1
|
Gruenbacher S, Jaritz M, Hill L, Schäfer M, Busslinger M. Essential role of the Pax5 C-terminal domain in controlling B cell commitment and development. J Exp Med 2023; 220:e20230260. [PMID: 37725138 PMCID: PMC10509461 DOI: 10.1084/jem.20230260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 07/28/2023] [Accepted: 08/29/2023] [Indexed: 09/21/2023] Open
Abstract
The B cell regulator Pax5 consists of multiple domains whose function we analyzed in vivo by deletion in Pax5. While B lymphopoiesis was minimally affected in mice with homozygous deletion of the octapeptide or partial homeodomain, both sequences were required for optimal B cell development. Deletion of the C-terminal regulatory domain 1 (CRD1) interfered with B cell development, while elimination of CRD2 modestly affected B-lymphopoiesis. Deletion of CRD1 and CRD2 arrested B cell development at an uncommitted pro-B cell stage. Most Pax5-regulated genes required CRD1 or both CRD1 and CRD2 for their activation or repression as these domains induced or eliminated open chromatin at Pax5-activated or Pax5-repressed genes, respectively. Co-immunoprecipitation experiments demonstrated that the activating function of CRD1 is mediated through interaction with the chromatin-remodeling BAF, H3K4-methylating Set1A-COMPASS, and H4K16-acetylating NSL complexes, while its repressing function depends on recruitment of the Sin3-HDAC and MiDAC complexes. These data provide novel molecular insight into how different Pax5 domains regulate gene expression to promote B cell commitment and development.
Collapse
Affiliation(s)
- Sarah Gruenbacher
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Markus Jaritz
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Louisa Hill
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Markus Schäfer
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| | - Meinrad Busslinger
- Research Institute of Molecular Pathology, Vienna BioCenter, Vienna, Austria
| |
Collapse
|
2
|
Fregona V, Bayet M, Gerby B. Oncogene-Induced Reprogramming in Acute Lymphoblastic Leukemia: Towards Targeted Therapy of Leukemia-Initiating Cells. Cancers (Basel) 2021; 13:cancers13215511. [PMID: 34771671 PMCID: PMC8582707 DOI: 10.3390/cancers13215511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 10/28/2021] [Indexed: 12/16/2022] Open
Abstract
Simple Summary Acute lymphoblastic leukemia is a heterogeneous disease characterized by a diversity of genetic alterations, following a sophisticated and controversial organization. In this review, we present and discuss the concepts exploring the cellular, molecular and functional heterogeneity of leukemic cells. We also review the emerging evidence indicating that cell plasticity and oncogene-induced reprogramming should be considered at the biological and clinical levels as critical mechanisms for identifying and targeting leukemia-initiating cells. Abstract Our understanding of the hierarchical structure of acute leukemia has yet to be fully translated into therapeutic approaches. Indeed, chemotherapy still has to take into account the possibility that leukemia-initiating cells may have a distinct chemosensitivity profile compared to the bulk of the tumor, and therefore are spared by the current treatment, causing the relapse of the disease. Therefore, the identification of the cell-of-origin of leukemia remains a longstanding question and an exciting challenge in cancer research of the last few decades. With a particular focus on acute lymphoblastic leukemia, we present in this review the previous and current concepts exploring the phenotypic, genetic and functional heterogeneity in patients. We also discuss the benefits of using engineered mouse models to explore the early steps of leukemia development and to identify the biological mechanisms driving the emergence of leukemia-initiating cells. Finally, we describe the major prospects for the discovery of new therapeutic strategies that specifically target their aberrant stem cell-like functions.
Collapse
|
3
|
Variable Expression of Notch1 and Pax5 in Classical Hodgkin Lymphoma and Infection with Epstein-Barr in Pediatric Patients. Microorganisms 2020; 8:microorganisms8060958. [PMID: 32604737 PMCID: PMC7356576 DOI: 10.3390/microorganisms8060958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 12/29/2022] Open
Abstract
NOTCH1 and PAX5 participate in the proliferation and differentiation of B and T lymphocytes. Their expression can be modified by activation of NOTCH1, induced by the Epstein–Barr (EBV) viral proteins identified as LMP1 and LMP2. To identify whether PAX5, NOTCH1, and EBV latency genes participate in the oncogenic process of pediatric patients with classical Hodgkin lymphoma (cHL), the present study aimed to identify the variable expression of NOTCH1 among disease subtypes and to assess its effect on PAX5 expression. A total of 41 paraffin-embedded tissues from Mexican pediatric patients with cHL were analyzed. The expression of CD30, CD20, NOTCH1, PAX5, and LMP1 was evaluated by immunohistochemistry and immunofluorescence. EBV detection was performed by in situ hybridization. Out of all cases, 78% (32/41) of the cHL cases were EBV positive. NOTCH1 expression was detected in 78.1% (25/32) of EBV-positive cases, nodular sclerosis being the most frequent subtype (11/25, 44%). In cases where the expression of both genes was identified, double immunofluorescence assays were conducted, finding no colocalization. We found that Reed–Sternberg cells had aberrant expression compared to their cells of origin (B lymphocytes) due to the molecular mechanisms involved in the loss of expression of PAX5 and that the identification of NOTCH1 could be considered as a candidate diagnostic/prognostic marker and a therapeutic target in pediatric cHL.
Collapse
|
4
|
Rituximab Plus Chemotherapy Provides No Clinical Benefit in a Peripheral T-Cell Lymphoma Not Otherwise Specified with Aberrant Expression of CD20 and CD79a: A Case Report and Review of the Literature. Diagnostics (Basel) 2020; 10:diagnostics10060341. [PMID: 32466492 PMCID: PMC7344438 DOI: 10.3390/diagnostics10060341] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/13/2020] [Accepted: 05/20/2020] [Indexed: 12/31/2022] Open
Abstract
Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is the most common entity of mature T-cell neoplasms. PTCL-NOS generally has an aggressive behavior and is often refractory to standard therapy. Only a few cases of PTCL with aberrant expression of B-cell antigens have been reported so far. This phenotypic aberrancy may lead to misdiagnosis as B-cell non-Hodgkin lymphomas and eventual inappropriate patient management, whereas in an accurately diagnosed PTCL, the presence of CD20 may appear as an appealing therapeutic target. In this setting, response to anti-CD20 monoclonal antibody in combination with chemotherapy has been poorly explored. We describe the case of a 59-year-old male diagnosed by a pathological and molecular approach as PTCL-NOS with aberrant co-expression of the B-cell antigens CD20 and CD79a, which proved non-responsive to the addition of rituximab to standard polychemotherapy. This case highlights that the presence of CD20 in PTCL may be misleading in the diagnosis and also act as a lure for the clinician to adopt a rituximab-based treatment, the effectiveness of which is undefined as the molecular mechanisms underlying B-cell marker expression in PTCL.
Collapse
|
5
|
Sigvardsson M. Molecular Regulation of Differentiation in Early B-Lymphocyte Development. Int J Mol Sci 2018; 19:ijms19071928. [PMID: 29966360 PMCID: PMC6073616 DOI: 10.3390/ijms19071928] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 06/27/2018] [Accepted: 06/28/2018] [Indexed: 12/15/2022] Open
Abstract
B-lymphocyte differentiation is one of the best understood developmental pathways in the hematopoietic system. Our understanding of the developmental trajectories linking the multipotent hematopoietic stem cell to the mature functional B-lymphocyte is extensive as a result of efforts to identify and prospectively isolate progenitors at defined maturation stages. The identification of defined progenitor compartments has been instrumental for the resolution of the molecular features that defines given developmental stages as well as for our understanding of the mechanisms that drive the progressive maturation process. Over the last years it has become increasingly clear that the regulatory networks that control normal B-cell differentiation are targeted by mutations in human B-lineage malignancies. This generates a most interesting link between development and disease that can be explored to improve diagnosis and treatment protocols in lymphoid malignancies. The aim of this review is to provide an overview of our current understanding of molecular regulation in normal and malignant B-cell development.
Collapse
Affiliation(s)
- Mikael Sigvardsson
- Division of Molecular Hematology, Lund Stem Cell Center, Department of Laboratory Medicine, Lund University, 22184 Lund, Sweden.
