1
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Yang M, Tang Y, Zhu P, Lu H, Wan X, Guo Q, Xiao L, Liu C, Guo L, Liu W, Yang Y. The advances of E2A-PBX1 fusion in B-cell acute lymphoblastic Leukaemia. Ann Hematol 2024; 103:3385-3398. [PMID: 38148344 DOI: 10.1007/s00277-023-05595-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 12/17/2023] [Indexed: 12/28/2023]
Abstract
The E2A-PBX1 gene fusion is a common translocation in B-cell acute lymphoblastic leukaemia. Patients harbouring the E2A-PBX1 fusion gene typically exhibit an intermediate prognosis. Furthermore, minimal residual disease has unsatisfactory prognostic value in E2A-PBX1 B-cell acute lymphoblastic leukaemia. However, the mechanism of E2A-PBX1 in the occurrence and progression of B-cell acute lymphoblastic leukaemia is not well understood. Here, we mainly review the roles of E2A and PBX1 in the differentiation and development of B lymphocytes, the mechanism of E2A-PBX1 gene fusion in B-cell acute lymphoblastic leukaemia, and the potential therapeutic approaches.
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Affiliation(s)
- Mengting Yang
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China
| | - Yanhui Tang
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China
| | - Peng Zhu
- School of Pharmacy, Wannan Medical College, Wuhu, 241000, People's Republic of China
| | - Haiquan Lu
- The Second Hospital, Centre for Reproductive Medicine, Advanced Medical Research Institute, Key Laboratory for Experimental Teratology of the Ministry of Education, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Xiaohong Wan
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China
| | - Qulian Guo
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China
| | - Lan Xiao
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China
| | - Chunyan Liu
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China
| | - Ling Guo
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China
| | - Wenjun Liu
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China.
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China.
| | - You Yang
- Department of Paediatrics (Children Haematological Oncology), Birth Defects and Childhood Haematological Oncology Laboratory, Sichuan Clinical Research Centre for Birth Defects, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, China.
- Department of Paediatrics, Southwest Medical University, Luzhou, Sichuan, China.
- The Second Hospital, Centre for Reproductive Medicine, Advanced Medical Research Institute, Key Laboratory for Experimental Teratology of the Ministry of Education, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
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2
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Choi J, Ceribelli M, Phelan JD, Häupl B, Huang DW, Wright GW, Hsiao T, Morris V, Ciccarese F, Wang B, Corcoran S, Scheich S, Yu X, Xu W, Yang Y, Zhao H, Zhou J, Zhang G, Muppidi J, Inghirami GG, Oellerich T, Wilson WH, Thomas CJ, Staudt LM. Molecular targets of glucocorticoids that elucidate their therapeutic efficacy in aggressive lymphomas. Cancer Cell 2024; 42:833-849.e12. [PMID: 38701792 PMCID: PMC11168741 DOI: 10.1016/j.ccell.2024.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 03/29/2024] [Accepted: 04/09/2024] [Indexed: 05/05/2024]
Abstract
Glucocorticoids have been used for decades to treat lymphomas without an established mechanism of action. Using functional genomic, proteomic, and chemical screens, we discover that glucocorticoids inhibit oncogenic signaling by the B cell receptor (BCR), a recurrent feature of aggressive B cell malignancies, including diffuse large B cell lymphoma and Burkitt lymphoma. Glucocorticoids induce the glucocorticoid receptor (GR) to directly transactivate genes encoding negative regulators of BCR stability (LAPTM5; KLHL14) and the PI3 kinase pathway (INPP5D; DDIT4). GR directly represses transcription of CSK, a kinase that limits the activity of BCR-proximal Src-family kinases. CSK inhibition attenuates the constitutive BCR signaling of lymphomas by hyperactivating Src-family kinases, triggering their ubiquitination and degradation. With the knowledge that glucocorticoids disable oncogenic BCR signaling, they can now be deployed rationally to treat BCR-dependent aggressive lymphomas and used to construct mechanistically sound combination regimens with inhibitors of BTK, PI3 kinase, BCL2, and CSK.
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MESH Headings
- Humans
- Glucocorticoids/pharmacology
- Receptors, Antigen, B-Cell/metabolism
- Animals
- Signal Transduction/drug effects
- Receptors, Glucocorticoid/metabolism
- Mice
- Cell Line, Tumor
- Lymphoma, Large B-Cell, Diffuse/drug therapy
- Lymphoma, Large B-Cell, Diffuse/genetics
- Lymphoma, Large B-Cell, Diffuse/metabolism
- Burkitt Lymphoma/drug therapy
- Burkitt Lymphoma/genetics
- Burkitt Lymphoma/metabolism
- Burkitt Lymphoma/pathology
- Molecular Targeted Therapy/methods
- Phosphatidylinositol 3-Kinases/metabolism
- src-Family Kinases/metabolism
- Gene Expression Regulation, Neoplastic/drug effects
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Affiliation(s)
- Jaewoo Choi
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Michele Ceribelli
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - James D Phelan
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Björn Häupl
- Department of Medicine II, Hematology/Oncology, Goethe University, Frankfurt, Germany; German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, 60528 Frankfurt am Main, Germany
| | - Da Wei Huang
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - George W Wright
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Tony Hsiao
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Vivian Morris
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Francesco Ciccarese
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA; Immunology and Molecular Oncology Unit, Veneto Institute of Oncology IOV-IRCCS, via Gattamelata 64, 35128 Padova, Italy
| | - Boya Wang
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sean Corcoran
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sebastian Scheich
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Department of Medicine II, Hematology/Oncology, Goethe University, Frankfurt, Germany; German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, 60528 Frankfurt am Main, Germany; University Cancer Center (UCT) Frankfurt, University Hospital, Goethe University, 60590 Frankfurt am Main, Germany; Frankfurt Cancer Institute, Goethe University, 60596 Frankfurt am Main, Germany
| | - Xin Yu
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Weihong Xu
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yandan Yang
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Hong Zhao
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Joyce Zhou
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Grace Zhang
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jagan Muppidi
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Giorgio G Inghirami
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, 1300 York Avenue, New York, NY 10065, USA
| | - Thomas Oellerich
- Department of Medicine II, Hematology/Oncology, Goethe University, Frankfurt, Germany; German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, 60528 Frankfurt am Main, Germany
| | - Wyndham H Wilson
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Craig J Thomas
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD, USA
| | - Louis M Staudt
- Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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3
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Shu X, Wang J, Zeng H, Shao L. Progression of Notch signaling regulation of B cells under radiation exposure. Front Immunol 2024; 15:1339977. [PMID: 38524139 PMCID: PMC10957566 DOI: 10.3389/fimmu.2024.1339977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 02/14/2024] [Indexed: 03/26/2024] Open
Abstract
With the continuous development of nuclear technology, the radiation exposure caused by radiation therapy is a serious health hazard. It is of great significance to further develop effective radiation countermeasures. B cells easily succumb to irradiation exposure along with immunosuppressive response. The approach to ameliorate radiation-induced B cell damage is rarely studied, implying that the underlying mechanisms of B cell damage after exposure are eager to be revealed. Recent studies suggest that Notch signaling plays an important role in B cell-mediated immune response. Notch signaling is a critical regulator for B cells to maintain immune function. Although accumulating studies reported that Notch signaling contributes to the functionality of hematopoietic stem cells and T cells, its role in B cells is scarcely appreciated. Presently, we discussed the regulation of Notch signaling on B cells under radiation exposure to provide a scientific basis to prevent radiation-induced B cell damage.
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Affiliation(s)
- Xin Shu
- Department of Occupational Health and Toxicology, School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Jiangxi Medical College, School of Public Health, Nanchang University, Nanchang, China
| | - Jie Wang
- Department of Histology and Embryology, School of Basic Medicine Sciences, Nanchang University, Nanchang, China
| | - Huihong Zeng
- Department of Histology and Embryology, School of Basic Medicine Sciences, Nanchang University, Nanchang, China
| | - Lijian Shao
- Department of Occupational Health and Toxicology, School of Public Health, Jiangxi Medical College, Nanchang University, Nanchang, China
- Jiangxi Provincial Key Laboratory of Preventive Medicine, Jiangxi Medical College, School of Public Health, Nanchang University, Nanchang, China
- Jiangxi Provincial Key Laboratory of Interdisciplinary Science, Nanchang University, Nanchang, China
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4
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Kojima Y, Kawashima F, Yasuda T, Odaira K, Inagaki Y, Yamada C, Muraki A, Noura M, Okamoto S, Tamura S, Iwamoto E, Sanada M, Matsumura I, Miyazaki Y, Kojima T, Kiyoi H, Tsuzuki S, Hayakawa F. EBF1-JAK2 inhibits the PAX5 function through physical interaction with PAX5 and kinase activity. Int J Hematol 2023:10.1007/s12185-023-03585-z. [PMID: 37149540 DOI: 10.1007/s12185-023-03585-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 03/13/2023] [Accepted: 03/16/2023] [Indexed: 05/08/2023]
Abstract
Gene aberrations of B-cell regulators and growth signal components such as the JAK-STAT pathway are frequently found in B-cell acute lymphoblastic leukemia (B-ALL). EBF1 is a B-cell regulator that regulates the expression of PAX5 and co-operates with PAX5 to regulate B-cell differentiation. Here, we analyzed the function of the fusion protein of EBF1 and JAK2, EBF1-JAK2 (E-J). E-J caused constitutive activation of JAK-STAT and MAPK pathways and induced autonomous cell growth in a cytokine-dependent cell line. E-J did not affect the transcriptional activity of EBF1 but inhibited that of PAX5. Both the physical interaction of E-J with PAX5 and kinase activity of E-J were required for E-J to inhibit PAX5 function, although the detailed mechanism of inhibition remains unclear. Importantly, gene set enrichment analysis using the results of our previous RNA-seq data of 323 primary BCR-ABL1-negative ALL samples demonstrated repression of the transcriptional target genes of PAX5 in E-J-positive ALL cells, which suggests that E-J also inhibited PAX5 function in ALL cells. Our results shed new light on the mechanisms of differentiation block by kinase fusion proteins.
