1
|
Garcia-Perez L, Famili F, Cordes M, Brugman M, van Eggermond M, Wu H, Chouaref J, Granado DSL, Tiemessen MM, Pike-Overzet K, Daxinger L, Staal FJT. Functional definition of a transcription factor hierarchy regulating T cell lineage commitment. SCIENCE ADVANCES 2020; 6:eaaw7313. [PMID: 32789164 PMCID: PMC7400773 DOI: 10.1126/sciadv.aaw7313] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 06/17/2020] [Indexed: 05/02/2023]
Abstract
T cell factor 1 (Tcf1) is the first T cell-specific protein induced by Notch signaling in the thymus, leading to the activation of two major target genes, Gata3 and Bcl11b. Tcf1 deficiency results in partial arrests in T cell development, high apoptosis, and increased development of B and myeloid cells. Phenotypically, seemingly fully T cell-committed thymocytes with Tcf1 deficiency have promiscuous gene expression and an altered epigenetic profile and can dedifferentiate into more immature thymocytes and non-T cells. Restoring Bcl11b expression in Tcf1-deficient cells rescues T cell development but does not strongly suppress the development of non-T cells; in contrast, expressing Gata3 suppresses their development but does not rescue T cell development. Thus, T cell development is controlled by a minimal transcription factor network involving Notch signaling, Tcf1, and the subsequent division of labor between Bcl11b and Gata3, thereby ensuring a properly regulated T cell gene expression program.
Collapse
Affiliation(s)
- Laura Garcia-Perez
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Farbod Famili
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Martijn Cordes
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Martijn Brugman
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Marja van Eggermond
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Haoyu Wu
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Jihed Chouaref
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | | | | | - Karin Pike-Overzet
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| | - Lucia Daxinger
- Department of Human Genetics, Leiden University Medical Center, Leiden, Netherlands
| | - Frank J. T. Staal
- Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, Netherlands
| |
Collapse
|
2
|
Malleske DT, Hayes D, Lallier SW, Hill CL, Reynolds SD. Regulation of Human Airway Epithelial Tissue Stem Cell Differentiation by β-Catenin, P300, and CBP. Stem Cells 2018; 36:1905-1916. [PMID: 30171668 DOI: 10.1002/stem.2906] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/10/2018] [Accepted: 08/18/2018] [Indexed: 12/22/2022]
Abstract
The wingless/integrase-1 (WNT)/β-catenin signaling pathway is active in several chronic lung diseases including idiopathic pulmonary fibrosis, asthma, and chronic obstructive pulmonary disease. Although this WNT/β-catenin pathway activity is associated with an increase in mucus cell frequency and a decrease in ciliated cell frequency, a cause and consequence relationship between signaling and cell frequency has not been established. We previously demonstrated that genetic stabilization of β-catenin inhibited differentiation of mouse bronchiolar tissue stem cells (TSC). This study determined the effect of β-catenin and its co-factors P300 (E1A-binding protein, 300 kDa) and cAMP response element binding (CREB)-binding protein (CBP) on human bronchial epithelial TSC differentiation to mucus and ciliated cells. We developed a modified air-liquid interface (ALI) culture system in which mucus and ciliated cell frequency is similar. These cultures were treated with the β-catenin agonist CHIR99021 (CHIR) and antagonists to β-catenin (XAV939), P300 (IQ1), and CBP (ICG001). We report that human TSC differentiation to mucus and ciliated cells can be divided into two stages, specification and commitment. CHIR treatment inhibited mucus and ciliated cell commitment while XAV939 treatment demonstrated that β-catenin was necessary for mucus and ciliated cell specification. Additional studies demonstrate that a β-catenin/P300 complex promotes mucus cell specification and that β-catenin interacts with either P300 or CBP to inhibit ciliated cell commitment. These data indicate that activation of β-catenin-dependent signaling in chronic lung disease leads to changes in mucus and ciliated cell frequency and that P300 and CBP tune the β-catenin signal to favor mucus cell differentiation. Stem Cells 2018;36:1905-12.
Collapse
Affiliation(s)
- Daniel T Malleske
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Don Hayes
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA.,Department of Surgery, The Ohio State University, Columbus, Ohio, USA
| | - Scott W Lallier
- Centers for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Cynthia L Hill
- Centers for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio, USA
| | - Susan D Reynolds
- Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA.,Centers for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio, USA
| |
Collapse
|
3
|
Hosokawa H, Rothenberg EV. Cytokines, Transcription Factors, and the Initiation of T-Cell Development. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a028621. [PMID: 28716889 DOI: 10.1101/cshperspect.a028621] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Multipotent blood progenitor cells migrate into the thymus and initiate the T-cell differentiation program. T-cell progenitor cells gradually acquire T-cell characteristics while shedding their multipotentiality for alternative fates. This process is supported by extracellular signaling molecules, including Notch ligands and cytokines, provided by the thymic microenvironment. T-cell development is associated with dynamic change of gene regulatory networks of transcription factors, which interact with these environmental signals. Together with Notch or pre-T-cell-receptor (TCR) signaling, cytokines always control proliferation, survival, and differentiation of early T cells, but little is known regarding their cross talk with transcription factors. However, recent results suggest ways that cytokines expressed in distinct intrathymic niches can specifically modulate key transcription factors. This review discusses how stage-specific roles of cytokines and transcription factors can jointly guide development of early T cells.
Collapse
Affiliation(s)
- Hiroyuki Hosokawa
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| | - Ellen V Rothenberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125
| |
Collapse
|
4
|
Multiplexed imaging of intracellular protein networks. Cytometry A 2016; 89:761-75. [DOI: 10.1002/cyto.a.22876] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 04/21/2016] [Accepted: 04/26/2016] [Indexed: 12/19/2022]
|
5
|
ZNF423 and ZNF521: EBF1 Antagonists of Potential Relevance in B-Lymphoid Malignancies. BIOMED RESEARCH INTERNATIONAL 2015; 2015:165238. [PMID: 26788497 PMCID: PMC4695665 DOI: 10.1155/2015/165238] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 11/25/2015] [Indexed: 12/26/2022]
Abstract
The development of the B-lymphoid cell lineage is tightly controlled by the concerted action of a network of transcriptional and epigenetic regulators. EBF1, a central component of this network, is essential for B-lymphoid specification and commitment as well as for the maintenance of the B-cell identity. Genetic alterations causing loss of function of these B-lymphopoiesis regulators have been implicated in the pathogenesis of B-lymphoid malignancies, with particular regard to B-cell acute lymphoblastic leukaemias (B-ALLs), where their presence is frequently detected. The activity of the B-cell regulatory network may also be disrupted by the aberrant expression of inhibitory molecules. In particular, two multi-zinc finger transcription cofactors named ZNF423 and ZNF521 have been characterised as potent inhibitors of EBF1 and are emerging as potentially relevant contributors to the development of B-cell leukaemias. Here we will briefly review the current knowledge of these factors and discuss the importance of their functional cross talk with EBF1 in the development of B-cell malignancies.
Collapse
|
6
|
Tenedini E, Roncaglia E, Ferrari F, Orlandi C, Bianchi E, Bicciato S, Tagliafico E, Ferrari S. Integrated analysis of microRNA and mRNA expression profiles in physiological myelopoiesis: role of hsa-mir-299-5p in CD34+ progenitor cells commitment. Cell Death Dis 2011; 1:e28. [PMID: 21364636 PMCID: PMC3032330 DOI: 10.1038/cddis.2010.5] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Hematopoiesis entails a series of hierarchically organized events that proceed throughout cell specification and terminates with cell differentiation. Commitment needs the transcription factors' effort, which, in concert with microRNAs, drives cell fate and responds to promiscuous patterns of gene expression by turning on lineage-specific genes and repressing alternate lineage transcripts. We obtained microRNA profiles from human CD34+ hematopoietic progenitor cells and in vitro differentiated erythroblasts, megakaryoblasts, monoblasts and myeloblast precursors that we analyzed together with their gene expression profiles. The integrated analysis of microRNA-mRNA expression levels highlighted an inverse correlation between microRNAs specifically upregulated in one single-cell progeny and their putative target genes, which resulted in downregulation. Among the upregulated lineage-enriched microRNAs, hsa-miR-299-5p emerged as having a role in controlling CD34+ progenitor fate, grown in multilineage culture conditions. Gain- and loss-of-function experiments revealed that hsa-miR-299-5p participates in the regulation of hematopoietic progenitor fate, modulating megakaryocytic-granulocytic versus erythroid-monocytic differentiation.