- Department of Clinical and Experimental Medicine, Linköping University, SE-581 85 Linköping, Sweden.
| |
Collapse
|
6
|
Kobayashi M, Nabinger SC, Bai Y, Yoshimoto M, Gao R, Chen S, Yao C, Dong Y, Zhang L, Rodriguez S, Yashiro-Ohtani Y, Pear WS, Carlesso N, Yoder MC, Kapur R, Kaplan MH, Daniel Lacorazza H, Zhang ZY, Liu Y. Protein Tyrosine Phosphatase PRL2 Mediates Notch and Kit Signals in Early T Cell Progenitors. Stem Cells 2017; 35:1053-1064. [PMID: 28009085 DOI: 10.1002/stem.2559] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 11/23/2016] [Accepted: 12/08/2016] [Indexed: 01/18/2023]
Abstract
The molecular pathways regulating lymphoid priming, fate, and development of multipotent bone marrow hematopoietic stem and progenitor cells (HSPCs) that continuously feed thymic progenitors remain largely unknown. While Notch signal is indispensable for T cell specification and differentiation, the downstream effectors are not well understood. PRL2, a protein tyrosine phosphatase that regulates hematopoietic stem cell proliferation and self-renewal, is highly expressed in murine thymocyte progenitors. Here we demonstrate that protein tyrosine phosphatase PRL2 and receptor tyrosine kinase c-Kit are critical downstream targets and effectors of the canonical Notch/RBPJ pathway in early T cell progenitors. While PRL2 deficiency resulted in moderate defects of thymopoiesis in the steady state, de novo generation of T cells from Prl2 null hematopoietic stem cells was significantly reduced following transplantation. Prl2 null HSPCs also showed impaired T cell differentiation in vitro. We found that Notch/RBPJ signaling upregulated PRL2 as well as c-Kit expression in T cell progenitors. Further, PRL2 sustains Notch-mediated c-Kit expression and enhances stem cell factor/c-Kit signaling in T cell progenitors, promoting effective DN1-DN2 transition. Thus, we have identified a critical role for PRL2 phosphatase in mediating Notch and c-Kit signals in early T cell progenitors. Stem Cells 2017;35:1053-1064.
Collapse
Affiliation(s)
| | - Sarah C Nabinger
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Yunpeng Bai
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Momoko Yoshimoto
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Rui Gao
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Sisi Chen
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Chonghua Yao
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Yuanshu Dong
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Lujuan Zhang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Sonia Rodriguez
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Yumi Yashiro-Ohtani
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Warren S Pear
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Nadia Carlesso
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Mervin C Yoder
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Reuben Kapur
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Mark H Kaplan
- Department of Pediatrics, Herman B Wells Center for Pediatric Research
| | - Hugo Daniel Lacorazza
- Department of Pathology, Baylor College of Medicine, Texas Children's Hospital, Houston, Texas, USA
| | - Zhong-Yin Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA
| | - Yan Liu
- Department of Pediatrics, Herman B Wells Center for Pediatric Research.,Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| |
Collapse
|
7
|
Ohmura S, Mizuno S, Oishi H, Ku CJ, Hermann M, Hosoya T, Takahashi S, Engel JD. Lineage-affiliated transcription factors bind the Gata3 Tce1 enhancer to mediate lineage-specific programs. J Clin Invest 2016; 126:865-78. [PMID: 26808502 DOI: 10.1172/jci83894] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 12/10/2015] [Indexed: 01/09/2023] Open
Abstract
The transcription factor GATA3 is essential for the genesis and maturation of the T cell lineage, and GATA3 dysregulation has pathological consequences. Previous studies have shown that GATA3 function in T cell development is regulated by multiple signaling pathways and that the Notch nuclear effector, RBP-J, binds specifically to the Gata3 promoter. We previously identified a T cell-specific Gata3 enhancer (Tce1) lying 280 kb downstream from the structural gene and demonstrated in transgenic mice that Tce1 promoted T lymphocyte-specific transcription of reporter genes throughout T cell development; however, it was not clear if Tce1 is required for Gata3 transcription in vivo. Here, we determined that the canonical Gata3 promoter is insufficient for Gata3 transcriptional activation in T cells in vivo, precluding the possibility that promoter binding by a host of previously implicated transcription factors alone is responsible for Gata3 expression in T cells. Instead, we demonstrated that multiple lineage-affiliated transcription factors bind to Tce1 and that this enhancer confers T lymphocyte-specific Gata3 activation in vivo, as targeted deletion of Tce1 in a mouse model abrogated critical functions of this T cell-regulatory element. Together, our data show that Tce1 is both necessary and sufficient for critical aspects of Gata3 T cell-specific transcriptional activity.
Collapse
|
8
|
Ungerbäck J, Åhsberg J, Strid T, Somasundaram R, Sigvardsson M. Combined heterozygous loss of Ebf1 and Pax5 allows for T-lineage conversion of B cell progenitors. ACTA ACUST UNITED AC 2015; 212:1109-23. [PMID: 26056231 PMCID: PMC4493409 DOI: 10.1084/jem.20132100] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 05/11/2015] [Indexed: 01/07/2023]
Abstract
Ungerbäck et al. show that transcription factors Ebf1 and Pax5 act in a coordinated, dose-dependent manner to preserve B-lineage cell fate. Combined heterozygous loss of both transcription factors results in increased T cell lineage skewing in B cell progenitors. To investigate how transcription factor levels impact B-lymphocyte development, we generated mice carrying transheterozygous mutations in the Pax5 and Ebf1 genes. Whereas combined reduction of Pax5 and Ebf1 had minimal impact on the development of the earliest CD19+ progenitors, these cells displayed an increased T cell potential in vivo and in vitro. The alteration in lineage fate depended on a Notch1-mediated conversion process, whereas no signs of de-differentiation could be detected. The differences in functional response to Notch signaling in Wt and Pax5+/−Ebf1+/− pro–B cells were reflected in the transcriptional response. Both genotypes responded by the generation of intracellular Notch1 and activation of a set of target genes, but only the Pax5+/−Ebf1+/− pro–B cells down-regulated genes central for the preservation of stable B cell identity. This report stresses the importance of the levels of transcription factor expression during lymphocyte development, and suggests that Pax5 and Ebf1 collaborate to modulate the transcriptional response to Notch signaling. This provides an insight on how transcription factors like Ebf1 and Pax5 preserve cellular identity during differentiation.
Collapse
Affiliation(s)
- Jonas Ungerbäck
- Department of Clinical and Experimental Medicine, Experimental Hematopoiesis Unit, Faculty of Health Sciences, Linköping University, 58183 Linköping, Sweden
| | - Josefine Åhsberg
- Department of Clinical and Experimental Medicine, Experimental Hematopoiesis Unit, Faculty of Health Sciences, Linköping University, 58183 Linköping, Sweden
| | - Tobias Strid
- Department of Clinical and Experimental Medicine, Experimental Hematopoiesis Unit, Faculty of Health Sciences, Linköping University, 58183 Linköping, Sweden
| | - Rajesh Somasundaram
- Department of Clinical and Experimental Medicine, Experimental Hematopoiesis Unit, Faculty of Health Sciences, Linköping University, 58183 Linköping, Sweden
| | - Mikael Sigvardsson
- Department of Clinical and Experimental Medicine, Experimental Hematopoiesis Unit, Faculty of Health Sciences, Linköping University, 58183 Linköping, Sweden
| |
Collapse
|
9
|
Differential PAX5 levels promote malignant B-cell infiltration, progression and drug resistance, and predict a poor prognosis in MCL patients independent of CCND1. Leukemia 2015; 30:580-93. [PMID: 26073757 PMCID: PMC4644730 DOI: 10.1038/leu.2015.140] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 05/06/2015] [Accepted: 05/11/2015] [Indexed: 01/06/2023]
Abstract
Reduced Paired box 5 (PAX5) levels have important roles in the pathogenesis of human B-cell acute lymphoblastic leukemia. However, the role of PAX5 in human lymphoma remains unclear. We generated PAX5-silenced cells using mantle cell lymphoma (MCL) as a model system. These PAX5(-) MCL cells exhibited unexpected phenotypes, including increased proliferation in vitro, enhanced tumor infiltration in vivo, robust adhesion to the bone marrow stromal cells and increased retention of quiescent stem-like cells. These phenotypes were attributed to alterations in the expression of genes including p53 and Rb, and to phosphoinositide 3-kinase/mammalian target of rapamycin and phosphorylated signal transducer and activator of transcription 3 pathway hyperactivation. On PAX5 silencing, the MCL cells displayed upregulated interleukin (IL)-6 expression and increased responses to paracrine IL-6. Moreover, decreased PAX5 levels in CD19+ MCL cells correlated with their increased infiltration and progression; thus, PAX5 levels can be used as a prognostic marker independent of cyclin D1 in advanced MCL patients. Importantly, high-throughput screening of 3800 chemical compounds revealed that PAX5(-) MCL cells are highly drug-resistant compared with PAX5 wild-type MCL cells. Collectively, the results of our study support a paradigm shift regarding the functions of PAX5 in human B-cell cancer and encourage future efforts to design effective therapies against MCL.