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Affiliation(s)
- Yukino Kojima
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Fumika Kawashima
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Takahiko Yasuda
- Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Japan
| | - Koya Odaira
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Yuichiro Inagaki
- Department of Hematology and Oncology, Anjo Kosei Hospital, Anjo, Japan
| | - Chiharu Yamada
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Ami Muraki
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Mina Noura
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Shuichi Okamoto
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Shogo Tamura
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
| | - Eisuke Iwamoto
- Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Japan
| | - Masashi Sanada
- Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Japan
| | - Itaru Matsumura
- Department of Hematology and Rheumatology, Kindai University School of Medicine, Osaka, Japan
| | - Yasushi Miyazaki
- Department of Hematology, Atomic Bomb Disease and Hibakusha Medicine Unit, Atomic Bomb Disease Institute, Nagasaki University, Nagasaki, Japan
| | - Tetsuhito Kojima
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan
- Aichi Health Promotion Foundation, Nagoya, Japan
| | - Hitoshi Kiyoi
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shinobu Tsuzuki
- Department of Biochemistry, Aichi Medical University School of Medicine, Nagakute, Japan
| | - Fumihiko Hayakawa
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-0047, Japan.
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5
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EBF1 is continuously required for stabilizing local chromatin accessibility in pro-B cells. Proc Natl Acad Sci U S A 2022; 119:e2210595119. [PMID: 36409886 PMCID: PMC9860308 DOI: 10.1073/pnas.2210595119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The establishment of de novo chromatin accessibility in lymphoid progenitors requires the "pioneering" function of transcription factor (TF) early B cell factor 1 (EBF1), which binds to naïve chromatin and induces accessibility by recruiting the BRG1 chromatin remodeler subunit. However, it remains unclear whether the function of EBF1 is continuously required for stabilizing local chromatin accessibility. To this end, we replaced EBF1 by EBF1-FKBPF36V in pro-B cells, allowing the rapid degradation by adding the degradation TAG13 (dTAG13) dimerizer. EBF1 degradation results in a loss of genome-wide EBF1 occupancy and EBF1-targeted BRG1 binding. Chromatin accessibility was rapidly diminished at EBF1-binding sites with a preference for sites whose occupancy requires the pioneering activity of the C-terminal domain of EBF1. Diminished chromatin accessibility correlated with altered gene expression. Thus, continuous activity of EBF1 is required for the stable maintenance of the transcriptional and epigenetic state of pro-B cells.
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6
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Peña-Pérez L, Kharazi S, Frengen N, Krstic A, Bouderlique T, Hauenstein J, He M, Somuncular E, Li Wang X, Dahlberg C, Gustafsson C, Johansson AS, Walfridsson J, Kadri N, Woll P, Kierczak M, Qian H, Westerberg L, Luc S, Månsson R. FOXO Dictates Initiation of B Cell Development and Myeloid Restriction in Common Lymphoid Progenitors. Front Immunol 2022; 13:880668. [PMID: 35603175 PMCID: PMC9116193 DOI: 10.3389/fimmu.2022.880668] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 03/23/2022] [Indexed: 12/23/2022] Open
Abstract
The development of B cells relies on an intricate network of transcription factors critical for developmental progression and lineage commitment. In the B cell developmental trajectory, a temporal switch from predominant Foxo3 to Foxo1 expression occurs at the CLP stage. Utilizing VAV-iCre mediated conditional deletion, we found that the loss of FOXO3 impaired B cell development from LMPP down to B cell precursors, while the loss of FOXO1 impaired B cell commitment and resulted in a complete developmental block at the CD25 negative proB cell stage. Strikingly, the combined loss of FOXO1 and FOXO3 resulted in the failure to restrict the myeloid potential of CLPs and the complete loss of the B cell lineage. This is underpinned by the failure to enforce the early B-lineage gene regulatory circuitry upon a predominantly pre-established open chromatin landscape. Altogether, this demonstrates that FOXO3 and FOXO1 cooperatively govern early lineage restriction and initiation of B-lineage commitment in CLPs.
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Affiliation(s)
- Lucía Peña-Pérez
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Shabnam Kharazi
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Nicolai Frengen
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Aleksandra Krstic
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Thibault Bouderlique
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Julia Hauenstein
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Minghui He
- Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Ece Somuncular
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Xiaoze Li Wang
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Carin Dahlberg
- Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Charlotte Gustafsson
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Ann-Sofie Johansson
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Julian Walfridsson
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Nadir Kadri
- Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden
| | - Petter Woll
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Marcin Kierczak
- Department of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Hong Qian
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Lisa Westerberg
- Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Sidinh Luc
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Medicine, Huddinge, Karolinska Institutet, Stockholm, Sweden
| | - Robert Månsson
- Center for Hematology and Regenerative Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.,Hematology Center, Karolinska University Hospital, Stockholm, Sweden
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7
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Single-cell analysis identifies dynamic gene expression networks that govern B cell development and transformation. Nat Commun 2021; 12:6843. [PMID: 34824268 PMCID: PMC8617197 DOI: 10.1038/s41467-021-27232-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 11/02/2021] [Indexed: 12/22/2022] Open
Abstract
Integration of external signals and B-lymphoid transcription factor activities organise B cell lineage commitment through alternating cycles of proliferation and differentiation, producing a diverse repertoire of mature B cells. We use single-cell transcriptomics/proteomics to identify differentially expressed gene networks across B cell development and correlate these networks with subtypes of B cell leukemia. Here we show unique transcriptional signatures that refine the pre-B cell expansion stages into pre-BCR-dependent and pre-BCR-independent proliferative phases. These changes correlate with reciprocal changes in expression of the transcription factor EBF1 and the RNA binding protein YBX3, that are defining features of the pre-BCR-dependent stage. Using pseudotime analysis, we further characterize the expression kinetics of different biological modalities across B cell development, including transcription factors, cytokines, chemokines, and their associated receptors. Our findings demonstrate the underlying heterogeneity of developing B cells and characterise developmental nodes linked to B cell transformation.
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8
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Elsaid R, Yang J, Cumano A. The influence of space and time on the establishment of B cell identity. Biomed J 2019; 42:209-217. [PMID: 31627863 PMCID: PMC6818146 DOI: 10.1016/j.bj.2019.07.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/21/2019] [Accepted: 07/01/2019] [Indexed: 02/01/2023] Open
Abstract
During embryonic development multiple waves of hematopoietic progenitors with distinct lineage potential are differentially regulated in time and space. Consistent with this view, some specialized lymphocytes emerge during a limited time-window in embryogenesis and migrate to the tissues where they contribute to organogenesis and to tissue homeostasis. These cells are not constantly produced by bone marrow derived hematopoietic stem cells but are maintained in tissues and self-renew throughout life. These particular cell subsets are produced from lymphoid restricted progenitors only found in the first days of fetal liver hematopoietic activity. Growing evidence of the heterogeneity and layered organization of the hematopoietic system is leading to a common view that some lymphocyte subsets are functionally different because they follow distinct developmental programs and emerge from distinct waves of lymphoid progenitors. However, understanding the influence of developmental origin and the relative contribution of local microenvironment on the development of these specialized lymphocyte subsets needs further analysis. In this review, we discuss how different pathways followed by developing B cells during ontogeny may contribute to the diverse functions.
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Affiliation(s)
- Ramy Elsaid
- Unit of Lymphopoiesis, Immunology Department, Institut Pasteur, U1223, INSERM, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Junjie Yang
- Unit of Lymphopoiesis, Immunology Department, Institut Pasteur, U1223, INSERM, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France; CNBG Company, China
| | - Ana Cumano
- Unit of Lymphopoiesis, Immunology Department, Institut Pasteur, U1223, INSERM, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France.
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9
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Khan MR, Ahmad A, Kayani N, Minhas K. Expression of PAX-5 in B Cell Hodgkin and Non Hodgkin Lymphoma. Asian Pac J Cancer Prev 2018; 19:3463-3466. [PMID: 30583670 PMCID: PMC6428548 DOI: 10.31557/apjcp.2018.19.12.3463] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background: B-cell malignancies including Precursor B-cell lymphoblastic lymphoma/leukemia and Hodgkin Lymphoma show a wide spectrum of B-cell differentiation from early stage B-cell precursors to mature B-cells ending in terminal differentiation to plasma cells. Pan-B-cell antigens routinely used for the diagnosis of B-cell lymphoma, include CD19, CD20, CD22 and CD79a.PAX-5 protein, also known as B-cell-specific activation protein is a B-cell-specific transcription factor; essential for commitment and functional maintenance used in the diagnosis of B cell Hodgkin and non-Hodgkin lymphoma. PAX-5 show nuclear positivity in B cell lymphomas and moderate (dim) positivity in Hodgkinlymphoma Reed Sternberg cells make this marker ideal for diagnosing B cell malignances. Objective: To determine the expression of PAX-5 in B cell Hodgkin and non-Hodgkin Lymphoma in order to improve the diagnosis of B-cell lymphomas. Methods: In this Prospective study, all the cases of B cell lymphoma diagnosed at The Aga Khan University Hospital, Karachi from July 2010 to July 2011were included. A panel of Immunohistochemical stain was performed in all cases along with additional PAX- 5 stain with appropriate controls. Results: Total 125 cases were included. Hodgkin Lymphoma (Mixed cellularity) was the commonest B-cell lymphoma subtype, 32 (25%) cases. Other common subtypes included Hodgkin lymphoma (Nodular sclerosis subtype), diffuse large B-cell lymphoma and B lymphoblastic lymphoma. Conclusion: This study demonstrates that PAX-5 is the most sensitive and reliable immuhohistochemicalmarker in the diagnosis of B cell Hodgkin and non-Hodgkin lymphoma.
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Affiliation(s)
- Muhammad Rahil Khan
- Department of Pathology, Bilawal Medical College, Liaquat University of Medical and Health Sciences, Pakistan.
