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Lagou MK, Karagiannis GS. Obesity-induced thymic involution and cancer risk. Semin Cancer Biol 2023; 93:3-19. [PMID: 37088128 DOI: 10.1016/j.semcancer.2023.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 04/25/2023]
Abstract
Declining thymic functions associated either with old age (i.e., age-related thymic involution), or with acute involution as a result of stress, infectious disease, or cytoreductive therapies (e.g., chemotherapy/radiotherapy), have been associated with cancer development. A key mechanism underlying such increased cancer risk is the thymus-dependent debilitation of adaptive immunity, which is responsible for orchestrating immunoediting mechanisms and tumor immune surveillance. In the past few years, a blooming set of evidence has intriguingly linked obesity with cancer development and progression. The majority of such studies has focused on obesity-driven chronic inflammation, steroid/sex hormone and adipokine production, and hyperinsulinemia, as principal factors affecting the tumor microenvironment and driving the development of primary malignancy. However, experimental observations about the negative impact of obesity on T cell development and maturation have existed for more than half a century. Here, we critically discuss the molecular and cellular mechanisms of obesity-driven thymic involution as a previously underrepresented intermediary pathology leading to cancer development and progression. This knowledge could be especially relevant in the context of childhood obesity, because impaired thymic function in young individuals leads to immune system abnormalities, and predisposes to various pediatric cancers. A thorough understanding behind the molecular and cellular circuitries governing obesity-induced thymic involution could therefore help towards the rationalized development of targeted thymic regeneration strategies for obese individuals at high risk of cancer development.
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Affiliation(s)
- Maria K Lagou
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA; Tumor Microenvironment of Metastasis Program, Albert Einstein Cancer Center, Bronx, NY, USA
| | - George S Karagiannis
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA; Tumor Microenvironment of Metastasis Program, Albert Einstein Cancer Center, Bronx, NY, USA; Cancer Dormancy and Tumor Microenvironment Institute, Albert Einstein College of Medicine, Bronx, NY, USA; Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA; Integrated Imaging Program for Cancer Research, Albert Einstein College of Medicine, Bronx, NY, USA.
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Herppich S, Beckstette M, Huehn J. The thymic microenvironment gradually modulates the phenotype of thymus-homing peripheral conventional dendritic cells. IMMUNITY INFLAMMATION AND DISEASE 2021; 10:175-188. [PMID: 34748687 PMCID: PMC8767516 DOI: 10.1002/iid3.559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/20/2021] [Accepted: 10/25/2021] [Indexed: 11/11/2022]
Abstract
Background & Aims Thymic conventional dendritic cells (t‑DCs) are crucial for the development of T cells. A substantial fraction of t‑DCs originates extrathymically and migrates to the thymus. Here, these cells contribute to key processes of central tolerance like the clonal deletion of self‑reactive thymocytes and the generation of regulatory T (Treg) cells. So far, it is only incompletely understood which impact the thymic microenvironment has on thymus‑homing conventional DCs (cDCs), which phenotypic changes occur after the entry of peripheral cDCs into the thymus and which functional properties these modulated cells acquire. Materials & Methods In the present study, we mimicked the thymus‑homing of peripheral cDCs by introducing ex vivo isolated splenic cDCs (sp‑DCs) into reaggregated thymic organ cultures (RTOCs). Results Already after two days of culture, the transcriptomic profile of sp‑DCs was modulated and had acquired certain key signatures of t‑DCs. The regulated genes included immunomodulatory cytokines and chemokines as well as costimulatory molecules. After four days of culture, sp‑DCs appeared to have at least partially acquired the peculiar Treg cell‐inducing capacity characteristic of t‑DCs. Discussion & Conclusion Taken together, our findings indicate that peripheral cDCs possess a high degree of plasticity enabling them to quickly adapt to the thymus‐specific microenvironment. We further provide indirect evidence that thymus‐specific properties such as the efficient induction of Treg cells under homeostatic conditions can be partially transferred to thymus‑homing peripheral cDC subsets.
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Affiliation(s)
- Susanne Herppich
- Department Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Michael Beckstette
- Department Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Department of Computational Biology for Individualised Medicine, Centre for Individualised Infection Medicine, Helmholtz Centre for Infection Research and Hannover Medical School, Hannover, Germany
| | - Jochen Huehn
- Department Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
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Song Y, Sullivan T, Klarmann K, Gilbert D, O’Sullivan TN, Lu L, Wang S, Haines DC, Van Dyke T, Keller JR. RB inactivation in keratin 18 positive thymic epithelial cells promotes non-cell autonomous T cell hyperproliferation in genetically engineered mice. PLoS One 2017; 12:e0171510. [PMID: 28158249 PMCID: PMC5291521 DOI: 10.1371/journal.pone.0171510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/20/2017] [Indexed: 11/25/2022] Open
Abstract
Thymic epithelial cells (TEC), as part of thymic stroma, provide essential growth factors/cytokines and self-antigens to support T cell development and selection. Deletion of Rb family proteins in adult thymic stroma leads to T cell hyperplasia in vivo. To determine whether deletion of Rb specifically in keratin (K) 18 positive TEC was sufficient for thymocyte hyperplasia, we conditionally inactivated Rb and its family members p107 and p130 in K18+ TEC in genetically engineered mice (TgK18GT121; K18 mice). We found that thymocyte hyperproliferation was induced in mice with Rb inactivation in K18+ TEC, while normal T cell development was maintained; suggesting that inactivation of Rb specifically in K18+ TEC was sufficient and responsible for the phenotype. Transplantation of wild type bone marrow cells into mice with Rb inactivation in K18+ TEC resulted in donor T lymphocyte hyperplasia confirming the non-cell autonomous requirement for Rb proteins in K18+ TEC in regulating T cell proliferation. Our data suggests that thymic epithelial cells play an important role in regulating lymphoid proliferation and thymus size.
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Affiliation(s)
- Yurong Song
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Teresa Sullivan
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Kimberly Klarmann
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
- Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Debra Gilbert
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - T. Norene O’Sullivan
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Lucy Lu
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Sophie Wang
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Diana C. Haines
- Pathology/ Histotechnology Laboratory, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Terry Van Dyke
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Jonathan R. Keller
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
- Basic Science Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
- * E-mail:
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Roh KH, Roy K. Engineering approaches for regeneration of T lymphopoiesis. Biomater Res 2016; 20:20. [PMID: 27358746 PMCID: PMC4926289 DOI: 10.1186/s40824-016-0067-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/13/2016] [Indexed: 12/19/2022] Open
Abstract
T cells play a central role in immune-homeostasis; specifically in the induction of antigen-specific adaptive immunity against pathogens and mutated self with immunological memory. The thymus is the unique organ where T cells are generated. In this review, first the complex structures and functions of various thymic microcompartments are briefly discussed to identify critical engineering targets for regeneration of thymic functions in vitro and in vivo. Then the biomimetic regenerative engineering approaches are reviewed in three categories: 1) reconstruction of 3-D thymic architecture, 2) cellular engineering, and 3) biomaterials-based artificial presentation of critical biomolecules. For each engineering approach, remaining challenges and clinical opportunities are also identified and discussed.
