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Sunaoshi M, Amasaki Y, Hirano-Sakairi S, Blyth BJ, Morioka T, Kaminishi M, Shang Y, Nishimura M, Shimada Y, Tachibana A, Kakinuma S. The effect of age at exposure on the inactivating mechanisms and relative contributions of key tumor suppressor genes in radiation-induced mouse T-cell lymphomas. Mutat Res 2015; 779:58-67. [PMID: 26141385 DOI: 10.1016/j.mrfmmm.2015.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/15/2015] [Accepted: 06/07/2015] [Indexed: 06/04/2023]
Abstract
Children are considered more sensitive to radiation-induced cancer than adults, yet any differences in genomic alterations associated with age-at-exposure and their underlying mechanisms remain unclear. We assessed genome-wide DNA copy number and mutation of key tumor suppressor genes in T-cell lymphomas arising after weekly irradiation of female B6C3F1 mice with 1.2Gy X-rays for 4 consecutive weeks starting during infancy (1 week old), adolescence (4 weeks old) or as young adults (8 weeks old). Although T-cell lymphoma incidence was similar, loss of heterozygosity at Cdkn2a on chromosome 4 and at Ikaros on chromosome 11 was more frequent in the two older groups, while loss at the Pten locus on chromosome 19 was more frequent in the infant-irradiated group. Cdkn2a and Ikaros mutation/loss was a common feature of the young adult-irradiation group, with Ikaros frequently (50%) incurring multiple independent hits (including deletions and mutations) or suffering a single hit predicted to result in a dominant negative protein (such as those lacking exon 4, an isoform we have designated Ik12, which lacks two DNA binding zinc-finger domains). Conversely, Pten mutations were more frequent after early irradiation (60%) than after young adult-irradiation (30%). Homozygous Pten mutations occurred without DNA copy number change after irradiation starting in infancy, suggesting duplication of the mutated allele by chromosome mis-segregation or mitotic recombination. Our findings demonstrate that while deletions on chromosomes 4 and 11 affecting Cdkn2a and Ikaros are a prominent feature of young adult irradiation-induced T-cell lymphoma, tumors arising after irradiation from infancy suffer a second hit in Pten by mis-segregation or recombination. This is the first report showing an influence of age-at-exposure on genomic alterations of tumor suppressor genes and their relative involvement in radiation-induced T-cell lymphoma. These data are important for considering the risks associated with childhood exposure to radiation.
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Affiliation(s)
- Masaaki Sunaoshi
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
| | - Yoshiko Amasaki
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Shinobu Hirano-Sakairi
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Benjamin J Blyth
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Takamitsu Morioka
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Mutsumi Kaminishi
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Yi Shang
- Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Mayumi Nishimura
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Yoshiya Shimada
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
| | - Akira Tachibana
- Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
| | - Shizuko Kakinuma
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan; Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
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2
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Hirano S, Kakinuma S, Amasaki Y, Nishimura M, Imaoka T, Fujimoto S, Hino O, Shimada Y. Ikaros is a critical target during simultaneous exposure to X-rays and N-ethyl-N-nitrosourea in mouse T-cell lymphomagenesis. Int J Cancer 2013; 132:259-68. [PMID: 22684892 DOI: 10.1002/ijc.27668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 05/21/2012] [Indexed: 11/09/2022]
Abstract
Cancer risk associated with radiation exposure is considered the result of concurrent exposure to other natural and manmade carcinogens. Available data on the molecular characteristics of cancer after simultaneous exposure to radiation and chemicals are insufficient. In our study, we used a mouse thymic lymphoma (TL) model that was synergistically induced by simultaneous exposure to X-rays and N-ethyl-N-nitrosourea (ENU) at subcarcinogenic doses and analyzed the mutation frequency and spectrum of the TL-associated genes Ikaros, Notch1, p53 and Kras. We found that the point mutation frequency in Ikaros was significantly increased to 47% for simultaneous exposure compared to 13 and 0% for X-ray and ENU exposure alone, respectively. These mutations were mostly G:C > A:T at non-CpG sites and T:A > C:G, both of which are characteristic of ENU mutagenesis. About half of the point mutations were accompanied by loss of heterozygosity (LOH), typical of X-irradiation. The remaining half did not include LOH, which suggests that they were dominant-negative mutations. In Notch1, the frequency of abnormalities was high (>58%) regardless of the treatment, suggesting that Notch1 aberration may be important for T-cell lymphomagenesis. The p53 and Kras mutation frequencies were low for all treatments (<23%). Importantly, the frequency of TLs containing mutations in multiple genes, especially both Ikaros and Notch1, increased after simultaneous exposure. Thus, after simultaneous exposure, Ikaros is a critical target and is inactivated by ENU-induced point mutations and/or X-ray-induced LOH in T-cell lymphomagenesis. Furthermore, concomitant alterations of multiple tumor-associated genes may contribute to enhanced lymphomagenesis after simultaneous exposure.
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Affiliation(s)
- Shinobu Hirano
- Radiobiology for Children's Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, Inage-Ku, Chiba, Japan
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3
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Three chemokine receptors cooperatively regulate homing of hematopoietic progenitors to the embryonic mouse thymus. Proc Natl Acad Sci U S A 2011; 108:7517-22. [PMID: 21502490 DOI: 10.1073/pnas.1016428108] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The thymus lacks self-renewing hematopoietic cells, and thymopoiesis fails rapidly when the migration of progenitor cells to the thymus ceases. Hence, the process of thymus homing is an essential step for T-cell development and cellular immunity. Despite decades of research, the molecular details of thymus homing have not been elucidated fully. Here, we show that chemotaxis is the key mechanism regulating thymus homing in the mouse embryo. We determined the number of early thymic progenitors in the thymic rudiments of mice deficient for one, two, or three of the chemokine receptor genes, chemokine (C-C motif) receptor 9 (Ccr9), chemokine (C-C motif) receptor 7 (Ccr7), and chemokine (C-X-C motif) receptor 4 (Cxcr4). In the absence of all three chemokine receptors, thymus homing was reduced about 100-fold both before and after vascularization of the thymic rudiment. In the absence of only two of these three chemokine receptor genes, thymus homing was much less affected (only two- to 10-fold), indicating that the chemotactic regulation of thymus homing is remarkably robust. Our results reveal the redundant roles of Ccr9, Ccr7, and Cxcr4 for thymic homing and provide a framework to examine the regulation of progenitor homing in the postnatal thymus.
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4
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Osada M, Jardine L, Misir R, Andl T, Millar SE, Pezzano M. DKK1 mediated inhibition of Wnt signaling in postnatal mice leads to loss of TEC progenitors and thymic degeneration. PLoS One 2010; 5:e9062. [PMID: 20161711 PMCID: PMC2817005 DOI: 10.1371/journal.pone.0009062] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2009] [Accepted: 01/07/2010] [Indexed: 11/24/2022] Open
Abstract
Background Thymic epithelial cell (TEC) microenvironments are essential for the
recruitment of T cell precursors from the bone marrow, as well as the
subsequent expansion and selection of thymocytes resulting in a mature
self-tolerant T cell repertoire. The molecular mechanisms, which control
both the initial development and subsequent maintenance of these critical
microenvironments, are poorly defined. Wnt signaling has been shown to be
important to the development of several epithelial tissues and organs.
Regulation of Wnt signaling has also been shown to impact both early
thymocyte and thymic epithelial development. However, early blocks in thymic
organogenesis or death of the mice have prevented analysis of a role of
canonical Wnt signaling in the maintenance of TECs in the postnatal
thymus. Methodology/Principal Findings Here we demonstrate that tetracycline-regulated expression of the canonical
Wnt inhibitor DKK1 in TECs localized in both the cortex and medulla of adult
mice, results in rapid thymic degeneration characterized by a loss of
ΔNP63+ Foxn1+ and
Aire+ TECs, loss of K5K8DP TECs thought to represent
or contain an immature TEC progenitor, decreased TEC proliferation and the
development of cystic structures, similar to an aged thymus. Removal of DKK1
from DKK1-involuted mice results in full recovery, suggesting that canonical
Wnt signaling is required for the differentiation or proliferation of TEC
populations needed for maintenance of properly organized adult thymic
epithelial microenvironments. Conclusions/Significance Taken together, the results of this study demonstrate that canonical Wnt
signaling within TECs is required for the maintenance of epithelial
microenvironments in the postnatal thymus, possibly through effects on TEC
progenitor/stem cell populations. Downstream targets of Wnt signaling, which
are responsible for maintenance of these TEC progenitors may provide useful
targets for therapies aimed at counteracting age associated thymic
involution or the premature thymic degeneration associated with cancer
therapy and bone marrow transplants.