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10
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Li R, Cauchy P, Ramamoorthy S, Boller S, Chavez L, Grosschedl R. Dynamic EBF1 occupancy directs sequential epigenetic and transcriptional events in B-cell programming. Genes Dev 2018; 32:96-111. [PMID: 29440261 PMCID: PMC5830932 DOI: 10.1101/gad.309583.117] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 12/20/2017] [Indexed: 01/07/2023]
Abstract
B-cell fate determination requires the action of transcription factors that operate in a regulatory network to activate B-lineage genes and repress lineage-inappropriate genes. However, the dynamics and hierarchy of events in B-cell programming remain obscure. To uncouple the dynamics of transcription factor expression from functional consequences, we generated induction systems in developmentally arrested Ebf1-/- pre-pro-B cells to allow precise experimental control of EBF1 expression in the genomic context of progenitor cells. Consistent with the described role of EBF1 as a pioneer transcription factor, we show in a time-resolved analysis that EBF1 occupancy coincides with EBF1 expression and precedes the formation of chromatin accessibility. We observed dynamic patterns of EBF1 target gene expression and sequential up-regulation of transcription factors that expand the regulatory network at the pro-B-cell stage. A continuous EBF1 function was found to be required for Cd79a promoter activity and for the maintenance of an accessible chromatin domain that is permissive for binding of other transcription factors. Notably, transient EBF1 occupancy was detected at lineage-inappropriate genes prior to their silencing in pro-B cells. Thus, persistent and transient functions of EBF1 allow for an ordered sequence of epigenetic and transcriptional events in B-cell programming.
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Affiliation(s)
- Rui Li
- Department of Cellular and Molecular Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
- International Max Planck Research School for Molecular and Cellular Biology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Pierre Cauchy
- Department of Cellular and Molecular Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Senthilkumar Ramamoorthy
- Department of Cellular and Molecular Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Sören Boller
- Department of Cellular and Molecular Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
| | - Lukas Chavez
- Division of Pediatric Neurooncology, German Cancer Research Center, 69120 Heidelberg, Germany
- Department of Medicine, Division of Medial Genetics, School of Medicine, University of California at San Diego, La Jolla, California 92093, USA
| | - Rudolf Grosschedl
- Department of Cellular and Molecular Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany
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11
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Glaser LV, Rieger S, Thumann S, Beer S, Kuklik-Roos C, Martin DE, Maier KC, Harth-Hertle ML, Grüning B, Backofen R, Krebs S, Blum H, Zimmer R, Erhard F, Kempkes B. EBF1 binds to EBNA2 and promotes the assembly of EBNA2 chromatin complexes in B cells. PLoS Pathog 2017; 13:e1006664. [PMID: 28968461 PMCID: PMC5638620 DOI: 10.1371/journal.ppat.1006664] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 10/12/2017] [Accepted: 09/22/2017] [Indexed: 12/26/2022] Open
Abstract
Epstein-Barr virus (EBV) infection converts resting human B cells into permanently proliferating lymphoblastoid cell lines (LCLs). The Epstein-Barr virus nuclear antigen 2 (EBNA2) plays a key role in this process. It preferentially binds to B cell enhancers and establishes a specific viral and cellular gene expression program in LCLs. The cellular DNA binding factor CBF1/CSL serves as a sequence specific chromatin anchor for EBNA2. The ubiquitous expression of this highly conserved protein raises the question whether additional cellular factors might determine EBNA2 chromatin binding selectively in B cells. Here we used CBF1 deficient B cells to identify cellular genes up or downregulated by EBNA2 as well as CBF1 independent EBNA2 chromatin binding sites. Apparently, CBF1 independent EBNA2 target genes and chromatin binding sites can be identified but are less frequent than CBF1 dependent EBNA2 functions. CBF1 independent EBNA2 binding sites are highly enriched for EBF1 binding motifs. We show that EBNA2 binds to EBF1 via its N-terminal domain. CBF1 proficient and deficient B cells require EBF1 to bind to CBF1 independent binding sites. Our results identify EBF1 as a co-factor of EBNA2 which conveys B cell specificity to EBNA2. Epstein-Barr virus (EBV) infection is closely linked to cancer development. At particular risk are immunocompromised individuals like post-transplant patients which can develop B cell lymphomas. In healthy individuals EBV preferentially infects B cells and establishes a latent infection without causing apparent clinical symptoms in most cases. Upon infection, Epstein-Barr virus nuclear antigen 2 (EBNA2) initiates a B cell specific gene expression program that causes activation and proliferation of the infected cells. EBNA2 is a transcription factor well known to use a cellular protein, CBF1/CSL, as a DNA adaptor. CBF1/CSL is a sequence specific DNA binding protein robustly expressed in all tissues. Here we show that EBNA2 can form complexes with early B cell factor 1 (EBF1), a B cell specific DNA binding transcription factor, and EBF1 stabilizes EBNA2 chromatin binding. This EBNA2/EBF1 complex might serve as a novel target to develop future small molecule strategies that act as antivirals in latent B cell infection.
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Affiliation(s)
- Laura V Glaser
- Department of Gene Vectors, Helmholtz Center Munich, Munich, Germany
| | - Simone Rieger
- Department of Gene Vectors, Helmholtz Center Munich, Munich, Germany
| | - Sybille Thumann
- Department of Gene Vectors, Helmholtz Center Munich, Munich, Germany
| | - Sophie Beer
- Department of Gene Vectors, Helmholtz Center Munich, Munich, Germany
| | | | | | | | | | - Björn Grüning
- Bioinformatics, Institute for Informatics, Albert-Ludwigs-University, Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics, Institute for Informatics, Albert-Ludwigs-University, Freiburg, Germany
| | - Stefan Krebs
- Gene Center, Ludwig-Maximilians-University, Munich, Germany
| | - Helmut Blum
- Gene Center, Ludwig-Maximilians-University, Munich, Germany
| | - Ralf Zimmer
- Teaching and Research Unit Bioinformatics, Institute of Informatics, Ludwig-Maximilians-University, Munich, Germany
| | - Florian Erhard
- Teaching and Research Unit Bioinformatics, Institute of Informatics, Ludwig-Maximilians-University, Munich, Germany
| | - Bettina Kempkes
- Department of Gene Vectors, Helmholtz Center Munich, Munich, Germany
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12
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Pharmacological restoration and therapeutic targeting of the B-cell phenotype in classical Hodgkin lymphoma. Blood 2017; 129:71-81. [DOI: 10.1182/blood-2016-02-700773] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 09/23/2016] [Indexed: 02/06/2023] Open
Abstract
Key Points
A pharmacological screening identified compounds that reactivate B-cell–specific gene expression in cHL cell lines. B-cell phenotype-restoring drug combinations render cHL cell lines susceptible to B-NHL–reminiscent targeted therapies.
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13
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Estrogen receptor signal in regulation of B cell activation during diverse immune responses. Int J Biochem Cell Biol 2015; 68:42-7. [PMID: 26299327 DOI: 10.1016/j.biocel.2015.08.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 08/12/2015] [Accepted: 08/13/2015] [Indexed: 12/21/2022]
Abstract
The role of signalling through oestrogen receptors (ERs) in the regulation of B cell activation is an area of growing importance not only in terms protective immunity but also in the determination of the mechanisms of the onset of autoimmune disorders and cancers. The mode of signalling action of this single chain nuclear receptor protein molecule depends on its ability to bind to the promoters of Pax5, HOXC4 and apolipoprotein B RNA-editing enzyme activation-induced cytidine deaminase (AID) genes. ER-mediated transcriptional regulation induces class switch recombination of the immunoglobulin heavy chain variable (VH) to DH-JH genes and somatic hypermutation in developing B cells. The mode of action of ER is associated with BCR-signal pathways that involve the regulator proteins BAFF and APRIL. Additionally, the plasma membrane-bound G protein-coupled oestrogen receptor-1 (GEPR1) directs diverse cell signalling events in B cells that involve the MAPK pathways. These signals are immensely important during progenitor and precursor B cell activation. We have focused our goals on the medicinal aspects of ER-signalling mechanisms and their effects on polyclonal B cell activation.
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14
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Buchner M, Swaminathan S, Chen Z, Müschen M. Mechanisms of pre-B-cell receptor checkpoint control and its oncogenic subversion in acute lymphoblastic leukemia. Immunol Rev 2015; 263:192-209. [PMID: 25510278 DOI: 10.1111/imr.12235] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Pre-B cells within the bone marrow represent the normal counterpart for most acute lymphoblastic leukemia (ALL). During normal early B-cell development, survival and proliferation signals are dominated by cytokines, particularly interleukin-7 (IL-7) for murine developing B cells. With expression of a functional pre-B-cell receptor (BCR), cytokine signaling is attenuated and the tonic/autonomous pre-BCR signaling pathway provides proliferation as well as differentiation signals. In this review, we first describe checkpoint mechanisms during normal B-cell development and then discuss how genetic lesions in these pathways function as oncogenic mimicries and allow transformed pre-B cells to bypass checkpoint control. We focus on cytokine receptor signaling that is mimicked by activating lesions in receptor subunits or downstream mediators as well as aberrant activation of non-B lymphoid cytokine receptors. Furthermore, we describe the molecular switch from cytokine receptor to pre-BCR signaling, how this pathway is of particular importance for certain ALL subtypes, and how pre-BCR signaling is engaged by genetic lesions, such as BCR-ABL1. We discuss the transcriptional control mechanisms downstream of both cytokine- and pre-BCR signaling and how normal checkpoint control mechanisms are circumvented in pre-B ALL. Finally, we highlight new therapeutic concepts for targeted inhibition of oncogenic cytokine or pre-BCR signaling pathways.