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Affiliation(s)
- Kyung-Ho Roh
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Drive NW, Atlanta, GA 30332 USA
| | - Krishnendu Roy
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 950 Atlantic Drive NW, Atlanta, GA 30332 USA
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Bain V, Richie ER. Identifying the Spatial Relationships of Thymic Stromal and Thymocyte Subsets by Immunofluorescence Analysis. Methods Mol Biol 2016; 1323:75-85. [PMID: 26294399 DOI: 10.1007/978-1-4939-2809-5_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Immunofluorescence analysis of thymic tissue sections is an indispensable technique for visualizing spatial relationships among thymocyte and stromal cell subsets. The thymus is organized into distinct microenvironmental zones in which particular thymic epithelial cell (TEC) subsets support specific stages of thymocyte maturation. Conversely, thymocytes and lymphoid tissue inducer cells support functional maturation of TECs. The composition and organization of TECs change during ontogeny to generate a maximally functional organ in the young adult. Deterioration of thymic architecture and stromal organization occurs with age as the thymus undergoes involution. Such changes can be monitored by immunofluorescent staining of thymic sections obtained at different ages throughout the life-span. Here we describe methods to generate frozen or paraffin-embedded thymic tissue sections for multicolor immunofluorescence staining using antibodies to surface and/or cytoplasmic antigens.
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Affiliation(s)
- Virginia Bain
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas MD Anderson Cancer Center, 1808 Park Rd 1C, Smithville, TX, 78957, USA,
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Nitta T, Suzuki H. Thymic stromal cell subsets for T cell development. Cell Mol Life Sci 2016; 73:1021-37. [PMID: 26825337 PMCID: PMC11108406 DOI: 10.1007/s00018-015-2107-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 11/26/2015] [Accepted: 12/01/2015] [Indexed: 12/20/2022]
Abstract
The thymus provides a specialized microenvironment in which a variety of stromal cells of both hematopoietic and non-hematopoietic origin regulate development and repertoire selection of T cells. Recent studies have been unraveling the inter- and intracellular signals and transcriptional networks for spatiotemporal regulation of development of thymic stromal cells, mainly thymic epithelial cells (TECs), and the molecular mechanisms of how different TEC subsets control T cell development and selection. TECs are classified into two functionally different subsets: cortical TECs (cTECs) and medullary TECs (mTECs). cTECs induce positive selection of diverse and functionally distinct T cells by virtue of unique antigen-processing systems, while mTECs are essential for establishing T cell tolerance via ectopic expression of peripheral tissue-restricted antigens and cooperation with dendritic cells. In addition to reviewing the role of the thymic stroma in conventional T cell development, we will discuss recently discovered novel functions of TECs in the development of unconventional T cells, such as natural killer T cells and γδT cells.
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Affiliation(s)
- Takeshi Nitta
- Department of Immunology and Pathology, Research Institute, National Center for Global Health and Medicine, Chiba, 272-8516, Japan.
| | - Harumi Suzuki
- Department of Immunology and Pathology, Research Institute, National Center for Global Health and Medicine, Chiba, 272-8516, Japan.
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Satoh R, Kakugawa K, Yasuda T, Yoshida H, Sibilia M, Katsura Y, Levi B, Abramson J, Koseki Y, Koseki H, van Ewijk W, Hollander GA, Kawamoto H. Requirement of Stat3 Signaling in the Postnatal Development of Thymic Medullary Epithelial Cells. PLoS Genet 2016; 12:e1005776. [PMID: 26789017 PMCID: PMC4720355 DOI: 10.1371/journal.pgen.1005776] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 12/08/2015] [Indexed: 01/20/2023] Open
Abstract
Thymic medullary regions are formed in neonatal mice as islet-like structures, which increase in size over time and eventually fuse a few weeks after birth into a continuous structure. The development of medullary thymic epithelial cells (TEC) is dependent on NF-κB associated signaling though other signaling pathways may contribute. Here, we demonstrate that Stat3-mediated signals determine medullary TEC cellularity, architectural organization and hence the size of the medulla. Deleting Stat3 expression selectively in thymic epithelia precludes the postnatal enlargement of the medulla retaining a neonatal architecture of small separate medullary islets. In contrast, loss of Stat3 expression in cortical TEC neither affects the cellularity or organization of the epithelia. Activation of Stat3 is mainly positioned downstream of EGF-R as its ablation in TEC phenocopies the loss of Stat3 expression in these cells. These results indicate that Stat3 meditated signal via EGF-R is required for the postnatal development of thymic medullary regions. Thymic medulla is known to be an essential site for the deletion of auto-reactive T cells. Whereas it has been well documented that the development of medullary thymic epithelial cells (mTECs) depends on NF-κB associated signaling, it remained unclear whether other signaling pathways are also involved. In this context, it had been reported that conditional deletion of Stat3 alleles in TECs using cytokeratin-5 (CK5) promoter controlled Cre expression results in a profound impairment in TEC development. However, a detailed analysis of phenotypes in mTECs remained unstudied. In the present study, we show that thymic medullary regions remain as small islets when Stat3 is conditionally deleted in thymic epithelial cells, while they normal fuse to form continuous structures during postnatal development. Furthermore, we identified EGF-R mediated signal to be placed upstream of Stat3 activation, as its ablation phenocopied the loss of Stat3 expression in TECs. Thus, the present study revealed that Stat3 is required for the postnatal development of medullary regions.
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Affiliation(s)
- Rumi Satoh
- Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Kiyokazu Kakugawa
- Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan
- Laboratory for Immune Crosstalk, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Takuwa Yasuda
- Laboratory for Immunogenetics, RIKEN Center for Integrative Medical Sciences, Yokoham, Japan
| | - Hisahiro Yoshida
- Laboratory for Immunogenetics, RIKEN Center for Integrative Medical Sciences, Yokoham, Japan
| | - Maria Sibilia
- Department of Medicine I, Institute of Cancer Research, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Yoshimoto Katsura
- Division of Cell Regeneration and Transplantation, Advanced Medical Research Center, Nihon University School of Medicine, Tokyo, Japan
| | - Ben Levi
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
| | - Jakub Abramson
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
| | - Yoko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Haruhiko Koseki
- Laboratory for Developmental Genetics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Willem van Ewijk
- Department of Molecular Cell Biology and Department of Immunology, Leiden University Medical Center, RA Leiden, the Netherlands
| | - Georg A. Hollander
- Laboratory of Pediatric Immunology, Center for Biomedicine, University of Basel, and the University Children’s Hospital, Basel, Switzerland
- Laboratory of Developmental Immunology Weatherall Institute of Molecular Medicine and Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Hiroshi Kawamoto
- Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, Yokohama, Japan
- Department of Immunology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan
- * E-mail:
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9
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Roberts N, Horsley V. Developing stratified epithelia: lessons from the epidermis and thymus. WILEY INTERDISCIPLINARY REVIEWS. DEVELOPMENTAL BIOLOGY 2014; 3:389-402. [PMID: 25176390 PMCID: PMC4283209 DOI: 10.1002/wdev.146] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Revised: 06/25/2014] [Accepted: 07/02/2014] [Indexed: 01/01/2023]
Abstract
Stratified squamous epithelial cells are found in a number of organs, including the skin epidermis and the thymus. The progenitor cells of the developing epidermis form a multi-layered epithelium and appendages, like the hair follicle, to generate an essential barrier to protect against water loss and invasion of foreign pathogens. In contrast, the thymic epithelium forms a three-dimensional mesh of keratinocytes that are essential for positive and negative selection of self-restricted T cells. While these distinct stratified epithelial tissues derive from distinct embryonic germ layers, both tissues instruct immunity, and the epithelial differentiation programs and molecular mechanisms that control their development are remarkably similar. In this review, we aim to highlight some of the similarities between the thymus and the skin epidermis and its appendages during developmental specification.