Collapse
Affiliation(s)
- E Tenedini
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Xiong Y, Bosselut R. The enigma of CD4-lineage specification. Eur J Immunol 2011; 41:568-74. [PMID: 21341258 PMCID: PMC3388806 DOI: 10.1002/eji.201041098] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 11/10/2010] [Accepted: 12/15/2010] [Indexed: 01/20/2023]
Abstract
CD4(+) T cells are essential for defenses against pathogens and affect the functions of most cells involved in the immune response. Although CD4(+) T cells generally recognize peptide antigens bound to MHC-II molecules, important subsets are restricted by other MHC or MHC-like molecules, including CD1d-restricted "invariant" iNK T cells. This review discusses recently identified nodes in the transcriptional circuits that are involved in controlling CD4(+) T-cell differentiation, notably the commitment factor Thpok and its interplay with Runx transcriptional regulators, and focuses on how transcription factors acting upstream of Thpok, including Gata3, Tox and E-box proteins, promote the emergence of CD4-lineage-specific gene expression patterns.
Collapse
Affiliation(s)
- Yumei Xiong
- Laboratory of Immune Cell Biology, Center for Cancer Research (CCR), NCI, NIH, Bethesda, MD 20892-4259, USA
| | | |
Collapse
|
8
|
Kupffer cells support extramedullary erythropoiesis induced by nitrogen-containing bisphosphonate in splenectomized mice. Cell Immunol 2011; 271:197-204. [DOI: 10.1016/j.cellimm.2011.06.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 05/28/2011] [Accepted: 06/28/2011] [Indexed: 11/20/2022]
|
9
|
Braunstein M, Anderson MK. Developmental progression of fetal HEB(-/-) precursors to the pre-T-cell stage is restored by HEBAlt. Eur J Immunol 2010; 40:3173-82. [PMID: 21061441 DOI: 10.1002/eji.201040360] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 08/12/2010] [Accepted: 08/20/2010] [Indexed: 02/06/2023]
Abstract
Gene knockout studies have shown that the E-protein transcription factor HEB is required for normal thymocyte development. We have identified a unique form of HEB, called HEBAlt, which is expressed only during the early stages of T-cell development, whereas HEBCan is expressed throughout T-cell development. Here, we show that HEB(-/-) precursors are inhibited at the β-selection checkpoint of T-cell development due to impaired expression of pTα and function of CD3ε, both of which are necessary for pre-TCR signaling. Transgenic expression of HEBAlt in HEB(-/-) precursors, however, upregulated pTα and allowed development to CD4(+) CD8(+) stage in fetal thymocytes. Moreover, HEBAlt did overcome the CD3ε signaling defect in HEB(-/-) Rag-1(-/-) thymocytes. The HEBAlt transgene did not permit Rag-1(-/-) precursors to bypass β-selection, indicating that it was not acting as a dominant negative inhibitor of other E-proteins. Therefore, our results provide the first mechanistic evidence that HEBAlt plays a critical role in early T-cell development and show that it can collaborate with fetal thymic stromal elements to create a regulatory environment that supports T-cell development past the β-selection checkpoint.
Collapse
Affiliation(s)
- Marsela Braunstein
- Sunnybrook Health Sciences Centre and Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | | |
Collapse
|
10
|
Mohamed AA, Tan SH, Mikhalkevich N, Ponniah S, Vasioukhin V, Bieberich CJ, Sesterhenn IA, Dobi A, Srivastava S, Sreenath TL. Ets family protein, erg expression in developing and adult mouse tissues by a highly specific monoclonal antibody. J Cancer 2010; 1:197-208. [PMID: 21060730 PMCID: PMC2974237 DOI: 10.7150/jca.1.197] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 10/24/2010] [Indexed: 12/03/2022] Open
Abstract
Oncogenic activation of the ETS Related Gene (ERG) in humans was originally identified in subsets of Ewing sarcomas, myeloid leukemias and, recently, in the majority of prostate cancers. Expression of human ERG protein and consequently its functions in normal and disease states needs to be better understood in light of its suggested role in cell differentiation and proliferation. Here, we analyzed temporal and spatial expression of the Erg (mouse protein) by immunohistochemical analysis during mouse embryonic and adult organogenesis using a highly specific ERG monoclonal antibody (ERG MAb). This study establishes widespread immunolocalization of Erg protein in endothelial cells and restricted expression in precartilage and hematopoietic tissues. Intriguingly, Erg is not expressed in any epithelial tissue including prostate epithelium, or in infiltrating lymphocytes that are occasionally seen in the prostate environment, a common site of tumors with ERG rearrangements and unscheduled ERG expression. These findings will further aid in investigations of Erg functions in normal and disease conditions.
Collapse
Affiliation(s)
- Ahmed A Mohamed
- 1. Center For Prostate Disease Research, Department of Surgery, United States Military Cancer Institute, Uniformed Services University of the Health Sciences, Bethesda MD 20814, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Wang L, Bosselut R. CD4-CD8 lineage differentiation: Thpok-ing into the nucleus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2009; 183:2903-10. [PMID: 19696430 PMCID: PMC3387994 DOI: 10.4049/jimmunol.0901041] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The mature alphabeta T cell population is divided into two main lineages that are defined by the mutually exclusive expression of CD4 and CD8 surface molecules (coreceptors) and that differ in their MHC restriction and function. CD4 T cells are typically MHC-II restricted and helper (or regulatory), whereas CD8 T cells are typically cytotoxic. Several transcription factors are known to control the emergence of CD4 and CD8 lineages, including the zinc finger proteins Thpok and Gata3, which are required for CD4 lineage differentiation, and the Runx factors Runx1 and Runx3, which contribute to CD8 lineage differentiation. This review summarizes recent advances on the function of these transcription factors in lineage differentiation. We also discuss how the "circuitry" connecting these factors could operate to match the expression of the lineage-committing factors Thpok and Runx3, and therefore lineage differentiation, to MHC specificity.
Collapse
Affiliation(s)
- Lie Wang
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4259, USA
| | | |
Collapse
|
12
|
Abstract
The innate or natural immunity is the basis and key for all immune processes. Specific receptors on macrophages, dendrites, NK cells and natural antibodies producing B cells act as a first line defense and remove all 'foreign' and potentially harmful substances, that is, bacteria, viruses, cellular waste, modified molecules and, most importantly, cancer cells. Recognition and removal of transformed cells is a lifelong task of immune surveillance processes. Antibodies are hallmark components of this anti-cancer activity. To investigate their nature, specificity, and function, we used the human hybridoma technology for isolating antibodies from cancer patients. These were then tested with a panel of assays against cancer cell lines in vitro and in vivo. Interestingly, all the tumor-specific antibodies we found were germ-line coded and belonged nearly exclusively to the IgM class. Furthermore, they all bound to new carbohydrates on post-translationally modified cell surface receptors on malignant cells. So far no affinity maturated immunoglobulins detecting tumor-specific peptides were found. However, only the presentation of peptide motifs can create an immunological memory. In general malignant cells are detected at very early precursor stages and manifest tumors can be considered as exceptional events. In addition, malignant cells are neither infectious nor hide intracellularly like viruses and some bacteria. Therefore, it makes sense that anti-tumor immunity seems to be solely a part of the natural immunity and a memory is not needed and therefore not induced. This indicates that the tumor immunity seems to be restricted to innate immune mechanisms and the instruments used by nature, like natural antibodies, are obviously excellent therapeutics.
Collapse
|
13
|
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
|
14
|
Wang L, Wildt KF, Zhu J, Zhang X, Feigenbaum L, Tessarollo L, Paul WE, Fowlkes BJ, Bosselut R. Distinct functions for the transcription factors GATA-3 and ThPOK during intrathymic differentiation of CD4(+) T cells. Nat Immunol 2008; 9:1122-30. [PMID: 18776904 DOI: 10.1038/ni.1647] [Citation(s) in RCA: 166] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 07/23/2008] [Indexed: 12/11/2022]
Abstract
The transcription factors GATA-3 and ThPOK are required for intrathymic differentiation of CD4(+) T cells, but their precise functions in this process remain unclear. Here we show that, contrary to previous findings, Gata3 disruption blocked differentiation into the CD4(+) T cell lineage before commitment to the CD4(+) lineage and in some contexts permitted the 'redirection' of major histocompatibility complex class II-restricted thymocytes into the CD8(+) lineage. GATA-3 promoted ThPOK expression and bound to a region of the locus encoding ThPOK established as being critical for ThPOK expression. Finally, ThPOK promoted differentiation into the CD4(+) lineage in a way dependent on GATA-3 but inhibited differentiation into the CD8(+) lineage independently of GATA-3. We propose that GATA-3 acts as a specification factor for the CD4(+) lineage 'upstream' of the ThPOK-controlled CD4(+) commitment checkpoint.