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Affiliation(s)
- Maike Buchner
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA, USA
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15
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The role of the Janus-faced transcription factor PAX5-JAK2 in acute lymphoblastic leukemia. Blood 2014; 125:1282-91. [PMID: 25515960 DOI: 10.1182/blood-2014-04-570960] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
PAX5-JAK2 has recently been identified as a novel recurrent fusion gene in B-cell precursor acute lymphoblastic leukemia, but the function of the encoded chimeric protein has not yet been characterized in detail. Herein we show that the PAX5-JAK2 chimera, which consists of the DNA-binding paired domain of PAX5 and the active kinase domain of JAK2, is a nuclear protein that has the ability to bind to wild-type PAX5 target loci. Moreover, our data provide compelling evidence that PAX5-JAK2 functions as a nuclear catalytically active kinase that autophosphorylates and in turn phosphorylates and activates downstream signal transducers and activators of transcription (STATs) in an apparently noncanonical mode. The chimeric protein also enables cytokine-independent growth of Ba/F3 cells and therefore possesses transforming potential. Importantly, the kinase activity of PAX5-JAK2 can be efficiently blocked by JAK2 inhibitors, rendering it a potential target for therapeutic intervention. Together, our data show that PAX5-JAK2 simultaneously deregulates the PAX5 downstream transcriptional program and activates the Janus kinase-STAT signaling cascade and thus, by interfering with these two important pathways, may promote leukemogenesis.
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16
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Boller S, Grosschedl R. The regulatory network of B-cell differentiation: a focused view of early B-cell factor 1 function. Immunol Rev 2014; 261:102-15. [PMID: 25123279 PMCID: PMC4312928 DOI: 10.1111/imr.12206] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
During the last decades, many studies have investigated the transcriptional and epigenetic regulation of lineage decision in the hematopoietic system. These efforts led to a model in which extrinsic signals and intrinsic cues establish a permissive chromatin context upon which a regulatory network of transcription factors and epigenetic modifiers act to guide the differentiation of hematopoietic lineages. These networks include lineage-specific factors that further modify the epigenetic landscape and promote the generation of specific cell types. The process of B lymphopoiesis requires a set of transcription factors, including Ikaros, PU.1, E2A, and FoxO1 to 'prime' cis-regulatory regions for subsequent activation by the B-lineage-specific transcription factors EBF1 and Pax-5. The expression of EBF1 is initiated by the combined action of E2A and FoxO1, and it is further enhanced and maintained by several positive feedback loops that include Pax-5 and IL-7 signaling. EBF1 acts in concert with Ikaros, PU.1, Runx1, E2A, FoxO1, and Pax-5 to establish the B cell-specific transcription profile. EBF1 and Pax-5 also collaborate to repress alternative cell fates and lock cells into the B-lineage fate. In addition to the functions of EBF1 in establishing and maintaining B-cell identity, EBF1 is required to coordinate differentiation with cell proliferation and survival.
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Affiliation(s)
- Sören Boller
- Department of Cellular and Molecular Immunology, Max Planck Institute of Immunobiology and EpigeneticsFreiburg, Germany
| | - Rudolf Grosschedl
- Department of Cellular and Molecular Immunology, Max Planck Institute of Immunobiology and EpigeneticsFreiburg, Germany
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17
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A novel allosteric mechanism on protein-DNA interactions underlying the phosphorylation-dependent regulation of Ets1 target gene expressions. J Mol Biol 2014; 427:1655-69. [PMID: 25083921 DOI: 10.1016/j.jmb.2014.07.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/27/2014] [Accepted: 07/17/2014] [Indexed: 11/23/2022]
Abstract
Cooperative assemblies of transcription factors (TFs) on target gene enhancers coordinate cell proliferation, fate specification, and differentiation through precise and complicated transcriptional mechanisms. Chemical modifications, such as phosphorylation, of TFs induced by cell signaling further modulate the dynamic cooperativity of TFs. In this study, we found that various Ets1-containing TF-DNA complexes respond differently to calcium-induced phosphorylation of Ets1, which is known to inhibit Ets1-DNA binding. Crystallographic analysis of a complex comprising Ets1, Runx1, and CBFβ at the TCRα enhancer revealed that Ets1 acquires robust binding stability in the Runx1 and DNA-complexed state, via allosteric mechanisms. This allows phosphorylated Ets1 to be retained at the TCRα enhancer with Runx1, in contrast to other Ets1 target gene enhancers including mb-1 and stromelysin-1. This study provides a structure-based model for cell-signaling-dependent regulation of target genes, mediated via chemical modification of TFs.
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18
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Levin-Klein R, Kirillov A, Rosenbluh C, Cedar H, Bergman Y. A novel pax5-binding regulatory element in the igκ locus. Front Immunol 2014; 5:240. [PMID: 24904588 PMCID: PMC4033077 DOI: 10.3389/fimmu.2014.00240] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 05/08/2014] [Indexed: 12/31/2022] Open
Abstract
The Igκ locus undergoes a variety of different molecular processes during B cell development, including V(D)J rearrangement and somatic hypermutations (SHM), which are influenced by cis regulatory regions (RRs) within the locus. The Igκ locus includes three characterized RRs termed the intronic (iEκ), 3′Eκ, and Ed enhancers. We had previously noted that a region of DNA upstream of the iEκ and matrix attachment region (MAR) was necessary for demethylation of the locus in cell culture. In this study, we further characterized this region, which we have termed Dm, for demethylation element. Pre-rearranged Igκ transgenes containing a deletion of the entire Dm region, or of a Pax5-binding site within the region, fail to undergo efficient CpG demethylation in mature B cells in vivo. Furthermore, we generated mice with a deletion of the full Dm region at the endogenous Igκ locus. The most prominent phenotype of these mice is reduced SHM in germinal center B cells in Peyer’s patches. In conclusion, we propose the Dm element as a novel Pax5-binding cis regulatory element, which works in concert with the known enhancers, and plays a role in Igκ demethylation and SHM.
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Affiliation(s)
- Rena Levin-Klein
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hebrew University Medical School , Jerusalem , Israel
| | - Andrei Kirillov
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hebrew University Medical School , Jerusalem , Israel
| | - Chaggai Rosenbluh
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hebrew University Medical School , Jerusalem , Israel
| | - Howard Cedar
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hebrew University Medical School , Jerusalem , Israel
| | - Yehudit Bergman
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hebrew University Medical School , Jerusalem , Israel
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19
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Swaminathan S, Duy C, Müschen M. BACH2-BCL6 balance regulates selection at the pre-B cell receptor checkpoint. Trends Immunol 2014; 35:131-7. [PMID: 24332591 PMCID: PMC3943645 DOI: 10.1016/j.it.2013.11.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/16/2013] [Accepted: 11/10/2013] [Indexed: 11/21/2022]
Abstract
At the pre-B cell receptor (BCR) checkpoint, developing pre-B cells are selected for successful rearrangement of V(H)-DJ(H) gene segments and expression of a pre-BCR. Reduced stringency at this checkpoint may obstruct the B cell repertoire with nonfunctional B cell clones. Earlier studies have described that activation of B cell lymphoma/leukemia (BCL)6 by a functional pre-BCR mediates positive selection of pre-B cells that have passed the checkpoint. This concept is now further elaborated by the recent finding that the BTB and CNC homology 1 basic leucine zipper transcription factor 2 (BACH2) induces negative selection and opposes BCL6 function prior to the pre-BCR checkpoint. Here, we discuss the antagonism between BCL6 and BACH2 during early B cell development, as well as its implications in both repertoire selection and counter-selection of premalignant clones for leukemia suppression.
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Affiliation(s)
- Srividya Swaminathan
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - Cihangir Duy
- Departments of Medicine and Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Markus Müschen
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, CA 94143, USA.
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20
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Fortschegger K, Anderl S, Denk D, Strehl S. Functional heterogeneity of PAX5 chimeras reveals insight for leukemia development. Mol Cancer Res 2014; 12:595-606. [PMID: 24435167 DOI: 10.1158/1541-7786.mcr-13-0337] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED PAX5, a transcription factor pivotal for B-cell commitment and maintenance, is one of the most frequent targets of somatic mutations in B-cell precursor acute lymphoblastic leukemia. A number of PAX5 rearrangements result in the expression of in-frame fusion genes encoding chimeric proteins, which at the N-terminus consistently retain the PAX5 DNA-binding paired domain fused to the C-terminal domains of a markedly heterogeneous group of fusion partners. PAX5 fusion proteins are thought to function as aberrant transcription factors, which antagonize wild-type PAX5 activity. To gain mechanistic insight into the role of PAX5 fusion proteins in leukemogenesis, the biochemical and functional properties of uncharacterized fusions: PAX5-DACH1, PAX5-DACH2, PAX5-ETV6, PAX5-HIPK1, and PAX5-POM121 were ascertained. Independent of the subcellular distribution of the wild-type partner proteins, ectopic expression of all PAX5 fusion proteins showed a predominant nuclear localization, and by chromatin immunoprecipitation all of the chimeric proteins exhibited binding to endogenous PAX5 target sequences. Furthermore, consistent with the presence of potential oligomerization motifs provided by the partner proteins, the self-interaction capability of several fusion proteins was confirmed. Remarkably, a subset of the PAX5 fusion proteins conferred CD79A promoter activity; however, in contrast with wild-type PAX5, the fusion proteins were unable to induce Cd79a transcription in a murine plasmacytoma cell line. These data show that leukemia-associated PAX5 fusion proteins share some dominating characteristics such as nuclear localization and DNA binding but also show distinctive features. IMPLICATIONS This comparative study of multiple PAX5 fusion proteins demonstrates both common and unique properties, which likely dictate their function and impact on leukemia development.
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Affiliation(s)
- Klaus Fortschegger
- Children's Cancer Research Institute (CCRI), St. Anna Kinderkrebsforschung e.V. Zimmermannplatz 10, 1090 Vienna, Austria.