Collapse
|
10
|
de Almeida CR, Hendriks RW, Stadhouders R. Dynamic Control of Long-Range Genomic Interactions at the Immunoglobulin κ Light-Chain Locus. Adv Immunol 2015; 128:183-271. [DOI: 10.1016/bs.ai.2015.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
11
|
GATA-3 promotes T-cell specification by repressing B-cell potential in pro-T cells in mice. Blood 2013; 121:1749-59. [PMID: 23287858 DOI: 10.1182/blood-2012-06-440065] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Transcription factors orchestrate T-lineage differentiation in the thymus. One critical checkpoint involves Notch1 signaling that instructs T-cell commitment at the expense of the B-lineage program. While GATA-3 is required for T-cell specification, its mechanism of action is poorly understood. We show that GATA-3 works in concert with Notch1 to commit thymic progenitors to the T-cell lineage via 2 distinct pathways. First, GATA-3 orchestrates a transcriptional “repertoire” that is required for thymocyte maturation up to and beyond the pro-T-cell stage. Second, GATA-3 critically suppresses a latent B-cell potential in pro–T cells. As such, GATA-3 is essential to sealing in Notch-induced T-cell fate in early thymocyte precursors by promoting T-cell identity through the repression of alternative developmental options.
Collapse
|
12
|
Krolewski RC, Packard A, Jang W, Wildner H, Schwob JE. Ascl1 (Mash1) knockout perturbs differentiation of nonneuronal cells in olfactory epithelium. PLoS One 2012; 7:e51737. [PMID: 23284756 PMCID: PMC3524087 DOI: 10.1371/journal.pone.0051737] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/09/2012] [Indexed: 12/19/2022] Open
Abstract
The embryonic olfactory epithelium (OE) generates only a very few olfactory sensory neurons when the basic helix-loop-helix transcription factor, ASCL1 (previously known as MASH1) is eliminated by gene mutation. We have closely examined the structure and composition of the OE of knockout mice and found that the absence of neurons dramatically affects the differentiation of multiple other epithelial cell types as well. The most prominent effect is observed within the two known populations of stem and progenitor cells of the epithelium. The emergence of horizontal basal cells, a multipotent progenitor population in the adult epithelium, is anomalous in the Ascl1 knockout mice. The differentiation of globose basal cells, another multipotent progenitor population in the adult OE, is also aberrant. All of the persisting globose basal cells are marked by SOX2 expression, suggesting a prominent role for SOX2 in progenitors upstream of Ascl1. However, NOTCH1-expressing basal cells are absent from the knockout; since NOTCH1 signaling normally acts to suppress Ascl1 via HES1 and drives sustentacular (Sus) cell differentiation during adult epithelial regeneration, its absence suggests reciprocity between neurogenesis and the differentiation of Sus cells. Indeed, the Sus cells of the mutant mice express a markedly lower level of HES1, strengthening that notion of reciprocity. Duct/gland development appears normal. Finally, the expression of cKIT by basal cells is also undetectable, except in those small patches where neurogenesis escapes the effects of Ascl1 knockout and neurons are born. Thus, persistent neurogenic failure distorts the differentiation of multiple other cell types in the olfactory epithelium.
Collapse
Affiliation(s)
- Richard C. Krolewski
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Program in Cellular, Molecular, and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Adam Packard
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Program in Cellular, Molecular, and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Woochan Jang
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Hendrik Wildner
- Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland
| | - James E. Schwob
- Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
13
|
Notch is active in Langerhans cell histiocytosis and confers pathognomonic features on dendritic cells. Blood 2012; 120:5199-208. [PMID: 23074278 DOI: 10.1182/blood-2012-02-410241] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Langerhans cell histiocytosis (LCH) is an enigmatic disease defined by the accumulation of Langerhans cell-like dendritic cells (DCs). In the present study, we demonstrate that LCH cells exhibit a unique transcription profile that separates them not only from plasmacytoid and myeloid DCs, but also from epidermal Langerhans cells, indicating a distinct DC entity. Molecular analysis revealed that isolated and tissue-bound LCH cells selectively express the Notch ligand Jagged 2 (JAG2) and are the only DCs that express both Notch ligand and its receptor. We further show that JAG2 signaling induces key LCH-cell markers in monocyte-derived DCs, suggesting a functional role of Notch signaling in LCH ontogenesis. JAG2 also induced matrix-metalloproteinases 1 and 12, which are highly expressed in LCH and may account for tissue destruction in LCH lesions. This induction was selective for DCs and was not recapitulated in monocytes. The results of the present study suggest that JAG2-mediated Notch activation confers phenotypic and functional aspects of LCH to DCs; therefore, interference with Notch signaling may be an attractive strategy to combat this disease.
Collapse
|
14
|
Single-cell analysis of early B-lymphocyte development suggests independent regulation of lineage specification and commitment in vivo. Proc Natl Acad Sci U S A 2012; 109:15871-6. [PMID: 23019372 DOI: 10.1073/pnas.1210144109] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To better understand the process of B-lymphocyte lineage restriction, we have investigated molecular and functional properties in early B-lineage cells from Pax-5-deficient animals crossed to a B-lineage-restricted reporter mouse, allowing us to identify B-lineage-specified progenitors independently of conventional surface markers. Pax-5 deficiency resulted in a dramatic increase in the frequency of specified progenitor B-cells marked by expression of a λ5 (Igll1) promoter-controlled reporter gene. Gene expression analysis of ex vivo isolated progenitor cells revealed that Pax-5 deficiency has a minor impact on B-cell specification. However, single-cell in vitro differentiation analysis of ex vivo isolated cells revealed that specified B-lineage progenitors still displayed a high degree of plasticity for development into NK or T lineage cells. In contrast, we were unable to detect any major changes in myeloid lineage potential in specified Pax-5-deficient cells. By comparison of gene expression patterns in ex vivo isolated Pax-5- and Ebf-1-deficient progenitors, it was possible to identify a set of B-cell-restricted genes dependent on Ebf-1 but not Pax-5, supporting the idea that B-cell specification and commitment is controlled by distinct regulatory networks.
Collapse
|
15
|
Nakagawa R, Vukovic M, Cosimo E, Michie AM. Modulation of PKC-α promotes lineage reprogramming of committed B lymphocytes. Eur J Immunol 2012; 42:1005-15. [PMID: 22531924 DOI: 10.1002/eji.201141442] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
During hematopoietic lineage development, hematopoietic stem cells sequentially commit toward myeloid or lymphoid lineages in a tightly regulated manner, which under normal circumstances is irreversible. However, studies have established that targeted deletion of the B-lineage specific transcription factor, paired box gene 5 (Pax5), enables B cells to differentiate toward other hematopoietic lineages, in addition to generating progenitor B-cell lymphomas. Our previous studies showed that subversion of protein kinase C (PKC)-α in developing B cells transformed B-lineage cells. Here, we demonstrate that PKC-α modulation in committed CD19(+) B lymphocytes also promoted lineage conversion toward myeloid, NK-, and T-cell lineages upon Notch ligation. This occurred via a reduction in Pax5 expression resulting from a downregulation of E47, a product of the E2A gene. T-cell lineage commitment was indicated by the expression of T-cell associated genes Ptcra, Cd3e, and gene rearrangement at the Tcrb gene locus. Importantly, the lineage-converted T cells carried Igh gene rearrangements reminiscent of their B-cell origin. Our findings suggest that modulation of PKC-α induces hematopoietic-lineage plasticity in committed B-lineage cells by perturbing expression of critical B-lineage transcription factors, and deregulation of PKC-α activity/expression represents a potential mechanism for lineage trans-differentiation during malignancies.