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Affiliation(s)
- Natalie Roberts
- Department of Molecular, Cell and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Valerie Horsley
- Department of Molecular, Cell and Developmental Biology, Yale University, New Haven, CT 06511, USA
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Paul WE, Grossman Z. Pathogen-sensing and regulatory T cells: integrated regulators of immune responses. Cancer Immunol Res 2014; 2:503-9. [PMID: 24894087 PMCID: PMC4277876 DOI: 10.1158/2326-6066.cir-14-0046] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
We present the concept that pathogen-sensing and regulatory T cells (Treg) mutually regulate immune responses to conventional and tumor antigens through countervailing effects on dendritic cells (DC). Normally, conventional CD4 T cells recognizing their cognate antigen presented by a DC will respond only if the DC also receives a signal through its pathogen-sensing/danger/adjuvant recognition systems (the pathogen-sensing triad). However, in the absence of Tregs capable of interacting with the same DC, DCs are competent to present antigens, both foreign and self, even without the stimulation provided by the pathogen-sensing triad. Tregs recognizing an antigen presented by the DC that is also presenting antigen to a conventional CD4 T cell will prevent the activation of the CD4 T-cell responses, but a signal delivered by a member of the pathogen-sensing triad will overcome the inhibitory action of Tregs, thus allowing CD4 T-cell responses to go forward. These considerations take on special meaning for responses to "weak antigens" such as many of the antigens displayed by spontaneous human tumors.
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Affiliation(s)
- William E Paul
- Authors' Affiliation: Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland
| | - Zvi Grossman
- Authors' Affiliation: Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, Maryland
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Mignini F, Sabbatini M, Mattioli L, Cosenza M, Artico M, Cavallotti C. Neuro-immune modulation of the thymus microenvironment (review). Int J Mol Med 2014; 33:1392-400. [PMID: 24676230 DOI: 10.3892/ijmm.2014.1709] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 02/13/2014] [Indexed: 11/05/2022] Open
Abstract
The thymus is the primary site for T-cell lympho-poiesis. Its function includes the maturation and selection of antigen specific T cells and selective release of these cells to the periphery. These highly complex processes require precise parenchymal organization and compartmentation where a plethora of signalling pathways occur, performing strict control on the maturation and selection processes of T lymphocytes. In this review, the main morphological characteristics of the thymus microenvironment, with particular emphasis on nerve fibers and neuropeptides were assessed, as both are responsible for neuro-immune‑modulation functions. Among several neurotransmitters that affect thymus function, we highlight the dopaminergic system as only recently has its importance on thymus function and lymphocyte physiology come to light.
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Affiliation(s)
- Fiorenzo Mignini
- Human Anatomy, School of Drug and Health Products Science, University of Camerino, Ι-62032 Camerino, Italy
| | - Maurizio Sabbatini
- Human Anatomy, Department of Health Sciences, University of Eastern Piedmont ̔Amedeo Avogadro̓, I-28100 Novara, Italy
| | - Laura Mattioli
- Human Anatomy, School of Drug and Health Products Science, University of Camerino, Ι-62032 Camerino, Italy
| | - Monica Cosenza
- Human Anatomy, School of Drug and Health Products Science, University of Camerino, Ι-62032 Camerino, Italy
| | - Marco Artico
- Department of Anatomical, Histological, Medico-legal and Locomotor System Sciences, Sapienza University of Rome, Ι-00185 Rome, Italy
| | - Carlo Cavallotti
- Department of Sensory Organs, Sapienza University of Rome, Ι-00185 Rome, Italy
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Rezzani R, Nardo L, Favero G, Peroni M, Rodella LF. Thymus and aging: morphological, radiological, and functional overview. AGE (DORDRECHT, NETHERLANDS) 2014; 36:313-51. [PMID: 23877171 PMCID: PMC3889907 DOI: 10.1007/s11357-013-9564-5] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Accepted: 07/01/2013] [Indexed: 05/20/2023]
Abstract
Aging is a continuous process that induces many alterations in the cytoarchitecture of different organs and systems both in humans and animals. Moreover, it is associated with increased susceptibility to infectious, autoimmune, and neoplastic processes. The thymus is a primary lymphoid organ responsible for the production of immunocompetent T cells and, with aging, it atrophies and declines in functions. Universality of thymic involution in all species possessing thymus, including human, indicates it as a long-standing evolutionary event. Although it is accepted that many factors contribute to age-associated thymic involution, little is known about the mechanisms involved in the process. The exact time point of the initiation is not well defined. To address the issue, we report the exact age of thymus throughout the review so that readers can have a nicely pictured synoptic view of the process. Focusing our attention on the different stages of the development of the thymus gland (natal, postnatal, adult, and old), we describe chronologically the morphological changes of the gland. We report that the thymic morphology and cell types are evolutionarily preserved in several vertebrate species. This finding is important in understanding the similar problems caused by senescence and other diseases. Another point that we considered very important is to indicate the assessment of the thymus through radiological images to highlight its variability in shape, size, and anatomical conformation.
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Affiliation(s)
- Rita Rezzani
- Anatomy and Physiopathology Division, Department of Clinical and Experimental Sciences, Viale Europa 11, 25123, Brescia, Italy,
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Liang CC, You LR, Yen JJY, Liao NS, Yang-Yen HF, Chen CM. Thymic epithelial β-catenin is required for adult thymic homeostasis and function. Immunol Cell Biol 2013; 91:511-23. [PMID: 23856765 DOI: 10.1038/icb.2013.34] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 06/10/2013] [Accepted: 06/22/2013] [Indexed: 12/22/2022]
Abstract
The role of β-catenin in thymocyte development has been extensively studied, however, the function of β-catenin in thymic epithelial cells (TECs) remains largely unclear. Here, we demonstrate a requirement for β-catenin in keratin 5 (K5)-expressing TECs, which comprise the majority of medullary TECs (mTECs) and a progenitor subset for cortical TECs (cTECs) in the young adult thymus. We found that conditionally ablated β-catenin in K5(+)-TECs and their progeny cells resulted in thymic atrophy. The composition of TECs was also aberrantly affected. Percentages of K5(hi)K8(+)-TECs, K5(+)K8(-)-TECs and UEA1(+)-mTECs were significantly decreased and the percentage of K5(lo)K8(+)-TECs and Ly51(+)-cTECs were increased in β-catenin-deficient thymi compared with that in the control thymi. We also observed that β-catenin-deficient TEC lineage could give rise to K8(+)-cTECs more efficiently than wild-type TECs using lineage-tracing approach. Importantly, the expression levels of several transcription factors (p63, FoxN1 and Aire), which are essential for TEC differentiation, were altered in β-catenin-deficient thymi. Under the aberrant differentiation of TECs, development of all thymocytes in β-catenin-deficient thymi was impaired. Interleukin-7 (IL-7) and chemokines (Ccl19, Ccl25 and Cxcl12) levels were also downregulated in the thymic stromal cells in the mutants. Finally, introducing a BCL2 transgene in lymphoid lineages, which has been shown to rescue IL-7-deficient thymopoiesis, partially rescued the thymic atrophy and thymocyte development defects caused by induced ablation of β-catenin in K5(+)-TECs. Collectively, these findings suggest that β-catenin is required for the differentiation of TECs, thereby contributing to thymocyte development in the postnatal thymus.