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Affiliation(s)
- Masako Osada
- Department of Biology, The City College of New York, New York, New York,
United States of America
| | - Logan Jardine
- Department of Biology, The City College of New York, New York, New York,
United States of America
| | - Ruth Misir
- Department of Biology, The City College of New York, New York, New York,
United States of America
| | - Thomas Andl
- Vanderbilt University Medical Center, Nashville, Tennessee, United States
of America
| | - Sarah E. Millar
- Departments of Dermatology and Cell and Developmental Biology, University
of Pennsylvania, Philadelphia, Pennsylvania, United States of
America
| | - Mark Pezzano
- Department of Biology, The City College of New York, New York, New York,
United States of America
- * E-mail:
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5
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Osada M, Ito E, Fermin HA, Vazquez-Cintron E, Venkatesh T, Friedel RH, Pezzano M. The Wnt signaling antagonist Kremen1 is required for development of thymic architecture. Clin Dev Immunol 2007; 13:299-319. [PMID: 17162372 PMCID: PMC2270768 DOI: 10.1080/17402520600935097] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Wnt signaling has been reported to regulate thymocyte proliferation and selection at several stages during T cell ontogeny, as well as the expression of FoxN1 in thymic epithelial cells (TECs). Kremen1 (Krm1) is a negative regulator of the canonical Wnt signaling pathway, and functions together with the secreted Wnt inhibitor Dickkopf (Dkk) by competing for the lipoprotein receptor-related protein (LRP)-6 co-receptor for Wnts. Here krm1 knockout mice were used to examine krm1 expression in the thymus and its function in thymocyte and TEC development. krm1 expression was detected in both cortical and medullary TEC subsets, as well as in immature thymocyte subsets, beginning at the CD25+CD44+ (DN2) stage and continuing until the CD4+CD8+(DP) stage. Neonatal mice show elevated expression of krm1 in all TEC subsets. krm1− / − mice exhibit a severe defect in thymic cortical architecture, including large epithelial free regions. Much of the epithelial component remains at an immature Keratin 5+ (K5) Keratin 8+(K8) stage, with a loss of defined cortical and medullary regions. A TOPFlash assay revealed a 2-fold increase in canonical Wnt signaling in TEC lines derived from krm1− / − mice, when compared with krm1+ / + derived TEC lines. Fluorescence activated cell sorting (FACS) analysis of dissociated thymus revealed a reduced frequency of both cortical (BP1+EpCAM+) and medullary (UEA-1+ EpCAMhi) epithelial subsets, within the krm1− / − thymus. Surprisingly, no change in thymus size, total thymocyte number or the frequency of thymocyte subsets was detected in krm1− / − mice. However, our data suggest that a loss of Krm1 leads to a severe defect in thymic architecture. Taken together, this study revealed a new role for Krm1 in proper development of thymic epithelium.
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Affiliation(s)
- Masako Osada
- Department of Biology, The City College of the City University of New York, RCMI Center for the Study of the Cellular and Molecular Basis of Development, 138th Street and Convent Avenue, New York, NY 10031, USA
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6
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Corbel C, Lemarchandel V, Thomas-Vaslin V, Pelus AS, Agboton C, Roméo PH. Neuropilin 1 and CD25 co-regulation during early murine thymic differentiation. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2007; 31:1082-94. [PMID: 17374393 DOI: 10.1016/j.dci.2007.01.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 01/17/2007] [Accepted: 01/26/2007] [Indexed: 05/14/2023]
Abstract
Neuropilin 1 (NP1) is a receptor for both semaphorin and vascular endothelial growth factor expressed by subpopulations of neuronal and endothelial cells. In the immune system, NP1 is present on dendritic and regulatory T cells. Here, we show that NP1 is expressed in the murine thymus, starting on day 12.5 of gestation. In the adult, NP1 is mainly expressed by CD4(-)CD8(-) double negative cells, CD4+CD8+ double positive cells, and CD4+CD25+ regulatory T cells but barely detected in single CD4+ and CD8+ positive thymocytes. Within the CD4(-)CD8(-)CD3(-) (triple-negative, TN) immature cells, NP1 expression starts in TN3 (CD44(-)CD25+) and increases in TN4 (CD44(-)CD25(-)) cells. In order to study the role of NP1 in thymocyte differentiation, we generated mice in which the np1 gene is selectively disrupted in the T-cell lineage. The mutant mice display normal thymocyte, peripheral, conventional and CD4+CD25+Foxp3+ regulatory T-cell populations. However, we observe a down-regulation of the CD25 expression between the TN3 and TN4 stages that is (i) correlated to increased expression of NP1 in control mice and (ii) altered in mutant mice, suggesting that NP1 is co-regulated with CD25 during early immature thymocyte differentiation.
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Affiliation(s)
- Catherine Corbel
- Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France.
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7
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Yokota T, Huang J, Tavian M, Nagai Y, Hirose J, Zúñiga-Pflücker JC, Péault B, Kincade PW. Tracing the first waves of lymphopoiesis in mice. Development 2006; 133:2041-51. [PMID: 16611687 DOI: 10.1242/dev.02349] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
RAG1/GFP knock-in mice were used to precisely chart the emergence and expansion of cells that give rise to the immune system. Lymphopoietic cells detectable in stromal co-cultures arose as early as E8.5, i.e. prior to establishment of the circulation within the paraaortic splanchnopleura (P-Sp). These cells were Tie2+ RAG1- CD34Lo/-Kit+ CD41-. While yolk sac (YS) also contained lymphopoietic cells after E9.5, CD41+ YS cells from ⩽25-somite embryos produced myelo-erythroid cells but no lymphocytes. Notch receptor signaling directed P-Sp cells to T lymphocytes but did not confer lymphopoietic potential on YS cells. Thus, definitive hematopoiesis arises in at least two independent sites that differ in lymphopoietic potential. Expression of RAG1, the earliest known lymphoid event, first occurred around E10.5 within the embryos. RAG1/GFP+ cells appeared in the liver at E11.0 and progenitors with B and/or T lineage potential were enumerated at subsequent developmental stages.
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Affiliation(s)
- Takafumi Yokota
- Immunobiology and Cancer Program, Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA
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8
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Holländer G, Gill J, Zuklys S, Iwanami N, Liu C, Takahama Y. Cellular and molecular events during early thymus development. Immunol Rev 2006; 209:28-46. [PMID: 16448532 DOI: 10.1111/j.0105-2896.2006.00357.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The thymic stromal compartment consists of several cell types that collectively enable the attraction, survival, expansion, migration, and differentiation of T-cell precursors. The thymic epithelial cells constitute the most abundant cell type of the thymic microenvironment and can be differentiated into morphologically, phenotypically, and functionally separate subpopulations of the postnatal thymus. All thymic epithelial cells are derived from the endodermal lining of the third pharyngeal pouch. Very soon after the formation of a thymus primordium and prior to its vascularization, thymic epithelial cells orchestrate the first steps of intrathymic T-cell development, including the attraction of lymphoid precursor cells to the thymic microenvironment. The correct segmentation of pharyngeal epithelial cells and their subsequent crosstalk with cells in the pharyngeal arches are critical prerequisites for the formation of a thymus anlage. Mutations in several transcription factors and their target genes have been informative to detail some of the complex mechanisms that control the development of the thymus anlage. This review highlights recent findings related to the genetic control of early thymus organogenesis and provides insight into the molecular basis by which lymphocyte precursors are attracted to the thymus.
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Affiliation(s)
- Georg Holländer
- Pediatric Immunology, The Center for Biomedicine, Department of Clinical-Biological Sciences, University of Basel, and The University Children's Hospital of Basel, Basel, Switzerland.
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9
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Abstract
Transcriptional regulation of T-cell development involves successive interactions between complexes of transcriptional regulators and their binding sites within the regulatory regions of each gene. The regulatory modules that control expression of T-lineage genes frequently include binding sites for a core set of regulators that set the T-cell-specific background for signal-dependent control, including GATA-3, Notch/CSL, c-myb, TCF-1, Ikaros, HEB/E2A, Ets, and Runx factors. Additional regulators in early thymocytes include PU.1, Id-2, SCL, Spi-B, Erg, Gfi-1, and Gli. Many of these factors are involved in simultaneous regulation of non-T-lineage genes, T-lineage genes, and genes involved in cell cycle control, apoptosis, or survival. Potential and known interactions between early thymic transcription factors such as GATA-3, SCL, PU.1, Erg, and Spi-B are explored. Regulatory modules involved in the expression of several critical T-lineage genes are described, and models are presented for shifting occupancy of the DNA-binding sites in the regulatory modules of pre-Talpha, T-cell receptor beta (TCRbeta), recombinase activating genes 1 and 2 (Rag-1/2), and CD4 during T-cell development. Finally, evidence is presented that c-kit, Erg, Hes-1, and HEBAlt are expressed differently in Rag-2(-/-) thymocytes versus normal early thymocytes, which provide insight into potential regulatory interactions that occur during normal T-cell development.
