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Montero-Herradón S, García-Ceca J, Zapata AG. Thymus Ontogeny and Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2025; 1471:21-49. [PMID: 40067583 DOI: 10.1007/978-3-031-77921-3_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2025]
Abstract
The thymus is a primary lymphoid organ composed of a three-dimensional (3D) epithelial network that provides a specialized microenvironment for the phenotypical and functional maturation of lymphoid progenitors. The specification of the pharyngeal endoderm to thymus fate occurs during the early stages of thymic organogenesis, independent of the expression of the transcription factor Foxn1. However, Foxn1 governs the later organogenesis of thymus together with the colonizing lymphoid cells. In the present chapter, we will review recent evidence on the topic covered in our original chapter (Muñoz and Zapata 2019). It described the early development of thymus and its resemblance to the development of endoderm-derived epithelial organs based on tubulogenesis and branching morphogenesis as well as the molecules known to be involved in these processes.
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Affiliation(s)
- Sara Montero-Herradón
- Department of Cell Biology. Faculty of Biological Sciences, Complutense University of Madrid, Madrid, Spain
- Health Research Institute, Madrid, Spain
| | - Javier García-Ceca
- Department of Cell Biology. Faculty of Biological Sciences, Complutense University of Madrid, Madrid, Spain
- Health Research Institute, Madrid, Spain
| | - Agustín G Zapata
- Department of Cell Biology. Faculty of Biological Sciences, Complutense University of Madrid, Madrid, Spain.
- Health Research Institute, Madrid, Spain.
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2
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Pardini E, Barachini S, Alì G, Infirri GS, Burzi IS, Montali M, Petrini I. Single-cell sequencing has revealed a more complex array of thymic epithelial cells. Immunol Lett 2024; 269:106904. [PMID: 39117004 DOI: 10.1016/j.imlet.2024.106904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/23/2024] [Accepted: 07/29/2024] [Indexed: 08/10/2024]
Abstract
Thymic epithelial cells participate in the maturation and selection of T lymphocytes. This review explores recent insights from single-cell sequencing regarding classifying thymic epithelial cells in both normal and neoplastic thymus. Cortical thymic epithelial cells facilitate thymocyte differentiation and contribute to positive selection. Medullary epithelial cells are distinguished by their expression of AIRE. Cells progress from a pre-AIRE state, containing precursors with cortical and medullary characteristics, termed junctional cells. Mature medullary epithelial cells exhibit promiscuous gene expression and after that downregulate AIRE mRNA. Post-AIRE cells can adopt a Hassall corpuscle-like phenotype or exhibit distinctive differentiation characteristics including tuft cells, ionocytes, neuroendocrine cells, and myoid cells.
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Affiliation(s)
- Eleonora Pardini
- Department of Translational Research and New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
| | - Serena Barachini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
| | - Greta Alì
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, Pisa, Italy
| | - Gisella Sardo Infirri
- Department of Translational Research and New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
| | - Irene Sofia Burzi
- Department of Translational Research and New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
| | - Marina Montali
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Iacopo Petrini
- Department of Translational Research and New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
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3
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Dinges SS, Amini K, Notarangelo LD, Delmonte OM. Primary and secondary defects of the thymus. Immunol Rev 2024; 322:178-211. [PMID: 38228406 PMCID: PMC10950553 DOI: 10.1111/imr.13306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The thymus is the primary site of T-cell development, enabling generation, and selection of a diverse repertoire of T cells that recognize non-self, whilst remaining tolerant to self- antigens. Severe congenital disorders of thymic development (athymia) can be fatal if left untreated due to infections, and thymic tissue implantation is the only cure. While newborn screening for severe combined immune deficiency has allowed improved detection at birth of congenital athymia, thymic disorders acquired later in life are still underrecognized and assessing the quality of thymic function in such conditions remains a challenge. The thymus is sensitive to injury elicited from a variety of endogenous and exogenous factors, and its self-renewal capacity decreases with age. Secondary and age-related forms of thymic dysfunction may lead to an increased risk of infections, malignancy, and autoimmunity. Promising results have been obtained in preclinical models and clinical trials upon administration of soluble factors promoting thymic regeneration, but to date no therapy is approved for clinical use. In this review we provide a background on thymus development, function, and age-related involution. We discuss disease mechanisms, diagnostic, and therapeutic approaches for primary and secondary thymic defects.
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Affiliation(s)
- Sarah S. Dinges
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kayla Amini
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Luigi D. Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ottavia M. Delmonte
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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4
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Zhong X, Peddada N, Wang J, Moresco JJ, Zhan X, Shelton JM, SoRelle JA, Keller K, Lazaro DR, Moresco EMY, Choi JH, Beutler B. OVOL2 sustains postnatal thymic epithelial cell identity. Nat Commun 2023; 14:7786. [PMID: 38012144 PMCID: PMC10682436 DOI: 10.1038/s41467-023-43456-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 11/09/2023] [Indexed: 11/29/2023] Open
Abstract
Distinct pathways and molecules may support embryonic versus postnatal thymic epithelial cell (TEC) development and maintenance. Here, we identify a mechanism by which TEC numbers and function are maintained postnatally. A viable missense allele (C120Y) of Ovol2, expressed ubiquitously or specifically in TECs, results in lymphopenia, in which T cell development is compromised by loss of medullary TECs and dysfunction of cortical TECs. We show that the epithelial identity of TECs is aberrantly subverted towards a mesenchymal state in OVOL2-deficient mice. We demonstrate that OVOL2 inhibits the epigenetic regulatory BRAF-HDAC complex, specifically disrupting RCOR1-LSD1 interaction. This causes inhibition of LSD1-mediated H3K4me2 demethylation, resulting in chromatin accessibility and transcriptional activation of epithelial genes. Thus, OVOL2 controls the epigenetic landscape of TECs to enforce TEC identity. The identification of a non-redundant postnatal mechanism for TEC maintenance offers an entry point to understanding thymic involution, which normally begins in early adulthood.