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Affiliation(s)
- Chih-Chia Liang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
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Romano R, Palamaro L, Fusco A, Giardino G, Gallo V, Del Vecchio L, Pignata C. FOXN1: A Master Regulator Gene of Thymic Epithelial Development Program. Front Immunol 2013; 4:187. [PMID: 23874334 PMCID: PMC3709140 DOI: 10.3389/fimmu.2013.00187] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/25/2013] [Indexed: 11/18/2022] Open
Abstract
T cell ontogeny is a sophisticated process, which takes place within the thymus through a series of well-defined discrete stages. The process requires a proper lympho-stromal interaction. In particular, cortical and medullary thymic epithelial cells (cTECs, mTECs) drive T cell differentiation, education, and selection processes, while the thymocyte-dependent signals allow thymic epithelial cells (TECs) to maturate and provide an appropriate thymic microenvironment. Alterations in genes implicated in thymus organogenesis, including Tbx1, Pax1, Pax3, Pax9, Hoxa3, Eya1, and Six1, affect this well-orchestrated process, leading to disruption of thymic architecture. Of note, in both human and mice, the primordial TECs are yet unable to fully support T cell development and only after the transcriptional activation of the Forkhead-box n1 (FOXN1) gene in the thymic epithelium this essential function is acquired. FOXN1 is a master regulator in the TEC lineage specification in that it down-stream promotes transcription of genes, which, in turn, regulate TECs differentiation. In particular, FOXN1 mainly regulates TEC patterning in the fetal stage and TEC homeostasis in the post-natal thymus. An inborn null mutation in FOXN1 leads to Nude/severe combined immunodeficiency (SCID) phenotype in mouse, rat, and humans. In Foxn1−/− nude animals, initial formation of the primordial organ is arrested and the primordium is not colonized by hematopoietic precursors, causing a severe primary T cell immunodeficiency. In humans, the Nude/SCID phenotype is characterized by congenital alopecia of the scalp, eyebrows, and eyelashes, nail dystrophy, and a severe T cell immunodeficiency, inherited as an autosomal recessive disorder. Aim of this review is to summarize all the scientific information so far available to better characterize the pivotal role of the master regulator FOXN1 transcription factor in the TEC lineage specifications and functionality.
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Affiliation(s)
- Rosa Romano
- Department of Translational Medical Sciences, "Federico II" University , Naples , Italy
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16
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Lai JJ, Lai KP, Zeng W, Chuang KH, Altuwaijri S, Chang C. Androgen receptor influences on body defense system via modulation of innate and adaptive immune systems: lessons from conditional AR knockout mice. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1504-12. [PMID: 22959669 DOI: 10.1016/j.ajpath.2012.07.008] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 07/09/2012] [Accepted: 07/18/2012] [Indexed: 12/18/2022]
Abstract
Upon insult, such as infection or tissue injury, the innate and adaptive immune systems initiate a series of responses to defend the body. Recent studies from immune cell-specific androgen receptor (AR) knockout mice demonstrated that androgen and its receptor (androgen/AR) play significant roles in both immune regulations. In the innate immunity, androgen/AR is required for generation and proper function of neutrophils; androgen/AR also regulates wound healing processes through macrophage recruitment and proinflammatory cytokine production. In adaptive immunity, androgen/AR exerts suppressive effects on development and activation of T and B cells. Removal of such suppression causes thymic enlargement and excessive export of immature B cells. Altogether, androgen/AR plays distinct roles in individual immune cells, and targeting androgen/AR may help in treatment and management of immune-related diseases.
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Affiliation(s)
- Jiann-Jyh Lai
- George Whipple Laboratory for Cancer Research, University of Rochester Medical Center, Rochester, New York, USA
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17
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Li J, Cai H, Jin J, Wang Q, Miao D. X-ray irradiation selectively kills thymocytes of different stages and impairs the maturation of donor-derived CD4(+)CD8(+) thymocytes in recipient thymus. J Biomed Res 2012; 26:355-64. [PMID: 23554771 PMCID: PMC3613732 DOI: 10.7555/jbr.26.20120003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/03/2012] [Accepted: 02/25/2012] [Indexed: 12/13/2022] Open
Abstract
The aim of the present study was to determine whether the sensitivity of thymocytes to X-ray radiation depends on their proliferative states and whether radiation impairs the maturation of donor-derived thymocytes in recipient thymus. We assigned 8-week-old C57BL/6J mice into three treatment groups: 1) untreated; 2) X-ray radiation; 3) X-ray radiation plus bone marrow transplantation with donor bone marrow cells from transgenic mice expressing enhanced green fluorescent protein (GFP) on a universal promoter. After 4 weeks, the size of the thymus, the number and proliferation of thymocytes and ratios of different stage thymocytes were analyzed by immunohistochemistry and flow cytometry. The results showed that: 1) CD4+CD8+ thymocytes were more sensitive to X-ray radiation-induced cell death than other thymocytes; 2) the proliferative capacity of CD4+CD8+ thymocytes was higher than that of other thymocytes; 3) the size of the thymus, the number of thymocytes and ratios of thymocytes of different stages in irradiated mice recovered to the normal level of untreated mice by bone marrow transplantation; 4) the ratio of GFP-positive CD4+CD8+ thymocytes increased significantly, whereas the ratio of GFP-positive CD4+ or CD8+ thymocytes decreased significantly. These results indicate that the degree of sensitivity of thymocytes to X-ray radiation depends on their proliferative states and radiation impairs the maturation of donor-derived CD4+CD8+ thymocytes in recipient thymus.