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Affiliation(s)
- Michele K Anderson
- Sunnybrook and Women's College Health Sciences Center, Division of Molecular and Cell Biology, University of Toronto, Department of Immunology, Toronto, ON, Canada.
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10
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Kahler RA, Galindo M, Lian J, Stein GS, van Wijnen AJ, Westendorf JJ. Lymphocyte enhancer-binding factor 1 (Lef1) inhibits terminal differentiation of osteoblasts. J Cell Biochem 2006; 97:969-83. [PMID: 16267835 DOI: 10.1002/jcb.20702] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Lef1 is a transcriptional regulator of the Wnt/beta-catenin signaling cascade. Wnts directly augment bone formation and osteoblast differentiation from mesenchymal stem cells by receptor-mediated pathways involving Lrp5 and Frizzled. We previously reported that Lef1 represses Runx2-dependent activation of the late osteoblast differentiation gene, osteocalcin. Lef1 is expressed in preosteoblasts but is undetectable in fully differentiated osteoblasts. To determine if downregulation of Lef1 is necessary for osteoblast maturation, we constitutively overexpressed Lef1 in MC3T3-E1 preosteoblasts. Lef1-overexpressing cells produced alkaline phosphatase (ALP) and osteocalcin later, and at lower levels than control cells. Moreover, the extracellular matrices of Lef1-overexpressing cell cultures never mineralized. To further examine the role of Lef1 in osteoblasts, we suppressed Lef1 expression in MC3T3-E1 cells by RNA interference. Transient expression of a Lef1 shRNA efficiently reduced murine Lef1 levels and transcriptional activity. Stable suppression of Lef1 in MC3T3 preosteoblasts did not affect proliferation or Runx2 levels; however, ALP production and matrix mineralization were accelerated by 3-4 days. Gene chip analyses identified 14 genes that are differentially regulated in Lef1-suppressed cells. These data outline a role for Lef1 in delaying osteoblast maturation and suggest that Lef1 controls the expression of multiple genes in osteoblasts.
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Affiliation(s)
- Rachel A Kahler
- Graduate Program in Microbiology, Immunology and Cancer Biology, University of Minnesota, Minneapolis, Minnesota 55455, USA
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11
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Masuda K, Kubagawa H, Ikawa T, Chen CC, Kakugawa K, Hattori M, Kageyama R, Cooper MD, Minato N, Katsura Y, Kawamoto H. Prethymic T-cell development defined by the expression of paired immunoglobulin-like receptors. EMBO J 2005; 24:4052-60. [PMID: 16292344 PMCID: PMC1356317 DOI: 10.1038/sj.emboj.7600878] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2005] [Accepted: 10/25/2005] [Indexed: 12/19/2022] Open
Abstract
T cells are produced in the thymus from progenitors of extrathymic origin. As no specific markers are available, the developmental pathway of progenitors preceding thymic colonization remains unclear. Here we show that progenitors in murine fetal liver and blood, which are capable of giving rise to T cells, NK cells and dendritic cells, but not B cells, can be isolated by their surface expression of paired immunoglobulin-like receptors (PIR). PIR expression is maintained until the earliest intrathymic stage, then downregulated before the onset of CD25 expression. Unlike intrathymic progenitors, generation of prethymic PIR(+) progenitors does not require Hes1-mediated Notch signaling. These findings disclose a prethymic stage of T-cell development programmed for immigration of the thymus, which is genetically separable from intrathymic stages.
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MESH Headings
- Animals
- Basic Helix-Loop-Helix Transcription Factors/physiology
- Cell Differentiation/immunology
- Cell Lineage/immunology
- Cells, Cultured
- Dendritic Cells/cytology
- Dendritic Cells/immunology
- Homeodomain Proteins/physiology
- Killer Cells, Natural/cytology
- Killer Cells, Natural/immunology
- Liver/cytology
- Liver/embryology
- Liver/immunology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred ICR
- Mice, Transgenic
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Immunologic/biosynthesis
- Receptors, Immunologic/genetics
- Receptors, Notch/physiology
- Signal Transduction/physiology
- Stem Cells/cytology
- Stem Cells/immunology
- Stem Cells/metabolism
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Thymus Gland/cytology
- Thymus Gland/immunology
- Transcription Factor HES-1
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Affiliation(s)
- Kyoko Masuda
- Department of Immunology and Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan
| | - Hiromi Kubagawa
- Department of Pathology, Division of Developmental and Clinical Immunology, University of Alabama, Birmingham, AL, USA
| | - Tomokatsu Ikawa
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
| | - Ching-Cheng Chen
- Department of Pathology, Division of Developmental and Clinical Immunology, University of Alabama, Birmingham, AL, USA
| | - Kiyokazu Kakugawa
- Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan
| | - Masakazu Hattori
- Department of Immunology and Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Ryoichiro Kageyama
- Laboratory of Growth Regulation, Institute for Virus Research, Kyoto University, Kyoto, Japan
| | - Max D Cooper
- Department of Pathology, Division of Developmental and Clinical Immunology, University of Alabama, Birmingham, AL, USA
| | - Nagahiro Minato
- Department of Immunology and Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Yoshimoto Katsura
- Division of Cell Regeneration and Transplantation, Advanced Medical Research Center, Nihon University School of Medicine, Tokyo, Japan
| | - Hiroshi Kawamoto
- Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan
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12
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Suzuki H, Motohara M, Miyake A, Ibuki K, Fukazawa Y, Inaba K, Masuda K, Minato N, Kawamoto H, Hayami M, Miura T. Intrathymic effect of acute pathogenic SHIV infection on T-lineage cells in newborn macaques. Microbiol Immunol 2005; 49:667-79. [PMID: 16034211 DOI: 10.1111/j.1348-0421.2005.tb03646.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We intrarectally infected newborn macaques with a pathogenic simian/human immunodeficiency virus (SHIV) that induced rapid and profound CD4 (+) T cell depletion, and examined the early effects of this SHIV on the thymus. After intrarectal infection, viral loads were much higher in the thymus than in other lymphoid tissues in newborns. In contrast, no clear difference was seen in the viral loads of different tissues in adults. Histological and immunohistochemical observations showed severe thymic involution. Depletion of CD4 (+) thymocytes began in the medulla at 2 weeks post infection and spread over the whole thymus. After in vivo infection, the CD2 (+) subpopulation, which represents a relatively later stage of T cell progenitors, was selectively reduced and development of thymocytes from CD3 (-) CD4 (-) CD8 (-) cells to CD4 (+) CD8 (+) cells was impaired. These results suggest that profound and irreversible loss of CD4 (+) cells that are observed in the peripheral blood of SHIV-infected monkeys are due to destruction of the thymus and impaired thymopoiesis as a result of SHIV infection in the thymus.
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Affiliation(s)
- Hajime Suzuki
- Laboratory of Primate Model, Institute for Virus Research, Kyoto University, Japan
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13
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Majora M, Frericks M, Temchura V, Reichmann G, Esser C. Detection of a novel population of fetal thymocytes characterized by preferential emigration and a TCRγδ+ T cell fate after dioxin exposure. Int Immunopharmacol 2005; 5:1659-74. [PMID: 16102516 DOI: 10.1016/j.intimp.2005.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2005] [Revised: 02/02/2005] [Accepted: 02/21/2005] [Indexed: 10/25/2022]
Abstract
T cell maturation into TCRalphabeta(+) or TCRgammadelta(+) cells from common immature CD4(-)CD8(-)(DN) precursors occurs in the thymus, and is controlled through ordered regulation of genes. The aryl hydrocarbon receptor (AHR), a latent cytoplasmic transcription factor, affects thymocyte maturation and differentiation at several stages, also including DN cells. We analyzed in murine fetal thymus organ cultures (FTOC) the outcome of AHR-signaling and found a higher frequency of DN TCRgammadelta(+) cells in the presence of the AHR-activating ligand TCDD. We detected a novel population of CD25(int/lo)CD44(hi) cells associated with preferential emigration and a TCRgammadelta(+) T cell fate of thymocytes. Sorted DN TCRgammadelta(+) emigrants could proliferate if IL-2 was available. Moreover, they suppressed the proliferation of co-cultivated, activated CD4(+) T cells. Gene expression profiles of purified DN emigrants from TCDD*FTOC revealed 295 modulated genes, 10% of which are genes of the immune system. For instance, RAG-1, TdT, and Gfi-1 were downregulated, yet genes indicative of mature thymocytes were upregulated. In conclusion, we have detected changes in the differentiation programme of fetal DN thymocytes after ligand-activation of the AHR. In particular, we observed a higher frequency of DN TCRgammadelta(+) cells with high emigration potential, and possible regulatory functions.