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Affiliation(s)
- Xue Zhong
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
| | - Nagesh Peddada
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
| | - Jianhui Wang
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
| | - James J Moresco
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
| | - Xiaowei Zhan
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
- Department of Population and Data Sciences, Quantitative Biomedical Research Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8821, USA
| | - John M Shelton
- Intermal Medicine-Histopathology Core, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8573, USA
| | - Jeffrey A SoRelle
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390-9072, USA
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, 75390-9063, USA
| | - Katie Keller
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
| | - Danielle Renee Lazaro
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
| | - Eva Marie Y Moresco
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA
| | - Jin Huk Choi
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA.
| | - Bruce Beutler
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390-8505, USA.
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5
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Bhalla P, Du Q, Kumar A, Xing C, Moses A, Dozmorov I, Wysocki CA, Cleaver OB, Pirolli TJ, Markert ML, de la Morena MT, Baldini A, van Oers NS. Mesenchymal cell replacement corrects thymic hypoplasia in murine models of 22q11.2 deletion syndrome. J Clin Invest 2022; 132:e160101. [PMID: 36136514 PMCID: PMC9663160 DOI: 10.1172/jci160101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 09/21/2022] [Indexed: 11/17/2022] Open
Abstract
22q11.2 deletion syndrome (22q11.2DS) is the most common human chromosomal microdeletion, causing developmentally linked congenital malformations, thymic hypoplasia, hypoparathyroidism, and/or cardiac defects. Thymic hypoplasia leads to T cell lymphopenia, which most often results in mild SCID. Despite decades of research, the molecular underpinnings leading to thymic hypoplasia in 22q11.2DS remain unknown. Comparison of embryonic thymuses from mouse models of 22q11.2DS (Tbx1neo2/neo2) revealed proportions of mesenchymal, epithelial, and hematopoietic cell types similar to those of control thymuses. Yet, the small thymuses were growth restricted in fetal organ cultures. Replacement of Tbx1neo2/neo2 thymic mesenchymal cells with normal ones restored tissue growth. Comparative single-cell RNA-Seq of embryonic thymuses uncovered 17 distinct cell subsets, with transcriptome differences predominant in the 5 mesenchymal subsets from the Tbx1neo2/neo2 cell line. The transcripts affected included those for extracellular matrix proteins, consistent with the increased collagen deposition we observed in the small thymuses. Attenuating collagen cross-links with minoxidil restored thymic tissue expansion for hypoplastic lobes. In colony-forming assays, the Tbx1neo2/neo2-derived mesenchymal cells had reduced expansion potential, in contrast to the normal growth of thymic epithelial cells. These findings suggest that mesenchymal cells were causal to the small embryonic thymuses in the 22q11.2DS mouse models, which was correctable by substitution with normal mesenchyme.
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Affiliation(s)
| | | | - Ashwani Kumar
- Eugene McDermott Center for Human Growth and Development
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development
- Departments of Bioinformatics and
- Population and Data Sciences, Departments of
| | | | | | | | | | - Timothy J. Pirolli
- Division of Pediatric Cardiothoracic Surgery, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Mary Louise Markert
- Departments of Pediatrics and Immunology, Duke University Medical Center, Durham, North Carolina, USA
| | - Maria Teresa de la Morena
- Division of Immunology, Department of Pediatrics, University of Washington, and Seattle Children’s Hospital, Seattle, Washington, USA
| | - Antonio Baldini
- Department Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Nicolai S.C. van Oers
- Department of Immunology
- Pediatrics
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Wang X, Liang Y, Zhu Z, Li W, Shi B, Deng Y, Li C, Sha O. Fn1 Regulates the Third Pharyngeal Pouch Patterning and Morphogenesis. J Dent Res 2022; 101:1082-1091. [PMID: 35259939 DOI: 10.1177/00220345221078775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The parathyroid and thymus are derived from the common primordia, the third pharyngeal pouch. During their development, endodermal cells actively interact with surrounding mesenchymal cells, mainly derived from neural crest cells (NCCs). However, the mechanism by which NCCs regulate the development of the third pharyngeal pouch remains largely unknown. In this study, we showed that fibronectin 1 (Fn1), which is synthesized by NCCs, modulates the functions of NCCs in the third pharyngeal pouch patterning and in the morphogenesis of the thymus/parathyroid. Loss of Fn1 in NCCs leads to decreased Foxn1 expression in the presumptive thymus domain at E11.5. In the mutant, we detected upregulation of the Hedgehog signaling activity in the presumptive parathyroid domain and downregulation of Bmp4 in the presumptive thymus domain. Tbx1, a Hedgehog signaling target gene in endoderm development, was ectopically expanded to the presumptive mutant thymus domain at E11.5. Fgf10, an important gene regulating the proliferation of endoderm development, was downregulated in the mutant NCCs. At later organogenesis stages, derivatives of the third pharyngeal pouch endoderm of mutant embryos were abnormal, showing conditions such as hypoparathyroidism, hypoplastic thymus, and ectopic thymus and parathyroid. These data support that Fn1 plays an important role in NCCs by regulating the patterning of the third pharyngeal pouch and morphogenesis of the thymus/parathyroid.