Collapse
Affiliation(s)
- Lie Wang
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
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
|
16
|
Michie AM, Chan AC, Ciofani M, Carleton M, Lefebvre JM, He Y, Allman DM, Wiest DL, Zúñiga-Pflücker JC, Izon DJ. Constitutive Notch signalling promotes CD4 CD8 thymocyte differentiation in the absence of the pre-TCR complex, by mimicking pre-TCR signals. Int Immunol 2007; 19:1421-30. [PMID: 17981791 DOI: 10.1093/intimm/dxm113] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Notch1 signalling is essential for the commitment of multipotent lymphocyte precursors towards the alphabeta T-cell lineage and plays an important role in regulating beta-selection in CD4(-)CD8(-) double-negative (DN) thymocytes. However, the role played by Notch in promoting the development of CD4(+)CD8(+) double-positive (DP) thymocytes is poorly characterized. Here, we demonstrate that the introduction of a constitutively active Notch1 (ICN1) construct into RAG(-/-) lymphocyte precursors resulted in the generation of DP thymocytes in in vitro T-cell culture systems. Notably, developmental rescue was dependent not only on the presence of an intact Notch1 RAM domain but also on Delta-like signals, as ICN1-induced DP development in RAG(-/-) thymocytes occurred within an intact thymus or in OP9-DL1 co-cultures, but not in OP9-control co-cultures. Interestingly, ICN1 expression in SLP-76(-/-) precursors resulted in only a minimal developmental rescue to the immature CD8(+) single-positive stage, suggesting that Notch is utilizing the same signalling pathway as the pre-TCR complex. In support of this, ICN1 introduction resulted in the activation of the ERK-MAPK-signalling cascade in RAG(-/-) thymocytes. Taken together, these studies demonstrate that constitutive Notch signalling can bypass beta-selection during early T-cell development by inducing pre-TCR-like signals within a T-cell-promoting environment.
Collapse
Affiliation(s)
- Alison M Michie
- Division of Cancer Sciences and Molecular Pathology, Section of Experimental Haematology, Royal Infirmary, University of Glasgow, Glasgow, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
Immunity is not only responsible for recognition and elimination of infectious particles, but also for removal of cellular waste, modified self structures and transformed cells. Innate or natural immunity acts as a first line defense and is also the link to acquired immunity and memory. A striking phenomenon of immunity against malignant cells is that neither in animals nor in humans affinity-maturated tumor-specific IgG antibodies have been detected so far. All tumor-specific isolated antibodies were germ-line coded natural IgM antibodies. It's also a fact that these IgM's preferentially bind to carbohydrate epitopes on post-transcriptionally modified surface receptors and that they all induce a cancer-specific apoptosis, by triggering the intrinsic apoptotic pathway. From an evolutionary point of view, this makes sense because cancer cells are not infectious, so there is no need for memory. Natural IgMs bind to conservative structures because they are coded by a limited set of genes and they use apoptosis, the "clean" way of killing, to avoid inflammatory processes.
Collapse
Affiliation(s)
- H Peter Vollmers
- Institute of Pathology, University of Würzburg, Josef-Schneider-Str. 2, D-97080 Würzburg, Germany.
| | | |
Collapse
|
18
|
Besseyrias V, Fiorini E, Strobl LJ, Zimber-Strobl U, Dumortier A, Koch U, Arcangeli ML, Ezine S, Macdonald HR, Radtke F. Hierarchy of Notch-Delta interactions promoting T cell lineage commitment and maturation. ACTA ACUST UNITED AC 2007; 204:331-43. [PMID: 17261636 PMCID: PMC2118717 DOI: 10.1084/jem.20061442] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Notch1 (N1) receptor signaling is essential and sufficient for T cell development, and recently developed in vitro culture systems point to members of the Delta family as being the physiological N1 ligands. We explored the ability of Delta1 (DL1) and DL4 to induce T cell lineage commitment and/or maturation in vitro and in vivo from bone marrow (BM) precursors conditionally gene targeted for N1 and/or N2. In vitro DL1 can trigger T cell lineage commitment via either N1 or N2. N1- or N2-mediated T cell lineage commitment can also occur in the spleen after short-term BM transplantation. However, N2-DL1-mediated signaling does not allow further T cell maturation beyond the CD25(+) stage due to a lack of T cell receptor beta expression. In contrast to DL1, DL4 induces and supports T cell commitment and maturation in vitro and in vivo exclusively via specific interaction with N1. Moreover, comparative binding studies show preferential interaction of DL4 with N1, whereas binding of DL1 to N1 is weak. Interestingly, preferential N1-DL4 binding reflects reduced dependence of this interaction on Lunatic fringe, a glycosyl transferase that generally enhances the avidity of Notch receptors for Delta ligands. Collectively, our results establish a hierarchy of Notch-Delta interactions in which N1-DL4 exhibits the greatest capacity to induce and support T cell development.
Collapse
Affiliation(s)
- Valerie Besseyrias
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, 1066 Epalinges, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Serfling E, Chuvpilo S, Liu J, Höfer T, Palmetshofer A. NFATc1 autoregulation: a crucial step for cell-fate determination. Trends Immunol 2006; 27:461-9. [PMID: 16931157 DOI: 10.1016/j.it.2006.08.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 07/17/2006] [Accepted: 08/09/2006] [Indexed: 01/08/2023]
Abstract
Nuclear factor of activated T cell c (NFATc) transcription factors appeared in evolution with the emergence of lymphocytes in jawed fish. They have decisive roles in the development of the immune system and adaptive immune responses. Following immunoreceptor stimulation, NFAT factors control the expression of a large set of genes and thereby the fate of peripheral lymphocytes. NFATc1 and NFATc2 are the most prominent NFAT factors in peripheral T cells; they overlap in their function but differ remarkably in the mode of expression. NFATc2 is constitutively synthesized in T cells, whereas the expression of NFATc1/alphaA, the most prominent of six NFATc1 isoforms in peripheral T cells, is strongly induced following T-cell receptor and co-receptor stimulation and maintained by positive autoregulation. Findings concerning NFATc1 autoregulation in peripheral T lymphocytes and other cells suggest that positive autoregulation of NFATc1 is a crucial step in cell-fate determination.
Collapse
Affiliation(s)
- Edgar Serfling
- Department of Molecular Pathology, Institute of Pathology, University of Wuerzburg, D-97080 Wuerzburg, Germany.
| | | | | | | | | |
Collapse
|
20
|
Abstract
Deltex1, Deltex2, and Deltex4 form a family of related proteins that are the mammalian homologues of Drosophila Deltex, a known regulator of Notch signals. Deltex1 is highly induced by Notch signaling in thymocytes, and overexpression of Deltex1 in T-cell progenitors can block Notch signals, suggesting that Deltex1 may play an important role in regulating Notch signals during T-cell development. A recent report found that T cells develop normally in mice carrying a targeted deletion in the Deltex1 gene (S. Storck, F. Delbos, N. Stadler, C. Thirion-Delalande, F. Bernex, C. Verthuy, P. Ferrier, J. C. Weill, and C. A. Reynaud, Mol. Cell. Biol. 25: 1437-1445, 2005), suggesting that other Deltex homologues may compensate in Deltex1-deficient T cells. We generated mice that lack expression of both Deltex1 and Deltex2 by gene targeting and further reduced expression of Deltex4 in Deltex1/Deltex2 double-deficient T-cell progenitors using RNA interference. Using a sensitive in vitro assay, we found that Notch signaling is more potent in cells expressing lower levels of Deltex proteins. Nevertheless, we were unable to detect any significant defects in thymocyte maturation in Deltex1/Deltex2 double-knockout mice. Together these data suggest that Deltex can act as a negative regulator of Notch signals in T cells but that endogenous levels of Deltex1 and Deltex2 are not important for regulating Notch signals during thymocyte development.