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21
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Griffin MJ, Zhou Y, Kang S, Zhang X, Mikkelsen TS, Rosen ED. Early B-cell factor-1 (EBF1) is a key regulator of metabolic and inflammatory signaling pathways in mature adipocytes. J Biol Chem 2013; 288:35925-39. [PMID: 24174531 DOI: 10.1074/jbc.m113.491936] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
EBF1 plays a crucial role in early adipogenesis; however, despite high expression in mature adipocytes, its function in these cells is currently unknown. To identify direct and indirect EBF1 targets in fat, we undertook a combination of transcriptional profiling of EBF1-deficient adipocytes and genome-wide EBF1 location analysis. Our results indicate that many components of metabolic and inflammatory pathways are positively and directly regulated by EBF1, including PI3K/AKT, MAPK, and STAT1 signaling. Accordingly, we observed significant reduction of multiple signaling events in EBF1 knockdown cells as well as a reduction in insulin-stimulated glucose uptake and lipogenesis. Inflammatory signaling, gene expression, and secretion of inflammatory cytokines were also significantly affected by loss of EBF1 in adipocytes, although ChIP-sequencing results suggest that these actions are indirect. We also found that EBF1 occupies some 35,000 sites in adipocytes, most of which occur in enhancers. Significantly, comparison with three other published EBF1 ChIP-sequencing data sets in B-cells reveals both gene- and cell type-specific patterns of EBF1 binding. These results advance our understanding of the transcriptional mechanisms regulating signaling pathways in mature fat cells and indicate that EBF1 functions as a key integrator of signal transduction, inflammation, and metabolism.
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Affiliation(s)
- Michael J Griffin
- From the Division of Endocrinology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02215
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22
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Linka Y, Ginzel S, Krüger M, Novosel A, Gombert M, Kremmer E, Harbott J, Thiele R, Borkhardt A, Landgraf P. The impact of TEL-AML1 (ETV6-RUNX1) expression in precursor B cells and implications for leukaemia using three different genome-wide screening methods. Blood Cancer J 2013; 3:e151. [PMID: 24121163 PMCID: PMC3816209 DOI: 10.1038/bcj.2013.48] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 08/18/2013] [Accepted: 09/04/2013] [Indexed: 02/03/2023] Open
Abstract
The reciprocal translocation t(12;21)(p13;q22), the most common structural genomic alteration in B-cell precursor acute lymphoblastic leukaemia in children, results in a chimeric transcription factor TEL-AML1 (ETV6-RUNX1). We identified directly and indirectly regulated target genes utilizing an inducible TEL-AML1 system derived from the murine pro B-cell line BA/F3 and a monoclonal antibody directed against TEL-AML1. By integration of promoter binding identified with chromatin immunoprecipitation (ChIP)-on-chip, gene expression and protein output through microarray technology and stable labelling of amino acids in cell culture, we identified 217 directly and 118 indirectly regulated targets of the TEL-AML1 fusion protein. Directly, but not indirectly, regulated promoters were enriched in AML1-binding sites. The majority of promoter regions were specific for the fusion protein and not bound by native AML1 or TEL. Comparison with gene expression profiles from TEL-AML1-positive patients identified 56 concordantly misregulated genes with negative effects on proliferation and cellular transport mechanisms and positive effects on cellular migration, and stress responses including immunological responses. In summary, this work for the first time gives a comprehensive insight into how TEL-AML1 expression may directly and indirectly contribute to alter cells to become prone for leukemic transformation.
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Affiliation(s)
- Y Linka
- Heinrich-Heine University of Dusseldorf, Medical Faculty, Clinic for Pediatric Oncology, Hematology and Clinical Immunology, Dusseldorf, Germany
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23
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Johnson RC, Ma L, Cherry AM, Arber DA, George TI. B-cell transcription factor expression and immunoglobulin gene rearrangement frequency in acute myeloid leukemia with t(8;21)(q22;q22). Am J Clin Pathol 2013; 140:355-62. [PMID: 23955454 DOI: 10.1309/ajcpfbcfxp94akwj] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVES To assess a large series of patients with acute myeloid leukemia (AML) with t(8;21) for both IGH@ and IGK@ B-cell gene rearrangements and for expression of PAX5, OCT2, and Bob.1 by immunohistochemistry and expression of CD19, CD79a, CD20, and CD22 by flow cytometry immunophenotyping. METHODS A total of 48 cases of AML with t(8;21)(q22;q22) were evaluated by immunohistochemistry and/or heavy chain and light chain immunoglobulin rearrangement studies where paraffin-embedded and/or fresh frozen material was available for study; previously performed flow cytometry studies were also reviewed in available cases. RESULTS Our study yielded 1 of 19 cases of AML with t(8;21) with an IGH@ gene rearrangement; blasts were associated with weak PAX5 expression. In addition, expression of antigens CD79a by flow cytometry and OCT2 by immunohistochemistry were highly associated with PAX5 expression, and CD19 was expressed in most cases assessed. CONCLUSIONS Although B-cell antigen and B-cell transcription factor expression is seen in the majority of AMLs with t(8;21)(q22;q22) and correlates with PAX5 expression, immunoglobulin gene rearrangements are an uncommon event in this group of leukemias.
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Affiliation(s)
- Ryan C. Johnson
- Department of Pathology, Stanford University School of Medicine, Stanford, CA
| | - Lisa Ma
- Department of Pathology, Stanford University School of Medicine, Stanford, CA
| | - Athena M. Cherry
- Department of Pathology, Stanford University School of Medicine, Stanford, CA
| | - Daniel A. Arber
- Department of Pathology, Stanford University School of Medicine, Stanford, CA
| | - Tracy I. George
- Department of Pathology, Stanford University School of Medicine, Stanford, CA
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Li R, Wang T, Bird S, Zou J, Dooley H, Secombes CJ. B cell receptor accessory molecule CD79α: characterisation and expression analysis in a cartilaginous fish, the spiny dogfish (Squalus acanthias). FISH & SHELLFISH IMMUNOLOGY 2013; 34:1404-15. [PMID: 23454429 PMCID: PMC4034164 DOI: 10.1016/j.fsi.2013.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 02/08/2013] [Accepted: 02/18/2013] [Indexed: 05/16/2023]
Abstract
CD79α (also known as Igα) is a component of the B cell antigen receptor complex and plays an important role in B cell signalling. The CD79α protein is present on the surface of B cells throughout their life cycle, and is absent on all other healthy cells, making it a highly reliable marker for B cells in mammals. In this study the spiny dogfish (Squalus acanthias) CD79α (SaCD79α) is described and its expression studied under constitutive and stimulated conditions. The spiny dogfish CD79α cDNA contains an open reading frame of 618 bp, encoding a protein of 205 amino acids. Comparison of the SaCD79α gene with that of other species shows that the gross structure (number of exons, exon/intron boundaries, etc.) is highly conserved across phylogeny. Additionally, analysis of the 5' flanking region shows SaCD79α lacks a TATA box and possesses binding sites for multiple transcription factors implicated in its B cell-specific gene transcription in other species. Spiny dogfish CD79α is most highly expressed in immune tissues, such as spleen, epigonal and Leydig organ, and its transcript level significantly correlates with those of spiny dogfish immunoglobulin heavy chains. Additionally, CD79α transcription is up-regulated, to a small but significant degree, in peripheral blood cells following stimulation with pokeweed mitogen. These results strongly indicate that, as in mammals, spiny dogfish CD79α is expressed by shark B cells where it associates with surface-bound immunoglobulin to form a fully functional BCR, and thus may serve as a pan-B cell marker in future shark immunological studies.
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Affiliation(s)
- Ronggai Li
- Scottish Fish Immunology Research Centre, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Tiehui Wang
- Scottish Fish Immunology Research Centre, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Steve Bird
- Department of Biological Sciences, School of Science and Engineering, University of Waikato, New Zealand
| | - Jun Zou
- Scottish Fish Immunology Research Centre, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Helen Dooley
- Scottish Fish Immunology Research Centre, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Christopher J. Secombes
- Scottish Fish Immunology Research Centre, University of Aberdeen, Zoology Building, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
- Corresponding author. Tel.: +44 1224 278272; fax: +44 (0)1224 272396.
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Banerjee A, Northrup D, Boukarabila H, Jacobsen SEW, Allman D. Transcriptional repression of Gata3 is essential for early B cell commitment. Immunity 2013; 38:930-42. [PMID: 23684985 PMCID: PMC3664383 DOI: 10.1016/j.immuni.2013.01.014] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 01/11/2013] [Indexed: 11/29/2022]
Abstract
The mechanisms underlying the silencing of alternative fate potentials in very early B cell precursors remain unclear. Using gain- and loss-of-function approaches together with a synthetic Zinc-finger polypeptide (6ZFP) engineered to prevent transcription factor binding to a defined cis element, we show that the transcription factor EBF1 promotes B cell lineage commitment by directly repressing expression of the T-cell-lineage-requisite Gata3 gene. Ebf1-deficient lymphoid progenitors exhibited increased T cell lineage potential and elevated Gata3 transcript expression, whereas enforced EBF1 expression inhibited T cell differentiation and caused rapid loss of Gata3 mRNA. Notably, 6ZFP-mediated perturbation of EBF1 binding to a Gata3 regulatory region restored Gata3 expression, abrogated EBF1-driven suppression of T cell differentiation, and prevented B cell differentiation via a GATA3-dependent mechanism. Furthermore, EBF1 binding to Gata3 regulatory sites induced repressive histone modifications across this region. These data identify a transcriptional circuit critical for B cell lineage commitment. The essential T cell gene Gata3 is a direct repressive target of EBF1 Inhibiting repression of Gata3 by EBF1 enhances T cell differentiation Inhibiting repression of Gata3 by EBF1 prevents B cell differentiation Binding of EBF1 to Gata3 induces repressive histone modifications
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Affiliation(s)
- Anupam Banerjee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6082, USA
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26
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Kikuchi H, Nakayama M, Takami Y, Kuribayashi F, Nakayama T. EBF1 acts as a powerful repressor of Blimp-1 gene expression in immature B cells. Biochem Biophys Res Commun 2012; 422:780-5. [PMID: 22634309 DOI: 10.1016/j.bbrc.2012.05.099] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 05/17/2012] [Indexed: 01/09/2023]
Abstract
The transcription factor, early B cell factor 1 (EBF1) with an atypical zinc-finger and helix-loop-helix motif, is essential for development and differentiation of lymphocytes. In mice, EBF1 is involved in the generation of pre-pro B cells (the first specified progenitors of B cells) from common lymphoid progenitors (CLPs) and transcription regulations of various genes involved in B cell-development, for instance, mb-1 and Pax5. During B lymphopoiesis, interestingly, EBF1 is detected throughout from CLPs to mature B cells. However, in immature B cells, the physiological role of EBF1 remains to be elucidated. Here, by analyzing EBF1-deficient DT40 cells, EBF1(-/-), generated by us, we show that EBF1-deficiency caused significant increases (to ∼800%) in both mRNA and protein levels of B lymphocyte-induced maturation protein-1 (Blimp-1), the master gene for plasma cell differentiation. In addition, both transcription and protein synthesis of Blimp-1 were remarkably down-regulated (to ∼20%) by re-expression (over-expression) of EBF1. Chromatin immunoprecipitation assay revealed that EBF1 binds to proximal 5'-upstream regions around two putative EBF1 binding motifs of the gene in vivo. These results suggest that EBF1 takes part in transcriptional regulations of the Blimp-1 gene in immature B cells, and may play a key role in B cell differentiation. This is the first report on a novel EBF1 function in immature B cells as a powerful repressor of Blimp-1 gene expression.