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Affiliation(s)
- X Wang
- Department of Anatomy and Histology, Shenzhen University Health Science Center, Shenzhen, China
| | - Y Liang
- Department of Anatomy and Histology, Shenzhen University Health Science Center, Shenzhen, China
| | - Z Zhu
- School of Dentistry, Shenzhen University Health Science Center, Shenzhen, China
| | - W Li
- Department of Anatomy and Histology, Shenzhen University Health Science Center, Shenzhen, China
| | - B Shi
- State Key Laboratory of Oral Diseases, National Clinical Research Centre for Oral Diseases, and Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Y Deng
- Department of Somatology, Shenzhen University General Hospital, Shenzhen, China
| | - C Li
- Department of Anatomy, Shantou University Medical College, Shantou, China
| | - O Sha
- Department of Anatomy and Histology, Shenzhen University Health Science Center, Shenzhen, China
- School of Dentistry, Shenzhen University Health Science Center, Shenzhen, China
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7
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Martinez-Ruíz GU, Morales-Sánchez A, Bhandoola A. Transcriptional and epigenetic regulation in thymic epithelial cells. Immunol Rev 2022; 305:43-58. [PMID: 34750841 PMCID: PMC8766885 DOI: 10.1111/imr.13034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 01/03/2023]
Abstract
The thymus is required for the development of both adaptive and innate-like T cell subsets. There is keen interest in manipulating thymic function for therapeutic purposes in circumstances of autoimmunity, immunodeficiency, and for purposes of immunotherapy. Within the thymus, thymic epithelial cells play essential roles in directing T cell development. Several transcription factors are known to be essential for thymic epithelial cell development and function, and a few transcription factors have been studied in considerable detail. However, the role of many other transcription factors is less well understood. Further, it is likely that roles exist for other transcription factors not yet known to be important in thymic epithelial cells. Recent progress in understanding of thymic epithelial cell heterogeneity has provided some new insight into transcriptional requirements in subtypes of thymic epithelial cells. However, it is unknown whether progenitors of thymic epithelial cells exist in the adult thymus, and consequently, developmental relationships linking putative precursors with differentiated cell types are poorly understood. While we do not presently possess a clear understanding of stage-specific requirements for transcription factors in thymic epithelial cells, new single-cell transcriptomic and epigenomic technologies should enable rapid progress in this field. Here, we review our current knowledge of transcription factors involved in the development, maintenance, and function of thymic epithelial cells, and the mechanisms by which they act.
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Affiliation(s)
- Gustavo Ulises Martinez-Ruíz
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Research Division, Faculty of Medicine, National Autonomous University of Mexico, Mexico City, Mexico
- Children’s Hospital of Mexico Federico Gomez, Mexico City, Mexico
| | - Abigail Morales-Sánchez
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
- Children’s Hospital of Mexico Federico Gomez, Mexico City, Mexico
| | - Avinash Bhandoola
- T Cell Biology and Development Unit, Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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8
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Collins C, Sharpe E, Silber A, Kulke S, Hsieh EWY. Congenital Athymia: Genetic Etiologies, Clinical Manifestations, Diagnosis, and Treatment. J Clin Immunol 2021; 41:881-895. [PMID: 33987750 PMCID: PMC8249278 DOI: 10.1007/s10875-021-01059-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 05/03/2021] [Indexed: 12/17/2022]
Abstract
Congenital athymia is an ultra-rare disease characterized by the absence of a functioning thymus. It is associated with several genetic and syndromic disorders including FOXN1 deficiency, 22q11.2 deletion, CHARGE Syndrome (Coloboma, Heart defects, Atresia of the nasal choanae, Retardation of growth and development, Genitourinary anomalies, and Ear anomalies), and Complete DiGeorge Syndrome. Congenital athymia can result from defects in genes that impact thymic organ development such as FOXN1 and PAX1 or from genes that are involved in development of the entire midline region, such as TBX1 within the 22q11.2 region, CHD7, and FOXI3. Patients with congenital athymia have profound immunodeficiency, increased susceptibility to infections, and frequently, autologous graft-versus-host disease (GVHD). Athymic patients often present with absent T cells but normal numbers of B cells and Natural Killer cells (T-B+NK+), similar to a phenotype of severe combined immunodeficiency (SCID); these patients may require additional steps to confirm the diagnosis if no known genetic cause of athymia is identified. However, distinguishing athymia from SCID is crucial, as treatments differ for these conditions. Cultured thymus tissue is being investigated as a treatment for congenital athymia. Here, we review what is known about the epidemiology, underlying etiologies, clinical manifestations, and treatments for congenital athymia.
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Affiliation(s)
- Cathleen Collins
- Department of Pediatrics, Division of Allergy Immunology, Rady Children's Hospital, University of California San Diego, San Diego, CA, USA
| | | | | | - Sarah Kulke
- Enzyvant Therapeutics, Inc, Cambridge, MA, USA
| | - Elena W Y Hsieh
- Department of Pediatrics, Section of Allergy and Immunology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA.
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, USA.
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9
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Giardino G, Borzacchiello C, De Luca M, Romano R, Prencipe R, Cirillo E, Pignata C. T-Cell Immunodeficiencies With Congenital Alterations of Thymic Development: Genes Implicated and Differential Immunological and Clinical Features. Front Immunol 2020; 11:1837. [PMID: 32922396 PMCID: PMC7457079 DOI: 10.3389/fimmu.2020.01837] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 07/08/2020] [Indexed: 02/06/2023] Open
Abstract
Combined Immunodeficiencies (CID) are rare congenital disorders characterized by defective T-cell development that may be associated with B- and NK-cell deficiency. They are usually due to alterations in genes expressed in hematopoietic precursors but in few cases, they are caused by impaired thymic development. Athymia was classically associated with DiGeorge Syndrome due to TBX1 gene haploinsufficiency. Other genes, implicated in thymic organogenesis include FOXN1, associated with Nude SCID syndrome, PAX1, associated with Otofaciocervical Syndrome type 2, and CHD7, one of the genes implicated in CHARGE syndrome. More recently, chromosome 2p11.2 microdeletion, causing FOXI3 haploinsufficiency, has been identified in 5 families with impaired thymus development. In this review, we will summarize the main genetic, clinical, and immunological features related to the abovementioned gene mutations. We will also focus on different therapeutic approaches to treat SCID in these patients.