Collapse
Affiliation(s)
- Rinako Nakagawa
- Institute of Cancer Sciences, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, UK
| | | | | | | |
Collapse
|
16
|
|
17
|
Okuyama K, Murata A, Sudo T, Yoshino M, Hayashi SI. A checkpoint in B-lymphopoiesis related to Notch resistance. Biochem Biophys Res Commun 2011; 417:141-6. [PMID: 22138652 DOI: 10.1016/j.bbrc.2011.11.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 11/15/2011] [Indexed: 12/29/2022]
Abstract
While murine B- and T-lymphopoiesis require overlapping molecules, they occur in separate organs: the bone marrow (BM) and the thymus, respectively. The BM microenvironment is incapable of supporting T-lymphopoiesis because of insufficient interactions of Notch1 with delta-like ligand (Dll). Notch1/Dll interactions also play a role in the suppression of B-lymphopoiesis in the thymus. However, it is still unclear whether the Notch1/Dll interaction alone explains why the thymus does not support B-lymphopoiesis. In this study, we compared the precursor population colonizing the thymus with that in the BM by culturing them on stromal cells expressing abundant Dll1. We demonstrated that Flt3(+) Il7r(+) B220(+) Cd19(+) BM cells gave rise to B cells under this condition. We defined them as resistant to Dll1. In the thymus, Dll1-resistant cells were undetectable. This suggested that the absence of Dll1-resistant cells might explain the absence of B-lymphopoiesis in the thymus.
Collapse
Affiliation(s)
- Kazuki Okuyama
- Division of Immunology, Department of Molecular and Cellular Biology, School of Life Science, Faculty of Medicine, Tottori University, Yonago, Tottori, Japan.
| | | | | | | | | |
Collapse
|
18
|
Rothenberg EV. T cell lineage commitment: identity and renunciation. THE JOURNAL OF IMMUNOLOGY 2011; 186:6649-55. [PMID: 21646301 DOI: 10.4049/jimmunol.1003703] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Precursors undertaking T cell development shed their access to other pathways in a sequential process that begins before entry into the thymus and continues through many cell cycles afterward. This process involves three levels of regulatory change, in which the cells' intrinsic transcriptional regulatory factors, expression of signaling receptors (e.g., Notch1), and expression of distinct homing receptors separately contribute to confirmation of T cell identity. Each alternative potential has a different underlying molecular basis that is neutralized and then permanently silenced through different mechanisms in early T cell precursors. This regulatory mosaic has notable implications for the hierarchy of relationships linking T lymphocytes to other hematopoietic fates.
Collapse
Affiliation(s)
- Ellen V Rothenberg
- Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
| |
Collapse
|
19
|
Thompson PK, Zúñiga-Pflücker JC. On becoming a T cell, a convergence of factors kick it up a Notch along the way. Semin Immunol 2011; 23:350-9. [PMID: 21981947 DOI: 10.1016/j.smim.2011.08.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 08/19/2011] [Indexed: 12/18/2022]
Abstract
The thymus is seeded by bone marrow-derived progenitors, which undergo a series of differentiation and proliferation events in order to generate functional T lymphocytes. The Notch signaling pathway, together with multiple transcription factors, act in concert to commit progenitors to a T-lineage fate, extinguishing non-T cell potential, inducing thymocyte differentiation and supporting proliferation and survival along the way to becoming a mature T cell. This review focuses on recent evidence regarding the complex interplay between the Notch pathway and other key transcription factors at specific lineage-decision points during the program of T cell development.
Collapse
Affiliation(s)
- Patrycja K Thompson
- Department of Immunology, University of Toronto, Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada
| | | |
Collapse
|
20
|
Welinder E, Ahsberg J, Sigvardsson M. B-lymphocyte commitment: identifying the point of no return. Semin Immunol 2011; 23:335-40. [PMID: 21944938 DOI: 10.1016/j.smim.2011.08.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 08/19/2011] [Indexed: 02/07/2023]
Abstract
Even though B-lymphocyte development is one of the best understood models for cell differentiation in the hematopoetic system, recent advances in cell sorting and functional genomics has increased this understanding further. This has suggested that already early lymphoid primed multipotent progenitor cells (LMPPs) express low levels of lymphoid restricted transcripts. The expression of these genes becomes more pronounced when cells enter the FLT-3/IL-7 receptor positive common lymphoid progenitor (CLP) stage. However, the expression of B-lineage specific genes is limited to a B-cell restricted Ly6D surface positive subpopulation of the CLP compartment. The gene expression patterns also reflect differences in lineage potential and while Ly6D negative FLT-3/IL-7 receptor positive cells represents true CLPs with an ability to generate B/T and NK cells, the Ly6D positive cells lack NK cell potential and display a reduced T-cell potential in vivo. These recent findings suggest that the CLP compartment is highly heterogenous and that the point of no return in B-cell development may occur already in B220(-)CD19(-) cells. These findings have allowed for a better understanding of the interplay between transcription factors like EBF-1, PAX-5 and E47, all known as crucial for normal B-cell development. In this review, we aim to provide a comprehensive overview of B-cell fate specification and commitment based on the recent advances in the understanding of molecular networks as well as functional properties of early progenitor populations.
Collapse
Affiliation(s)
- Eva Welinder
- Lund Stem Cell Center, BMC B10, 221 84 Lund, Sweden
| | | | | |
Collapse
|
21
|
Vallespinós M, Fernández D, Rodríguez L, Alvaro-Blanco J, Baena E, Ortiz M, Dukovska D, Martínez D, Rojas A, Campanero MR, Moreno de Alborán I. B Lymphocyte Commitment Program Is Driven by the Proto-Oncogene c-myc. THE JOURNAL OF IMMUNOLOGY 2011; 186:6726-36. [DOI: 10.4049/jimmunol.1002753] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
22
|
Medvedovic J, Ebert A, Tagoh H, Busslinger M. Pax5: a master regulator of B cell development and leukemogenesis. Adv Immunol 2011; 111:179-206. [PMID: 21970955 DOI: 10.1016/b978-0-12-385991-4.00005-2] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The B cell lineage of the hematopoietic system is responsible for the generation of high-affinity antibodies, which provide humoral immunity for protection against foreign pathogens. B cell commitment and development depend on many transcription factors including Pax5. Here, we review the different functions of Pax5 in regulating various aspects of B lymphopoiesis. At B cell commitment, Pax5 restricts the developmental potential of lymphoid progenitors to the B cell pathway by repressing B-lineage-inappropriate genes, while it simultaneously promotes B cell development by activating B-lymphoid-specific genes. Pax5 thereby controls gene transcription by recruiting chromatin-remodeling, histone-modifying, and basal transcription factor complexes to its target genes. Moreover, Pax5 contributes to the diversity of the antibody repertoire by controlling V(H)-DJ(H) recombination by inducing contraction of the immunoglobulin heavy-chain locus in pro-B cells, which is likely mediated by PAIR elements in the 5' region of the V(H) gene cluster. Importantly, all mature B cell types depend on Pax5 for their differentiation and function. Pax5 thus controls the identity of B lymphocytes throughout B cell development. Consequently, conditional loss of Pax5 allows mature B cells from peripheral lymphoid organs to develop into functional T cells in the thymus via dedifferentiation to uncommitted progenitors in the bone marrow. Pax5 has also been implicated in human B cell malignancies because it can function as a haploinsufficient tumor suppressor or oncogenic translocation fusion protein in B cell precursor acute lymphoblastic leukemia.
Collapse
Affiliation(s)
- Jasna Medvedovic
- Research Institute of Molecular Pathology, Vienna Biocenter, Vienna, Austria
| | | | | | | |
Collapse
|
23
|
Klein Wolterink RGJ, García-Ojeda ME, Vosshenrich CAJ, Hendriks RW, Di Santo JP. The intrathymic crossroads of T and NK cell differentiation. Immunol Rev 2010; 238:126-37. [DOI: 10.1111/j.1600-065x.2010.00960.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
24
|
Sanalkumar R, Dhanesh SB, James J. Non-canonical activation of Notch signaling/target genes in vertebrates. Cell Mol Life Sci 2010; 67:2957-68. [PMID: 20458516 PMCID: PMC11115867 DOI: 10.1007/s00018-010-0391-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 04/10/2010] [Accepted: 04/26/2010] [Indexed: 12/27/2022]
Abstract
Evolutionarily conserved Notch signaling orchestrates diverse physiological mechanisms during metazoan development and homeostasis. Classically, ligand-activated Notch receptors transduce the signaling cascade through the interaction of DNA-bound CBF1-co-repressor complex. However, recent reports have demonstrated execution of a CBF1-independent Notch pathway through signaling cross-talks in various cells/tissues. Here, we have tried to congregate the reports that describe the non-canonical/CBF1-independent Notch signaling and target gene activation in vertebrates with specific emphasis on their functional relevance.