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Affiliation(s)
- Marc Majora
- Institute for Environmental Medical Research (IUF) at the Heinrich-Heine University of Düsseldorf, Auf'm Hennekamp 50, 40225 Düsseldorf, Germany
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14
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Masuda K, Itoi M, Amagai T, Minato N, Katsura Y, Kawamoto H. Thymic Anlage Is Colonized by Progenitors Restricted to T, NK, and Dendritic Cell Lineages. THE JOURNAL OF IMMUNOLOGY 2005; 174:2525-32. [PMID: 15728458 DOI: 10.4049/jimmunol.174.5.2525] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It remains controversial whether the thymus-colonizing progenitors are committed to the T cell lineage. A major problem that has impeded the characterization of thymic immigrants has been that the earliest intrathymic progenitors thus far identified do not necessarily represent the genuine thymic immigrants, because their developmental potential should have been influenced by contact with the thymic microenvironment. In the present study, we examined the developmental potential of the ontogenically earliest thymic progenitors of day 11 murine fetus. These cells reside in the surrounding mesenchymal region and have not encountered thymic epithelial components. Flow cytometric and immunohistochemical analyses demonstrated that these cells are exclusively Lin(-)c-kit(+)IL-7R(+). Limiting dilution analyses disclosed that the progenitors with T cell potential were abundant, while those with B cell potential were virtually absent in the region of day 11 thymic anlage. Clonal analyses reveled that they are restricted to T, NK, and dendritic cell lineages. Each progenitor was capable of forming a large number of precursors that may clonally accommodate highly diverse TCRbeta chains. These results provide direct evidence that the progenitors restricted to the T/NK/dendritic cell lineage selectively immigrate into the thymus.
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Affiliation(s)
- Kyoko Masuda
- Department of Immunology and Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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15
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Esashi E, Ito H, Ishihara K, Hirano T, Koyasu S, Miyajima A. Development of CD4+Macrophages from Intrathymic T Cell Progenitors Is Induced by Thymic Epithelial Cells. THE JOURNAL OF IMMUNOLOGY 2004; 173:4360-7. [PMID: 15383565 DOI: 10.4049/jimmunol.173.7.4360] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
It was recently demonstrated that there are CD4(+) macrophages, which exhibit strong phagocytic activity, in the thymus. They are suggested to play an important role for the elimination of apoptotic thymocytes. However, the origin and nature of CD4(+) macrophages in the thymus remain unexplored. In this study, we describe that the most immature intrathymic progenitors (CD25(-)/CD44(+)/FcR(+)) give rise to CD4(+) macrophages by oncostatin M-responsive thymic epithelial cells (ORTEC) in an IL-7-dependent manner. Neither conditioned medium of ORTEC nor a mixture of cytokines induced CD4(+) macrophages, and oncostatin M receptor was not expressed in thymocytes, suggesting that the development of CD4(+) macrophages from the immature thymocytes requires a direct interaction with ORTEC. These results collectively suggest that the development of CD4(+) macrophages from the intrathymic T cell progenitors is induced by thymic epithelial cells.
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Affiliation(s)
- Eiji Esashi
- Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo, Japan
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16
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Kim HG, de Guzman CG, Swindle CS, Cotta CV, Gartland L, Scott EW, Klug CA. The ETS family transcription factor PU.1 is necessary for the maintenance of fetal liver hematopoietic stem cells. Blood 2004; 104:3894-900. [PMID: 15328162 DOI: 10.1182/blood-2002-08-2425] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
PU.1 is a member of the ETS family of transcription factors and is required for the development of multiple hematopoietic lineages. PU.1(-/-) mice die from hematopoietic failure at about embryonic day 18.5 (e18.5) and show a complete absence of B cells, mature T cells, and macrophages. This phenotype suggests that PU.1 may function at the level of the hematopoietic stem cell (HSC) or a multilineage progenitor. To investigate the role of PU.1 in the regulation of HSCs, PU.1(-/-) embryos were analyzed at various stages of embryonic development. The absolute number and frequency of HSCs were determined by flow cytometric analysis of c-Kit(+)Thy-1.1(lo)Lin(-)Sca-1(+) (KTLS) cells. We found that KTLS cells were absent or severely reduced in PU.1(-/-) fetal liver from e12.5 to e15.5. Progenitor cells with a c-Kit(+)Lin(-)AA4.1(+) and c-Kit(+)Lin(-)CD34(+) phenotype were also severely reduced. In addition, PU.1(-/-) fetal liver at e14.5 lacked common myeloid progenitors (CMPs) and granulocyte-macrophage progenitors (GMPs) but retained megakaryocyteerythroid progenitors (MEPs). Consistent with the loss of HSC activity, a 10-fold reduction in erythroid progenitors (mature erythroid burst-forming units [BFUEs]) was observed between e14.5 and e16.5. These data suggest that PU.1 plays an important role in the maintenance or expansion of HSC number in murine fetal liver.
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Affiliation(s)
- Hyung-Gyoon Kim
- Department of Microbiology and Division of Developmental and Clinical Immunology, The University of Alabama at Birmingham, WTI Room 387, 1824 Sixth Ave South, Birmingham AL 35294-3300, USA
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17
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Freitas CS, Dalmau SR, Abdelhay E. Differential expression of notch signaling-related transcripts accompanies Pro-thymocyte proliferation and phenotype transition induced by epidermal growth factor plus insulin in fetal thymus organ cultures. Mem Inst Oswaldo Cruz 2004; 99:381-8. [PMID: 15322627 DOI: 10.1590/s0074-02762004000400007] [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] [Indexed: 11/21/2022] Open
Abstract
Thymus regression upon stressing stimuli, such as infectious diseases, is followed by organ reconstitution, paralleling its development in ontogeny. A narrow window of thymus development was here studied, encompassing the pro-T lymphoid precursor expansion during specification stages, by the use of epidermal growth factor plus insulin (INS) in murine fetal thymus organ cultures. Aiming to disclose signaling pathways related to these stages, cultured thymus lobes had their RNA extracted, for the search of transcripts differentially expressed using RNAse protection assays and reverse transcriptase-polymerase chain reactions. We found no difference that could explain INS-driven thymocyte growth, in the pattern of transcripts for death/proliferation mediators, or for a series of growth factor receptors and transcriptional regulators known as essential for thymus development. Thymocyte suspensions from cultured lobes, stained for phenotype analysis by fluorescence activated cell sorting, showed a decreased staining for Notch1 protein at cell surfaces upon INS addition. We analyzed the expression of Notch-related elements, and observed the recruitment of a specific set of transcripts simultaneous and compatible with INS-driven thymocyte growth, namely, transcripts for Notch3, for its ligand Jagged2, and for Deltex1, a mediator of a poorly characterized alternative pathway downstream of the Notch receptor.
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Affiliation(s)
- Claudia Sondermann Freitas
- Laboratório de Biologia Molecular Maury Miranda, Instituto de Biofísica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21949-900, Brazil.
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18
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Ikawa T, Masuda K, Lu M, Minato N, Katsura Y, Kawamoto H. Identification of the earliest prethymic T-cell progenitors in murine fetal blood. Blood 2003; 103:530-7. [PMID: 14512296 DOI: 10.1182/blood-2003-06-1797] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During murine fetal development, hemato-poietic progenitors start to colonize the thymic anlage at day 11 of gestation via blood stream. The present study aims at identifying the earliest prethymic progenitors in circulation. Here, we show that the interleukin-7 receptor-positive (IL-7R+) cells in Lin- c-kit+ population are circulating exclusively between days 11 and 14 of fetal age. Clonal analysis revealed that these IL-7R+ cells mostly contain T-cell lineage-restricted progenitors (p-Ts). The proportion of circulating p-Ts reaches 30% of the total p-Ts during these fetal ages, whereas virtually all B-cell lineage-restricted progenitors stay in the fetal liver, suggesting that the p-Ts are selectively released to the circulation. The circulating p-Ts retain the potential to generate natural killer cells and dendritic cells and exhibit extensive proliferation before the occurrence of T-cell receptor beta (TCRbeta) chain gene rearrangement. We propose that the wave of p-Ts in fetal blood disclosed by this study represents the ontogenically earliest thymic immigrants.
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Affiliation(s)
- Tomokatsu Ikawa
- Department of Immunology and Cell Biology, Faculty of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
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19
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Shen HQ, Lu M, Ikawa T, Masuda K, Ohmura K, Minato N, Katsura Y, Kawamoto H. T/NK Bipotent Progenitors in the Thymus Retain the Potential to Generate Dendritic Cells. THE JOURNAL OF IMMUNOLOGY 2003; 171:3401-6. [PMID: 14500634 DOI: 10.4049/jimmunol.171.7.3401] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We have previously shown that the earliest thymic progenitors retain the potential to generate T and NK cells and that they lose the bipotentiality to give rise to unipotent T and NK progenitors during the progression of intrathymic developmental stages. The present study examines the ability of these thymic progenitors for generation of dendritic cells (DC) with a new clonal assay that is capable of determining the developmental potential for DC in addition to T cells and NK cells. We found that the large majority of the T/NK bipotential progenitors in the earliest population of fetal thymus was able to generate DC. Although the DC potential is lost with the progression of the differentiation stage, some of the T/NK bipotential progenitors still retain their DC potential even at the CD44(+)CD25(+) stage.