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Affiliation(s)
- Giuliana Giardino
- Department of Translational Medical Sciences, Pediatric Section, Federico II University of Naples, Naples, Italy
| | - Carla Borzacchiello
- Department of Translational Medical Sciences, Pediatric Section, Federico II University of Naples, Naples, Italy
| | - Martina De Luca
- Department of Translational Medical Sciences, Pediatric Section, Federico II University of Naples, Naples, Italy
| | - Roberta Romano
- Department of Translational Medical Sciences, Pediatric Section, Federico II University of Naples, Naples, Italy
| | - Rosaria Prencipe
- Department of Translational Medical Sciences, Pediatric Section, Federico II University of Naples, Naples, Italy
| | - Emilia Cirillo
- Department of Translational Medical Sciences, Pediatric Section, Federico II University of Naples, Naples, Italy
| | - Claudio Pignata
- Department of Translational Medical Sciences, Pediatric Section, Federico II University of Naples, Naples, Italy
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10
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Thymus Inception: Molecular Network in the Early Stages of Thymus Organogenesis. Int J Mol Sci 2020; 21:ijms21165765. [PMID: 32796710 PMCID: PMC7460828 DOI: 10.3390/ijms21165765] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 08/07/2020] [Indexed: 11/17/2022] Open
Abstract
The thymus generates central immune tolerance by producing self-restricted and self-tolerant T-cells as a result of interactions between the developing thymocytes and the stromal microenvironment, mainly formed by the thymic epithelial cells. The thymic epithelium derives from the endoderm of the pharyngeal pouches, embryonic structures that rely on environmental cues from the surrounding mesenchyme for its development. Here, we review the most recent advances in our understanding of the molecular mechanisms involved in early thymic organogenesis at stages preceding the expression of the transcription factor Foxn1, the early marker of thymic epithelial cells identity. Foxn1-independent developmental stages, such as the specification of the pharyngeal endoderm, patterning of the pouches, and thymus fate commitment are discussed, with a special focus on epithelial–mesenchymal interactions.
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11
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Liu D, Kousa AI, O'Neill KE, Rouse P, Popis M, Farley AM, Tomlinson SR, Ulyanchenko S, Guillemot F, Seymour PA, Jørgensen MC, Serup P, Koch U, Radtke F, Blackburn CC. Canonical Notch signaling controls the early thymic epithelial progenitor cell state and emergence of the medullary epithelial lineage in fetal thymus development. Development 2020; 147:dev.178582. [PMID: 32467237 PMCID: PMC7328009 DOI: 10.1242/dev.178582] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/04/2020] [Indexed: 12/27/2022]
Abstract
Thymus function depends on the epithelial compartment of the thymic stroma. Cortical thymic epithelial cells (cTECs) regulate T cell lineage commitment and positive selection, while medullary (m) TECs impose central tolerance on the T cell repertoire. During thymus organogenesis, these functionally distinct sub-lineages are thought to arise from a common thymic epithelial progenitor cell (TEPC). However, the mechanisms controlling cTEC and mTEC production from the common TEPC are not understood. Here, we show that emergence of the earliest mTEC lineage-restricted progenitors requires active NOTCH signaling in progenitor TEC and that, once specified, further mTEC development is NOTCH independent. In addition, we demonstrate that persistent NOTCH activity favors maintenance of undifferentiated TEPCs at the expense of cTEC differentiation. Finally, we uncover a cross-regulatory relationship between NOTCH and FOXN1, a master regulator of TEC differentiation. These data establish NOTCH as a potent regulator of TEPC and mTEC fate during fetal thymus development, and are thus of high relevance to strategies aimed at generating/regenerating functional thymic tissue in vitro and in vivo. Summary: Notch signaling regulates the initial emergence of medullary thymic epithelial sublineage, implicating Notch in the maintenance of primitive thymic epithelial progenitors and uncovering its cross-interaction with Foxn1.