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Affiliation(s)
- Hidehiko Kikuchi
- Section of Biochemistry and Molecular Biology, Department of Medical Sciences, Miyazaki Medical College, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan.
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27
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Rajan S, Chu Pham Dang H, Djambazian H, Zuzan H, Fedyshyn Y, Ketela T, Moffat J, Hudson TJ, Sladek R. Analysis of early C2C12 myogenesis identifies stably and differentially expressed transcriptional regulators whose knock-down inhibits myoblast differentiation. Physiol Genomics 2011; 44:183-97. [PMID: 22147266 DOI: 10.1152/physiolgenomics.00093.2011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Myogenesis is a tightly controlled process involving the transcriptional activation and repression of thousands of genes. Although many components of the transcriptional network regulating the later phases of myogenesis have been identified, relatively few studies have described the transcriptional landscape during the first 24 h, when myoblasts commit to differentiate. Through dense temporal profiling of differentiating C2C12 myoblasts, we identify 193 transcriptional regulators (TRs) whose expression is significantly altered within the first 24 h of myogenesis. A high-content shRNA screen of 77 TRs involving 427 stable lines identified 42 genes whose knockdown significantly inhibits differentiation of C2C12 myoblasts. Of the TRs that were differentially expressed within the first 24 h, over half inhibited differentiation when knocked down, including known regulators of myogenesis (Myod1, Myog, and Myf5), as well as 19 TRs not previously associated with this process. Surprisingly, a similar proportion (55%) of shRNAs targeting TRs whose expression did not change also inhibited C2C12 myogenesis. We further show that a subset of these TRs inhibits myogenesis by downregulating expression of known regulatory and structural proteins. Our findings clearly illustrate that several TRs critical for C2C12 myogenesis are not differentially regulated, suggesting that approaches that focus functional studies on differentially-expressed transcripts will fail to provide a comprehensive view of this complex process.
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28
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Santos P, Arumemi F, Park KS, Borghesi L, Milcarek C. Transcriptional and epigenetic regulation of B cell development. Immunol Res 2011; 50:105-12. [PMID: 21717070 DOI: 10.1007/s12026-011-8225-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
B cell development starts in the bone marrow where hematopoietic stem cells (HSCs) progress through sequential developmental stages, as it differentiates into a naïve B cell expressing surface immunoglobulin. In the periphery, B cells that encounter antigen can further differentiate into antibody-secreting plasma cells. In this review, we focus on two factors, E47 and ELL2, which play important roles in the regulation of B cell development in the bone marrow and differentiation of mature B cells into plasma cells in the periphery, respectively. First, E47 activity is required for B cell development in the bone marrow. In addition, we have identified a cell-intrinsic role for E47 in regulating efficient self-renewal and long-term multilineage bone marrow reconstitution potential of HSCs. Second, we explored the role of transcription elongation factors in the super elongation complex (SEC), including ELL2 (eleven-nineteen lysine-rich leukemia factor) in driving poly(A) site choice and plasma cell development. We found that elongation factors impel high levels of IgH mRNA production and alternative processing at the promoter proximal, secretory-specific (sec) poly(A) site in plasma cells by enhancing RNA polymerase II modifications and downstream events. The sec poly(A) site, essentially hidden in B cells, is found by SEC factors in plasma cells.
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Affiliation(s)
- Patricia Santos
- Department of Immunology, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15261, USA
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29
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Campos-Sanchez E, Toboso-Navasa A, Romero-Camarero I, Barajas-Diego M, Sanchez-García I, Cobaleda C. Acute lymphoblastic leukemia and developmental biology: a crucial interrelationship. Cell Cycle 2011; 10:3473-86. [PMID: 22031225 DOI: 10.4161/cc.10.20.17779] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The latest scientific findings in the field of cancer research are redefining our understanding of the molecular and cellular basis of the disease, moving the emphasis toward the study of the mechanisms underlying the alteration of the normal processes of cellular differentiation. The concepts best exemplifying this new vision are those of cancer stem cells and tumoral reprogramming. The study of the biology of acute lymphoblastic leukemias (ALLs) has provided seminal experimental evidence supporting these new points of view. Furthermore, in the case of B cells, it has been shown that all the stages of their normal development show a tremendous degree of plasticity, allowing them to be reprogrammed to other cellular types, either normal or leukemic. Here we revise the most recent discoveries in the fields of B-cell developmental plasticity and B-ALL research and discuss their interrelationships and their implications for our understanding of the biology of the disease.
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Affiliation(s)
- Elena Campos-Sanchez
- Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, Madrid, Spain
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30
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Directional DNA methylation changes and complex intermediate states accompany lineage specificity in the adult hematopoietic compartment. Mol Cell 2011; 44:17-28. [PMID: 21924933 DOI: 10.1016/j.molcel.2011.08.026] [Citation(s) in RCA: 220] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 07/19/2011] [Accepted: 08/26/2011] [Indexed: 01/11/2023]
Abstract
DNA methylation has been implicated as an epigenetic component of mechanisms that stabilize cell-fate decisions. Here, we have characterized the methylomes of human female hematopoietic stem/progenitor cells (HSPCs) and mature cells from the myeloid and lymphoid lineages. Hypomethylated regions (HMRs) associated with lineage-specific genes were often methylated in the opposing lineage. In HSPCs, these sites tended to show intermediate, complex patterns that resolve to uniformity upon differentiation, by increased or decreased methylation. Promoter HMRs shared across diverse cell types typically display a constitutive core that expands and contracts in a lineage-specific manner to fine-tune the expression of associated genes. Many newly identified intergenic HMRs, both constitutive and lineage specific, were enriched for factor binding sites with an implied role in genome organization and regulation of gene expression, respectively. Overall, our studies represent an important reference data set and provide insights into directional changes in DNA methylation as cells adopt terminal fates.
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31
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Diverse roles of inhibitor of differentiation 2 in adaptive immunity. Clin Dev Immunol 2011; 2011:281569. [PMID: 21437223 PMCID: PMC3061294 DOI: 10.1155/2011/281569] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Accepted: 01/15/2011] [Indexed: 11/17/2022]
Abstract
The helix-loop-helix (HLH) transcription factor inhibitor of DNA binding 2 (Id2) has been implicated as a regulator of hematopoiesis and embryonic development. While its role in early lymphopoiesis has been well characterized, new roles in adaptive immune responses have recently been uncovered opening exciting new directions for investigation. In the innate immune system, Id2 is required for the development of mature natural killer (NK) cells, lymphoid tissue-inducer (LTi) cells, and the recently identified interleukin (IL)-22 secreting nonconventional innate lymphocytes found in the gut. In addition, Id2 has been implicated in the development of specific dendritic cell (DC) subsets, decisions determining the formation of αβ and γδ T-cell development, NK T-cell behaviour, and in the maintenance of effector and memory CD8(+) T cells in peripheral tissues. Here, we review the current understanding of the role of Id2 in lymphopoiesis and in the development of the adaptive immune response required for maintaining immune homeostasis and immune protection.
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32
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He T, Hong SY, Huang L, Xue W, Yu Z, Kwon H, Kirk M, Ding SJ, Su K, Zhang Z. Histone acetyltransferase p300 acetylates Pax5 and strongly enhances Pax5-mediated transcriptional activity. J Biol Chem 2011; 286:14137-45. [PMID: 21357426 DOI: 10.1074/jbc.m110.176289] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pax5/B cell lineage specific activator protein (BSAP) is a B lineage-specific regulator that controls the B lineage-specific gene expression program and immunoglobulin gene V(H) to DJ(H) recombination. Despite extensive studies on its multiple functions, little is known about how the activity of Pax5 is regulated. Here, we show that co-expression of histone acetyltransferase E1A binding protein p300 dramatically enhances Pax5-mediated transcriptional activation. The p300-mediated enhancement is dependent on its intrinsic histone acetyltransferase activity. Moreover, p300 interacts with the C terminus of Pax5 and acetylates multiple lysine residues within the paired box DNA binding domain of Pax5. Mutations of lysine residues 67 and 87/89 to alanine within Pax5 abolish p300-mediated enhancement of Pax5-induced Luc-CD19 reporter expression in HEK293 cells and prevent Pax5 to activate endogenous Cd19 and Blnk expression in Pax5(-/-) murine pro B cells. These results uncover a novel level of regulation of Pax5 function by p300-mediated acetylation.
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Affiliation(s)
- Ti He
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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33
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B lymphocyte lineage specification, commitment and epigenetic control of transcription by early B cell factor 1. Curr Top Microbiol Immunol 2011; 356:17-38. [PMID: 21735360 DOI: 10.1007/82_2011_139] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Early B cell factor 1 (EBF1) is a transcription factor that is critical for both B lymphopoiesis and B cell function. EBF1 is a requisite component of the B lymphocyte transcriptional network and is essential for B lineage specification. Recent studies revealed roles for EBF1 in B cell commitment. EBF1 binds its target genes via a DNA-binding domain including a unique 'zinc knuckle', which mediates a novel mode of DNA recognition. Chromatin immunoprecipitation of EBF1 in pro-B cells defined hundreds of new, as well as previously identified, target genes. Notably, expression of the pre-B cell receptor (pre-BCR), BCR and PI3K/Akt/mTOR signaling pathways is controlled by EBF1. In this review, we highlight these current developments and explore how EBF1 functions as a tissue-specific regulator of chromatin structure at B cell-specific genes.