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Affiliation(s)
- Hui Qing Shen
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
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20
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Abstract
Wnt proteins are secreted signaling molecules that regulate cell-to-cell interactions during embryogenesis in many different tissues and species. Wnt signaling is required for normal thymocyte development, most dramatically at the pro-T-cell stage, although recent reports also indicate a role for Wnt proteins in later stages of thymocyte differentiation. The Wnt cascade induces the interaction of the normally cytoplasmic cofactor beta-catenin with the nuclear Tcf and Lef transcription factors. Active Wnt signaling is an absolute requirement for T-cell development, as demonstrated by the complete block in thymocyte development observed in the absence of Tcf1 and Lef1, or in the presence of extracellular Wnt inhibitors.
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Affiliation(s)
- Frank J T Staal
- Department of Immunology, Erasmus MC, Erasmus University Rotterdam, Dr. Molewaterplein 50, 3015 GE Rotterdam, The Netherlands.
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21
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Loza MJ, Perussia B. Peripheral immature CD2-/low T cell development from type 2 to type 1 cytokine production. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:3061-8. [PMID: 12218122 DOI: 10.4049/jimmunol.169.6.3061] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Immature myeloid and NK cells exist, and undergo cytokine-induced differentiation, in the periphery. In this study, we show that also immature CD2(-/low) T cells exist in peripheral blood. These cells produce the type 2 cytokines IL-13, IL-4, and IL-5, but not IFN-gamma or IL-10, and, upon culture with IL-12- and TCR-mediated stimuli, differentiate to IL-13(+)IFN-gamma(+) cells producing high IL-2 levels, and finally IL-13(-)IFN-gamma(+) cells. The monokine combination IL-12, IL-18, and IFN-alpha substitutes for TCR-mediated stimulation to induce the same differentiation process in both immature CD2(-/low) and primary mature CD2(+) IL-13(+) T cells. IFN-alpha is needed to maintain high level IL-2 production, which is confined to type 2 cytokine-producing cells and lost in the IFN-gamma(+) ones. Upon TCR-mediated stimulation, IFN-gamma(+) cells are then induced to produce IL-10 as they undergo apoptosis. These data indicate that peripheral type 2 cytokine(+) T cells are immature cells that can differentiate to effector IFN-gamma(+) cells following a linear monokine-regulated pathway identical with that previously described for NK cells. They define the cellular bases to support that cell-mediated immune responses are regulated not only via Ag-induced activation of mature effector cells, but also via bystander monokine-induced maturation of immature T cells.
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Affiliation(s)
- Matthew J Loza
- Kimmel Cancer Center, Department of Microbiology and Immunology, Jefferson Medical College, Philadelphia, PA 19107, USA
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22
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Kakinuma S, Nishimura M, Sasanuma SI, Mita K, Suzuki G, Katsura Y, Sado T, Shimada Y. Spectrum of Znfn1a1 (Ikaros) inactivation and its association with loss of heterozygosity in radiogenic T-cell lymphomas in susceptible B6C3F1 mice. Radiat Res 2002; 157:331-40. [PMID: 11839096 DOI: 10.1667/0033-7587(2002)157[0331:soziia]2.0.co;2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Ikaros (now known as Znfn1a1), a Krüppel-type zinc-finger transcription factor that plays a critical role in both lineage commitment and differentiation of lymphoid cells, has recently been shown to function as a tumor suppressor gene. We have previously reported a high frequency of LOH (approximately 50%) at the Znfn1a1 locus in radiation-induced T-cell lymphoma in susceptible B6C3F1 mice. The aim of the present study was to delineate the types of Znfn1a1 inactivation, with special reference to the LOH status, and to determine the relative contribution of each type of Znfn1a1 inactivation in radiation-induced T-cell lymphomas in B6C3F1 mice. We demonstrated that Znfn1a1 was frequently altered (in approximately 50% of T-cell lymphomas), and that its inactivation was caused by a variety of mechanisms, which came under one of the following four categories: (1) null expression (14%); (2) expression of unusual dominant-negative isoforms (11%); (3) amino acid substitutions in the N-terminal zinc-finger domain for DNA binding caused by point mutations (22%); (4) lack of the Znfn1a1 isoform 1 due to the creation of a stop codon by insertion of a dinucleotide in exon 3 (3%). The null expression, amino acid substitutions, and dinucleotide insertion inactivation types were well correlated with LOH at the Znfn1a1 allele (86%) and were consistent with Knudson's two-hit theory. On the other hand, T-cell lymphomas expressing dominant-negative Znfn1a1 isoforms retained both alleles. These results indicate that Znfn1a1 inactivation takes place by a variety of mechanisms in radiation-induced murine T-cell lymphomas and is frequently associated with LOH, this association depending on the type of inactivation.
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Affiliation(s)
- Shizuko Kakinuma
- Division of Low Dose Radiation and Experimental Carcinogenesis, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
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23
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Abstract
Although in vivo evidence supports a role for the murine intestinal epithelium in the extrathymic generation of certain intraepithelial T lymphocytes (IEL), no intraepithelial cells with in vitro lymphoid progenitor potential have yet been demonstrated. Using reaggregate fetal thymic organ culture techniques, we show that a subset of CD3(-) cells isolated from the intestinal epithelium of young mice is capable of generating T cells (alpha beta and gamma delta) and NK1.1(+) cells in vitro. A novel IEL subset bearing a low level of CD45 was identified and found to comprise cells expressing highly immature lymphoid markers including CD34, c-kit, CD122, CD127 and high levels of CD16 and CD44. This subset represents 20-30% of intraepithelial CD45(+) cells from 4-week-old wild-type and nude mouse strains and contains cells with in vitro T cell differentiation capacity. The identification of such an early pluripotent precursor phenotype within the intestinal epithelium implies that the potential for T cell generation exists at this site, and suggests that extrathymic T cell generation may occur within the epithelium itself.
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Affiliation(s)
- J Woodward
- Walsgrave Hospital, Coventry, Warwickshire, GB.
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24
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Abstract
It has long been controversial whether hematopoiesis progresses through ordered stages of determination as in embryonic development. This is due to the absence of a methodology capable of exactly determining the developmental potential of hematopoietic stem/progenitor cells. The multilineage progenitor (MLP) assay enabled us to discriminate among seven types of hematopoietic progenitors, which are multipotent progenitor p-MTB (capable of generating myeloid, T and B cells), bipotent progenitors p-MT, p-MB and p-TB, and unipotent progenitors p-M, p-T and p-B. Among these seven types, the p-TB type progenitor was found to be absent. These findings indicate that the process of lineage commitment proceeds through an ordered but not random process. By extending the area of investigation to include the erythroid lineage, more convincing evidence for the ordered process was obtained. Detailed and exact illustration of the process of hematopoiesis will provide an opportunity to revive hematopoiesis as one of the most fascinating targets of research in developmental biology.
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Affiliation(s)
- Y Katsura
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
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25
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Abstract
The degree of T cell commitment reached by cell precursors present in the fetal liver is a controversial issue. In the present work, the occurrence of fully T cell-committed progenitors among CD45+Thy-1+CD44+ 13-day-old rat fetal liver cells was demonstrated when limiting numbers of these cells in vitro reconstituted SCID mouse fetal thymic lobes providing single lineage-containing lobes for T, natural killer or dendritic cells. In addition, expression of rat pre-TCRalpha chain mRNA was detected in the CD45+ but not in the CD45- fetal liver cells and fully rearranged TCR VBeta8-Cbeta mRNA transcripts were specifically detected in the former population, demonstrating early transcription of some rearranged TCRVBeta genes in the rat fetal liver of 13 days of gestation. Finally, fetal liver organ cultures provided low numbers of TCR gamma delta T cells and CD2+CD8+NKR-P1A- intracytoplasmic CD3+ immature T cells, which intracellularly reacted with a mAb specific to the TCRalpha Beta molecule. These results prove T, NK and DC cell lineage determination at a prethymic stage in the fetal liver.