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Affiliation(s)
- Dong Liu
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
| | - Anastasia I Kousa
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
| | - Kathy E O'Neill
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
| | - Paul Rouse
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
| | - Martyna Popis
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
| | - Alison M Farley
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
| | - Simon R Tomlinson
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
| | - Svetlana Ulyanchenko
- Biotech Research and Innovation Centre (BRIC), Ole Maaløes Vej 5, 2200 Copenhagen, Denmark
| | | | - Philip A Seymour
- NNF Center for Stem Cell Biology, University of Copenhagen, Nørre Alle 14, DK-2200 Copenhagen N, Denmark
| | - Mette C Jørgensen
- NNF Center for Stem Cell Biology, University of Copenhagen, Nørre Alle 14, DK-2200 Copenhagen N, Denmark
| | - Palle Serup
- NNF Center for Stem Cell Biology, University of Copenhagen, Nørre Alle 14, DK-2200 Copenhagen N, Denmark
| | - Ute Koch
- Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Freddy Radtke
- Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - C Clare Blackburn
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, 5, Little France Drive, Edinburgh EH16 4UU, UK
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12
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Yang Z, Liu S, Wang Y, Chen Y, Zhang P, Liu Y, Zhang H, Zhang P, Tao Z, Xiong K. High expression of KITLG is a new hallmark activating the MAPK pathway in type A and AB thymoma. Thorac Cancer 2020; 11:1944-1954. [PMID: 32463597 PMCID: PMC7327682 DOI: 10.1111/1759-7714.13486] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 12/14/2022] Open
Abstract
Background KIT proto‐oncogene ligand (KITLG) is a pleiotropic factor which is found in diverse cancers and is involved in cell proliferation, differentiation, and survival. However, the value of KITLG in thymoma remains unclear. Methods A total of 121 thymoma samples from The Cancer Genome Atlas Thymoma (TCGA‐THYM) dataset were used to analyze KITLG related genome‐wide expression profiles, and microRNA profiles and methylation alterations and a GEO dataset‐GSE29695, including 37 samples was used as verification. For cell‐based studies, specific small interfering RNA targeting KITLG or a KITLG overexpression vector were used to clarify the changes of the MAPK pathway in an AB thymoma cell line Thy0517. Results Both datasets showed that high expression of KITLG was significantly associated with type A and AB thymoma. Through multiomic analysis of the TCGA‐THYM, it was found that with the high expression of KITLG, there were 220 upregulated and 72 downregulated genes at the mRNA level, 79 positive and 78 negative miRNAs, 28 hypermethylation and 163 hypomethylation regions. In the thymoma cell line Thy0517, it was found that the expression of GRB2 and the phosphorylation levels of BRAF, MEK1/2, and ERK1/2 in the MAPK pathway were positively correlated with the change in KITLG. Conclusions High expression of KITLG is a new hallmark of WHO type A and AB thymomas in which it might play a critical role through the activation of the MAPK signaling pathway. Additionally, it is hoped that KITLG will become a potential target for the diagnosis of type A and AB thymoma through further research in the future. Key points Significant findings of the study KIT proto‐oncogene ligand (KITLG) is a new hallmark of type A and AB thymomas which induce a series of aberrant alteration of mRNA, miRNA and DNA methylation. The expression of KITLG is significantly higher in type A and AB than other subtypes of thymoma. What this study adds KITLG activated the MAPK signaling pathway to promote type A and AB thymoma which might be a potential diagnostic biomarker or target.
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Affiliation(s)
- Zhaoyu Yang
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Shinan Liu
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Yuanguo Wang
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Yuan Chen
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Peng Zhang
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Yimei Liu
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Hui Zhang
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Peng Zhang
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Ziyou Tao
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Kai Xiong
- Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
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13
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Bhalla P, Wysocki CA, van Oers NSC. Molecular Insights Into the Causes of Human Thymic Hypoplasia With Animal Models. Front Immunol 2020; 11:830. [PMID: 32431714 PMCID: PMC7214791 DOI: 10.3389/fimmu.2020.00830] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/14/2020] [Indexed: 12/30/2022] Open
Abstract
22q11.2 deletion syndrome (DiGeorge), CHARGE syndrome, Nude/SCID and otofaciocervical syndrome type 2 (OTFCS2) are distinct clinical conditions in humans that can result in hypoplasia and occasionally, aplasia of the thymus. Thymic hypoplasia/aplasia is first suggested by absence or significantly reduced numbers of recent thymic emigrants, revealed in standard-of-care newborn screens for T cell receptor excision circles (TRECs). Subsequent clinical assessments will often indicate whether genetic mutations are causal to the low T cell output from the thymus. However, the molecular mechanisms leading to the thymic hypoplasia/aplasia in diverse human syndromes are not fully understood, partly because the problems of the thymus originate during embryogenesis. Rodent and Zebrafish models of these clinical syndromes have been used to better define the underlying basis of the clinical presentations. Results from these animal models are uncovering contributions of different cell types in the specification, differentiation, and expansion of the thymus. Cell populations such as epithelial cells, mesenchymal cells, endothelial cells, and thymocytes are variably affected depending on the human syndrome responsible for the thymic hypoplasia. In the current review, findings from the diverse animal models will be described in relation to the clinical phenotypes. Importantly, these results are suggesting new strategies for regenerating thymic tissue in patients with distinct congenital disorders.
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Affiliation(s)
- Pratibha Bhalla
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Christian A. Wysocki
- Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Nicolai S. C. van Oers
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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14
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Du Q, de la Morena MT, van Oers NSC. The Genetics and Epigenetics of 22q11.2 Deletion Syndrome. Front Genet 2020; 10:1365. [PMID: 32117416 PMCID: PMC7016268 DOI: 10.3389/fgene.2019.01365] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/12/2019] [Indexed: 12/19/2022] Open
Abstract
Chromosome 22q11.2 deletion syndrome (22q11.2del) is a complex, multi-organ disorder noted for its varying severity and penetrance among those affected. The clinical problems comprise congenital malformations; cardiac problems including outflow tract defects, hypoplasia of the thymus, hypoparathyroidism, and/or dysmorphic facial features. Additional clinical issues that can appear over time are autoimmunity, renal insufficiency, developmental delay, malignancy and neurological manifestations such as schizophrenia. The majority of individuals with 22q11.2del have a 3 Mb deletion of DNA on chromosome 22, leading to a haploinsufficiency of ~106 genes, which comprise coding RNAs, noncoding RNAs, and pseudogenes. The consequent haploinsufficiency of many of the coding genes are well described, including the key roles of T-box Transcription Factor 1 (TBX1) and DiGeorge Critical Region 8 (DGCR8) in the clinical phenotypes. However, the haploinsufficiency of these genes alone cannot account for the tremendous variation in the severity and penetrance of the clinical complications among those affected. Recent RNA and DNA sequencing approaches are uncovering novel genetic and epigenetic differences among 22q11.2del patients that can influence disease severity. In this review, the role of coding and non-coding genes, including microRNAs (miRNA) and long noncoding RNAs (lncRNAs), will be discussed in relation to their bearing on 22q11.2del with an emphasis on TBX1.