Collapse
Affiliation(s)
- Sophie M Lehar
- Department of Immunology and Howard Hughes Medical Institute, University of Washington, I-604D Health Science Center, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | | |
Collapse
|
21
|
Vollmers HP, Brändlein S. Natural IgM antibodies: the orphaned molecules in immune surveillance. Adv Drug Deliv Rev 2006; 58:755-65. [PMID: 16820243 DOI: 10.1016/j.addr.2005.08.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Accepted: 05/06/2006] [Indexed: 12/21/2022]
Abstract
Natural IgM antibodies are typical victims of prejudices which originated in the mid 80 s. Over the years, these molecules were considered as the pariahs among the immune competent molecules and their characteristic properties, like low affinity, cross-reactivity and pentameric structure, were assessed as useless, difficult, nebulous, etc. Today, mainly based on a few scientists' persistent work and the key discoveries on innate immune recognition, natural IgM antibodies are "back on stage". Their role in the immune response against bacteria, viruses, fungi and possibly modified self-components as well as in therapy and diagnosis of malignancies is accepted. All the so far negatively judged features are seen in a different light, e.g. low affinity seems to be good for function and does not exclude specificity, and cross-reactivity is no longer judged as unspecific, but instead as a very economic way of immune recognition. And at last, with the use of natural IgM antibodies, a new field of tumor-specific targets has been encountered, the carbo-neo-epitopes. Therefore, by having learned from nature, the renaissance of natural IgM antibodies opens a new area of cancer therapeutics and diagnostics.
Collapse
Affiliation(s)
- H Peter Vollmers
- Institute for Pathology, University Würzburg, Josef-Schneider-Str. 2, D-97080 Würzburg, Germany.
| | | |
Collapse
|
22
|
Taghon T, Yui MA, Pant R, Diamond RA, Rothenberg EV. Developmental and molecular characterization of emerging beta- and gammadelta-selected pre-T cells in the adult mouse thymus. Immunity 2006; 24:53-64. [PMID: 16413923 DOI: 10.1016/j.immuni.2005.11.012] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 11/06/2005] [Accepted: 11/30/2005] [Indexed: 01/12/2023]
Abstract
The first checkpoint in T cell development, beta selection, has remained incompletely characterized for lack of specific surface markers. We show that CD27 is upregulated in DN3 thymocytes initiating beta selection, concomitant with intracellular TCR-beta expression. Clonal analysis determined that CD27high DN3 cells generate CD4+CD8+ progeny with more than 90% efficiency, faster and more efficiently than the CD27low majority. CD27 upregulation also occurs in gammadelta-selected DN3 thymocytes in TCR-beta-/- mice and in IL2-GFP transgenic reporter mice where GFP marks the earliest emerging TCR-gammadelta cells from DN3 thymocytes. With CD27 to distinguish pre- and postselection DN3 cells, a detailed gene expression analysis defined regulatory changes associated with checkpoint arrest, with beta selection, and with gammadelta selection. gammadelta selection induces higher CD5, Egr, and Runx3 expression as compared to beta selection, but it triggers less proliferation. Our results also reveal differences in Notch/Delta dependence at the earliest stages of divergence between developing alphabeta and gammadelta T-lineage cells.
Collapse
MESH Headings
- Animals
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- Cell Lineage/genetics
- Gene Expression Profiling
- Gene Expression Regulation, Developmental
- Interleukin-2/genetics
- Intracellular Signaling Peptides and Proteins
- Membrane Proteins/metabolism
- Mice
- Mice, Mutant Strains
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Receptors, Notch/metabolism
- Stem Cells/cytology
- Stem Cells/immunology
- Thymus Gland/cytology
- Thymus Gland/growth & development
- Transgenes
- Tumor Necrosis Factor Receptor Superfamily, Member 7/analysis
- Tumor Necrosis Factor Receptor Superfamily, Member 7/metabolism
- Up-Regulation
Collapse
Affiliation(s)
- Tom Taghon
- Division of Biology, MC 156-29, California Institute of Technology, 1200 E California Boulevard, Pasadena, California 91125, USA
| | | | | | | | | |
Collapse
|
23
|
Abstract
Gene expression, differentiation and the specialized function of various cell types are controlled epigenetically by post-translational histone modifications. These modifications establish a "histone code" that is recognized by various regulatory proteins, thereby creating a stable pattern of gene expression. The focus of this review is to discuss how the chromatin modifications regulate immunoglobulin gene rearrangement and B cell differentiation.
Collapse
Affiliation(s)
- I-hsin Su
- Laboratory of Lymphocyte Signalling, The Rockefeller University, 1230 York Avenue, Box 301, New York, NY 10021, USA.
| | | |
Collapse
|
24
|
Taghon TN, David ES, Zúñiga-Pflücker JC, Rothenberg EV. Delayed, asynchronous, and reversible T-lineage specification induced by Notch/Delta signaling. Genes Dev 2005; 19:965-78. [PMID: 15833919 PMCID: PMC1080135 DOI: 10.1101/gad.1298305] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Using the OP9-DL1 system to deliver temporally controlled Notch/Delta signaling, we show that pluripotent hematolymphoid progenitors undergo T-lineage specification and B-lineage inhibition in response to Notch signaling in a delayed and asynchronous way. Highly enriched progenitors from fetal liver require > or =3 d to begin B- or T-lineage differentiation. Clonal switch-culture analysis shows that progeny of some single cells can still generate both B- and T-lineage cells, after 1 wk of continuous delivery or deprivation of Notch/Delta signaling. Notch signaling induces T-cell genes and represses B-cell genes, but kinetics of activation of lineage-specific transcription factors are significantly delayed after induction of Notch target genes and can be temporally uncoupled from the Notch response. In the cells that initiate T-cell differentiation and gene expression most slowly in response to Notch/Delta signaling, Notch target genes are induced to the same level as in the cells that respond most rapidly. Early lineage-specific gene expression is also rapidly reversible in switch cultures. Thus, while necessary to induce and sustain T-cell development, Notch/Delta signaling is not sufficient for T-lineage specification and commitment, but instead can be permissive for the maintenance and proliferation of uncommitted progenitors that are omitted in binary-choice models.
Collapse
Affiliation(s)
- Tom N Taghon
- Division of Biology, California Institute of Technology, Pasadena, California 91125, USA
| | | | | | | |
Collapse
|
25
|
Abstract
T cell development is guided by a complex set of transcription factors that act recursively, in different combinations, at each of the developmental choice points from T-lineage specification to peripheral T cell specialization. This review describes the modes of action of the major T-lineage-defining transcription factors and the signal pathways that activate them during intrathymic differentiation from pluripotent precursors. Roles of Notch and its effector RBPSuh (CSL), GATA-3, E2A/HEB and Id proteins, c-Myb, TCF-1, and members of the Runx, Ets, and Ikaros families are critical. Less known transcription factors that are newly recognized as being required for T cell development at particular checkpoints are also described. The transcriptional regulation of T cell development is contrasted with that of B cell development, in terms of their different degrees of overlap with the stem-cell program and the different roles of key transcription factors in gene regulatory networks leading to lineage commitment.
Collapse
Affiliation(s)
- Ellen V Rothenberg
- Division of Biology, California Institute of Technology, Pasadena, California 91125, USA.
| | | |
Collapse
|
26
|
Cinquin O, Demongeot J. High-dimensional switches and the modelling of cellular differentiation. J Theor Biol 2004; 233:391-411. [PMID: 15652148 DOI: 10.1016/j.jtbi.2004.10.027] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2004] [Revised: 10/13/2004] [Accepted: 10/14/2004] [Indexed: 12/31/2022]
Abstract
Many genes have been identified as driving cellular differentiation, but because of their complex interactions, the understanding of their collective behaviour requires mathematical modelling. Intriguingly, it has been observed in numerous developmental contexts, and particularly haematopoiesis, that genes regulating differentiation are initially co-expressed in progenitors despite their antagonism, before one is upregulated and others downregulated. We characterise conditions under which three classes of generic "master regulatory networks", modelled at the molecular level after experimentally observed interactions (including bHLH protein dimerisation), and including an arbitrary number of antagonistic components, can behave as a "multi-switch", directing differentiation in an all-or-none fashion to a specific cell-type chosen among more than two possible outcomes. bHLH dimerisation networks can readily display coexistence of many antagonistic factors when competition is low (a simple characterisation is derived). Decision-making can be forced by a transient increase in competition, which could correspond to some unexplained experimental observations related to Id proteins; the speed of response varies with the initial conditions the network is subjected to, which could explain some aspects of cell behaviour upon reprogramming. The coexistence of antagonistic factors at low levels, early in the differentiation process or in pluripotent stem cells, could be an intrinsic property of the interaction between those factors, not requiring a specific regulatory system.