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Affiliation(s)
- L M Alonso-C
- Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, Madrid, Spain
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26
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Oida T, Suzuki K, Nanno M, Kanamori Y, Saito H, Kubota E, Kato S, Itoh M, Kaminogawa S, Ishikawa H. Role of gut cryptopatches in early extrathymic maturation of intestinal intraepithelial T cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:3616-26. [PMID: 10725718 DOI: 10.4049/jimmunol.164.7.3616] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Lympho-hemopoietic progenitors residing in murine gut cryptopatches (CP) have been shown to generate intestinal intraepithelial T cells (IEL). To investigate the role of CP in progenitor maturation, we analyzed IEL in male mice with a truncated mutation of common cytokine receptor gamma-chain (CRgamma-/Y) in which CP were undetectable. IEL-expressing TCR-gammadelta (gammadelta-IEL) were absent, and a drastically reduced number of Thy-1highCD4+ and Thy-1highCD8alphabeta+ alphabeta-IEL were present in CRgamma-/Y mice, whereas these alphabeta-IEL disappeared from athymic CRgamma-/Y littermate mice. Athymic CRgamma-/Y mice possessed a small TCR- and alphaEbeta7 integrin-negative IEL population, characterized by the disappearance of the extrathymic CD8alphaalpha+ subset, that expressed pre-Talpha, RAG-2, and TCR-Cbeta but not CD3epsilon transcripts. These TCR- IEL from athymic CRgamma-/Y mice did not undergo Dbeta-Jbeta and Vdelta-Jdelta joinings, despite normal rearrangements at the TCR-beta and -delta loci in thymocytes from euthymic CRgamma-/Y mice. In contrast, athymic severe combined immunodeficient mice in which CP developed normally possessed two major TCR-alphaEbeta7+ CD8alphaalpha+ and CD8- IEL populations that expressed pre-Talpha, RAG-2, TCR-Cbeta, and CD3epsilon transcripts. These findings underscore the role of gut CP in the early extrathymic maturation of CD8alphaalpha+ IEL, including cell-surface expression of alphaEbeta7 integrin, CD3epsilon gene transcription, and TCR gene rearrangements.
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MESH Headings
- Animals
- CD3 Complex/genetics
- CD8 Antigens/biosynthesis
- CD8 Antigens/genetics
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- DNA-Binding Proteins/biosynthesis
- Female
- Gene Rearrangement, T-Lymphocyte
- Integrins/biosynthesis
- Integrins/deficiency
- Integrins/genetics
- Intestinal Mucosa/cytology
- Intestinal Mucosa/immunology
- Intestinal Mucosa/metabolism
- Lymphoid Tissue/cytology
- Lymphoid Tissue/immunology
- Lymphoid Tissue/metabolism
- Lymphopenia/immunology
- Lymphopenia/metabolism
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Nude
- Mice, SCID
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/deficiency
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/biosynthesis
- Receptors, Antigen, T-Cell, gamma-delta/deficiency
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Cytokine/biosynthesis
- Receptors, Cytokine/deficiency
- Receptors, Cytokine/genetics
- Stem Cells/immunology
- Stem Cells/metabolism
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- Thy-1 Antigens/biosynthesis
- Thy-1 Antigens/genetics
- Thymus Gland/cytology
- Thymus Gland/immunology
- Thymus Gland/metabolism
- Transcription, Genetic
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Affiliation(s)
- T Oida
- Department of Microbiology, Keio University School of Medicine, Tokyo, Japan
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27
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Michie AM, Carlyle JR, Schmitt TM, Ljutic B, Cho SK, Fong Q, Zúñiga-Pflücker JC. Clonal characterization of a bipotent T cell and NK cell progenitor in the mouse fetal thymus. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:1730-3. [PMID: 10657617 DOI: 10.4049/jimmunol.164.4.1730] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We recently described a population of fetal thymocytes with a CD117+NK1.1+CD90lowCD25- phenotype, which were shown to contain committed T cell and NK cell progenitors. However, the characterization of a single cell with a restricted T and NK cell precursor potential was lacking. Here, using an in vitro model for T and NK cell differentiation, we provide conclusive evidence demonstrating the existence of a clonal lineage-restricted T and NK cell progenitor. These results establish that fetal thymocytes with a CD117+NK1.1+CD90lowCD25- phenotype represent bipotent T and NK cell progenitors.
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Affiliation(s)
- A M Michie
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
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28
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Dejbakhsh-Jones S, Strober S. Identification of an early T cell progenitor for a pathway of T cell maturation in the bone marrow. Proc Natl Acad Sci U S A 1999; 96:14493-8. [PMID: 10588733 PMCID: PMC24464 DOI: 10.1073/pnas.96.25.14493] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We have identified a rare ( approximately 0.05-0.1%) population of cells (Thy-1(hi)CD16(+)CD44(hi)CD2(-)TCRalphabeta(-)B220(-)M ac-1(-)NK1. 1(-)) in the adult mouse bone marrow that generates CD4(+) and CD8(+) TCRalphabeta(+) T cells after tissue culture for 48 hr in the presence of Ly5 congenic marrow cells. The essential stages in the maturation of the progenitors were determined; the stages included an early transition from CD2(-)CD16(+)CD44(hi)TCRalphabeta(-) to CD2(+)CD16(int/-)CD44(int/-)TCRalphabeta(-) cells, and a later transition to CD4(+)CD8(+)TCRalphabeta(+) double-positive T cells that rapidly generate the CD4(+) and CD8(+) single-positive T cells. The maturation of the progenitors is almost completely arrested at the CD2(+)TCRalphabeta(-) stage by the presence of mature T cells at the initiation of cultures. This alternate pathway is supported by the marrow microenvironment; it recapitulates critical intermediary steps in intrathymic T cell maturation.
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Affiliation(s)
- S Dejbakhsh-Jones
- Division of Immunology, Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305-5111, USA
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29
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Ikawa T, Kawamoto H, Fujimoto S, Katsura Y. Commitment of common T/Natural killer (NK) progenitors to unipotent T and NK progenitors in the murine fetal thymus revealed by a single progenitor assay. J Exp Med 1999; 190:1617-26. [PMID: 10587352 PMCID: PMC2195728 DOI: 10.1084/jem.190.11.1617] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
We have established a new clonal assay system that can evenly support the development of T and natural killer (NK) cells. With this system, we show that all T cell progenitors in the earliest CD44(+)CD25(-)FcgammaRII/III(-) fetal thymus (FT) cell population retain NK potential, and that the NK lineage-committed progenitors (p-NK) also exist in this population. T cell lineage-committed progenitors (p-T), which are unable to generate NK cells, first appear at the CD44(+)CD25(-) FcgammaRII/III(+) stage in day 12 FT. The proportion of p-T markedly increases during the transition from the CD44(+)CD25(-) stage to the CD44(+)CD25(+) stage in day 14 FT. On the other hand, p-NK preferentially increase in number at the CD44(+)CD25(-) stage between days 12 and 14 of gestation. The production of p-NK continues up to the CD44(+)CD25(+) stage, but ceases before the rearrangement of T cell receptor beta chain genes. It was further shown that the CD44(+)CD25(-) CD122(+) population of day 14 FT exclusively contains p-NK. These results indicate that the earliest T cell progenitor migrating into the FT is T/NK bipotent, and strongly suggest that the bipotent progenitor continuously produces p-NK and p-T until the CD44(+)CD25(+) stage.
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Affiliation(s)
- Tomokatsu Ikawa
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Hiroshi Kawamoto
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Shinji Fujimoto
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Yoshimoto Katsura
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
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30
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Ohmura K, Kawamoto H, Fujimoto S, Ozaki S, Nakao K, Katsura Y. Emergence of T, B, and Myeloid Lineage-Committed as well as Multipotent Hemopoietic Progenitors in the Aorta-Gonad- Mesonephros Region of Day 10 Fetuses of the Mouse. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.9.4788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
We investigated the developmental potential of hemopoietic progenitors in the aorta-gonad-mesonephros (AGM) region, where the definitive type hemopoietic progenitors have been shown to emerge before the fetal liver develops. By using an assay system that is able to determine the developmental potential of individual progenitors toward the T, B, and myeloid lineages, we show that not only multipotent progenitors but also progenitors committed to the T, B, or myeloid lineage already exist in this region of day 10 fetuses. Bipotent progenitors generating myeloid and T cells or those generating myeloid and B cells were also detected, suggesting that the commitment to T and B cell lineages is in progress in the AGM region. The numbers of these progenitors, however, were only 1/200–1/1000 of those in fetal liver of day 12 fetuses. Such small numbers of progenitors suggest that hemopoiesis has just started in the AGM region of day 10 fetuses. Although most of T cell lineage-committed progenitors in the AGM region generated only a small number of immature T cells, some were able to generate a large number of mature T cells. The detection of various types of lineage-committed progenitors strongly suggests that the AGM region is not only the site of stem cell emergence, but also the site of hemopoiesis, including lineage commitment. The T cell progenitors found in the AGM region may represent the first immigrants to the thymus anlage.
