrated an impaired activation of the immunoglobulin promoter as a superior mechanism. As immunoglobulin transcription is mainly regulated by the B-cell transcription factors Oct2 and BOB.1/OBF.1, we analyzed 35 cases of LPHD, 32 cases of cHD, and 2 Hodgkin disease cell lines for the expression of these transcription factors and also in parallel for immunoglobulin expression. Our results demonstrate an absence of Oct2 and/or BOB.1/OBF.1 in cHD and a striking overexpression of Oct2 in LPHD. Immunoglobulin expression was lacking in cHD but present in LPHD. Furthermore, the reintroduction of BOB.1/OBF.1 and Oct2 into cultured HRS cells restored the activity of cotransduced immunoglobulin promoter constructs. Our findings dismiss the concept that the different immunoglobulin expression in cHD and LPHD is due to disrupting mutations of immunoglobulin V genes in cHD but is most likely due to a down-regulation of Oct2 and/or BOB.1/OBF.1. This study further revealed Oct2 as a new and valuable marker for the identification of L&H cells and their distinction from HRS cells. The impairment of immunoglobulin transcription with a down-regulated synthesis of Oct2 and BOB.1/OBF.1 is the first established general recurrent defect found in HRS cells.
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Affiliation(s)
- H Stein
- Institute of Pathology, Consultation and Reference Centre for Lymph Node Pathology and Haematopathology, University Hospital Benjamin Franklin, Free University, Berlin, Germany.
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Schubart K, Massa S, Schubart D, Corcoran LM, Rolink AG, Matthias P. B cell development and immunoglobulin gene transcription in the absence of Oct-2 and OBF-1. Nat Immunol 2001; 2:69-74. [PMID: 11135581 DOI: 10.1038/83190] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oct-2 and OBF-1 (also called OCA-B or Bob-1) are B cell-specific transcription factors that bind to the conserved octamer site of immunoglobulin promoters, yet their role in immunoglobulin transcription has remained unclear. We generated mice in which the lymphoid compartment was reconstituted with cells that lack both Oct-2 and OBF-1. Even in the absence of these two transcription factors, B cells develop normally to the membrane immunoglobulin M-positive (IgM+) stage and immunoglobulin gene transcription is essentially unaffected. These observations imply that the ubiquitous factor Oct-1 plays a previously unrecognized role in the control of immunoglobulin gene transcription and suggest the existence of another, as yet unidentified, cofactor. In addition, both factors are essential for germinal center formation, although OBF-1 is more important than Oct-2 for IgG production after immunization.
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Affiliation(s)
- K Schubart
- Friedrich Miescher Institute, Maulbeerstr. 66, CH-4058 Basel, Switzerland
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32
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Differential expression of Rel/NF-κB and octamer factors is a hallmark of the generation and maturation of dendritic cells. Blood 2000. [DOI: 10.1182/blood.v95.1.277] [Citation(s) in RCA: 131] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Abstract
A key feature of maturation of dendritic cells is the down-regulation of antigen-processing and up-regulation of immunostimulatory capacities. To study the differential expression of transcription factors in this process, we investigated the nuclear translocation and DNA binding of Rel/NF-κB and octamer factors during in vitro generation and maturation of dendritic cells compared with macrophage development. RelB was the only factor strongly up-regulated during the generation of both immature dendritic cells and macrophages. Cytokine-induced maturation of dendritic cells resulted in an increase in nuclear RelB, p50, p52, and especially c-Rel, whereas cytokine-treated macrophages responded poorly. This up-regulation of NF-κB factors did not correlate with lower levels of cytosolic NF-κB inhibitors, the IκBs. One IκB, Bcl-3, was strongly expressed only in mature dendritic cells. Furthermore, generation and maturation of dendritic cells led to a continuous down-regulation of the octamer factor Oct-2, whereas monocytes and macrophages displayed high Oct-2 levels. A similar pattern of maturation-induced changes in transcription factor levels was found in cultured murine epidermal Langerhans cells, suggesting a general physiological significance of these findings. Finally, this pattern of differential activation of Rel and octamer factors appears to be suitable in determining the maturation stage of dendritic cells generated by treatment with different cytokine combinations in vitro. (Blood. 2000;95:277-285)