Collapse
Affiliation(s)
- Rajendran Sanalkumar
- Neuro-Stem Cell Biology Laboratory, Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram, 695 014 Kerala India
| | - Sivadasan Bindu Dhanesh
- Neuro-Stem Cell Biology Laboratory, Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram, 695 014 Kerala India
| | - Jackson James
- Neuro-Stem Cell Biology Laboratory, Neurobiology Division, Rajiv Gandhi Centre for Biotechnology, Thycaud PO, Poojappura, Thiruvananthapuram, 695 014 Kerala India
| |
Collapse
|
25
|
Mohtashami M, Shah DK, Nakase H, Kianizad K, Petrie HT, Zúñiga-Pflücker JC. Direct comparison of Dll1- and Dll4-mediated Notch activation levels shows differential lymphomyeloid lineage commitment outcomes. THE JOURNAL OF IMMUNOLOGY 2010; 185:867-76. [PMID: 20548034 DOI: 10.4049/jimmunol.1000782] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the thymus, Notch signaling is essential for T lymphopoiesis, with Delta-like (Dll)4 uniquely involved in this process. However, using cocultures, either Dll4 or Dll1 were shown to support T lymphopoiesis. To address which Dll is more effective at inducing hematopoietic progenitor cells to give rise to T lineage cells in vitro, we generated OP9 cells expressing a series of incrementally discrete and equivalent levels of Dll1 or Dll4. In keeping with previous findings, OP9 cells expressing high levels of either Dll1 or Dll4 gave rise to T lineage cells with similar efficacy, and prevented the differentiation of B and myeloid-lineage cells. However, at limiting levels, Dll4 maintained its ability to inhibit B lineage choice and induce T lineage commitment and differentiation at lower levels than Dll1. This manifest property of Dll4 is evident despite lower levels of steady-state surface expression than Dll1 on OP9 cells. The heightened effectiveness of Dll4 over Dll1 also corresponded to the induction of Notch target genes, and inhibition of B and myeloid-specific transcription factors. Furthermore, we show that OP9 cells expressing levels of Dll4 equivalent to those present in thymic epithelial cells, as expected, gave rise to T lineage cells, but were also permissive for the differentiation of myeloid cells; whereas, still inhibiting B lymphopoiesis. Our findings show that Dll4 expressed at physiological levels on OP9 cells is functionally distinct from similarly expressed levels of Dll1, illustrating the unique properties of Dll4 in supporting the combined T lineage and specific myeloid-lineage outcomes that underpin its function within the thymus.
Collapse
Affiliation(s)
- Mahmood Mohtashami
- Sunnybrook Research Institute, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
26
|
Main H, Lee KL, Yang H, Haapa-Paananen S, Edgren H, Jin S, Sahlgren C, Kallioniemi O, Poellinger L, Lim B, Lendahl U. Interactions between Notch- and hypoxia-induced transcriptomes in embryonic stem cells. Exp Cell Res 2010; 316:1610-24. [DOI: 10.1016/j.yexcr.2009.12.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 12/15/2009] [Indexed: 12/12/2022]
|
27
|
Abstract
RBP-J/Su(H)/Lag1, the main transcriptional mediator of Notch signaling, binds DNA with the consensus sequence YRTGDGAD. Notch target genes can be controlled by two opposing activities of RBP-J. The interaction of the Notch intracellular domain with RBP-J induces a weak transcriptional activation and requires an additional tissue-specific transcriptional activator such as bHLH proteins or GATA to mediate strong target gene expression. For example, during Drosophila sensory organ precursor (SOP) cell development, proneural bHLH interacts with Da, a Drosophila orthologue of E2A, to form a tissue-specific activator of Su(H), the Drosophila orthologue of RBP-J. This complex and Su(H) act synergistically to promote the epidermal cell fate. In contrast, a complex of Su(H) with Hairless, a Drosophila functional homologue of MINT, has transcriptional repression activity that promotes SOP differentiation to neurons. Recent conditional loss-of-function studies demonstrated that transcriptional networks involving RBP-J, MINT, and E2A are conserved in mammalian cell differentiation, including multiple steps of lymphocyte development, and probably also in neuronal maturation in adult neurogenesis. During neurogenesis, Notch-RBP-J signaling was thought historically to be involved mainly in the maintenance of undifferentiated neural progenitors. However, the identification of a tissue-specific transcriptional activator of RBP-J-Notch has revealed new roles of RBP-J in the promotion of neuronal maturation. Finally, the Notch-independent function of RBP-J was recently discovered and will be reviewed here.
Collapse
|
28
|
Benne C, Lelievre JD, Balbo M, Henry A, Sakano S, Levy Y. Notch Increases T/NK Potential of Human Hematopoietic Progenitors and Inhibits B Cell Differentiation at a Pro-B Stage. Stem Cells 2009; 27:1676-85. [DOI: 10.1002/stem.94] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
29
|
Fürthauer M, González-Gaitán M. Endocytosis, asymmetric cell division, stem cells and cancer: unus pro omnibus, omnes pro uno. Mol Oncol 2009; 3:339-53. [PMID: 19581131 DOI: 10.1016/j.molonc.2009.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Accepted: 05/25/2009] [Indexed: 12/17/2022] Open
Abstract
Carcinogenesis can be initiated in adult stem cells, suggesting that tumours arise as a consequence of stem-cell dysfunction. In the fruitfly, cancer arises in stem cells that fail to undergo asymmetric cell division. In flies and mammals, a specific regulation of the endocytic trafficking machinery allows stem cells to self-renew and generate the differentiating cells required to form and maintain mature organs. We review recent findings suggesting that an understanding of the relationship between endocytosis, asymmetric cell division, stem cells and cancer will be crucial to unravel the cell biological basis of tumourigenesis.
Collapse
Affiliation(s)
- Maximilian Fürthauer
- Department of Biochemistry, University of Geneva, Sciences II, CH-1211 Geneva 4, Switzerland.
| | | |
Collapse
|
30
|
SATB1 defines the developmental context for gene silencing by Xist in lymphoma and embryonic cells. Dev Cell 2009; 16:507-16. [PMID: 19386260 DOI: 10.1016/j.devcel.2009.03.006] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Revised: 02/12/2009] [Accepted: 03/03/2009] [Indexed: 12/17/2022]
Abstract
The noncoding Xist RNA triggers silencing of one of the two female X chromosomes during X inactivation in mammals. Gene silencing by Xist is restricted to a special developmental context in early embryos and specific hematopoietic precursors. Here, we show that Xist can initiate silencing in a lymphoma model. We identify the special AT-rich binding protein SATB1 as an essential silencing factor. Loss of SATB1 in tumor cells abrogates the silencing function of Xist. In lymphocytes Xist localizes along SATB1-organized chromatin and SATB1 and Xist influence each other's pattern of localization. SATB1 and its homolog SATB2 are expressed during the initiation window for X inactivation in ES cells. Importantly, viral expression of SATB1 or SATB2 enables gene silencing by Xist in embryonic fibroblasts, which normally do not provide an initiation context. Thus, our data establish SATB1 as a crucial silencing factor contributing to the initiation of X inactivation.