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Affiliation(s)
- Koichiro Ohmura
- *Department of Immunology, Institute for Frontier Medical Sciences, and
- †Department of Medicine and Clinical Science, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Hiroshi Kawamoto
- *Department of Immunology, Institute for Frontier Medical Sciences, and
| | - Shinji Fujimoto
- *Department of Immunology, Institute for Frontier Medical Sciences, and
| | - Shoichi Ozaki
- †Department of Medicine and Clinical Science, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Kazuwa Nakao
- †Department of Medicine and Clinical Science, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - Yoshimoto Katsura
- *Department of Immunology, Institute for Frontier Medical Sciences, and
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31
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Spain LM, Guerriero A, Kunjibettu S, Scott EW. T Cell Development in PU.1-Deficient Mice. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.163.5.2681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
These studies address the role of PU.1 in T cell development through the analysis of PU.1−/− mice. We show that the majority of PU.1−/− thymocytes are blocked in differentiation prior to T cell commitment, and contain a population of thymocyte progenitors with the cell surface phenotype of CD44+, HSAbright, c-kitint, Thy-1−, CD25−, Sca-1−, CD4−, and CD8−. These cells correspond in both number and cell surface phenotype with uncommitted thymocyte progenitors found in wild-type fetal thymus. RT-PCR analysis demonstrated that PU.1 is normally expressed in this early progenitor population, but is down-regulated during T cell commitment. Rare PU.1−/− thymi, however, contained small numbers of thymocytes expressing markers of T cell commitment. Furthermore, almost 40% of PU.1−/− thymi placed in fetal thymic organ culture are capable of T cell development. Mature PU.1−/− thymocytes generated during organ culture proliferated and produced IL-2 in response to stimulation through the TCR. These data demonstrate that PU.1 is not absolutely required for T cell development, but does play a role in efficient commitment and/or early differentiation of most T progenitors.
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Affiliation(s)
| | - Anastasia Guerriero
- †Institute for Human Gene Therapy, University of Pennsylvania Medical School, Philadelphia, PA 19104
| | | | - Edward W. Scott
- †Institute for Human Gene Therapy, University of Pennsylvania Medical School, Philadelphia, PA 19104
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32
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Alonso-C LM, Vicente A, Varas A, Zapata AG. Development of rat CD45+ 13-day-old fetal liver cells in SCID mouse fetal thymic organ cultures. Int Immunol 1999; 11:1119-29. [PMID: 10383945 DOI: 10.1093/intimm/11.7.1119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A phenotypic analysis of the lympho-hemopoietic cells which occur in the liver of 13-day-old fetal rats was achieved by flow cytometry in an attempt to further characterize the rat lymphoid progenitor cells. A small fraction of rat 13-day-old fetal liver (r13FL) cells, which weakly expressed the leukocyte common antigen CD45, constituted a homogeneous Thy-1(hi), CD71(-), CD44(+), MHC class I+, CD43(+) cell subpopulation negative for CD45RC, CD3, TCRalphabeta, TCRgammadelta, CD2, CD5, CD4, CD8, CD25, CD28, NKR-P1a and sIg. On the contrary, the CD45(-) cells were a heterogeneous cell subset which expressed Thy-1, CD71 and CD44 at distinct levels. After MACS separation, the CD45(+) r13FL cells, but not the CD45(-) cell subset, in vitro repopulated 14-day-old SCID mouse fetal thymic lobes providing rat T cells, both TCRalphabeta and TCRgammadelta, NK cells, and thymic dendritic cells but not B lymphocytes. Interestingly, NKR-P1a(lo) TCRalphabeta+ or TCRgammadelta+ cells developed in the xenogeneic cultures, and a rare CD4(+)CD8(+) double-positive subpopulation among the TCRgammadelta-expressing cells accumulated in the oldest cultures. These results are discussed from the double perspective of the nature of the precursor cells which colonize the fetal thymus and the relevance of the xenogeneic SCID mouse fetal thymic microenvironment for supporting rat lymphopoiesis.
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Affiliation(s)
- L M Alonso-C
- Department of Cell Biology, Faculty of Biology, and Department of Cell Biology, Faculty of Medicine, Complutense University of Madrid, 28040 Madrid, Spain
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33
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Quantification of T-Cell Progenitors During Ontogeny: Thymus Colonization Depends on Blood Delivery of Progenitors. Blood 1999. [DOI: 10.1182/blood.v93.7.2234] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
An in vivo thymus reconstitution assay based on intrathymic injection of hematopoietic progenitors into irradiated chicks was used to determine the number of T-cell progenitors in peripheral blood, paraaortic foci, bone marrow (BM), and spleen during ontogeny. This study allowed us to analyze the regulation of thymus colonization occurring in three waves during embryogenesis. It confirmed that progenitors of the first wave of thymus colonization originate from the paraaortic foci, whereas progenitors of the second and the third waves originate from the BM. The analysis of the number of T-cell progenitors indicates that each wave of thymus colonization is correlated with a peak number of T-cell progenitors in peripheral blood, whereas they are almost absent during the periods defined as refractory for colonization. Moreover, injection of T-cell progenitors into the blood circulation showed that they homed into the thymus without delay during the refractory periods. Thus, thymus colonization kinetics depend mainly on the blood delivery of T-cell progenitors during embryogenesis.
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34
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Quantification of T-Cell Progenitors During Ontogeny: Thymus Colonization Depends on Blood Delivery of Progenitors. Blood 1999. [DOI: 10.1182/blood.v93.7.2234.407k11_2234_2243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An in vivo thymus reconstitution assay based on intrathymic injection of hematopoietic progenitors into irradiated chicks was used to determine the number of T-cell progenitors in peripheral blood, paraaortic foci, bone marrow (BM), and spleen during ontogeny. This study allowed us to analyze the regulation of thymus colonization occurring in three waves during embryogenesis. It confirmed that progenitors of the first wave of thymus colonization originate from the paraaortic foci, whereas progenitors of the second and the third waves originate from the BM. The analysis of the number of T-cell progenitors indicates that each wave of thymus colonization is correlated with a peak number of T-cell progenitors in peripheral blood, whereas they are almost absent during the periods defined as refractory for colonization. Moreover, injection of T-cell progenitors into the blood circulation showed that they homed into the thymus without delay during the refractory periods. Thus, thymus colonization kinetics depend mainly on the blood delivery of T-cell progenitors during embryogenesis.
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35
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Kawamoto H, Ohmura K, Fujimoto S, Katsura Y. Emergence of T Cell Progenitors Without B Cell or Myeloid Differentiation Potential at the Earliest Stage of Hematopoiesis in the Murine Fetal Liver. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.5.2725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
It has been unclear whether the progenitors colonizing the thymus are multipotent or T cell lineage restricted. We investigated the developmental potential of hematopoietic progenitors in various populations of liver and blood cells from day 12 fetuses using the recently established in vitro experimental system effective in determining the capability of individual progenitors to generate T, B, and myeloid cells. Multipotent progenitors (p-Multi) were exclusively found in the Sca-1 high-positive (Sca-1high) subpopulation of lineage marker (Lin)−c-kit+CD45+ fetal liver cells. Restriction of developmental capacity begins at the Sca-1high stage, and a large majority of progenitors in the Sca-1low or Sca-1− population are restricted to generate T, B, or myeloid cells. Such a lineage commitment or restriction taking place in the fetal liver is independent of the thymus, because no difference in the proportion of different types of progenitors were seen between nu/nu and nu/+ fetuses. T cell lineage-restricted progenitors (p-T) were abundant in the blood of day 12 fetuses, whereas p-Multi were undetectable. It was further shown that the p-Multi generated a large number of B and myeloid cells in the thymic lobe. These results strongly suggest that it is p-T but not p-Multi that migrate into the thymus.
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Affiliation(s)
- Hiroshi Kawamoto
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
| | - Koichiro Ohmura
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
| | - Shinji Fujimoto
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
| | - Yoshimoto Katsura
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
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36
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Abstract
Stem cells first enter the thymus around the 11th to 12th days of gestation in BALB/c mouse embryos. The phenotype of these stem cells has been difficult to determine because their entry occurs when the thymic primordium is very small and involves too few stem cells to allow studies by flow cytometry. We have been able to microdissect the thymus from embryos during this stage and immunophenotype cells in sections using a sensitive tyramide amplification system. Our results show that migrant stem cells express CD45, c-kit, CD44, CD34 and alpha4 integrin, but other markers such as CD62L, CD25, Thy-1.2, CD3epsilon, alpha5 integrin and RAG-1 expression are detected only after stem cell entry. These results should help to improve the isolation and characterization of migrant thymic stem cells.
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Affiliation(s)
- R K Suniara
- Department of Anatomy, Medical School, University of Birmingham, Edgbaston, GB.