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33
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Differential expression of Rel/NF-κB and octamer factors is a hallmark of the generation and maturation of dendritic cells. Blood 2000. [DOI: 10.1182/blood.v95.1.277.001k45_277_285] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A key feature of maturation of dendritic cells is the down-regulation of antigen-processing and up-regulation of immunostimulatory capacities. To study the differential expression of transcription factors in this process, we investigated the nuclear translocation and DNA binding of Rel/NF-κB and octamer factors during in vitro generation and maturation of dendritic cells compared with macrophage development. RelB was the only factor strongly up-regulated during the generation of both immature dendritic cells and macrophages. Cytokine-induced maturation of dendritic cells resulted in an increase in nuclear RelB, p50, p52, and especially c-Rel, whereas cytokine-treated macrophages responded poorly. This up-regulation of NF-κB factors did not correlate with lower levels of cytosolic NF-κB inhibitors, the IκBs. One IκB, Bcl-3, was strongly expressed only in mature dendritic cells. Furthermore, generation and maturation of dendritic cells led to a continuous down-regulation of the octamer factor Oct-2, whereas monocytes and macrophages displayed high Oct-2 levels. A similar pattern of maturation-induced changes in transcription factor levels was found in cultured murine epidermal Langerhans cells, suggesting a general physiological significance of these findings. Finally, this pattern of differential activation of Rel and octamer factors appears to be suitable in determining the maturation stage of dendritic cells generated by treatment with different cytokine combinations in vitro. (Blood. 2000;95:277-285)
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34
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Kern P, Kolowos W, Hagenhofer M, Frank C, Kalden JR, Herrmann M. Alternatively spliced mRNA molecules of the thrombospondin receptor (CD36) in human PBMC. EUROPEAN JOURNAL OF IMMUNOGENETICS : OFFICIAL JOURNAL OF THE BRITISH SOCIETY FOR HISTOCOMPATIBILITY AND IMMUNOGENETICS 1999; 26:337-42. [PMID: 10553499 DOI: 10.1046/j.1365-2370.1999.00167.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We employed reverse transcription polymerase chain reaction (RT-PCR) to detect alternatively spliced CD36 mRNA in human peripheral blood mononuclear cells (PBMC). Sequencing of cloned cDNA revealed alternatively spliced mRNA molecules in 13 out of 39 clones. We observed exon skipping of up to 10 out of 12 coding exons in eight alternative transcripts. Additionally, in five of the transcripts, alternative splice donor or acceptor sites were used during mRNA maturation. Considering the CD36 molecule serves many functions in coagulation, host defence, lipid metabolism, and scavenging, we speculate that the proteins encoded by the alternatively spliced mRNA molecules may be involved in regulation of both CD36 gene expression and function.
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Affiliation(s)
- P Kern
- Department of Internal Medicine III, Friedrich-Alexander-University of Erlangen-Nuremberg, Germany
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35
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Abstract
The POU (Pit-Oct-Unc) family of transcription factors was originally defined on the basis of a common DNA binding domain in the mammalian factors Pit-1, Oct-1, and Oct-2 as well as the nematode protein Unc-86. Subsequently, a number of other POU family factors have been identified in both vertebrates and invertebrates. Many of these original and subsequently isolated members of the family have been shown to play critical roles in the development and functioning of the nervous system. To exemplify this, studies are described involving the functional characterisation of the Oct-2 factor, one of the original POU factors, and of the Brn-3 factors, which were isolated subsequently and are the mammalian factors most closely related to Unc-86.