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Affiliation(s)
- Jinbo Li
- The Research Center for Bone and Stem Cells, Department of Human Anatomy, Nanjing Medical University, Nanjing, Jiangsu 210029, China
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18
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From murine to human nude/SCID: the thymus, T-cell development and the missing link. Clin Dev Immunol 2012; 2012:467101. [PMID: 22474479 PMCID: PMC3303720 DOI: 10.1155/2012/467101] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 12/09/2011] [Indexed: 11/17/2022]
Abstract
Primary immunodeficiencies (PIDs) are disorders of the immune system, which lead to increased susceptibility to infections. T-cell defects, which may affect T-cell development/function, are approximately 11% of reported PIDs. The pathogenic mechanisms are related to molecular alterations not only of genes selectively expressed in hematopoietic cells but also of the stromal component of the thymus that represents the primary lymphoid organ for T-cell differentiation. With this regard, the prototype of athymic disorders due to abnormal stroma is the Nude/SCID syndrome, first described in mice in 1966. In man, the DiGeorge Syndrome (DGS) has long been considered the human prototype of a severe T-cell differentiation defect. More recently, the human equivalent of the murine Nude/SCID has been described, contributing to unravel important issues of the T-cell ontogeny in humans. Both mice and human diseases are due to alterations of the FOXN1, a developmentally regulated transcription factor selectively expressed in skin and thymic epithelia.
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Milićević NM, Miljković MD, Milićević Z, Labudović-Borović M, Wang X, Laan M, Peterson P, Randall TD, Westermann J. Role of CCL19/21 and its possible signaling through CXCR3 in development of metallophilic macrophages in the mouse thymus. Histochem Cell Biol 2011; 135:593-601. [PMID: 21611855 DOI: 10.1007/s00418-011-0818-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/12/2011] [Indexed: 01/01/2023]
Abstract
We have already shown that metallophilic macrophages, which represent an important component in the thymus physiology, are lacking in lymphotoxin-β receptor-deficient mice. However, further molecular requirements for the development and correct tissue positioning of these cells are unknown. To this end, we studied a panel of mice deficient in different chemokine ligand or receptor genes. In contrast to normal mice, which have these cells localized in the thymic cortico-medullary zone (CMZ) as a distinct row positioned between the cortex and medulla, in plt/plt (paucity of lymph node T cells) mice lacking the functional CCL19/CCL21 chemokines, metallophilic macrophages are not present in the thymic tissue. Interestingly, in contrast to the CCL19/21-deficient thymus, metallophilic macrophages are present in the CCR7-deficient thymus. However, these cells are not appropriately located in the CMZ, but are mostly crowded in central parts of thymic medulla. The double staining revealed that these metallophilic macrophages are CCR7-negative and CXCR3-positive. In the CXCL13-deficient thymus the number, morphology and localization of metallophilic macrophages are normal. Thus, our study shows that CCL19/21 and its possible signaling through CXCR3 are required for the development of thymic metallophilic macrophages, whereas the CXCL13-CXCR5 signaling is not necessary.
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Affiliation(s)
- Novica M Milićević
- Institute of Histology and Embryology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
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20
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Abstract
Immunoglobulin E (IgE) is a key mediator of anti-parasitic and anti-tumour immunity. However it is also a critical component of atopic and autoimmune diseases, and elevated serum IgE levels are a common indicator of immune dysregulation. In this review we survey the literature on genetic associations of elevated IgE in humans and mice. We find that defects in a limited number of pathways explain the majority of gene associations with IgE. Commonly, elevated IgE is associated with defects in Th bias and B cell class switching, severe T cell tolerance defects and defects in immunity at the host-environment interface. These genetic data demonstrate the mechanisms of control over IgE production and the manner in which they can be circumvented.
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Affiliation(s)
- John Altin
- John Curtin School of Medical Research, Australian National University, Canberra 0200, Australia
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21
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Goldberg GL, Dudakov JA, Reiseger JJ, Seach N, Ueno T, Vlahos K, Hammett MV, Young LF, Heng TSP, Boyd RL, Chidgey AP. Sex steroid ablation enhances immune reconstitution following cytotoxic antineoplastic therapy in young mice. THE JOURNAL OF IMMUNOLOGY 2010; 184:6014-24. [PMID: 20483779 DOI: 10.4049/jimmunol.0802445] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cytotoxic antineoplastic therapy is used to treat malignant disease but results in long-term immunosuppression in postpubertal and adult individuals, leading to increased incidence and severity of opportunistic infections. We have previously shown that sex steroid ablation (SSA) reverses immunodeficiencies associated with age and hematopoietic stem cell transplantation in both autologous and allogeneic settings. In this study, we have assessed the effects of SSA by surgical castration on T cell recovery of young male mice following cyclophosphamide treatment as a model for the impact of chemotherapy. SSA increased thymic cellularity, involving all of the thymocyte subsets and early T lineage progenitors. It also induced early repair of damage to the thymic stromal microenvironment, which is crucial to the recovery of a fully functional T cell-based immune system. These functional changes in thymic stromal subsets included enhanced production of growth factors and chemokines important for thymopoiesis, which preceded increases in both thymocyte and stromal cellularity. These effects collectively translated to an increase in peripheral and splenic naive T cells. In conclusion, SSA enhances T cell recovery following cyclophosphamide treatment of mice, at the level of the thymocytes and their stromal niches. This provides a new approach to immune reconstitution following antineoplastic therapy.
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Affiliation(s)
- Gabrielle L Goldberg
- Immune Regeneration Laboratory, Monash Immunology and Stem Cell Laboratories, Monash University, Clayton, Australia.
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22
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Yamamoto T, Morita SI, Go R, Obata M, Katsuragi Y, Fujita Y, Maeda Y, Yokoyama M, Aoyagi Y, Ichikawa H, Mishima Y, Kominami R. Clonally Expanding Thymocytes Having Lineage Capability in Gamma-Ray–Induced Mouse Atrophic Thymus. Int J Radiat Oncol Biol Phys 2010; 77:235-43. [DOI: 10.1016/j.ijrobp.2009.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 11/05/2009] [Accepted: 11/07/2009] [Indexed: 01/06/2023]
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23
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Medina-Contreras O, Soldevila G, Patiño-Lopez G, Canche-Pool E, Valle-Rios R, Ortiz-Navarrete V. Role of CRTAM during mouse early T lymphocytes development. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2010; 34:196-202. [PMID: 19799932 DOI: 10.1016/j.dci.2009.09.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2009] [Revised: 09/07/2009] [Accepted: 09/21/2009] [Indexed: 05/28/2023]
Abstract
CRTAM was reported as a novel receptor expressed in activated NKT and CD8 T lymphocytes. However, we have recently shown that it is also expressed in several non-immune tissues. In opposition to what has been stated for lymphoid cells, CRTAM expression is constitutive in epithelia, suggesting a role in cell-cell interactions. Given the importance of cell interactions during T lymphocyte development, we evaluated CRTAM during T lymphocyte ontogeny. Here we show that CRTAM has an unexpected constitutive expression in adult thymocytes and, remarkably, it is sustained during all stages of thymocyte development. CRTAM expression is restricted to CD8 and all DN subpopulations, with a consistent pattern from E13.5 stage to adult mice. Blocking CRTAM interaction with CADM1 impairs thymus growth, uncovering a novel role in thymus development, with a consequent impact in thymocyte maturation. Thus, CRTAM interaction with CADM1 is involved in structural maintenance of the thymic lobes.