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37
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Carlyle JR, Zúñiga-Pflücker JC. Regulation of NK1.1 Expression During Lineage Commitment of Progenitor Thymocytes. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.12.6544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
We recently identified a stage in fetal ontogeny (NK1.1+/CD117+) that defines committed progenitors for T and NK lymphocytes. These cells are found in the fetal thymus as early as day 13 of gestation, but are absent in the fetal liver. Nonetheless, multipotent precursors derived from both the fetal thymus and fetal liver are capable of rapidly differentiating to the NK1.1+ stage upon transfer into fetal thymic organ culture (FTOC). This suggests that expression of NK1.1 marks a thymus-induced lineage commitment event. We now report that a subset of the most immature fetal thymocytes (NK1.1−/CD117+) is capable of up-regulating NK1.1 expression spontaneously upon short-term in vitro culture. Interestingly, fetal liver-derived CD117+ precursors remain NK1.1− upon similar culture. Spontaneous up-regulation of NK1.1 surface expression is minimally affected by transcriptional blockade, mitogen-induced activation, or exposure of these cells to exogenous cytokines or stromal cells. These data suggest that induction of NK1.1 expression on cultured thymocytes may be predetermined by exposure to the thymic microenvironment in vivo. Importantly, multipotent CD117+ thymocytes subdivided on the basis of NK1.1 expression after short-term in vitro culture show distinct precursor potential in lymphocyte lineage reconstitution assays. This demonstrates that even the earliest precursor thymocyte population, although phenotypically homogeneous, contains a functionally heterogeneous subset of lineage-committed progenitors. These findings characterize a thymus-induced pathway in the control of lymphocyte lineage commitment to the T and NK cell fates.
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Affiliation(s)
- James R. Carlyle
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
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38
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Lacaud G, Carlsson L, Keller G. Identification of a fetal hematopoietic precursor with B cell, T cell, and macrophage potential. Immunity 1998; 9:827-38. [PMID: 9881973 DOI: 10.1016/s1074-7613(00)80648-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Despite years of investigation, precursor-progeny relationships within the developing lymphoid lineages of the hematopoietic system remain poorly defined. We have characterized the potential of precursors found within a subpopulation of fetal liver defined by AA4.1 and Fc gammaRII/III expression and predominantly restricted to lymphoid and macrophage development. When cultured in methylcellulose with appropriate cytokines, AA4.1+/Fc gammaR+ precursors generate colonies consisting of various lineages, including the combination of B cell, T cell, and macrophage. Retroviral marking studies showed that the lymphoid cells and macrophages within these colonies arise from a common precursor. These results demonstrate the presence of a common precursor with B cell-, T cell-, and macrophage-restricted potential and as such define an early restriction point within the fetal lymphoid system.
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Affiliation(s)
- G Lacaud
- National Jewish Medical and Research Center, Department of Medicine, Denver, Colorado 80206, USA
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39
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Kawamoto H, Ohmura K, Katsura Y. Cutting Edge: Presence of Progenitors Restricted to T, B, or Myeloid Lineage, but Absence of Multipotent Stem Cells, in the Murine Fetal Thymus. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.161.8.3799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The most immature population of fetal thymus (FT) cells has been shown to generate not only T but also B and myeloid cells. The present study was undertaken to clarify whether such a multipotent activity of the earliest population of FT cells is attributed to multipotent hemopoietic progenitors or to a mixture of lineage-restricted progenitors. Examination of individual FT progenitors by a recently established clonal assay system, which is able to determine the developmental potential of each progenitor toward T, B, and myeloid lineages, elucidated that a large majority of progenitors in FT were restricted to the T cell lineage. Presence of a small number of B or myeloid lineage-restricted progenitors was also disclosed. No multipotent progenitors, however, were detected in FT. These results are consistent with our recent finding that restriction of hemopoietic stem cells to T, B, and myeloid lineages takes place in the fetal liver.
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Affiliation(s)
- Hiroshi Kawamoto
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
| | - Koichiro Ohmura
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
| | - Yoshimoto Katsura
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
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40
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Carlyle JR, Zúñiga-Pflücker JC. Lineage commitment and differentiation of T and natural killer lymphocytes in the fetal mouse. Immunol Rev 1998; 165:63-74. [PMID: 9850852 DOI: 10.1111/j.1600-065x.1998.tb01230.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
T cells and natural killer (NK) cells are presumed to share a common intrathymic precursor. The development of conventional alpha beta T lymphocytes begins within the early fetal thymus, after the colonization of multipotent CD117+ precursors. Irrevocable commitment to the T lineage is marked by thymus-induced expression of CD25. However, the contribution of the fetal thymus to NK lineage commitment and differentiation remains largely unappreciated. Recently, we demonstrated that the development of functional mouse NK cells occurs first in the fetal thymus. Moreover, the appearance of mature fetal thymic NK cells (NK1.1+/CD117-) is preceded by a thymus-induced developmental stage (NK1.1+/CD117+) that marks lineage commitment of multipotent hematopoietic precursors to the T and NK-cell fates. Commitment to the T/NK bipotent stage is induced by fetal thymic stroma, but is not thymus dependent. Recent data indicate that CD90+/CD117lo fetal blood prothymocytes exhibit NK lineage potential and are phenotypically and functionally identical to fetal thymic NK1.1+/CD117+ progenitors. This finding also indicates that full commitment of circulating precursors to the T-cell lineage occurs after thymus colonization. In this review, we discuss recent insights into the cellular and molecular events involved in fetal mouse T and NK lineage commitment and differentiation to unipotent progenitors.
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Affiliation(s)
- J R Carlyle
- Department of Immunology, University of Toronto, Ontario, Canada.
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41
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Abstract
We recently identified a fetal thymic developmental stage (NK1.1+/CD117(lo)) that characterizes committed T/NK progenitors. We now report the existence of phenotypically and functionally identical T/NK progenitors in mouse fetal blood and spleen but not in fetal liver. These precursors are indistinguishable from previously characterized fetal blood "prothymocytes" (CD90+/CD117(lo)), with the exception that they express NK1.1, lack markers associated with T lineage commitment, maintain a germline TCRbeta locus, and can give rise to both T and NK cells. Moreover, NK1.1+/CD90+/CD117(lo) fetal blood precursors are present in athymic nude mice. These results suggest that the T/NK lineage commitment pathway is thymus-independent. In contrast, full commitment to the alphabeta T lineage does not precede thymus colonization.
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Affiliation(s)
- J R Carlyle
- Department of Immunology, University of Toronto, Ontario, Canada
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42
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Abstract
The generation of T cell precursors in the liver of murine embryos was studied. The total number of T cell precursors in the liver was measured in thymic organ cultures by a limiting dilution assay. Sixty T cell precursors were detected in the liver at day 11 of gestation. By day 12 the number of precursors showed a 20-fold increase, half of which could be explained by in situ proliferation as ascertained by a fetal liver organ culture assay. By day 13 a further 2-3-fold increase was observed. Whereas the number of total liver cells continued to increase, that of T cell precursors declined in the following days, suggesting a massive exit of these cells after day 13. The capacity to generate a TCRB repertoire in the cells was evaluated by a PCR assay. T cell precursors in day 11 fetal liver developed a TCRB repertoire at day 8 of culture. The cells from days 12-15 developed an identically diverse repertoire by day 6, suggesting that day 11 precursors are more immature than those of later days. A mechanism for yielding a single wave of T cell precursors in the fetal liver is discussed with a proposed model.
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Affiliation(s)
- H Ema
- INSERM U227, Département d'Immunologie, Institut Pasteur, Paris, France
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44
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Carlyle JR, Michie AM, Furlonger C, Nakano T, Lenardo MJ, Paige CJ, Zúñiga-Pflücker JC. Identification of a novel developmental stage marking lineage commitment of progenitor thymocytes. J Exp Med 1997; 186:173-82. [PMID: 9221746 PMCID: PMC2198984 DOI: 10.1084/jem.186.2.173] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Bipotent progenitors for T and natural killer (NK) lymphocytes are thought to exist among early precursor thymocytes. The identification and functional properties of such a progenitor population remain undefined. We report the identification of a novel developmental stage during fetal thymic ontogeny that delineates a population of T/NK-committed progenitors (NK1. 1(+)/CD117(+)/CD44(+)/CD25(-)). Thymocytes at this stage in development are phenotypically and functionally distinguishable from the pool of multipotent lymphoid-restricted (B, T, and NK) precursor thymocytes. Exposure of multipotent precursor thymocytes or fetal liver- derived hematopoietic progenitors to thymic stroma induces differentiation to the bipotent developmental stage. Continued exposure to a thymic microenvironment results in predominant commitment to the T cell lineage, whereas coculture with a bone marrow-derived stromal cell line results in the generation of mature NK cells. Thus, the restriction point to T and NK lymphocyte destinies from a multipotent progenitor stage is marked by a thymus-induced differentiation step.
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Affiliation(s)
- J R Carlyle
- Department of Immunology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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