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Affiliation(s)
- D S Latchman
- Department of Molecular Pathology, Windeyer Institute of Medical Sciences, University College London, United Kingdom
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36
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Chapman CM, Latchman DS. The different alternatively spliced isoforms of the Oct-2 transcription factor repress the involucrin promoter in a cell type-specific manner. Mol Biol Rep 1998; 25:253-7. [PMID: 9870616 DOI: 10.1023/a:1006801002594] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
It has previously been reported that several octamer binding transcription factors including the Oct-2 factor can repress the involucrin gene promoter in keratinocyte cells. As the Oct-2 factor exists in several different cell type-specific isoforms with distinct activating or inhibiting effects on gene expression, we have tested the effect of these forms on the involucrin promoter. We report here that at high concentrations each of these isoforms can inhibit the involucrin promoter in keratinocytes. In other cell types however, all three isoforms activate the involucrin promoter and this effect is also observed at low concentrations of Oct-2 in keratinocytes. The mechanisms responsible for these effects are discussed.
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Affiliation(s)
- C M Chapman
- Department of Molecular Pathology, The Windeyer Institute of Medical Sciences, University College London Medical School, UK
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37
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Wolf I, Pevzner V, Kaiser E, Bernhardt G, Claudio E, Siebenlist U, Förster R, Lipp M. Downstream activation of a TATA-less promoter by Oct-2, Bob1, and NF-kappaB directs expression of the homing receptor BLR1 to mature B cells. J Biol Chem 1998; 273:28831-6. [PMID: 9786883 DOI: 10.1074/jbc.273.44.28831] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The chemokine receptor, BLR1, is a major regulator of the microenvironmental homing of B cells in lymphoid organs. In vitro studies identify three essential elements of the TATA-less blr1 core promoter that confer cell type- and differentiation-specific expression in the B cells of both humans and mice, a functional promoter region (-36 with respect to the transcription start site), a NF-kappaB motif (+44), and a noncanonical octamer motif (+157). The importance of these sites was confirmed by in vivo studies in gene-targeted mice deficient of either Oct-2, Bob1, or both NF-kappaB subunits p50 and p52. In all of these animals, the expression of BLR1 was reduced or absent. In mice deficient only of p52/NF-kappaB, BLR1 expression was unaffected. Thus our data demonstrate that BLR1 is a target gene for Oct-2, Bob1, and members of the NF-kappaB/Rel family and provides a link to the impaired B cell functions in mice deficient for these factors.
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Affiliation(s)
- I Wolf
- Department of Tumorgenetics and Immunogenetics, Max Delbrück Center for Molecular Medicine, Robert-Rössle-Strasse 10, D-13122, Berlin-Buch, Germany
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38
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Abstract
Information is increasingly available concerning the molecular events that occur during primary and antigen-dependent stages of B cell development. In this review the roles of transcription factors and coactivators are discussed with respect to changes in expression patterns of various genes during B cell development. Transcriptional regulation is also discussed in the context of developmentally regulated immunoglobulin gene V(D)J recombination, somatic hypermutation, and isotype switch recombination.
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Affiliation(s)
- A Henderson
- Department of Veterinary Science, Pennsylvania State University, University Park 16802, USA.
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39
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Liu YZ, Lee IK, Locke I, Dawson SJ, Latchman DS. Adjacent proline residues in the inhibitory domain of the Oct-2 transcription factor play distinct functional roles. Nucleic Acids Res 1998; 26:2464-72. [PMID: 9580701 PMCID: PMC147571 DOI: 10.1093/nar/26.10.2464] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A 40 amino acid region of Oct-2 from amino acids 142 to 181 functions as an active repressor domain capable of inhibiting both basal activity and activation of promoters containing a TATA box, but not of those that contain an initiator element. Based on our observation that the equivalent region of the closely related Oct-1 factor does not act as an inhibitory domain, we have mutated specific residues in the Oct-2 domain in an attempt to probe their importance in repressor domain function. Although mutations of several residues have no or minimal effect, mutation of proline 175 to arginine abolishes the ability to inhibit both basal and activated transcription. In contrast, mutation of proline 174 to arginine confers upon the domain the ability to repress activation of an initiator-containing promoter by acidic activation domains, and also suppresses the effect of the proline 175 mutation. Hence, adjacent proline residues play key roles in the functioning of the inhibitory domain and in limiting its specificity to TATA-box-containing promoters.