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34
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Braunstein M, Rajkumar P, Claus CL, Vaccarelli G, Moore AJ, Wang D, Anderson MK. HEBAlt enhances the T-cell potential of fetal myeloid-biased precursors. Int Immunol 2010; 22:963-72. [PMID: 21115673 DOI: 10.1093/intimm/dxq450] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Hematopoiesis is controlled by the interplay between transcription factors and environmental signals. One of the primary determinants of the T-lineage choice is Delta-like (DL)-Notch signaling, which promotes T-cell development and inhibits B-cell development. We have found that the transcription factor HEBAlt is up-regulated in early hematopoietic precursors in response to DL-Notch signaling and that it can promote early T-cell development. Here, we identified a population of lineage-negative Sca-1⁻c-kit(+) (LK) cells in the mouse fetal liver that rapidly gave rise to myeloid cells and B cells but exhibited very little T-cell potential. However, forced expression of HEBAlt in these precursors restored their ability to develop into T cells. We also showed that Ikaros and Notch1 are up-regulated in response to HEBAlt over-expression and that activated Notch1 enhances the ability of LK cells to enter the T-cell lineage. Furthermore, the myeloid transcription factor C/EBPα is down-regulated in response to HEBAlt. We therefore propose that HEBAlt plays a role in the network that enforces the T-lineage fate and limits myeloid fate during hematopoiesis.
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Affiliation(s)
- Marsela Braunstein
- Division of Molecular and Cellular Biology, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada
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35
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Zandi S, Bryder D, Sigvardsson M. Load and lock: the molecular mechanisms of B-lymphocyte commitment. Immunol Rev 2010; 238:47-62. [DOI: 10.1111/j.1600-065x.2010.00950.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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36
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Tran AH, Berger A, Wu GE, Kee BL, Paige CJ. Early B-cell factor regulates the expression of Hemokinin-1 in the olfactory epithelium and differentiating B lymphocytes. J Neuroimmunol 2010; 232:41-50. [PMID: 20965576 DOI: 10.1016/j.jneuroim.2010.09.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 09/23/2010] [Accepted: 09/28/2010] [Indexed: 12/13/2022]
Abstract
Hemokinin-1, encoded by the TAC4 gene, is a tachykinin most closely related to substance P. Previous studies have shown that TAC4 distinguishes itself from other tachykinins by its predominantly non-neuronal expression profile, particularly in cells of the immune system. Here we report for the first time that the highest levels of TAC4 expression are found in the olfactory epithelium. Furthermore, we identify olfactory neuron-specific transcription factor (Olf-1), also known as early B-cell factor (EBF), as a novel regulator of TAC4 expression. EBF present in the olfactory epithelium and in B cells binds to two sites in the TAC4 promoter and modulates expression in developing B cells. Our findings suggest a role for TAC4 in cell differentiation, and represent a regulatory bridge between the nervous system and the immune system.
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Affiliation(s)
- Anne H Tran
- Department of Stem Cell and Developmental Biology, Princess Margaret Hospital, Ontario Cancer Institute, University Health Network, 610 University Ave, Toronto, ON, M5G 2M9, Canada.
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37
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Early B Cell Factor 1 Regulates B Cell Gene Networks by Activation, Repression, and Transcription- Independent Poising of Chromatin. Immunity 2010; 32:714-25. [DOI: 10.1016/j.immuni.2010.04.013] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 02/24/2010] [Accepted: 03/23/2010] [Indexed: 11/21/2022]
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38
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Compound haploinsufficiencies of Ebf1 and Runx1 genes impede B cell lineage progression. Proc Natl Acad Sci U S A 2010; 107:7869-74. [PMID: 20385820 DOI: 10.1073/pnas.1003525107] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Early B cell factor (EBF)1 is essential for B lineage specification. Previously, we demonstrated the synergistic activation of Cd79a (mb-1) genes by EBF1 and its functional partner, RUNX1. Here, we identified consequences of Ebf1 haploinsufficiency together with haploinsufficiency of Runx1 genes in mice. Although numbers of "committed" pro-B cells were maintained in Ebf1(+/-)Runx1(+/-) (ER(het)) mice, activation of B cell-specific gene transcription was depressed in these cells. Expression of genes encoding Aiolos, kappa0 sterile transcripts, CD2 and CD25 were reduced and delayed in ER(het) pro-B cells, whereas surface expression of BP-1 was increased on late pro-B cells in ER(het) mice. Late pre-B and immature and mature B cells were decreased in the bone marrow of Ebf1(+/-) (E(het)) mice and were nearly absent in ER(het) mice. Although we did not observe significant effects of haploinsuficiencies on IgH or Igkappa rearrangements, a relative lack of Iglambda rearrangements was detected in E(het) and ER(het) pre-B cells. Together, these observations suggest that B cell lineage progression is impaired at multiple stages in the bone marrow of E(het) and ER(het) mice. Furthermore, enforced expression of EBF1 and RUNX1 in terminally differentiated plasmacytoma cells activated multiple early B cell-specific genes synergistically. Collectively, these studies illuminate the effects of reduced Ebf1 dosage and the compounding effects of reduced Runx1 dosage. Our data confirm and extend the importance of EBF1 in regulating target genes and Ig gene rearrangements necessary for B cell lineage specification, developmental progression, and homeostasis.
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Ramírez J, Lukin K, Hagman J. From hematopoietic progenitors to B cells: mechanisms of lineage restriction and commitment. Curr Opin Immunol 2010; 22:177-84. [PMID: 20207529 DOI: 10.1016/j.coi.2010.02.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Accepted: 02/10/2010] [Indexed: 01/23/2023]
Abstract
The generation of B lymphocytes from hematopoietic progenitors requires lineage-specific transcription factors that progressively direct cell fate choices. Differentiation of hematopoietic stem cells to lymphoid progenitors requires Ikaros-dependent lineage priming and graded levels of PU.1, which are controlled by Ikaros and Gfi1. E2A drives expression of EBF1, which initiates B lineage specification. EBF1, in addition to Pax5, is necessary for commitment to the B cell lineage. As a model of gene activation in early B lymphopoiesis, mb-1 genes are activated sequentially by factors (e.g. EBF1) that initiate chromatin modifications before transcription. This review highlights the requisite interplay between transcription factors and epigenetic mechanisms in the context of B cell development.
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Affiliation(s)
- Julita Ramírez
- Integrated Department of Immunology, National Jewish Health, Denver, CO 80206, USA
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40
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Anderson KR, Torres CA, Solomon K, Becker TC, Newgard CB, Wright CV, Hagman J, Sussel L. Cooperative transcriptional regulation of the essential pancreatic islet gene NeuroD1 (beta2) by Nkx2.2 and neurogenin 3. J Biol Chem 2009; 284:31236-48. [PMID: 19759004 DOI: 10.1074/jbc.m109.048694] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Nkx2.2 and NeuroD1 are two critical regulators of pancreatic beta cell development. Nkx2.2 is a homeodomain transcription factor that is essential for islet cell type specification and mature beta cell function. NeuroD1 is a basic helix-loop-helix transcription factor that is critical for islet beta cell maturation and maintenance. Although both proteins influence beta cell development directly downstream of the endocrine progenitor factor, neurogenin3 (Ngn3), a connection between the two proteins in the regulation of beta cell fate and function has yet to be established. In this study, we demonstrate that Nkx2.2 transcriptional activity is required to facilitate the activation of NeuroD1 by Ngn3. Furthermore, Nkx2.2 is necessary to maintain high levels of NeuroD1 expression in developing mouse and zebrafish islets and in mature beta cells. Interestingly, Nkx2.2 regulates NeuroD1 through two independent promoter elements, one that is bound and activated directly by Nkx2.2 and one that appears to be regulated by Nkx2.2 through an indirect mechanism. Together, these findings suggest that Nkx2.2 coordinately activates NeuroD1 with Ngn3 within the endocrine progenitor cell and also plays a role in the maintenance of NeuroD1 expression to regulate beta cell function in the mature islet. Collectively, these findings further define the conserved regulatory networks involved in islet beta cell formation and function.
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Affiliation(s)
- Keith R Anderson
- Department of Biochemistry, University of Colorado Health Science Center, Denver, Colorado 80045, USA
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41
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Opposing effects of SWI/SNF and Mi-2/NuRD chromatin remodeling complexes on epigenetic reprogramming by EBF and Pax5. Proc Natl Acad Sci U S A 2009; 106:11258-63. [PMID: 19549820 DOI: 10.1073/pnas.0809485106] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Transcriptionally silent genes are maintained in inaccessible chromatin. Accessibility of these genes requires their modification by chromatin remodeling complexes (CRCs), which are recruited to promoters by sequence-specific DNA-binding proteins. Early B-cell factor (EBF), which is crucial for B-cell lineage specification, reprograms mb-1 (Ig-alpha) promoters by increasing chromatin accessibility and initiating the loss of DNA methylation. In turn, this facilitates promoter activation by Pax5. Here, we investigated the roles of ATP-dependent CRCs in these mechanisms. Fusion of EBF and Pax5 with the ligand-binding domain of ERalpha allowed for 4-hydroxytamoxifen-dependent, synergistic activation of mb-1 transcription in plasmacytoma cells. Knock-down of the SWI/SNF ATPases Brg1 and Brm inhibited transcriptional activation by EBF:ER and Pax5:ER. In contrast, knock-down of the Mi-2/NuRD complex subunit Mi-2beta greatly enhanced chromatin accessibility and mb-1 transcription in response to the activators. The reduction of Mi-2beta also propagated DNA demethylation in response to EBF:ER and Pax5:ER, resulting in fully unmethylated mb-1 promoters. In EBF- or EBF/Pax5-deficient fetal liver cells, both EBF and Pax5 were required for efficient demethylation of mb-1 promoters. Together, our data suggest that Mi-2/NuRD is important for the maintenance of hypermethylated chromatin in B cells. We conclude that SWI/SNF and Mi-2/NuRD function in opposition to enable or limit the reprogramming of genes by EBF and Pax5 during B-cell development.