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Affiliation(s)
- Qiumei Du
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - M. Teresa de la Morena
- Department of Pediatrics, The University of Washington and Seattle Children’s Hospital, Seattle, WA, United States
| | - Nicolai S. C. van Oers
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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15
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Luan R, Liang Z, Zhang Q, Sun L, Zhao Y. Molecular regulatory networks of thymic epithelial cell differentiation. Differentiation 2019; 107:42-49. [PMID: 31238242 DOI: 10.1016/j.diff.2019.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 06/04/2019] [Accepted: 06/12/2019] [Indexed: 01/15/2023]
Abstract
Functional mature T cells are generated in the thymus. Thymic epithelial cells (TECs) provide the essential microenvironment for T cell development and maturation. According to their function and localization, TECs are roughly divided into cortical TECs (cTECs) and medullary TECs (mTECs), which are responsible for positive and negative selection, respectively. This review summarizes the current understanding of TEC biology, the identification of fetal and adult bipotent TEC progenitors, and the signaling pathways that control the development and maturation of TECs. The understanding of the ontogeny, differentiation, maturation and function of cTECs lags behind that of mTECs. Better understanding TEC biology will provide clues about TEC development and the applications of thymus engineering.
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Affiliation(s)
- Rong Luan
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhanfeng Liang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Qian Zhang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Liguang Sun
- Institute of Translational Medicine, The First Hospital, Jilin University, Changchun, Jilin, China.
| | - Yong Zhao
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China.
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16
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Banfai K, Ernszt D, Pap A, Bai P, Garai K, Belharazem D, Pongracz JE, Kvell K. "Beige" Cross Talk Between the Immune System and Metabolism. Front Endocrinol (Lausanne) 2019; 10:369. [PMID: 31275241 PMCID: PMC6591453 DOI: 10.3389/fendo.2019.00369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 05/24/2019] [Indexed: 12/25/2022] Open
Abstract
With thymic senescence the epithelial network shrinks to be replaced by adipose tissue. Transcription factor TBX-1 controls thymus organogenesis, however, the same TBX-1 has also been reported to orchestrate beige adipose tissue development. Given these different roles of TBX-1, we have assessed if thymic TBX-1 expression persists and demonstrates this dualism during adulthood. We have also checked whether thymic adipose involution could yield beige adipose tissue. We have used adult mouse and human thymus tissue from various ages to evaluate the kinetics of TBX-1 expression, as well as mouse (TEP1) and human (1889c) thymic epithelial cells (TECs) for our studies. Electron micrographs show multi-locular lipid deposits typical of beige adipose cells. Histology staining shows the accumulation of neutral lipid deposits. qPCR measurements show persistent and/or elevating levels of beige-specific and beige-indicative markers (TBX-1, EAR-2, UCP-1, PPAR-gamma). We have performed miRNome profiling using qPCR-based QuantStudio platform and amplification-free NanoString platform. We have observed characteristic alterations, including increased miR21 level (promoting adipose tissue development) and decreased miR34a level (bias toward beige adipose tissue differentiation). Finally, using the Seahorse metabolic platform we have recorded a metabolic profile (OCR/ECAR ratio) indicative of beige adipose tissue. In summary, our results support that thymic adipose tissue emerging with senescence is bona fide beige adipose tissue. Our data show how the borders blur between a key immune tissue (the thymus) and a key metabolic tissue (beige adipose tissue) with senescence. Our work contributes to the understanding of cross talk between the immune system and metabolism.
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Affiliation(s)
- Krisztina Banfai
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, University of Pécs, Pécs, Hungary
- Szentagothai Research Center, University of Pécs, Pécs, Hungary
| | - David Ernszt
- Szentagothai Research Center, University of Pécs, Pécs, Hungary
- Department of Physiology, Medical School, University of Pécs, Pécs, Hungary
| | - Attila Pap
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Peter Bai
- Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- MTA-DE Cell Biology and Signaling Research Group, Debrecen, Hungary
- MTA-DE Lendulet Laboratory of Cellular Metabolism, Debrecen, Hungary
- Research Center for Molecular Medicine, University of Debrecen, Debrecen, Hungary
| | - Kitti Garai
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, University of Pécs, Pécs, Hungary
- Szentagothai Research Center, University of Pécs, Pécs, Hungary
| | - Djeda Belharazem
- Department of Pathology, University Hospital of Mannheim, Mannheim, Germany
| | - Judit E. Pongracz
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, University of Pécs, Pécs, Hungary
- Szentagothai Research Center, University of Pécs, Pécs, Hungary
| | - Krisztian Kvell
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, University of Pécs, Pécs, Hungary
- Szentagothai Research Center, University of Pécs, Pécs, Hungary
- *Correspondence: Krisztian Kvell
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Abstract
The parathyroid glands are essential for regulating calcium homeostasis in the body. The genetic programs that control parathyroid fate specification, morphogenesis, differentiation, and survival are only beginning to be delineated, but are all centered around a key transcription factor, GCM2. Mutations in the Gcm2 gene as well as in several other genes involved in parathyroid organogenesis have been found to cause parathyroid disorders in humans. Therefore, understanding the normal development of the parathyroid will provide insight into the origins of parathyroid disorders.