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Affiliation(s)
- Y Z Liu
- Department of Molecular Pathology, Windeyer Institute of Medical Sciences, University College London Medical School, The Windeyer Building, Cleveland Street, London W1P 6DB, UK
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40
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Patel Y, Gough G, Coffin RS, Thomas S, Cohen JI, Latchman DS. Cell type specific repression of the varicella zoster virus immediate early gene 62 promoter by the cellular Oct-2 transcription factor. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1397:268-74. [PMID: 9582435 DOI: 10.1016/s0167-4781(97)00216-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The cellular transcription factor Oct-2.1 has previously been shown to repress the transactivation of the varicella zoster virus (VZV) immediate early gene promoter by viral transactivators but not to inhibit its basal activity. In the case of the related virus herpes simplex virus (HSV), the effect of Oct-2 on the IE promoters has been shown to be cell type specific and to differ between the different alternatively spliced forms of Oct-2. Here we show that as well as Oct-2.1, the Oct-2.4 and 2.5 isoforms which are expressed in neuronal cells can inhibit transactivation of the VZV immediate early promoter regardless of the cell type used. In contrast, all the isoforms of Oct-2 can inhibit basal activity of the VZV promoter in neuronal cells but not in other cell types indicating that this effect is cell type specific. These effects are discussed in terms of the differential regulation of latent infections with HSV or VZV in dorsal root ganglia.
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Affiliation(s)
- Y Patel
- Department of Molecular Pathology, Windeyer Institute of Medical Sciences, University College London Medical School, The Windeyer Building, 46 Cleveland Street, London W1P 6DB, UK
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41
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Nutt SL, Morrison AM, Dörfler P, Rolink A, Busslinger M. Identification of BSAP (Pax-5) target genes in early B-cell development by loss- and gain-of-function experiments. EMBO J 1998; 17:2319-33. [PMID: 9545244 PMCID: PMC1170575 DOI: 10.1093/emboj/17.8.2319] [Citation(s) in RCA: 243] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The Pax-5 gene codes for the transcription factor BSAP which is essential for the progression of adult B lymphopoiesis beyond an early progenitor (pre-BI) cell stage. Although several genes have been proposed to be regulated by BSAP, CD19 is to date the only target gene which has been genetically confirmed to depend on this transcription factor for its expression. We have now taken advantage of cultured pre-BI cells of wild-type and Pax-5 mutant bone marrow to screen a large panel of B lymphoid genes for additional BSAP target genes. Four differentially expressed genes were shown to be under the direct control of BSAP, as their expression was rapidly regulated in Pax-5-deficient pre-BI cells by a hormone-inducible BSAP-estrogen receptor fusion protein. The genes coding for the B-cell receptor component Ig-alpha (mb-1) and the transcription factors N-myc and LEF-1 are positively regulated by BSAP, while the gene coding for the cell surface protein PD-1 is efficiently repressed. Distinct regulatory mechanisms of BSAP were revealed by reconstituting Pax-5-deficient pre-BI cells with full-length BSAP or a truncated form containing only the paired domain. IL-7 signalling was able to efficiently induce the N-myc gene only in the presence of full-length BSAP, while complete restoration of CD19 synthesis was critically dependent on the BSAP protein concentration. In contrast, the expression of the mb-1 and LEF-1 genes was already reconstituted by the paired domain polypeptide lacking any transactivation function, suggesting that the DNA-binding domain of BSAP is sufficient to recruit other transcription factors to the regulatory regions of these two genes. In conclusion, these loss- and gain-of-function experiments demonstrate that BSAP regulates four newly identified target genes as a transcriptional activator, repressor or docking protein depending on the specific regulatory sequence context.