Collapse
Affiliation(s)
- Olivier Cinquin
- CoMPLEX, University College London, Gower Street, London WC1E 6BT, UK.
| | | |
Collapse
|
27
|
Lehar SM, Dooley J, Farr AG, Bevan MJ. Notch ligands Delta 1 and Jagged1 transmit distinct signals to T-cell precursors. Blood 2004; 105:1440-7. [PMID: 15486060 PMCID: PMC2776671 DOI: 10.1182/blood-2004-08-3257] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Signaling through the Notch pathway plays an essential role in inducing T-lineage commitment and promoting the maturation of immature thymocytes. Using an in vitro culture system, we show that 2 different classes of Notch ligands, Jagged1 or Delta1, transmit distinct signals to T-cell progenitors. OP9 stromal cells expressing either Jagged1 or Delta1 inhibit the differentiation of DN1 thymocytes into the B-cell lineage, but only the Delta1-expressing stromal cells promote the proliferation and maturation of T-cell progenitors through the early double-negative (DN) stages of thymocyte development. Whereas the majority of bone marrow-derived stem cells do not respond to Jagged1 signals, T-cell progenitors respond to Jagged1 signals during a brief window of their development between the DN1 and DN3 stages of thymic development. During these stages, Jagged1 signals can influence the differentiation of immature thymocytes along the natural killer (NK) and gamma delta T-cell lineages.
Collapse
Affiliation(s)
- Sophie M Lehar
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
| | | | | | | |
Collapse
|
28
|
Pohle T, Brändlein S, Ruoff N, Müller-Hermelink HK, Vollmers HP. Lipoptosis: tumor-specific cell death by antibody-induced intracellular lipid accumulation. Cancer Res 2004; 64:3900-6. [PMID: 15173000 DOI: 10.1158/0008-5472.can-03-3149] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A balanced lipid metabolism is crucial for all cells. Disturbance of this homeostasis by nonphysiological intracellular accumulation of fatty acids can result in apoptosis. This was proven in animal studies and was correlated to some human diseases, like lipotoxic cardiomyopathy. Some metabolic mechanisms of lipo-apoptosis were described, and some causes were discussed, but reagents, which directly induce lipo-apoptosis, have thus far not been identified. The human monoclonal IgM antibody SAM-6 was isolated from a stomach cancer patient by using the conventional human hybridoma technology (trioma technique). The addition of SAM-6 to tumor cells leads to an increase in the intracellular accumulation of neutral lipids, followed by tumor cell apoptosis. The antibody SAM-6 does not react with noncancerous human epithelial and fibroblastic cells, because the M(r) 140000 membrane molecule, recognized by the antibody, is specifically expressed on human malignant cells. The antibody is coded by the germ-line genes IgHV3-30.3*01 and IgLV3-1*01 and is a component of the innate immunity to cancer. In this article, we describe an antibody-induced tumor-specific cell death, named lipoptosis. This is, to our knowledge, the first description of this specific form of lipo-apoptosis as an antibody-mediated mechanism of tumor cell killing.
Collapse
Affiliation(s)
- Tina Pohle
- Institute of Pathology, University Würzburg, Würzburg, Germany
| | | | | | | | | |
Collapse
|
29
|
Pang K, Matus DQ, Martindale MQ. The ancestral role of COE genes may have been in chemoreception: evidence from the development of the sea anemone, Nematostella vectensis (Phylum Cnidaria; Class Anthozoa). Dev Genes Evol 2004; 214:134-8. [PMID: 14752662 DOI: 10.1007/s00427-004-0383-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2003] [Accepted: 11/29/2003] [Indexed: 11/26/2022]
Abstract
An orthologue of the COE family of helix-loop-helix transcription factors was recovered from the anthozoan Nematostella vectensis (Cnidaria). NvCOE has high sequence similarity to vertebrate and invertebrate orthologues in all three major functional domains of the protein. In situ hybridization studies show early expression through the cleavage period but transcripts are down regulated at gastrulation while remaining expressed at high levels only in the apical tuft of cilia at the aboral end of the planula larva. It is likely that one of the ancestral roles of the COE family of genes may have been in the development of chemosensory neurons.
Collapse
Affiliation(s)
- Kevin Pang
- Kewalo Marine Laboratory, Pacific Biomedical Research Center, University of Hawaii, 41 Ahui St., Honolulu, HI 96813, USA
| | | | | |
Collapse
|
30
|
Alcobia I, Quina AS, Neves H, Clode N, Parreira L. The spatial organization of centromeric heterochromatin during normal human lymphopoiesis: evidence for ontogenically determined spatial patterns. Exp Cell Res 2003; 290:358-69. [PMID: 14567993 DOI: 10.1016/s0014-4827(03)00335-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
It is believed that pericentromeric heterochromatin may play a major role in the epigenetic regulation of gene expression. We have previously shown that centromeres in human peripheral blood cells aggregate into distinct "myeloid" and "lymphoid" spatial patterns, suggesting that the three-dimensional organization of centromeric heterochromatin in interphase may be ontogenically determined during hematopoietic differentiation. To investigate this possibility, the spatial patterns of association of different centromeres were analyzed in hematopoietic progenitors and compared with those in early-B and early-T cells, mature B and T lymphocytes, and, additionally, mature granulocytes and monocytes. We show that those patterns change during lymphoid differentiation, with major spatial arrangements taking place at different stages during T and B cell differentiation. Heritable patterns of centromere association are observed, which can occur either at the level of the common lymphoid progenitor, or in early-T or early-B committed cells. A correlation of the observed patterns of centromere association with the gene content of the respective chromosomes further suggests that the variation in the composition of these heterochromatic structures may contribute to the dynamic relocation of genes in different nuclear compartments during cell differentiation, which might have functional implications for cell-stage-specific gene expression.
Collapse
Affiliation(s)
- Isabel Alcobia
- Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, 1649-028 Lisboa, Portugal
| | | | | | | | | |
Collapse
|
31
|
García-Peydró M, de Yébenes VG, Toribio ML. Sustained Notch1 signaling instructs the earliest human intrathymic precursors to adopt a gammadelta T-cell fate in fetal thymus organ culture. Blood 2003; 102:2444-51. [PMID: 12829602 DOI: 10.1182/blood-2002-10-3261] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Notch1 activity is essential for the specification of T-lineage fate in hematopoietic progenitors. Once the T-cell lineage is specified, T-cell precursors in the thymus must choose between alphabeta and gammadelta lineages. However, the impact of Notch1 signaling on intrathymic pro-T cells has not been addressed directly. To approach this issue, we used retroviral vectors to express constitutively active Notch1 in human thymocyte progenitors positioned at successive developmental stages, and we followed their differentiation in fetal thymus organ culture (FTOC). Here we show that sustained Notch1 signaling impairs progression to the double-positive (DP) stage and efficiently diverts the earliest thymic progenitors from the main alphabeta T-cell pathway toward development of gammadelta T cells. The impact of Notch1 signaling on skewed gammadelta production decreases progressively along intrathymic maturation and is restricted to precursor stages upstream of the pre-T-cell receptor checkpoint. Close to and beyond that point, Notch1 is not further able to instruct gammadelta cell fate, but promotes an abnormal expansion of alphabeta-committed thymocytes. These results stress the stage-specific impact of Notch1 signaling in intrathymic differentiation and suggest that regulation of Notch1 activity at defined developmental windows is essential to control alphabeta versus gammadelta T-cell development and to avoid deregulated expansion of alphabeta-lineage cells.
Collapse
MESH Headings
- Animals
- Antigens, CD34/analysis
- Cell Differentiation/immunology
- Cell Lineage/immunology
- Child, Preschool
- Fetus
- Flow Cytometry
- Gene Expression Regulation, Developmental/immunology
- Humans
- Infant
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Organ Culture Techniques
- Receptor, Notch1
- Receptors, Antigen, T-Cell, alpha-beta/analysis
- Receptors, Antigen, T-Cell, alpha-beta/physiology
- Receptors, Antigen, T-Cell, gamma-delta/analysis
- Receptors, Antigen, T-Cell, gamma-delta/physiology
- Receptors, Cell Surface
- Signal Transduction/immunology
- Stem Cells/chemistry
- Stem Cells/cytology
- Stem Cells/immunology
- Thymus Gland/cytology
- Thymus Gland/embryology
- Transcription Factors
Collapse
Affiliation(s)
- Marina García-Peydró
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain
| | | | | |
Collapse
|
32
|
Steidl U, Kronenwett R, Martin S, Haas R. Molecular biology of hematopoietic stem cells. VITAMINS AND HORMONES 2003; 66:1-28. [PMID: 12852251 DOI: 10.1016/s0083-6729(03)01001-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Human CD34+ hematopoietic stem and progenitor cells are capable of maintaining a life-long supply of the entire spectrum of blood cells dependent on systemic needs. Recent studies suggest that hematopoietic stem cells are, beyond their hematopoietic potential, able to differentiate into nonhematopoietic cell types, which could open novel avenues in the field of cellular therapy. Here, we concentrate on the molecular biology underlying basic features of hematopoietic stem cells. Immunofluorescence analyses, culture assays, and transplantation models permit an extensive immunological as well as functional characterization of human hematopoietic stem and progenitor cells. New methods such as cDNA array technology have demonstrated that distinct gene expression patterns of transcription factors and cell cycle genes molecularly control self-renewal, differentiation, and proliferation. Furthermore, several adhesion molecules have been shown to play an important role in the regulation of hematopoiesis and stem cell trafficking. Progress has also been made in elucidating molecular mechanisms of stem cell aging that limit replicative potential. Finally, more recent data provide the first molecular basis for a better understanding of transdifferentiation and developmental plasticity of hematopoietic stem cells. These findings could be helpful for non-hematopoietic cell therapeutic approaches.