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Affiliation(s)
- Kristen Peissig
- Department of Genetics, University of Georgia, 500 DW Brooks Drive, Coverdell Building Suite 270, Athens, GA 30602, USA
| | - Brian G Condie
- Department of Genetics, University of Georgia, 500 DW Brooks Drive, Coverdell Building Suite 270, Athens, GA 30602, USA
| | - Nancy R Manley
- Department of Genetics, University of Georgia, 500 DW Brooks Drive, Coverdell Building Suite 270, Athens, GA 30602, USA.
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18
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Singarapu N, Ma K, Reeh KAG, Shen J, Lancaster JN, Yi S, Xie H, Orkin SH, Manley NR, Ehrlich LIR, Jiang N, Richie ER. Polycomb Repressive Complex 2 is essential for development and maintenance of a functional TEC compartment. Sci Rep 2018; 8:14335. [PMID: 30254371 PMCID: PMC6156232 DOI: 10.1038/s41598-018-32729-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 09/12/2018] [Indexed: 12/15/2022] Open
Abstract
Thymic epithelial cells (TEC) are essential for thymocyte differentiation and repertoire selection. Despite their indispensable role in generating functional T cells, the molecular mechanisms that orchestrate TEC development from endodermal progenitors in the third pharyngeal pouch (3rd PP) are not fully understood. We recently reported that the T-box transcription factor TBX1 negatively regulates TEC development. Although initially expressed throughout the 3rd PP, Tbx1 becomes downregulated in thymus-fated progenitors and when ectopically expressed impairs TEC progenitor proliferation and differentiation. Here we show that ectopic Tbx1 expression in thymus fated endoderm increases expression of Polycomb repressive complex 2 (PRC2) target genes in TEC. PRC2 is an epigenetic modifier that represses gene expression by catalyzing trimethylation of lysine 27 on histone H3. The increased expression of PRC2 target genes suggests that ectopic Tbx1 interferes with PRC2 activity and implicates PRC2 as an important regulator of TEC development. To test this hypothesis, we used Foxn1Cre to delete Eed, a PRC2 component required for complex stability and function in thymus fated 3rd PP endoderm. Proliferation and differentiation of fetal and newborn TEC were disrupted in the conditional knockout (EedCKO) mutants leading to severely dysplastic adult thymi. Consistent with PRC2-mediated transcriptional silencing, the majority of differentially expressed genes (DEG) were upregulated in EedCKO TEC. Moreover, a high frequency of EedCKO DEG overlapped with DEG in TEC that ectopically expressed Tbx1. These findings demonstrate that PRC2 plays a critical role in TEC development and suggest that Tbx1 expression must be downregulated in thymus fated 3rd PP endoderm to ensure optimal PRC2 function.
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Affiliation(s)
- Nandini Singarapu
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, Texas, 78957, USA
| | - Keyue Ma
- Department of Biomedical Engineering, Cockrell School of Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Kaitlin A G Reeh
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, Texas, 78957, USA
| | - Jianjun Shen
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, Texas, 78957, USA
| | - Jessica N Lancaster
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Song Yi
- Department of Oncology, Dell Medical School and Department of Biomedical Engineering, Cockrell School of Engineering, The University of Texas at Austin, Austin, TX, 78712, USA.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Huafeng Xie
- Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, 02115, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Stuart H Orkin
- Division of Hematology/Oncology, Boston Children's Hospital, Boston, MA, 02115, USA.,Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA.,Harvard Stem Cell Institute, Harvard University, Cambridge, MA, 02138, USA.,Howard Hughes Medical Institute, Boston, MA, 02115, USA
| | - Nancy R Manley
- Department of Genetics, Paul D. Coverdell Center, 500 DW Brooks Drive, University of Georgia, Athens, GA, 30602, USA
| | - Lauren I R Ehrlich
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, 78712, USA.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Ning Jiang
- Department of Biomedical Engineering, Cockrell School of Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Ellen R Richie
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Science Park, Smithville, Texas, 78957, USA.
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19
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Assis AF, Li J, Donate PB, Dernowsek JA, Manley NR, Passos GA. Predicted miRNA-mRNA-mediated posttranscriptional control associated with differences in cervical and thoracic thymus function. Mol Immunol 2018; 99:39-52. [DOI: 10.1016/j.molimm.2018.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 03/09/2018] [Accepted: 04/05/2018] [Indexed: 12/12/2022]
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20
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Figueiredo M, Silva JC, Santos AS, Proa V, Alcobia I, Zilhão R, Cidadão A, Neves H. Notch and Hedgehog in the thymus/parathyroid common primordium: Crosstalk in organ formation. Dev Biol 2016; 418:268-82. [DOI: 10.1016/j.ydbio.2016.08.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 08/12/2016] [Accepted: 08/13/2016] [Indexed: 12/30/2022]
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21
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Bain VE, Gordon J, O'Neil JD, Ramos I, Richie ER, Manley NR. Tissue-specific roles for sonic hedgehog signaling in establishing thymus and parathyroid organ fate. Development 2016; 143:4027-4037. [PMID: 27633995 DOI: 10.1242/dev.141903] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/01/2016] [Indexed: 12/17/2022]
Abstract
The thymus and parathyroids develop from third pharyngeal pouch (3rd pp) endoderm. Our previous studies show that Shh null mice have smaller, aparathyroid primordia in which thymus fate specification extends into the pharynx. SHH signaling is active in both dorsal pouch endoderm and neighboring neural crest (NC) mesenchyme. It is unclear which target tissue of SHH signaling is required for the patterning defects in Shh mutants. Here, we used a genetic approach to ectopically activate or delete the SHH signal transducer Smo in either pp endoderm or NC mesenchyme. Although no manipulation recapitulated the Shh null phenotype, manipulation of SHH signaling in either the endoderm or NC mesenchyme had direct and indirect effects on both cell types during fate specification and organogenesis. SHH pathway activation throughout pouch endoderm activated ectopic Tbx1 expression and partially suppressed the thymus-specific transcription factor Foxn1, identifying Tbx1 as a key target of SHH signaling in the 3rd pp. However, ectopic SHH signaling was insufficient to expand the GCM2-positive parathyroid domain, indicating that multiple inputs, some of which might be independent of SHH signaling, are required for parathyroid fate specification. These data support a model in which SHH signaling plays both positive and negative roles in patterning and organogenesis of the thymus and parathyroids.