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Affiliation(s)
- S L Nutt
- Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria
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42
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Hess J, Laumen H, Wirth T. Application of differential cDNA screening techniques to the identification of unique gene expression in tumours and lymphocytes. Curr Opin Immunol 1998; 10:125-30. [PMID: 9602299 DOI: 10.1016/s0952-7915(98)80239-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Development, differentiation and cell death in all organisms are mediated by tightly regulated programs of differential gene expression. Furthermore, changes in gene expression profiles are responsible for tumour formation and tumour progression, as well as for many other human diseases. Thus, the definition of distinct patterns of gene expression is not only essential for understanding complex biological processes but also leads to the identification of novel targets for therapy of various diseases.
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Affiliation(s)
- J Hess
- Institut für Medizinische Strahlenkunde und Zellforschung, Universität Würzburg, Germany
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43
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Kistler B, Rolink A, Marienfeld R, Neumann M, Wirth T. Induction of Nuclear Factor-κB During Primary B Cell Differentiation. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.5.2308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
We have investigated activation of nuclear factor-κB (NF-κB) in the process of primary B cell differentiation in vitro. In this system, NF-κB is strongly induced when B cells develop from the pre-B cell to the immature B cell stage. Unlike the typical NF-κB activation in response to exogenous stimuli, induction proceeds with a slow time course. NF-κB induction is only observed in B cells that undergo differentiation, not in Rag2-deficient cells. Nuclear DNA binding complexes predominantly comprise p50/RelA heterodimers and, to a lesser extent, c-Rel-containing dimers. The increase in NF-κB binding activity is accompanied by a slow and steady decrease in IκBβ protein levels. Interestingly, absolute RelA protein levels remain unaffected, whereas RelB and c-Rel synthesis is induced. The reason for preferential nuclear translocation of RelA complexes appears to be selective inhibition by the IκBβ protein. IκBβ can efficiently inhibit p50/RelA complexes, but has a much reduced ability to interfere with p50/c-Rel DNA binding both in vitro and in vivo. Interestingly, p50/RelB complexes are not at all targeted by IκBβ, and coimmunoprecipitation experiments show no evidence for an association of IκBβ and RelB in vivo. Consistent with these observations, IκBβ cotransfection can inhibit p50/RelA-mediated trans-activation, but barely affects p50/RelB mediated trans-activation.
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Affiliation(s)
- Barbara Kistler
- *MSZ, Institut für Medizinische Strahlenkunde und Zellforschung, and
| | | | - Ralf Marienfeld
- †Pathologisches Institut, Universität Würzburg, Wurzburg, Germany
| | - Manfred Neumann
- †Pathologisches Institut, Universität Würzburg, Wurzburg, Germany
| | - Thomas Wirth
- *MSZ, Institut für Medizinische Strahlenkunde und Zellforschung, and
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44
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Kato Y, Hori S, Fujita N, Tsuruo T. A novel anti-platelet monoclonal antibody induces mouse platelet aggregation through an Fc receptor-independent mechanism. Biochem Biophys Res Commun 1998; 242:250-5. [PMID: 9446779 DOI: 10.1006/bbrc.1997.7917] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Platelets are nonproliferative and terminally differentiated cells. Platelets offer an attractive model system to study the various biochemical events leading to structural and functional alterations in activated cells. When platelets are exposed to stimuli, they are activated, undergo a dramatic shape change, adhere to each other, and aggregate. Several monoclonal antibodies (mAbs) that recognize CD9, GPIIb/IIIa (alpha IIb beta 3 intergrins), or GPIV are known to stimulate human platelet aggregation. However, no mAbs able to induce aggregation of mouse platelets have been reported. We have established an anti-mouse platelet mAb (AIP21) that can promote mouse platelet aggregation by itself. Because mouse platelets did not express the Fc receptor (FcR, CD32) on their surfaces and because AIP21 is an IgM subclass, AIP21 might promote platelet aggregation through an FcR-independent mechanism. We could not identify the antigen recognized by AIP21, but flow cytometric analysis revealed that it was not identical to CD9, GPIV, or integrins (i.e., alpha IIb, alpha v, alpha 5, alpha 6, beta 1, and beta 3 integrins). During the aggregation of mouse platelets mediated by AIP21, several 50-68-kDa proteins are rapidly phosphorylated at tyrosine residues. This phosphorylation by AIP21 was dose-dependent and did not require plasma components. We identified the 52-kDa phosphorylated protein as Shc. These results indicate that AIP21 could be useful for investigating the mechanisms of mouse platelet aggregation.