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Affiliation(s)
- Oscar Medina-Contreras
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados (CINVESTAV), México, D.F., Mexico
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24
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Dong P, Yang Y, Wang WP. The role of intestinal bifidobacteria on immune system development in young rats. Early Hum Dev 2010; 86:51-8. [PMID: 20106610 DOI: 10.1016/j.earlhumdev.2010.01.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 12/28/2009] [Accepted: 01/04/2010] [Indexed: 02/06/2023]
Abstract
AIM The effects of intestinal bifidobacteria on the development of immunity in early life were explored. METHODS Neonatal SD rats born and housed under strict barrier systems were fed from birth with sufficient antibiotics (bifidobacteria minimisation group) or supplemented daily with 1x10(10) colony-forming units of live Bifidobacterium longum (bifidobacteria supplementation group). Relevant indices of immune development were determined at one, three and six weeks old. RESULTS Compared to the control group, minimisation of the intestinal bifidobacteria delayed maturation of dendritic cells in Peyer's Patches and the development of T cells in the thymus, increased IL-4 secretion in the plasma, down-regulated IL-12, IL-10 mRNA and the interferon-gamma/IL-4 mRNA ratio in intestinal mucosa, decreased interferon-gamma mRNA in cultured peripheral blood mononuclear cells (PBMCs), and reduced immunoglobulin-M production in cultured PBMCs. Conversely, supplementation with bifidobacteria promoted dendritic cell maturation in Peyer's Patches, up-regulated IL-12, IL-10, interferon-gamma mRNA and the interferon-gamma/IL-4 ratio in intestinal mucosa, increased interferon-gamma gene expression in cultured PBMCs, and raised immunoglobulin-M secretion in cultured PBMCs. CONCLUSIONS Intestinal bifidobacteria could promote the maturation of dendritic cells and its expression of IL-12 locally in the gut, influence the development of T cells in the thymus, favour the development of T-helper cell type 1 response by increasing the local and systemic expression of interferon-gamma and ensure the intestinal regulatory T cell response by promoting the local expression of IL-10. In addition, they enhance antibody synthesis by PBMCs, thereby affecting the development of both the gut and systemic immunity in early life.
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Affiliation(s)
- Ping Dong
- Children's Hospital, Pediatrics Department of Shanghai Medical College, Fudan University, Shanghai, PR China
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25
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Dudakov JA, Goldberg GL, Reiseger JJ, Vlahos K, Chidgey AP, Boyd RL. Sex steroid ablation enhances hematopoietic recovery following cytotoxic antineoplastic therapy in aged mice. THE JOURNAL OF IMMUNOLOGY 2009; 183:7084-94. [PMID: 19890044 DOI: 10.4049/jimmunol.0900196] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Cytotoxic antineoplastic therapy is widely used in the clinic as a treatment for malignant diseases. The treatment itself, however, leads to long-term depletion of the adaptive immune system, which is more pronounced in older patients, predominantly due to thymic atrophy. We and others have previously shown that withdrawal of sex steroids is able to regenerate the aged thymus and enhance recovery from autologous and allogeneic hematopoietic stem cell transplant. In this study we have examined the effects of sex steroid ablation (SSA) on the recovery of lymphopoiesis in the bone marrow (BM) and thymus following treatment with the chemotherapeutic agent cyclophosphamide (Cy) in middle-aged and old mice. Furthermore, we have also examined the impact of this regeneration on peripheral immunity. SSA enhanced the recovery of BM resident hematopoietic stem cells and lymphoid progenitors and promoted lymphopoiesis. Interestingly, Cy alone caused a profound increase in the recently described common lymphoid progenitor 2 (CLP-2) population in the BM. In the thymus, SSA caused a profound increase in cellularity as well as all intrathymic T-lineage progenitors including early T-lineage progenitors (ETPs) and non-canonical T cell progenitors such as the CLP-2. We also found that these transferred into numerical increases in the periphery with enhanced B and T cell numbers. Furthermore, these lymphocytes were found to have an enhanced functional capacity with no perturbation of the TCR repertoire. Taken together, these results provide the basis for the use of SSA in the clinic to enhance treatment outcomes from cytotoxic antineoplastic therapy.
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Affiliation(s)
- Jarrod A Dudakov
- Immune Regeneration Laboratory, Monash Immunology and Stem Cell Laboratories, Monash University, Wellington Road, Clayton VIC 3800, Australia.
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26
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Abstract
As the expanding obese population grows older, their successful immunologic aging will be critical to enhancing the health span. Obesity increases risk of infections and cancer, suggesting adverse effects on immune surveillance. Here, we report that obesity compromises the mechanisms regulating T-cell generation by inducing premature thymic involution. Diet-induced obesity reduced thymocyte counts and significantly increased apoptosis of developing T-cell populations. Obesity accelerated the age-related reduction of T-cell receptor (TCR) excision circle bearing peripheral lymphocytes, an index of recently generated T cells from thymus. Consistent with reduced thymopoiesis, dietary obesity led to reduction in peripheral naive T cells with increased frequency of effector-memory cells. Defects in thymopoiesis in obese mice were related with decrease in the lymphoid-primed multipotent progenitor (Lin-Sca1+Kit+ Flt3+) as well as common lymphoid progenitor (Lin-Sca1+CD117(lo)CD127+) pools. The TCR spectratyping analysis showed that obesity compromised V-beta TCR repertoire diversity. Furthermore, the obesity induced by melanocortin 4 receptor deficiency also constricted the T-cell repertoire diversity, recapitulating the thymic defects observed with diet-induced obesity. In middle-aged humans, progressive adiposity with or without type 2 diabetes also compromised thymic output. Collectively, these findings establish that obesity constricts T-cell diversity by accelerating age-related thymic involution.
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27
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Relland LM, Mishra MK, Haribhai D, Edwards B, Ziegelbauer J, Williams CB. Affinity-based selection of regulatory T cells occurs independent of agonist-mediated induction of Foxp3 expression. THE JOURNAL OF IMMUNOLOGY 2009; 182:1341-50. [PMID: 19155480 DOI: 10.4049/jimmunol.182.3.1341] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Natural regulatory T (nT(reg)) cells recognize self-peptides with high affinity, yet the understanding of how affinity influences their selection in the thymus is incomplete. We use altered peptide ligands in transgenic mice and in organ culture to create thymic environments spanning a broad range of ligand affinity. We demonstrate that the nT(reg) TCR repertoire is shaped by affinity-based selection, similar to conventional T cells. The effect of each ligand on the two populations is distinct, consistent with early nT(reg) cell lineage specification. Foxp3 expression is an independent process that does not rely on "high affinity" binding per se, but requires a high-potency agonistic interaction for its induction. The timing of ligand exposure, TGFbeta signaling, and the organization of the thymic architecture are also important. The development of nT(reg) cells is therefore a multistep process in which ligand affinity, potency, and timing of presentation all play a role in determining cell fate.