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Affiliation(s)
- Virginia E Bain
- Department of Genetics, Paul D. Coverdell Center, 500 DW Brooks Drive, University of Georgia, Athens, GA 30602, USA
| | - Julie Gordon
- Department of Genetics, Paul D. Coverdell Center, 500 DW Brooks Drive, University of Georgia, Athens, GA 30602, USA
| | - John D O'Neil
- Department of Genetics, Paul D. Coverdell Center, 500 DW Brooks Drive, University of Georgia, Athens, GA 30602, USA
| | - Isaias Ramos
- Department of Genetics, Paul D. Coverdell Center, 500 DW Brooks Drive, University of Georgia, Athens, GA 30602, USA
| | - Ellen R Richie
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas, M.D. Anderson Cancer Center, Science Park Research Division, Smithville, TX 78957, USA
| | - Nancy R Manley
- Department of Genetics, Paul D. Coverdell Center, 500 DW Brooks Drive, University of Georgia, Athens, GA 30602, USA
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22
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Vaidya HJ, Briones Leon A, Blackburn CC. FOXN1 in thymus organogenesis and development. Eur J Immunol 2016; 46:1826-37. [PMID: 27378598 PMCID: PMC4988515 DOI: 10.1002/eji.201545814] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 06/21/2016] [Accepted: 06/29/2016] [Indexed: 01/11/2023]
Abstract
Development of the primary T-cell repertoire takes place in the thymus. The linked processes of T-cell differentiation and T-cell repertoire selection each depend on interactions between thymocytes and thymic stromal cells; in particular, with the epithelial cells of the cortical and medullary thymic compartments (cortical and medullary thymic epithelial cells; cTECs and mTECs, respectively). The importance of the thymic epithelial cell lineage in these processes was revealed in part through analysis of nude (nu/nu) mice, which are congenitally hairless and athymic. The nude phenotype results from null mutation of the forkhead transcription factor FOXN1, which has emerged as a pivotal regulator both of thymus development and homeostasis. FOXN1 has been shown to play critical roles in thymus development, function, maintenance, and even regeneration, which positions it as a master regulator of thymic epithelial cell (TEC) differentiation. In this review, we discuss current understanding of the regulation and functions of FOXN1 throughout thymus ontogeny, from the earliest stages of organogenesis through homeostasis to age-related involution, contextualising its significance through reference to other members of the wider Forkhead family.
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Affiliation(s)
- Harsh Jayesh Vaidya
- MRC Centre for Regenerative MedicineInstitute for Stem Cell ResearchSchool of Biological SciencesEdinburghUK
| | - Alberto Briones Leon
- MRC Centre for Regenerative MedicineInstitute for Stem Cell ResearchSchool of Biological SciencesEdinburghUK
| | - C. Clare Blackburn
- MRC Centre for Regenerative MedicineInstitute for Stem Cell ResearchSchool of Biological SciencesEdinburghUK
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23
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Functional Conservation of the Glide/Gcm Regulatory Network Controlling Glia, Hemocyte, and Tendon Cell Differentiation in Drosophila. Genetics 2015; 202:191-219. [PMID: 26567182 PMCID: PMC4701085 DOI: 10.1534/genetics.115.182154] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/03/2015] [Indexed: 12/21/2022] Open
Abstract
High-throughput screens allow us to understand how transcription factors trigger developmental processes, including cell specification. A major challenge is identification of their binding sites because feedback loops and homeostatic interactions may mask the direct impact of those factors in transcriptome analyses. Moreover, this approach dissects the downstream signaling cascades and facilitates identification of conserved transcriptional programs. Here we show the results and the validation of a DNA adenine methyltransferase identification (DamID) genome-wide screen that identifies the direct targets of Glide/Gcm, a potent transcription factor that controls glia, hemocyte, and tendon cell differentiation in Drosophila. The screen identifies many genes that had not been previously associated with Glide/Gcm and highlights three major signaling pathways interacting with Glide/Gcm: Notch, Hedgehog, and JAK/STAT, which all involve feedback loops. Furthermore, the screen identifies effector molecules that are necessary for cell-cell interactions during late developmental processes and/or in ontogeny. Typically, immunoglobulin (Ig) domain-containing proteins control cell adhesion and axonal navigation. This shows that early and transiently expressed fate determinants not only control other transcription factors that, in turn, implement a specific developmental program but also directly affect late developmental events and cell function. Finally, while the mammalian genome contains two orthologous Gcm genes, their function has been demonstrated in vertebrate-specific tissues, placenta, and parathyroid glands, begging questions on the evolutionary conservation of the Gcm cascade in higher organisms. Here we provide the first evidence for the conservation of Gcm direct targets in humans. In sum, this work uncovers novel aspects of cell specification and sets the basis for further understanding of the role of conserved Gcm gene regulatory cascades.
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