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Affiliation(s)
- Y Kato
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Japan
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45
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Pfisterer P, Hess J, Wirth T. Identification of target genes of the lymphoid-specific transcription factor Oct2. Immunobiology 1997; 198:217-26. [PMID: 9442393 DOI: 10.1016/s0171-2985(97)80042-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Oct2 transcription factor is expressed predominantly in B lymphocytes and plays an essential role during the terminal phase of B cell differentiation. The regulatory regions of several genes specifically expressed in B cells contain functional binding sites for Oct2. Nevertheless, none of the genes originally thought to be regulated by Oct2 were affected in their expression in Oct2-deficient B cells. In an attempt to find such elusive Oct2 target genes and to understand the molecular function of Oct2 in B cell development, we isolated cDNAs for Oct2 target genes. So far, we have identified five potential targets for Oct2: the membrane glycoprotein CD36, the cysteine-rich secreted protein 3 (CRISP-3), a mouse homolog of the human monocyte/neutrophil elastase inhibitor (mEI) and two unknown cDNA sequences Nov1 and Nov2. These target genes show quite distinct expression patterns demonstrating that transcription factors in addition to Oct2 are involved in their regulation. Whereas CD36 and mEI were expressed in all hematopoetic cell lines containing Oct2,. CRISP-3 is pre-B cell-specific, Nov1 is plasma B cell-specific and Nov2 is B cell-specifically expressed.
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Affiliation(s)
- P Pfisterer
- MSZ, Institut für Medizinische Strahlenkunde und Zellforschung, Universität Würzburg, Germany
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46
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Bendall HH, Scherer DC, Edson CR, Ballard DW, Oltz EM. Transcription factor NF-kappaB regulates inducible Oct-2 gene expression in precursor B lymphocytes. J Biol Chem 1997; 272:28826-8. [PMID: 9360945 DOI: 10.1074/jbc.272.46.28826] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The POU transcription factors Oct-1 and Oct-2 regulate the activity of octamer-dependent promoters, including those that direct transcription from rearranged immunoglobulin genes. Unlike Oct-1, which is constitutively expressed in many cell types, Oct-2 expression is restricted primarily to B lymphocytes and can be induced in precursor B cells by stimulation with bacterial lipopolysaccharide (LPS). However, the precise factors that mediate this induction mechanism remain unknown. In the present study, we monitored Oct-2 expression in cells arrested for the activation of NF-kappaB, an LPS-responsive member of the Rel transcription factor family. Despite stimulation with LPS, disruption of the NF-kappaB signaling pathway in precursor B cells led to the loss of inducible Oct-2 DNA binding activity in vitro and the suppression of Oct-2-directed transcription in vivo. This biochemical defect correlated with a specific block to Oct-2 gene expression at the level of transcription, whereas the expression of Oct-1 was unaffected. The finding that Oct-2 is under NF-kappaB control highlights an important cross-talk mechanism involving two distinct transcription factor families that regulate B lymphocyte function.