Collapse
|
31
|
Kutlesa S, Zayas J, Valle A, Levy RB, Jurecic R. T-cell differentiation of multipotent hematopoietic cell line EML in the OP9-DL1 coculture system. Exp Hematol 2009; 37:909-23. [PMID: 19447159 DOI: 10.1016/j.exphem.2009.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Revised: 05/04/2009] [Accepted: 05/07/2009] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Multipotent hematopoietic cell line EML can differentiate into myeloid, erythroid, megakaryocytic, and B-lymphoid lineages, but it remained unknown whether EML cells have T-cell developmental potential as well. The goal of this study was to determine whether the coculture with OP9 stromal cells expressing Notch ligand Delta-like 1 (OP9-DL1) could induce differentiation of EML cells into T-cell lineage. MATERIALS AND METHODS EML cells were cocultured with control OP9 or OP9-DL1 stromal cells in the presence of cytokines (stem cell factor, interleukin-7, and Fms-like tyrosine kinase 3 ligand). Their T-cell lineage differentiation was assessed through flow cytometry and reverse transcription polymerase chain reaction expression analysis of cell surface markers and genes characterizing and associated with specific stages of T-cell development. RESULTS The phenotypic, molecular, and functional analysis has revealed that in EML/OP9-DL1 cocultures with cytokines, but not in control EML/OP9 cocultures, EML cell line undergoes T-cell lineage commitment and differentiation. In OP9-DL1 cocultures, EML cell line has differentiated into cells that 1) resembled double-negative, double-positive, and single-positive stages of T-cell development; 2) initiated expression of GATA-3, Pre-Talpha, RAG-1, and T-cell receptor-Vbeta genes; and 3) produced interferon-gamma in response to T-cell receptor stimulation. CONCLUSIONS These results support the notion that EML cell line has the capacity for T-cell differentiation. Remarkably, induction of T-lineage gene expression and differentiation of EML cells into distinct stages of T-cell development were very similar to previously described T-cell differentiation of adult hematopoietic stem cells and progenitors in OP9-DL1 cocultures. Thus, EML/OP9-DL1 coculture could be a useful experimental system to study the role of particular genes in T-cell lineage specification, commitment, and differentiation.
Collapse
Affiliation(s)
- Snjezana Kutlesa
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, Fla. 33136, USA
| | | | | | | | | |
Collapse
|
32
|
Lazzi S, Bellan C, Onnis A, De Falco G, Sayed S, Kostopoulos I, Onorati M, D'Amuri A, Santopietro R, Vindigni C, Fabbri A, Righi S, Pileri S, Tosi P, Leoncini L. Rare lymphoid neoplasms coexpressing B- and T-cell antigens. The role of PAX-5 gene methylation in their pathogenesis. Hum Pathol 2009; 40:1252-61. [PMID: 19368954 DOI: 10.1016/j.humpath.2009.01.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 01/08/2009] [Accepted: 01/15/2009] [Indexed: 01/04/2023]
Abstract
We report 3 cases of lymphoid neoplasms with mixed lineage features of T-, NK-, or B-cell marker expression and clonal gene rearrangement for both T-cell receptor and immunoglobulin light chain IgK. A characteristic of our cases was the lack of expression of the specific B-cell transcription factor, Pax5, which is essential for maintaining the identity and function of mature B cells during late B lymphopoiesis. In the absence of Pax5, B cells in vitro can differentiate into macrophages, dendritic cells, granulocytes, and T/NK cells. Methylation analysis of the Pax5 gene in our cases suggests that its inactivation by this epigenetic event in a committed or mature B cell, before plasma cell differentiation, may well be a common pathogenetic mechanism in mature lymphoid neoplasms with expression of multilineage antigens. In particular, case 1 may represent a mixed NK- and B-cell lineage; and cases 2 and 3 may represent mixed T and B-cell lineage, respectively. Aberrations in the DNA methylation patterns are currently recognized as a hallmark of human cancer. Cases with aberrant phenotypes require molecular analysis for lineage assignment. Studies of such cases may be helpful to better elucidate whether they represent a distinct entity with clinical, immunophenotypic, and molecular characteristics or an incidental phenomenon during malignant transformation. Interestingly, these cases were all characterized by poor clinical outcome.
Collapse
Affiliation(s)
- Stefano Lazzi
- Department of Human Pathology and Oncology, University of Siena, 53100 Siena, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
GATA3 and the T-cell lineage: essential functions before and after T-helper-2-cell differentiation. Nat Rev Immunol 2009; 9:125-35. [PMID: 19151747 DOI: 10.1038/nri2476] [Citation(s) in RCA: 315] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Many advances in our understanding of the molecules that regulate the development, differentiation and function of T cells have been made over the past few years. One important regulator of T-cell differentiation is the transcription factor GATA-binding protein 3 (GATA3). Although the main function of GATA3 is to act as a master transcription factor for the differentiation of T helper 2 (T(H)2) cells, new research has helped to uncover crucial functions of GATA3 in T cells that go beyond T(H)2-cell differentiation and that are important at earlier stages of haematopoietic and lymphoid-cell development. This Review focuses on the functions of GATA3 from early thymocyte development to effector T-cell differentiation. In addition, we discuss the interactions between GATA3 and other transcription factors and signalling pathways, and highlight the functional significance of the GATA3 protein structure.
Collapse
|
34
|
Harman BC, Northrup DL, Allman D. Resolution of unique Sca-1highc-Kit- lymphoid-biased progenitors in adult bone marrow. THE JOURNAL OF IMMUNOLOGY 2008; 181:7514-24. [PMID: 19017941 DOI: 10.4049/jimmunol.181.11.7514] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have identified a distinctive lymphoid-restricted progenitor population in adult mouse bone marrow based on a unique c-Kit(-)Sca-1(high)Flt3(+) AA4(+) surface phenotype. These cells are highly lymphoid biased and rapidly generate B and T cells after adoptive transfer. However, whereas previously described lymphoid progenitors such as common lymphoid progenitors express TdT and relatively high levels of RAG2, and are enriched for cells with an active V(D)J recombinase, Flt3(+) AA4(+) cells within the c-Kit(-)Sca-1(high) bone marrow fraction are TdT(-), are RAG2(low), and do not display evidence for ongoing or past recombinase activity. Furthermore, unlike common lymphoid progenitors that readily generate B cells upon stimulation with IL-7, c-Kit(-)Sca-1(high)Flt3(+) precursors do not express abundant levels of the IL-7R, and require costimulation with Flt3 ligand and IL-7 to generate B cells in vitro. Moreover, these findings suggest that hematopoietic stem cells in adults generate an array of lymphoid-biased progenitor populations characterized by distinct gene expression and cytokine response profiles.
Collapse
Affiliation(s)
- Benjamin C Harman
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | | | | |
Collapse
|
35
|
Koch U, Fiorini E, Benedito R, Besseyrias V, Schuster-Gossler K, Pierres M, Manley NR, Duarte A, Macdonald HR, Radtke F. Delta-like 4 is the essential, nonredundant ligand for Notch1 during thymic T cell lineage commitment. ACTA ACUST UNITED AC 2008; 205:2515-23. [PMID: 18824585 PMCID: PMC2571927 DOI: 10.1084/jem.20080829] [Citation(s) in RCA: 335] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Thymic T cell lineage commitment is dependent on Notch1 (N1) receptor–mediated signaling. Although the physiological ligands that interact with N1 expressed on thymic precursors are currently unknown, in vitro culture systems point to Delta-like 1 (DL1) and DL4 as prime candidates. Using DL1- and DL4-lacZ reporter knock-in mice and novel monoclonal antibodies to DL1 and DL4, we show that DL4 is expressed on thymic epithelial cells (TECs), whereas DL1 is not detected. The function of DL4 was further explored in vivo by generating mice in which DL4 could be specifically inactivated in TECs or in hematopoietic progenitors. Although loss of DL4 in hematopoietic progenitors did not perturb thymus development, inactivation of DL4 in TECs led to a complete block in T cell development coupled with the ectopic appearance of immature B cells in the thymus. These immature B cells were phenotypically indistinguishable from those developing in the thymus of conditional N1 mutant mice. Collectively, our results demonstrate that DL4 is the essential and nonredundant N1 ligand responsible for T cell lineage commitment. Moreover, they strongly suggest that N1-expressing thymic progenitors interact with DL4-expressing TECs to suppress B lineage potential and to induce the first steps of intrathymic T cell development.
Collapse
Affiliation(s)
- Ute Koch
- Ecole Polytechnique Fédérale de Lausanne, Swiss Institute for Experimental Cancer Research, 1066 Epalinges, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Gene regulatory networks directing myeloid and lymphoid cell fates within the immune system. Semin Immunol 2008; 20:228-35. [PMID: 18771937 DOI: 10.1016/j.smim.2008.08.003] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 08/12/2008] [Accepted: 08/14/2008] [Indexed: 12/23/2022]
Abstract
Considerable progress is being achieved in the analysis of gene regulatory networks that direct cell fate decisions within the hematopoietic system. In addition to transcription factors that are pivotal for cell fate specification and commitment, recent evidence suggests the involvement of microRNAs. In this review we attempt to integrate these two types of regulatory components into circuits that dictate cell fate choices leading to the generation of innate as well as adaptive immune cells. The developmental circuits are placed in the context of a revised scheme for hematopoiesis that suggests that both the innate (myeloid) and adaptive (lymphoid) lineages of the immune system arise from a common progenitor.