Collapse
Affiliation(s)
- Ulrich Steidl
- Department of Hematology, Oncology, and Clinical Immunology, Heinrich Heine University of Düsseldorf, D-40225 Düsseldorf, Germany
| | | | | | | |
Collapse
|
33
|
Bouzin C, Clotman F, Renauld JC, Lemaigre FP, Rousseau GG. The onecut transcription factor hepatocyte nuclear factor-6 controls B lymphopoiesis in fetal liver. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:1297-303. [PMID: 12874218 DOI: 10.4049/jimmunol.171.3.1297] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mouse genetic models have helped to identify transcription factors that are expressed by hemopoietic cells and control their differentiation into lymphoid cells. However, little is known on transcription factors that are involved in this process, but are expressed in nonhemopoietic cells of the microenvironment. We show in this study that inactivation of the gene coding for hepatocyte nuclear factor-6 (HNF-6) in mice led to B lymphopenia in the bone marrow and spleen. This phenotype disappeared shortly after birth when fetal B lymphopoiesis is no longer active, pointing to a defect in fetal liver. Indeed, the number of B cells was decreased in this organ as well. An analysis of B cell developmental markers in fetal liver cells showed that B lymphopoiesis was impaired just beyond the pre-pro B cell stage. Hemopoietic cells from hnf6(-/-) fetal liver could reconstitute the lymphoid system when injected into scid mice. Because parenchymal cells, but not hemopoietic cells, expressed hnf6 in normal liver, we concluded that HNF-6 controls B lymphopoiesis in fetal liver and that HNF-6 exerts this control indirectly by acting in parenchymal cells. The involvement, in the B cell defect of hnf6(-/-) fetuses, of genes known to exert such an indirect control was ruled out by expression analysis, including microarrays, and by in vivo rescue experiments. This work identifies HNF-6 as the first noncell-intrinsic transcription factor known to control B lymphopoiesis specifically in fetal liver.
Collapse
Affiliation(s)
- Caroline Bouzin
- Hormone and Metabolic Research Unit, Université Catholique de Louvain and Institute of Cellular Pathology, Brussels, Belgium
| | | | | | | | | |
Collapse
|
34
|
Akashi K, He X, Chen J, Iwasaki H, Niu C, Steenhard B, Zhang J, Haug J, Li L. Transcriptional accessibility for genes of multiple tissues and hematopoietic lineages is hierarchically controlled during early hematopoiesis. Blood 2003; 101:383-9. [PMID: 12393558 DOI: 10.1182/blood-2002-06-1780] [Citation(s) in RCA: 305] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Hematopoietic stem cells (HSCs) maintain hematopoiesis by giving rise to all types of blood cells. Recent reports suggest that HSCs also possess the potential to generate nonhematopoietic tissues. To evaluate the underlying mechanisms in the commitment of HSCs into multitissue and multihematopoietic lineages, we performed oligonucleotide array analyses targeting for prospectively purified HSCs, multipotent progenitors (MPPs), common lymphoid progenitors (CLPs), and common myeloid progenitors (CMPs). Here we show that HSCs coexpress multiple nonhematopoietic genes as well as hematopoietic genes; MPPs coexpress myeloid and lymphoid genes; CMPs coexpress myeloerythroid, but not lymphoid genes, whereas CLPs coexpress T-, B-, and natural killer-lymphoid, but not myeloid, genes. Thus, the stepwise decrease in transcriptional accessibility for multilineage-affiliated genes may represent progressive restriction of developmental potentials in early hematopoiesis. These data support the hypothesis that stem cells possess a wide-open chromatin structure to maintain their multipotentiality, which is progressively quenched as they go down a particular pathway of differentiation.
Collapse
Affiliation(s)
- Koichi Akashi
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
The T cell compartment is continuously replenished by a renewable source of stem cells. In the adult, bone marrow-derived stem cells seed the thymus and initiate a developmental program that requires a series of incompletely understood signals that are normally provided by the thymus. Failure to recapitulate this process in simple in vitro cultures has hampered efforts to fully characterize these unique signals. In this issue of Immunity, Schmitt and Zúñiga-Pflücker describe a simple in vitro culture system that is able to generate mature T cells from fetal liver stem cells by expressing the Notch ligand Delta-1 on the OP9 stromal cell line. This finding should greatly enhance efforts to study T cell development and may provide a tool for generating defined T cell populations in vitro.
Collapse
Affiliation(s)
- Sophie M Lehar
- Department of Immunology and Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
| | | |
Collapse
|
36
|
Abstract
T lymphocytes originate from pluripotent precursors and undergo lasting commitment to the T cell developmental fate during their processing in the thymus. Commitment includes both the acquisition of essential T cell characteristics and the foreclosing of other developmental options. Gain of T cell characteristics is probably mediated by separate mechanisms, at least in detail, from loss of alternative developmental potentials. Programmed shifts in survival requirements make changes irreversible. Here we review the current evidence identifying the regulatory components of this commitment pathway, and the first hints of how they work together. Roles for PU.1, GATA-3, and their target genes are highlighted.
Collapse
Affiliation(s)
- Ellen V Rothenberg
- Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125, USA.
| |
Collapse
|
37
|
Philippoussis F, Arguin C, Fortin M, Steff AM, Hugo P. Cellular specificity related to monoglyceride-induced cell death. Immunol Lett 2002; 83:221-30. [PMID: 12095713 DOI: 10.1016/s0165-2478(02)00117-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We have recently observed that monoglycerides (MGs), a family of lipids consisting of a single fatty acid moiety attached to a glycerol backbone, induce rapid dose-dependent apoptosis in murine thymocytes. In this work, we evaluated the sensitivity of various normal and malignant immune and non-immune cells to MGs. We demonstrate that the propensity to MG-induced death displayed by both T and B lymphocytes is clearly modulated according to their differentiation and activation status. For instance, the earliest T and B cell precursors are refractory to MG-mediated cell death. In the T-cell lineage, immature thymocytes are the most susceptible to MG treatment, while B cells from peripheral lymphoid organs appear more sensitive than B-cell subsets from the bone marrow. On the other hand, both activated T and B cells are more resistant to MG exposure than their non-activated counterparts. In addition, other hematopoietic lineages such as natural killer cells, macrophages, and erythroid cells are quite resistant to MG-induced death. Furthermore, using various immortalized cell lines from different tissues, we found that lymphomas and thymomas are the most sensitive among all lineages tested, while epithelial cells and fibroblasts are unaffected by MG treatment. Finally, MG-induced death was shown to be independent of Fas/Fas ligand (FasL) interactions. Altogether, our findings indicate that there is a cellular specificity related to MG-mediated cell death biased towards T and B lymphocytes. This suggests that MGs could potentially be used in the treatment of specific lymphoid disorders by bypassing the requirement for the Fas/FasL system.
Collapse
Affiliation(s)
- Fabianne Philippoussis
- PROCREA BioSciences Inc., Division of Research & Development, 6100 Royalmount, Montreal, Quebec, Canada H4P 2R2
| | | | | | | | | |
Collapse
|
38
|
Abstract
The earliest stages of intrathymic T-cell development include not only the acquisition of T-cell characteristics but also programmed loss of potentials for B, natural killer, and dendritic cell development. Evidence from genetics and cell-transfer studies suggests an order and some components of the mechanisms involved in loss of these options, but some of the interpretations conflict. The conflicts can be resolved by a view that postulates overlapping windows of developmental opportunity and individual mechanisms regulating progression along each pathway. This view is consistent with molecular evidence for the expression patterns of positive regulators of non-T developmental pathways, SCL, PU.1 and Id2, in early thymocytes. To some extent, overexpression of such regulators redirects thymocyte development in vitro. Specific commitment functions may normally terminate this developmental plasticity. Both PU.1 overexpression and stimulation of ectopically expressed growth factor receptors can perturb T- and myeloid/dendritic-cell divergence, but only in permissive stages. A cell-line system that approximates DN3-stage thymocytes reveals that PU.1 can alter specification even in a homogeneous population. However, the response of the population to PU.1 is sharply discontinuous. These studies show a critical role for regulatory context in restricting plasticity, which is probably maintained by interacting transcription factor networks.