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Affiliation(s)
- H H Bendall
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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47
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Deans ZC, Dawson SJ, Kilimann MW, Wallace D, Wilson MC, Latchman DS. Differential regulation of genes encoding synaptic proteins by the Oct-2 transcription factor. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1997; 51:1-7. [PMID: 9427500 DOI: 10.1016/s0169-328x(97)00204-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In order to investigate the effect of the Oct-2 POU family transcription factor on the regulation of genes encoding synaptic proteins, we have used cell lines in which the level of Oct-2 has been greatly reduced using an antisense approach. The reduced Oct-2 level results in enhanced expression of SNAP-25 and synapsin I, indicating that the genes encoding these proteins are normally repressed by Oct-2 in neuronal cells. In contrast, no alteration was observed in the levels of the synaptic proteins, synaptophysin and synaptotagmin. Although the neuronal forms of Oct-2 can repress the synapsin I promoter in co-transfection experiments, indicating that they have a direct effect on the expression of this gene, they have no effect on the activity of the SNAP-25 promoter, indicating that the effect of Oct-2 on this gene is likely to be indirect. These effects are discussed in terms of the differential effect of Oct-2 and the related POU family transcription factor Brn-3a, on the promoters of genes encoding different synaptic proteins.
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Affiliation(s)
- Z C Deans
- Department of Molecular Pathology, University College Medical School, London, UK
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48
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Gay RD, Dawson SJ, Latchman DS. The different inhibitory domains of the Oct-2 transcription factor have distinct functional activities. FEBS Lett 1997; 416:135-8. [PMID: 9369198 DOI: 10.1016/s0014-5793(97)01184-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Oct-2 POU family transcription factor contains three distinct regions whose deletion reduces its ability to inhibit transcription via its octamer binding site. Here we show that only one of these inhibitory domains is capable of also inhibiting the activity of activating molecules bound at adjacent sites upstream of a TATA box-containing promoter whereas the other two regions are inactive in this assay. None of the three regions is able to achieve this effect when located upstream of the same promoter containing an initiator motif. The mechanisms of action of these domains and their role in the functioning of the Oct-2 factor are discussed.
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Affiliation(s)
- R D Gay
- The Windeyer Institute for Medical Sciences, Department of Molecular Pathology, University College London Medical School, UK
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49
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Veenstra GJ, van der Vliet PC, Destrée OH. POU domain transcription factors in embryonic development. Mol Biol Rep 1997; 24:139-55. [PMID: 9291088 DOI: 10.1023/a:1006855632268] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- G J Veenstra
- Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Utrecht, The Netherlands
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50
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Zwilling S, Dieckmann A, Pfisterer P, Angel P, Wirth T. Inducible expression and phosphorylation of coactivator BOB.1/OBF.1 in T cells. Science 1997; 277:221-5. [PMID: 9211847 DOI: 10.1126/science.277.5323.221] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BOB.1/OBF.1 is a transcriptional coactivator that is constitutively expressed in B cells and interacts with the Oct1 and Oct2 transcription factors. Upon activation of Jurkat T cells and primary murine thymocytes with phorbol esters and ionomycin, BOB.1/OBF.1 expression and transactivation function were induced. BOB.1/OBF.1 was phosphorylated at Ser184 both in vivo and in vitro, and this modification was required for inducible activation. Mutation of Ser184 also diminished transactivation function in B cells, suggesting that the activating phosphorylation that is inducible in T cells is constitutively present in B cells. Thus, BOB.1/OBF.1 is a transcriptional coactivator that is critically regulated by posttranslational modifications to mediate cell type-specific gene expression.
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Affiliation(s)
- S Zwilling
- MSZ, Institut für Medizinische Strahlenkunde und Zellforschung, Universität Würzburg, Versbacher Strasse 5, 97078 Würzburg, Germany
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