Collapse
|
37
|
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.
Collapse
Affiliation(s)
- Kara Lukin
- Integrated Department of Immunology, National Jewish Medical and Research Center, 1400 Jackson Street, K516B, Denver, CO 80206, USA
| | | | | | | |
Collapse
|
38
|
Cobaleda C, Busslinger M. Developmental plasticity of lymphocytes. Curr Opin Immunol 2008; 20:139-48. [PMID: 18472258 DOI: 10.1016/j.coi.2008.03.017] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 03/29/2008] [Accepted: 03/31/2008] [Indexed: 02/04/2023]
Abstract
Experimental perturbation of signaling or transcription factor networks has been used to study the developmental potential of lymphoid progenitors, lineage-committed precursors and mature lymphocytes. Common lymphoid progenitors and uncommitted pro-T cells can be efficiently diverted into myeloid or erythroid lineages by ectopic cytokine signaling or retroviral expression of the myeloid C/EBPalpha or erythroid GATA1 transcription factor. Forced C/EBPalpha expression furthermore induces direct transdifferentiation of immature thymocytes or B cells into macrophages. Notably, conditional inactivation of the B cell commitment factor Pax5 is sufficient to convert mature B cells into functional T cells via dedifferentiation to uncommitted progenitors. Together these experiments have uncovered an unanticipated developmental plasticity of lymphocytes, which may account for lineage switches observed in human malignancies.
Collapse
Affiliation(s)
- César Cobaleda
- Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | | |
Collapse
|
39
|
Aberrant expression of Notch1 interferes with the B-lymphoid phenotype of neoplastic B cells in classical Hodgkin lymphoma. Leukemia 2008; 22:1587-94. [PMID: 18449208 DOI: 10.1038/leu.2008.101] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Plasticity of committed mouse B cells has been demonstrated by inactivation of the B-cell commitment transcription factor PAX5, resulting in loss of the B-cell phenotype and differentiation into various hematopoietic lineages. Furthermore, mature mouse B cells could be reprogrammed into macrophages by overexpression of myeloid-specific transcription factors. Here, we report that aberrant activity of the transmembrane receptor, Notch1, interferes with the B-lymphoid phenotype of mature human germinal center-derived B cells in Hodgkin lymphoma, so called Hodgkin and Reed-Sternberg cells. They have lost the B-cell phenotype despite their mature B-cell origin. Notch1 remodels the B-cell transcription factor network by antagonizing the key transcription factors E2A and early B-cell factor (EBF). Through this mechanism, B lineage-specific genes were suppressed and B lineage-inappropriate genes were induced. We provide evidence that absence of the Notch inhibitor Deltex1 contributes to deregulated Notch activity in Hodgkin and Reed-Sternberg cells. These data suggest that Notch activation interferes with dedifferentiation of neoplastic B cells in Hodgkin lymphoma.
Collapse
|
40
|
Siemer D, Kurth J, Lang S, Lehnerdt G, Stanelle J, Küppers R. EBV transformation overrides gene expression patterns of B cell differentiation stages. Mol Immunol 2008; 45:3133-41. [PMID: 18430472 DOI: 10.1016/j.molimm.2008.03.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 03/03/2008] [Accepted: 03/06/2008] [Indexed: 01/25/2023]
Abstract
EBV-associated Hodgkin lymphoma (HL) and some post-transplant lymphoproliferative disease (PTLD) cases originate from pro-apoptotic germinal center (GC) B cells that have acquired destructive somatic Ig V gene mutations and were presumably rescued from apoptosis by EBV. To find out whether B cell receptor-crippled GC B cells acquire features of HL and/or PTLD cells upon EBV-infection and to reveal the impact of EBV on expression of B cell differentiation markers, we compared lymphoblastoid cell lines (LCLs) from GC B cells (including BCR-crippled GC-LCLs) to monoclonal LCLs from naïve B cells (N-LCLs). In addition, we analyzed the controversially discussed effect of EBV-infection on the GC B-cell-specific process of somatic hypermutation in vitro. Irrespective of their cellular origin, LCLs expressed CD20, CD30, CD38, AID, Pu.1, and with one exception Syk, but lacked expression of the GC B cell marker BCL-6. Interestingly, the T cell transcription factor GATA-3 that is aberrantly expressed in HL was induced in most GC-LCLs and the memory B cell marker CD27 was activated in N-LCLs. Remarkably, only 4 of 24 GC-LCLs showed significant somatic hypermutation activity, demonstrating that EBV usually silences hypermutation upon infection of GC B cells. Notably, one of three N-LCL showed a low level of intraclonal diversification. Thus, EBV-infection deregulates multiple differentiation factors and processes in B cells, leading to a largely homogenous phenotype of EBV-infected B cells in latency III.
Collapse
Affiliation(s)
- Dörte Siemer
- University of Duisburg-Essen, Medical School, Institute for Cell Biology (Tumor Research), Virchowst. 173, 45122 Essen, Germany.
| | | | | | | | | | | |
Collapse
|
41
|
Abstract
Multipotent blood progenitor cells enter the thymus and begin a protracted differentiation process in which they gradually acquire T-cell characteristics while shedding their legacy of developmental plasticity. Notch signalling and basic helix-loop-helix E-protein transcription factors collaborate repeatedly to trigger and sustain this process throughout the period leading up to T-cell lineage commitment. Nevertheless, the process is discontinuous with separately regulated steps that demand roles for additional collaborating factors. This Review discusses new evidence on the coordination of specification and commitment in the early T-cell pathway; effects of microenvironmental signals; the inheritance of stem-cell regulatory factors; and the ensemble of transcription factors that modulate the effects of Notch and E proteins, to distinguish individual stages and to polarize T-cell-lineage fate determination.
Collapse
|
42
|
Murre C. Epigenetics of antigen-receptor gene assembly. Curr Opin Genet Dev 2007; 17:415-21. [PMID: 17920858 PMCID: PMC2151926 DOI: 10.1016/j.gde.2007.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 07/17/2007] [Accepted: 08/17/2007] [Indexed: 02/05/2023]
Abstract
The antigen receptor genes are organized into distinct DNA elements that encode the variable (V), diversity (D) and joining (J) regions. It is now well established that the rearrangement of antigen receptor genes is regulated by developmental-specific modulation of chromatin structure. Further studies involving statistical mechanics should provide physical insight into the physical mechanisms that underlie the association of antigen receptor gene segments.
Collapse
Affiliation(s)
- Cornelis Murre
- Division of Biological Sciences, 03777, University of California, San Diego, La Jolla, CA 92093, United States.
| |
Collapse
|
43
|
Zhu X, Gui J, Dohkan J, Cheng L, Barnes PF, Su DM. Lymphohematopoietic progenitors do not have a synchronized defect with age-related thymic involution. Aging Cell 2007; 6:663-72. [PMID: 17681038 DOI: 10.1111/j.1474-9726.2007.00325.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
It has been speculated that aging lymphohematopoietic progenitor cells (LPC) including hematopoietic stem cells (HSC) and early T-cell progenitors (ETP) have intrinsic defects that trigger age-related thymic involution. However, using a different approach, we suggest that that is not the case. We provided a young thymic microenvironment to aged mice by transplanting a fetal thymus into the kidney capsule of aged animals, and demonstrated that old mouse-derived LPCs could re-establish normal thymic lymphopoiesis and all thymocyte subpopulations, including ETPs, double negative subsets, double positive, and CD4(+) and CD8(+) single positive T cells. LPCs derived from aged mice could turn over young RAG(-/-) thymic architecture by interactions, as well as elevate percentage of peripheral CD4(+)IL-2(+) T cells in response to costimulator in aged mice. Conversely, intrathymic injection of ETPs sorted from young animals into old mice did not restore normal thymic lymphopoiesis, implying that a shortage and/or defect of ETPs in aged thymus do not account for age-related thymic involution. Together, our findings suggest that the underlying cause of age-related thymic involution results primarily from changes in the thymic microenvironment, causing extrinsic, rather than intrinsic, defects in T-lymphocyte progenitors.