Collapse
Affiliation(s)
- Ellen V Rothenberg
- Division of Biology, 156-29, California Institute of Technology, Pasadena, CA 91125, USA.
| | | |
Collapse
|
39
|
French SW, Hoyer KK, Shen RR, Teitell MA. Transdifferentiation and nuclear reprogramming in hematopoietic development and neoplasia. Immunol Rev 2002; 187:22-39. [PMID: 12366680 DOI: 10.1034/j.1600-065x.2002.18703.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cell transplantation and tissue regeneration studies indicate a surprisingly broad developmental potential for lineage-committed hematopoietic stem cells (HSCs). Under these conditions HSCs transition into myocytes, neurons, hepatocytes or other types of nonhematopoietic effector cells. Equally impressive is the progression of committed neuronal stem cells (NSCs) to functional blood elements. Although critical cell-of-origin issues remain unresolved, the possibility of lineage switching is strengthened by a few well-controlled examples of cell-type conversion. At the molecular level, switching probably initiates from environmental signals that induce epigenetic modifications, resulting in changes in chromatin configuration. In turn, these changes affect patterns of gene expression that mediate divergent developmental programs. This review examines recent findings in nuclear reprogramming and cell fusion as potential causative mechanisms for transdifferentiation during normal and malignant hematopoiesis.
Collapse
Affiliation(s)
- Samuel W French
- Department of Pathology and Laboratory Medicine, UCLA School of Medicine, Los Angeles, CA 90095-1732, USA
| | | | | | | |
Collapse
|
40
|
Igarashi H, Gregory SC, Yokota T, Sakaguchi N, Kincade PW. Transcription from the RAG1 locus marks the earliest lymphocyte progenitors in bone marrow. Immunity 2002; 17:117-30. [PMID: 12196284 DOI: 10.1016/s1074-7613(02)00366-7] [Citation(s) in RCA: 355] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Viable Lin(-) CD27(+) c-kit(Hi) Sca-1(Hi) GFP(+) cells recovered from heterozygous RAG1/GFP knockin mice progressed through previously defined stages of B, T, and NK cell lineage differentiation. In contrast to the GFP(-) cohort, there was minimal myeloid or erythroid potential in cells with an active RAG1 locus. Partial overlap with TdT(+) cells suggested that distinctive early lymphocyte characteristics are not synchronously acquired. Rearrangement of Ig genes initiates before typical lymphoid lineage patterns of gene expression are established, and activation of the RAG1 locus transiently occurs in a large fraction of cells destined to become NK cells. These early lymphocyte progenitors (ELP) are distinct from stem cells, previously described prolymphocytes, or progenitors corresponding to other blood cell lineages.
Collapse
Affiliation(s)
- Hideya Igarashi
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, 825 Northeast 13th Street, Oklahoma City 73104, USA
| | | | | | | | | |
Collapse
|
41
|
Hertel CB, Zhou XG, Hamilton-Dutoit SJ, Junker S. Loss of B cell identity correlates with loss of B cell-specific transcription factors in Hodgkin/Reed-Sternberg cells of classical Hodgkin lymphoma. Oncogene 2002; 21:4908-20. [PMID: 12118370 DOI: 10.1038/sj.onc.1205629] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2002] [Revised: 04/23/2002] [Accepted: 04/26/2002] [Indexed: 11/09/2022]
Abstract
In classical Hodgkin lymphoma the malignant Hodgkin/Reed-Sternberg (HRS) cells characteristically constitute only a small minority of the tumour load. Their origin has been debated for decades, but on the basis of rearrangement and somatic hypermutations of their immunoglubulin (Ig) genes, HRS cells are now ascribed to the B-cell lineage. Nevertheless, phenotypically HRS cells have lost their B cell identity: they usually lack common B cell-specific surface markers such as CD19 and CD79a as well as Ig gene transcripts. Here we demonstrate that Ig promoters as well as both intronic and 3' enhancer sequences are transcriptionally inactive in HRS cell lines. This inactivity correlates with either reduced levels or even a complete lack of several B cell-specific transcription factors required for their expression: Oct-2, OBF-1, PU.1, E47/E12, PAX-5 and EBF. Moreover, we demonstrate that PU.1 and PAX-5 are significantly down-regulated in HRS cells in pathological specimens from primary tumour tissues. However, forced expression of these transcription factors can activate regulatory sequences of silenced B cell marker genes, and in one instance also transcription from a silenced endogenous locus. Thus, HRS cells are dedifferentiated B cells with global down-regulation of B cell-specific genes.
Collapse
Affiliation(s)
- Christina B Hertel
- Institute of Human Genetics, University of Aarhus, DK-8000 Aarhus C, Denmark
| | | | | | | |
Collapse
|
42
|
Anderson MK, Hernandez-Hoyos G, Dionne CJ, Arias AM, Chen D, Rothenberg EV. Definition of regulatory network elements for T cell development by perturbation analysis with PU.1 and GATA-3. Dev Biol 2002; 246:103-21. [PMID: 12027437 DOI: 10.1006/dbio.2002.0674] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PU.1 and GATA-3 are transcription factors that are required for development of T cell progenitors from the earliest stages. Neither one is a simple positive regulator for T lineage specification, however. When expressed at elevated levels at early stages of T cell development, each of these transcription factors blocks T cell development within a different, characteristic time window, with GATA-3 overexpression initially inhibiting at an earlier stage than PU.1. These perturbations are each associated with a distinct spectrum of changes in the regulation of genes needed for T cell development. Both transcription factors can interfere with expression of the Rag-1 and Rag-2 recombinases, while GATA-3 notably blocks PU.1 and IL-7Ralpha expression, and PU.1 reduces expression of HES-1 and c-Myb. A first-draft assembly of the regulatory targets of these two factors is presented as a provisional gene network. The target genes identified here provide insight into the basis of the effects of GATA-3 or PU.1 overexpression and into the regulatory changes that distinguish the developmental time windows for these effects.
Collapse
Affiliation(s)
- Michele K Anderson
- Division of Biology, California Institute of Technology, Pasadena 91125, USA
| | | | | | | | | | | |
Collapse
|
43
|
Wolfer A, Wilson A, Nemir M, MacDonald HR, Radtke F. Inactivation of Notch1 impairs VDJbeta rearrangement and allows pre-TCR-independent survival of early alpha beta Lineage Thymocytes. Immunity 2002; 16:869-79. [PMID: 12121668 DOI: 10.1016/s1074-7613(02)00330-8] [Citation(s) in RCA: 272] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Notch proteins influence cell fate decisions in many developmental systems. During lymphoid development, Notch1 signaling is essential to direct a bipotent T/B precursor toward the T cell fate, but the role of Notch1 at later stages of T cell development remains controversial. We have recently reported that tissue-specific inactivation of Notch1 in immature (CD44(-) CD25(+)) thymocytes does not affect subsequent T cell development. Here, we demonstrate that loss of Notch1 signaling at an earlier (CD44(+)CD25(+)) developmental stage results in severe perturbation of alpha beta but not gamma delta lineage development. Immature Notch1(-/-) thymocytes show impaired VDJ beta rearrangement and aberrant pre-TCR-independent survival. Collectively, our data demonstrate that Notch1 controls several nonredundant functions necessary for alpha beta lineage development.
Collapse
Affiliation(s)
- Anita Wolfer
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, 1066, Epalinges, Switzerland
| | | | | | | | | |
Collapse
|
44
|
Abstract
The past two decades have witnessed significant advances in our understanding of the cellular physiology and molecular regulation of hematopoiesis. At the heart of stem cell self-renewal and lineage commitment decisions lies the relative expression levels of lineage-specific transcription factors. The expression of these transcription factors in early stem cells may be promiscuous and fluctuate, but ultimately comes under the influence of extracellular regulatory signals in the form of hematopoietic cytokines. In this review, we first summarize our current understanding of the phenotypic characterization of hematopoietic stem cells. Next, we describe key known transcription factors which govern stem cell self-renewal and lineage commitment decisions. Finally, we review data concerning the role of specific cytokines in influencing these decisions. From this review, a picture emerges in which stem cell fate decisions are governed by the integrated effects of intrinsic transcription factors and external signaling pathways initiated by regulatory cytokines.