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Affiliation(s)
- Lance M Relland
- Section of Rheumatology, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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28
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Masuda K, Germeraad WTV, Satoh R, Itoi M, Ikawa T, Minato N, Katsura Y, van Ewijk W, Kawamoto H. Notch activation in thymic epithelial cells induces development of thymic microenvironments. Mol Immunol 2009; 46:1756-67. [PMID: 19250680 DOI: 10.1016/j.molimm.2009.01.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Accepted: 01/25/2009] [Indexed: 01/18/2023]
Abstract
The development and maintenance of thymic microenvironments depends on sustained crosstalk signals derived from developing thymocytes. However, the molecular basis for the initial phase in the lymphoid dependent development of thymic epithelial cells (TECs) remains unclear. Here we show that similarly to regular thymocytes, developing B cells enforced to express the Notch ligand Delta-like-1 (DLL1) efficiently induce the non-polarized, three-dimensional (3D) meshwork architecture of cortical TECs in fetal thymic organ culture. Moreover, the DLL1-overexpressing B cells induce well-developed distinct medullae. Such medullae also arose in lobes reconstituted with Rag2(-/-) thymocytes overexpressing DLL1. Our present findings thus strongly suggest that Notch signaling from thymocytes to TECs induces TEC development at an early phase of thymic organogenesis. The present approach using non-T lineage cells for the in vitro construction of thymic environments may also provide a novel tool for thymus regeneration and T cell production in immunocompromised individuals.
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Affiliation(s)
- Kyoko Masuda
- Laboratory for Lymphocyte Development, RIKEN Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
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29
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Odaka C. Localization of mesenchymal cells in adult mouse thymus: their abnormal distribution in mice with disorganization of thymic medullary epithelium. J Histochem Cytochem 2008; 57:373-82. [PMID: 19110482 DOI: 10.1369/jhc.2008.952895] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Thymic mesenchymal cells are known to be important for the development of the early fetal thymus into a functionally mature organ supporting T cell differentiation. We examined the expression of mesenchymal markers: pan-mesenchymal marker ER-TR7, desmin, alpha-smooth muscle actin (alpha-SMA), and alpha- and beta-chain of platelet-derived growth factor receptor (PDGFRalpha, PDGFRbeta) in thymi of normal adult mice. Desmin and ER-TR7 revealed specific staining in the capsule, septa, and perivascular cells. Most perivascular cells highly expressed PDGFRbeta at the same levels as desmin. Low expression of PDGFRalpha was detected in the capsule, intralobular septa, and some perivascular cells of normal adult thymi. alpha-SMA, used to identify vascular smooth muscle cells, was detectable on arterioles and some large venules but not on capillaries. Thus, desmin, PDGFRalpha, and PDGFRbeta were localized in the capsule, septa, and perivascular cells in thymus of adult mouse, although there were differences in the expression level among these markers. On the other hand, the expression of mesenchymal markers was detectable in the region of the thymic medullary epithelium of lymphotoxin beta receptor-deficient mice and plt/plt mice, indicating that mesenchymal cells were abnormally localized in the region. These results suggest that disorganization of the medullary epithelium may be accompanied by aberrant distribution of mesenchyme in adult mouse thymus.
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Affiliation(s)
- Chikako Odaka
- Department of Safety Research on Blood and Biological Products, National Institute of Infectious Diseases, 4-7-1, Gakuen, Musashimurayama, Tokyo 208-0011, Japan.
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30
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Holland AM, Zakrzewski JL, Goldberg GL, Ghosh A, van den Brink MRM. Adoptive precursor cell therapy to enhance immune reconstitution after hematopoietic stem cell transplantation in mouse and man. Semin Immunopathol 2008; 30:479-87. [PMID: 19015856 DOI: 10.1007/s00281-008-0138-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Accepted: 10/01/2008] [Indexed: 01/23/2023]
Abstract
Hematopoietic stem cell transplantation is a curative therapy for hematological malignancies. T cell deficiency following transplantation is a major cause of morbidity and mortality. In this review, we discuss adoptive transfer of committed precursor cells to enhance T cell reconstitution and improve overall prognosis after transplantation.
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Affiliation(s)
- Amanda M Holland
- Department of Immunology, Memorial Sloan-Kettering Cancer Center, New York, NY, 10065, USA
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31
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Foxn1 is required to maintain the postnatal thymic microenvironment in a dosage-sensitive manner. Blood 2008; 113:567-74. [PMID: 18978204 DOI: 10.1182/blood-2008-05-156265] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The postnatal thymus is the primary source of T cells in vertebrates, and many if not all stages of thymocyte development require interactions with thymic epithelial cells (TECs). The Foxn1 gene is a key regulator of TEC differentiation, and is required for multiple aspects of fetal TEC differentiation. Foxn1 is also expressed in the postnatal thymus, but its function after birth is unknown. We generated a Foxn1 allele with normal fetal expression and thymus development, but decreased expression in the postnatal thymus. This down-regulation causes rapid thymic compartment degeneration and reduced T-cell production. TEC subsets that express higher Foxn1 levels are most sensitive to its down-regulation, in particular MHCII(hi)UEA-1(hi) medullary TECs. The requirement for Foxn1 is extremely dosage sensitive, with small changes in Foxn1 levels having large effects on thymus phenotypes. Our results provide the first evidence that Foxn1 is required to maintain the postnatal thymus. Furthermore, the similarities of this phenotype to accelerated aging-related thymic involution support the possibility that changes in Foxn1 expression in TECs during aging contribute to the mechanism of involution.
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32
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Singh N, Singh SM, Singh G. Restoration of Thymic Homeostasis in a Tumor-Bearing Host by in Vivo Administration of Medicinal Herb Tinospora Cordifolia. Immunopharmacol Immunotoxicol 2008; 27:585-99. [PMID: 16435578 DOI: 10.1080/08923970500416764] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In vivo administration of alcoholic extract of medicinal plant Tinospora cordifolia (TC) to mice bearing a spontaneous T cell lymphoma designated as Dalton's lymphoma prevented tumor growth-dependent regression of thymus. TC was found to augment proliferation of thymocytes with a concomitant decrease in thymocyte apoptosis. It also resulted in a decrease in the number of Hassal's corpuscles. Restoration of thymus homeostasis was caused by TC-dependent augmentation in production of thymocyte growth promoting cytokines Interleukin-2 and Interferon-gamma from thymocytes. TC was found to downregulate thymocyte apoptosis by modulation of Caspase pathway. TC administration retarded tumor growth and prolonged survival of tumor-bearing mice. The possible mechanisms are discussed.
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Affiliation(s)
- Nisha Singh
- School of Biotechnology, Banaras Hindu University, Varanasi, UP, India
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33
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Frericks M, Burgoon LD, Zacharewski TR, Esser C. Promoter analysis of TCDD-inducible genes in a thymic epithelial cell line indicates the potential for cell-specific transcription factor crosstalk in the AhR response. Toxicol Appl Pharmacol 2008; 232:268-79. [DOI: 10.1016/j.taap.2008.07.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 06/20/2008] [Accepted: 07/07/2008] [Indexed: 12/19/2022]
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34
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Liston A, Enders A, Siggs OM. Unravelling the association of partial T-cell immunodeficiency and immune dysregulation. Nat Rev Immunol 2008; 8:545-58. [PMID: 18551129 DOI: 10.1038/nri2336] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Partial T-cell immunodeficiencies constitute a heterogeneous cluster of disorders characterized by an incomplete reduction in T-cell number or activity. The immune deficiency component of these diseases is less severe than that of the severe T-cell immunodeficiencies and therefore some ability to respond to infectious organisms is retained. Unlike severe T-cell immunodeficiencies, however, partial immunodeficiencies are commonly associated with hyper-immune dysregulation, including autoimmunity, inflammatory diseases and elevated IgE production. This causative association is counter-intuitive--immune deficiencies are caused by loss-of-function changes to the T-cell component, whereas the coincident autoimmune symptoms are the consequence of gain-of-function changes. This Review details the genetic basis of partial T -cell immunodeficiencies and draws on recent advances in mouse models to propose mechanisms by which a reduction in T-cell numbers or function may disturb the population-dependent balance between activation and tolerance.