Collapse
Affiliation(s)
- Xike Zhu
- Department of Biomedical Research, University of Texas Health Center at Tyler, Tyler, TX 75708, USA
| | | | | | | | | | | |
Collapse
|
44
|
Rothenberg EV. Negotiation of the T lineage fate decision by transcription-factor interplay and microenvironmental signals. Immunity 2007; 26:690-702. [PMID: 17582342 DOI: 10.1016/j.immuni.2007.06.005] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Notch-Delta signaling of hematopoietic precursors sets in motion a train of events that activates expression of T lineage genes. Even so, through many cell generations the pro-T cells remain uncommitted to the T cell fate, preserving alternative potentials as divergent as monocyte or dendritic cell fates. This plasticity can be explained by the tenacious expression of stem- and progenitor-associated regulatory genes in the cells, and by the combinatorial coding of T cell identity by factors that are not intrinsically T lineage specific in their spectra of activity. T lineage developmental success depends on precise temporal and quantitative regulation of these factors and on the continuing modulating influence of Notch-Delta signals that buffer the cells against mechanisms promoting non-T outcomes. An additional mechanism, still not fully defined, is required just prior to T cell receptor-mediated selection to end plasticity and make T lineage commitment irreversible.
Collapse
Affiliation(s)
- Ellen V Rothenberg
- Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125, USA.
| |
Collapse
|
45
|
Tydell CC, David-Fung ES, Moore JE, Rowen L, Taghon T, Rothenberg EV. Molecular dissection of prethymic progenitor entry into the T lymphocyte developmental pathway. THE JOURNAL OF IMMUNOLOGY 2007; 179:421-38. [PMID: 17579063 DOI: 10.4049/jimmunol.179.1.421] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Notch signaling activates T lineage differentiation from hemopoietic progenitors, but relatively few regulators that initiate this program have been identified, e.g., GATA3 and T cell factor-1 (TCF-1) (gene name Tcf7). To identify additional regulators of T cell specification, a cDNA library from mouse Pro-T cells was screened for genes that are specifically up-regulated in intrathymic T cell precursors as compared with myeloid progenitors. Over 90 genes of interest were identified, and 35 of 44 tested were confirmed to be more highly expressed in T lineage precursors relative to precursors of B and/or myeloid lineage. To a remarkable extent, however, expression of these T lineage-enriched genes, including zinc finger transcription factor, helicase, and signaling adaptor genes, was also shared by stem cells (Lin(-)Sca-1(+)Kit(+)CD27(-)) and multipotent progenitors (Lin(-)Sca-1(+)Kit(+)CD27(+)), although down-regulated in other lineages. Thus, a major fraction of these early T lineage genes are a regulatory legacy from stem cells. The few genes sharply up-regulated between multipotent progenitors and Pro-T cell stages included those encoding transcription factors Bcl11b, TCF-1 (Tcf7), and HEBalt, Notch target Deltex1, Deltex3L, Fkbp5, Eva1, and Tmem131. Like GATA3 and Deltex1, Bcl11b, Fkbp5, and Eva1 were dependent on Notch/Delta signaling for induction in fetal liver precursors, but only Bcl11b and HEBalt were up-regulated between the first two stages of intrathymic T cell development (double negative 1 and double negative 2) corresponding to T lineage specification. Bcl11b was uniquely T lineage restricted and induced by Notch/Delta signaling specifically upon entry into the T lineage differentiation pathway.
Collapse
Affiliation(s)
- C Chace Tydell
- Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA
| | | | | | | | | | | |
Collapse
|
46
|
|
47
|
Amsen D, Antov A, Jankovic D, Sher A, Radtke F, Souabni A, Busslinger M, McCright B, Gridley T, Flavell RA. Direct regulation of Gata3 expression determines the T helper differentiation potential of Notch. Immunity 2007; 27:89-99. [PMID: 17658279 PMCID: PMC2062505 DOI: 10.1016/j.immuni.2007.05.021] [Citation(s) in RCA: 312] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Revised: 02/26/2007] [Accepted: 05/23/2007] [Indexed: 12/30/2022]
Abstract
CD4(+) T helper cells differentiate into T helper 1 (Th1) or Th2 effector lineages, which orchestrate immunity to different types of microbes. Both Th1 and Th2 differentiation can be induced by Notch, but what dictates which of these programs is activated in response to Notch is not known. By using T cell-specific gene ablation of the Notch effector RBP-J or the Notch1 and 2 receptors, we showed here that Notch was required on CD4(+) T cells for physiological Th2 responses to parasite antigens. GATA-3 was necessary for Notch-induced Th2 differentiation, and we identified an upstream Gata3 promoter as a direct target for Notch signaling. Moreover, absence of GATA-3 turned Notch from a Th2 inducer into a powerful inducer of Th1 differentiation. Therefore, Gata3 is a critical element determining inductive Th2 differentiation and limiting Th1 differentiation by Notch.
Collapse
Affiliation(s)
- Derk Amsen
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Fang TC, Yashiro-Ohtani Y, Del Bianco C, Knoblock DM, Blacklow SC, Pear WS. Notch directly regulates Gata3 expression during T helper 2 cell differentiation. Immunity 2007; 27:100-10. [PMID: 17658278 PMCID: PMC2801546 DOI: 10.1016/j.immuni.2007.04.018] [Citation(s) in RCA: 299] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 03/29/2007] [Accepted: 04/27/2007] [Indexed: 12/14/2022]
Abstract
Notch signaling plays multiple roles to direct diverse decisions regarding cell fate during T cell development. During helper T (Th) cell differentiation, Notch is involved in generating optimal Th2 cell responses. Here, we present data investigating how Notch mediates Th2 cell differentiation. Notch showed a CD4(+) T cell intrinsic role in promoting IL-4 expression that required GATA-3. In the absence of Notch signals, Gata3 expression was markedly diminished. Introduction of an activated allele of Notch1 into CD4(+) T cells led to the specific and direct upregulation of a developmentally regulated Gata3 transcript that included the exon 1a sequences. Furthermore, Notch acted in parallel with GATA-3 to synergistically activate IL-4 expression. Together, these data implicate Gata3 as a direct transcriptional Notch target that acts in concert with Notch signaling to generate optimal Th2 cell responses.
Collapse
Affiliation(s)
- Terry C. Fang
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yumi Yashiro-Ohtani
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Cristina Del Bianco
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Dawson M. Knoblock
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephen C. Blacklow
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Warren S. Pear
- Department of Pathology and Laboratory Medicine, Abramson Family Cancer Research Institute, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
- Correspondence:
| |
Collapse
|
49
|
Abstract
This special issue highlights a pivotal set of regulatory molecules that have emerged as central controllers of cell-type identity in the immune system. Each in its own way has been considered as a kind of 'master' regulator of a particular cell fate choice, but the actual modes of action of these factors vary widely. The comparison among them sheds light on the different ways that an essential regulatory input can affect cellular identity.
Collapse
Affiliation(s)
- Ellen V Rothenberg
- Division of Biology, 156-29, California Institute of Technology, Pasadena, California 91125, USA.
| |
Collapse
|
50
|
Cobaleda C, Schebesta A, Delogu A, Busslinger M. Pax5: the guardian of B cell identity and function. Nat Immunol 2007; 8:463-70. [PMID: 17440452 DOI: 10.1038/ni1454] [Citation(s) in RCA: 463] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The transcription factor Pax5 is essential for commitment of lymphoid progenitors to the B lymphocyte lineage. Pax5 fulfils a dual role by repressing B lineage 'inappropriate' genes and simultaneously activating B lineage-specific genes. This transcriptional reprogramming restricts the broad signaling capacity of uncommitted progenitors to the B cell pathway, regulates cell adhesion and migration, induces V(H)-DJ(H) recombination, facilitates (pre-)B cell receptor signaling and promotes development to the mature B cell stage. Conditional Pax5 inactivation in early and late B lymphocytes revealed an essential role for Pax5 in controlling the identity and function of B cells throughout B lymphopoiesis. PAX5 has also been implicated in human B cell malignancies, as it is deregulated by chromosomal translocations in a subset of acute lymphoblastic leukemias and non-Hodgkin lymphomas.
Collapse
Affiliation(s)
- César Cobaleda
- Research Institute of Molecular Pathology, Vienna Biocenter, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria
| | | | | | | |
Collapse
|