Collapse
Affiliation(s)
- Jiang Zhu
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, PA 19104, USA
| | | |
Collapse
|
45
|
Abstract
Cell-fate decisions are controlled typically by conserved receptors that interact with co-evolved ligands. Therefore, the lineage-specific differentiation of immature CD4+ CD8+ T cells into CD4+ or CD8+ mature T cells is unusual in that it is regulated by clonally expressed, somatically generated T-cell receptors (TCRs) of unpredictable fine specificity. Yet, each mature T cell generally retains expression of the co-receptor molecule (CD4 or CD8) that has an MHC-binding property that matches that of its TCR. Two models were proposed initially to explain this remarkable outcome--'instruction' of lineage choice by initial signalling events or 'selection' after a stochastic fate decision that limits further development to cells with coordinated TCR and co-receptor specificities. Aspects of both models now appear to be correct; mistake-prone instruction of lineage choice precedes a subsequent selection step that filters out most incorrect decisions.
Collapse
Affiliation(s)
- Ronald N Germain
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-1892, USA.
| |
Collapse
|
46
|
Ellmeier W, Sunshine MJ, Maschek R, Littman DR. Combined deletion of CD8 locus cis-regulatory elements affects initiation but not maintenance of CD8 expression. Immunity 2002; 16:623-34. [PMID: 12049715 DOI: 10.1016/s1074-7613(02)00309-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Developmental stage-, subset-, and lineage-specific CD8 enhancers have been identified recently by transgenic reporter analyses. Enhancer E8(II) (CIV-4,5) is active in both immature double-positive thymocytes (DP) and mature CD8 single-positive (SP) thymocytes and T cells, whereas E8(I) (CIII-1,2) directs expression only in mature cells. In mice lacking either E8(I) (CIII-1,2) or E8(II) (CIV-4,5), there was no effect on CD8 expression in DP thymocytes. However, deletion of both enhancers resulted in variegated expression of CD8, with appearance of CD4(+)CD8(-) SP thymocytes expressing surface markers characteristic of DP thymocytes. Consequently, fewer mature CD8(+) T cells developed from the reduced pool of DP cells. These results suggest that the initiation of CD8 expression is mediated by cis-regulatory elements that are distinct from any that may be involved in maintenance of expression.
Collapse
|
47
|
Anderson MK, Weiss AH, Hernandez-Hoyos G, Dionne CJ, Rothenberg EV. Constitutive expression of PU.1 in fetal hematopoietic progenitors blocks T cell development at the pro-T cell stage. Immunity 2002; 16:285-96. [PMID: 11869688 DOI: 10.1016/s1074-7613(02)00277-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The essential hematopoietic transcription factor PU.1 is expressed in multipotent thymic precursors but downregulated during T lineage commitment. The significance of PU.1 downregulation was tested using retroviral vectors to force hematopoietic precursors to maintain PU.1 expression during differentiation in fetal thymic organ culture. PU.1 reduced thymocyte expansion and blocked development at the pro-T cell stage. PU.1-expressing cells could be rescued by switching to conditions permissive for macrophage development; thus, the inhibition depends on both lineage and developmental stage. An intact DNA binding domain was required for these effects. PU.1 expression can downregulate pre-Talpha, Rag-1, and Rag-2 in a dose-dependent manner, and higher PU.1 levels induce Mac-1 and Id-2. Thus, downregulation of PU.1 is specifically required for progression in the T cell lineage.
Collapse
Affiliation(s)
- Michele K Anderson
- Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125, USA
| | | | | | | | | |
Collapse
|
48
|
Reizis B, Leder P. Direct induction of T lymphocyte-specific gene expression by the mammalian Notch signaling pathway. Genes Dev 2002; 16:295-300. [PMID: 11825871 PMCID: PMC155334 DOI: 10.1101/gad.960702] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The Notch signaling pathway regulates the commitment and early development of T lymphocytes. We studied Notch-mediated induction of the pre-T cell receptor alpha (pTa) gene, a T-cell-specific transcriptional target of Notch. The pTa enhancer was activated by Notch signaling and contained binding sites for its nuclear effector, CSL. Mutation of the CSL-binding sites abolished enhancer induction by Notch and delayed the up-regulation of pTa transgene expression during T cell lineage commitment. These results show a direct mechanism of stage- and tissue-specific gene induction by the mammalian Notch/CSL signaling pathway.
Collapse
Affiliation(s)
- Boris Reizis
- Department of Genetics and Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | |
Collapse
|
49
|
Walker L, Carlson A, Tan-Pertel HT, Weinmaster G, Gasson J. The notch receptor and its ligands are selectively expressed during hematopoietic development in the mouse. Stem Cells 2002; 19:543-52. [PMID: 11713346 DOI: 10.1634/stemcells.19-6-543] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Members of the Notch family of transmembrane receptors are found on primitive hematopoietic precursors, and Notch ligand expression has been demonstrated on the surface of stromal cells, suggesting a role for Notch signaling in mammalian blood cell development. The current report examines the expression of Notch receptors and their ligands in murine hematopoietic tissues to determine: A) which blood cell lineages in the adult are influenced by Notch activity, and B) whether fetal hematopoiesis in the embryo involves the Notch pathway. In the adult mouse, a combination of flow cytometry, immunohistochemistry and Northern analysis was used to examine Notch receptor or ligand expression in bone marrow and spleen. In the embryo, Northern analysis and in situ hybridization were used to characterize Notch receptor and ligand expression in fetal liver on embryonic day 12 (E12) through E17, an active period encompassing both erythropoiesis and granulopoeisis. Flow cytometry demonstrated the presence of Notch1 and Notch2 receptors on bone marrow-derived myeloid cells but not on erythroid cells positive for the marker, Ter-119. In situ hybridization of E12 through E17 fetal liver demonstrated widespread expression of Jagged1 and Delta1 in a pattern similar to but less abundant than that of the erythropoietin receptor. Taken together with earlier functional results, the current expression data suggest a role for Notch activity in establishing definitive hematopoiesis in fetal liver, as well as a selective use of Notch signaling in adult erythropoiesis and granulopoiesis. Notch receptors in the adult are most likely utilized by early erythroid precursors and intermediate-stage granulocytes, but not by terminally differentiating cells of either subset.
Collapse
MESH Headings
- Animals
- Blotting, Northern
- Bone Marrow Cells/chemistry
- Bone Marrow Cells/cytology
- Calcium-Binding Proteins
- Cell Line
- Embryo, Mammalian/metabolism
- Female
- Flow Cytometry
- Gene Expression Regulation, Developmental
- Hematopoiesis/genetics
- Hematopoietic Stem Cells/cytology
- Hematopoietic Stem Cells/metabolism
- Immunohistochemistry
- In Situ Hybridization
- Intercellular Signaling Peptides and Proteins
- Jagged-1 Protein
- Ligands
- Liver/embryology
- Liver/metabolism
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Mice, Inbred BALB C
- Proteins/genetics
- Proteins/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, Notch1
- Receptor, Notch2
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Notch
- Serrate-Jagged Proteins
- Spleen/metabolism
- Time Factors
- Transcription Factors
Collapse
Affiliation(s)
- L Walker
- UCLA Molecular Biology Institute, Los Angeles, CA 90095-1781, USA
| | | | | | | | | |
Collapse
|
50
|
Abstract
The controlled expression of cytokine genes is an essential component of an immune response. The specific types of cytokines as well as the time and place of their production is important in generating an appropriate immune response to an infectious agent. Aberrant expression is associated with pathological conditions of the immune system such as autoimmunity, atopy and chronic inflammation. Cytokine gene transcription is generally induced in a cell-specific manner. Over the last 15 years, a large amount of information has been generated describing the transcriptional controls that are exerted on cytokine genes. Recently, efforts have been directed at understanding how these genes are transcribed in a chromatin context. This review will discuss the mechanisms by which cytokine genes become available for transcription in a cell-restricted manner as well as the mechanisms by which these genes sense their environment and activate high level transcription in a transient manner. Particular attention will be paid to the role of chromatin in allowing transcription factor access to appropriate genes.
Collapse
Affiliation(s)
- A F Holloway
- Division of Biochemistry and Molecular Biology, John Curtin School of Medical Research, Australian National University, Canberra ACT 2601, Australia
| | | | | |
Collapse
|