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de-Leon SBT, Davidson EH. Modeling the dynamics of transcriptional gene regulatory networks for animal development. Dev Biol 2009; 325:317-28. [PMID: 19028486 PMCID: PMC4100934 DOI: 10.1016/j.ydbio.2008.10.043] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2008] [Revised: 10/14/2008] [Accepted: 10/21/2008] [Indexed: 01/04/2023]
Abstract
The dynamic process of cell fate specification is regulated by networks of regulatory genes. The architecture of the network defines the temporal order of specification events. To understand the dynamic control of the developmental process, the kinetics of mRNA and protein synthesis and the response of the cis-regulatory modules to transcription factor concentration must be considered. Here we review mathematical models for mRNA and protein synthesis kinetics which are based on experimental measurements of the rates of the relevant processes. The model comprises the response functions of cis-regulatory modules to their transcription factor inputs, by incorporating binding site occupancy and its dependence on biologically measurable quantities. We use this model to simulate gene expression, to distinguish between cis-regulatory execution of "AND" and "OR" logic functions, rationalize the oscillatory behavior of certain transcriptional auto-repressors and to show how linked subcircuits can be dealt with. Model simulations display the effects of mutation of binding sites, or perturbation of upstream gene expression. The model is a generally useful tool for understanding gene regulation and the dynamics of cell fate specification.
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Affiliation(s)
| | - Eric H. Davidson
- Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125, USA
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Ebf1-mediated down-regulation of Id2 and Id3 is essential for specification of the B cell lineage. Proc Natl Acad Sci U S A 2009; 106:552-7. [PMID: 19122139 DOI: 10.1073/pnas.0802550106] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Gene knockout experiments in mice have suggested a hierarchical model of early B cell commitment wherein E2A proteins (E47 and E12) activate early B cell factor (Ebf1), which in turn activates expression of the B cell commitment factor, Pax5. In IL-7 receptor alpha (IL-7Ralpha) knockout mice, B cell development is blocked before B-lineage commitment at the prepro-B cell stage in adult animals. In IL-7Ralpha(-/-) prepro-B cells, E47 is expressed and yet is insufficient to transcriptionally activate the putative downstream target gene, Ebf1. In this study, we show that further increases of E47 expression in IL-7Ralpha(-/-) prepro-B cells fails to activate Ebf1, but rather leads to a dramatic induction of the E2A inhibitory factors, Id2 and Id3. In contrast, enforced expression of Ebf1 in IL-7Ralpha(-/-) bone marrow potently down-regulates Id2 and Id3 mRNA expression and restores B cell differentiation in vivo. Down-regulation of both Id2 and Id3 during B cell specification is essential in that overexpression of either Id2 or Id3 in wild-type bone marrow blocks B cell specification at the prepro-B cell stage. Collectively, these studies suggest a model where Ebf1 induction specifies the B cell fate by dramatically increasing activity of E47 at the posttranslational level.
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Regulation of V(D)J recombination by E-protein transcription factors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 650:148-56. [PMID: 19731808 DOI: 10.1007/978-1-4419-0296-2_12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Extensive study of the E-proteins E2A and HEB duringlymphocyte development has revealed various functions for these bHLH transcription factors in regulating V(D)J recombination in both B- and T-cells. The study of E-proteins in mammals began with the identification of E2A by its ability to bind immunoglobulin heavy and light chain enhancers. Subsequent analysis has identified numerous roles for E2A and HEB at the immunoglobulin and T-cell receptor loci. E-protein targets also include the rag genes and other factors critical for recombination and for regulation of the developmental windows when cells undergo recombination. E-proteins appear to be master regulators that coordinate antigen receptor gene rearrangement and expression. This chapter focuses on how E-proteins regulate V(D)J recombination by activating transcription, initiating rearrangement and driving differentiation during B- and T-cell development.
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Lobo MK, Yeh C, Yang XW. Pivotal role of early B-cell factor 1 in development of striatonigral medium spiny neurons in the matrix compartment. J Neurosci Res 2008; 86:2134-46. [PMID: 18338816 DOI: 10.1002/jnr.21666] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The mammalian striatum plays a critical function in motor control, motor and reward learning, and cognition. Dysfunction and degeneration of the striatal neurons are implicated in major neurological and psychiatric disorders. The vast majority of striatal neurons are medium spiny neurons (MSNs). MSNs can be further subdivided into distinct subtypes based on their physical localization in the striatal patch vs. matrix compartments and based on their axonal projections and marker gene expression (i.e., striatonigral MSNs vs. striatopallidal MSNs). Despite our extensive knowledge on the striatal cytoarchitecture and circuitry, little is known about the molecular mechanisms controlling the development of the MSN subtypes in the striatum. Early B-cell factor 1 (Ebf1) is a critical transcription factor implicated in striatal MSN development. One study shows that Ebf1 is critical for the differentiation of MSNs in the matrix, and our separate study demonstrates that Ebf1 is selectively expressed in the striatonigral MSNs and is essential for their postnatal differentiation. In the present study, we further validate the striatonigral MSN deficits in Ebf1(-/-) mice using multiple striatonigral MSN reporter mice. Moreover, we demonstrate that the striatonigral MSN deficits in these mice are restricted to those in the matrix, with relative sparing of those in the patch. Finally, we demonstrate that Ebf1 deficiency also results in reduced expression of another striatonigral-specific transcription factor, zinc finger binding protein 521 (Zfp521), which is a known Ebf1 functional partner. Overall, our study reveals that Ebf1 may play an essential role in controlling the differentiation of the striatonigral MSNs in the matrix compartment.
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Affiliation(s)
- Mary Kay Lobo
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience, Brain Research Institute, University of California, Los Angeles, California 90095, USA
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Zandi S, Mansson R, Tsapogas P, Zetterblad J, Bryder D, Sigvardsson M. EBF1 is essential for B-lineage priming and establishment of a transcription factor network in common lymphoid progenitors. THE JOURNAL OF IMMUNOLOGY 2008; 181:3364-72. [PMID: 18714008 DOI: 10.4049/jimmunol.181.5.3364] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Development of B-lymphoid cells in the bone marrow is a process under strict control of a hierarchy of transcription factors. To understand the development of a B-lymphoid-restricted functional network of transcription factors, we have investigated the cell autonomous role of the transcription factor EBF1 in early B cell development. This revealed that even though transplanted EBF1-deficient fetal liver cells were able to generate common lymphoid progenitors (CLPs) as well as B220(+)CD43(+)AA4.1(+) candidate precursor B cells, none of these populations showed signs of B lineage priming. The isolated CLPs were able to generate T lymphocytes in vitro supporting the idea that the phenotype of EBF1-deficient mice is restricted to the development of the B lineage. Furthermore, EBF deficient CLPs displayed a reduction in Ig H chain recombination as compared with their wild-type counterpart and essentially lacked transcription of B-lineage-associated genes. Among the genes displaying reduced expression in the EBF1 deficient CLPs were the transcription factors Pax5, Pou2af1 (OcaB), and FoxO1 that all appear to be direct genetic targets for EBF1 because their promoters contained functional binding sites for this factor. This leads us to suggest that EBF1 regulates a transcription factor network crucial for B lineage commitment.
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Affiliation(s)
- Sasan Zandi
- Department for Biomedicin and Surgery, Linköping University, Sweden
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Stem cell–specific epigenetic priming and B cell–specific transcriptional activation at the mouse Cd19 locus. Blood 2008; 112:1673-82. [DOI: 10.1182/blood-2008-02-142786] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Low-level expression of multiple lineage-specific genes is a hallmark of hematopoietic stem cells (HSCs). HSCs predominantly express genes specific for the myeloid or megakaryocytic-erythroid lineages, whereas the transcription of lymphoid specific genes appears to begin after lymphoid specification. It has been demonstrated for a number of genes that epigenetic priming occurs before gene expression and lineage specification; however, little is known about how epigenetic priming of lymphoid genes is regulated. To address the question of how B cell–restricted expression is established, we studied activation of the Cd19 gene during hematopoietic development. We identified a B cell–specific upstream enhancer and showed that the developmental regulation of Cd19 expression involves precisely coordinated alterations in transcription factor binding and chromatin remodeling at Cd19 cis-regulatory elements. In multipotent progenitor cells, Cd19 chromatin is first remodeled at the upstream enhancer, and this remodeling is associated with binding of E2A. This is followed by the binding of EBF and PAX5 during B-cell differentiation. The Cd19 promoter is transcriptionally activated only after PAX5 binding. Our experiments give important mechanistic insights into how widely expressed and B lineage–specific transcription factors cooperate to mediate the developmental regulation of lymphoid genes during hematopoiesis.
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Lukin K, Fields S, Hartley J, Hagman J. Early B cell factor: Regulator of B lineage specification and commitment. Semin Immunol 2008; 20:221-7. [PMID: 18722139 DOI: 10.1016/j.smim.2008.07.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 07/02/2008] [Accepted: 07/10/2008] [Indexed: 12/21/2022]
Abstract
B lymphocytes are generated from hematopoietic stem cells in a series of steps controlled by transcription factors. One of the most important regulators of this process is early B cell factor (EBF). Multiple lines of evidence indicate that expression of EBF is a principle determinant of the B cell fate. In the absence of EBF, progenitor cells fail to express classical markers of B cells, including immunoglobulins. EBF drives B cell differentiation by activating the Pax5 gene and other genes required for the pre-B and B cell receptors. New evidence suggests that expression of EBF in common lymphoid progenitors directs B cell fate decisions. Specification and commitment of cells to the B cell lineage are further established by Pax5, which increases expression of EBF. Recently, it was demonstrated that both EBF and Pax5 contribute to the commitment of cells to the B lineage. Together, these studies confirm that EBF is a keystone in the regulatory network that coordinates B cell lineage specification and commitment.
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Affiliation(s)
- Kara Lukin
- Integrated Department of Immunology, National Jewish Medical and Research Center, 1400 Jackson Street, K516B, Denver, CO 80206, USA
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