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Affiliation(s)
- Adrian Liston
- John Curtin School of Medical Research, Australian National University, Canberra, ACT 0200, Australia.
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35
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dos Santos NR, Williame M, Gachet S, Cormier F, Janin A, Weih D, Weih F, Ghysdael J. RelB-dependent stromal cells promote T-cell leukemogenesis. PLoS One 2008; 3:e2555. [PMID: 18596915 PMCID: PMC2440518 DOI: 10.1371/journal.pone.0002555] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Accepted: 05/28/2008] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The Rel/NF-kappaB transcription factors are often activated in solid or hematological malignancies. In most cases, NF-kappaB activation is found in malignant cells and results from activation of the canonical NF-kappaB pathway, leading to RelA and/or c-Rel activation. Recently, NF-kappaB activity in inflammatory cells infiltrating solid tumors has been shown to contribute to solid tumor initiation and progression. Noncanonical NF-kappaB activation, which leads to RelB activation, has also been reported in breast carcinoma, prostate cancer, and lymphoid leukemia. METHODOLOGY/PRINCIPAL FINDINGS Here we report a novel role for RelB in stromal cells that promote T-cell leukemogenesis. RelB deficiency delayed leukemia onset in the TEL-JAK2 transgenic mouse model of human T acute lymphoblastic leukemia. Bone marrow chimeric mouse experiments showed that RelB is not required in the hematopoietic compartment. In contrast, RelB plays a role in radio-resistant stromal cells to accelerate leukemia onset and increase disease severity. CONCLUSIONS/SIGNIFICANCE The present results are the first to uncover a role for RelB in the crosstalk between non-hematopoietic stromal cells and leukemic cells. Thus, besides its previously reported role intrinsic to specific cancer cells, the noncanonical NF-kappaB pathway may also play a pro-oncogenic role in cancer microenvironmental cells.
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Affiliation(s)
- Nuno R. dos Santos
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Maryvonne Williame
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Stéphanie Gachet
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Françoise Cormier
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
| | - Anne Janin
- INSERM Unité 728, Université Paris VII, Hôpital Saint-Louis, Paris, France
| | - Debra Weih
- Leibniz-Institute for Age Research – Fritz-Lipmann-Institute (FLI), Jena, Germany
| | - Falk Weih
- Leibniz-Institute for Age Research – Fritz-Lipmann-Institute (FLI), Jena, Germany
| | - Jacques Ghysdael
- Institut Curie, Centre de Recherche, Orsay, France
- CNRS UMR146, Orsay, France
- * E-mail:
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Histochemical and molecular overview of the thymus as site for T-cells development. ACTA ACUST UNITED AC 2008; 43:73-120. [PMID: 18555891 DOI: 10.1016/j.proghi.2008.03.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 03/11/2008] [Indexed: 12/19/2022]
Abstract
The thymus represents the primary site for T cell lymphopoiesis, providing a coordinated set for critical factors to induce and support lineage commitment, differentiation and survival of thymus-seeding cells. One irrefutable fact is that the presence of non-lymphoid cells through the thymic parenchyma serves to provide coordinated migration and differentiation of T lymphocytes. Moreover, the link between foetal development and normal anatomy has been stressed in this review. Regarding thymic embryology, its epithelium is derived from the embryonic endodermal layer, with possible contributions from the ectoderm. A series of differentiating steps is essential, each of which must be completed in order to provide the optimum environment for thymic development and function. The second part of this article is focused on thymic T-cell development and differentiation, which is a stepwise process, mediated by a variety of stromal cells in different regions of the organ. It depends strongly on the thymic microenvironment, a cellular network formed by epithelial cells, macrophages, dendritic cells and fibroblasts, that provide the combination of cellular interactions, cytokines and chemokines to induce thymocyte precursors for the generation of functional T cells. The mediators of this process are not well defined but it has been demonstrated that some interactions are under neuroendocrine control. Moreover, some studies pointed out that reciprocal signals from developing T cells also are essential for establishment and maintenance of the thymic microenvironment. Finally, we have also highlighted the heterogeneity of the lymphoid, non-lymphoid components and the multi-phasic steps of thymic differentiation. In conclusion, this review contributes to an understanding of the complex mechanisms in which the foetal and postnatal thymus is involved. This could be a prerequisite for developing new therapies specifically aimed to overcome immunological defects, linked or not-linked to aging.
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Picchietti S, Guerra L, Selleri L, Buonocore F, Abelli L, Scapigliati G, Mazzini M, Fausto AM. Compartmentalisation of T cells expressing CD8alpha and TCRbeta in developing thymus of sea bass Dicentrarchus labrax (L.). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2008; 32:92-9. [PMID: 17532466 DOI: 10.1016/j.dci.2007.04.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2006] [Revised: 04/05/2007] [Accepted: 04/08/2007] [Indexed: 05/15/2023]
Abstract
Eggs, larvae, post-larvae and sexually immature juveniles of the teleost Dicentrarchus labrax (L.) were assayed for the expression of genes encoding the T cell receptor beta and CD8alpha. RT-PCR of RNA extracted from larvae revealed TCRbeta transcripts from day 25 post-hatching (ph) and CD8alpha transcripts from 26 days later. At day 51 ph, CD8alpha and TCRbeta mRNAs were localised by in situ hybridisation in thymocytes of the outer and lateral zones of the thymic paired glands. From day 75 ph onwards the signal was mainly detected in the outer region, drawing a cortex-medulla demarcation. In 1-year-old fish, CD8alpha+ and TCRbeta+ thymocytes almost filled the cortex and extended in large cords in the medulla. A CD8alpha(-)TCRbeta+ subcapsular lymphoid zone was evident near the septa coming from the inner connective capsule that delimited the thymus. The localisation of CD8alpha and TCRbeta transcripts demonstrated a compartmentalisation of the juvenile thymus due to distinct localisation of thymocytes at different developmental stages.
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Affiliation(s)
- Simona Picchietti
- Dipartimento Scienze Ambientali, Università della Tuscia, 01100 Viterbo, Italy
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39
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Aging and the immune system. Clin Immunol 2008. [DOI: 10.1016/b978-0-323-04404-2.10033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Nitta T, Murata S, Ueno T, Tanaka K, Takahama Y. Thymic microenvironments for T-cell repertoire formation. Adv Immunol 2008; 99:59-94. [PMID: 19117532 DOI: 10.1016/s0065-2776(08)00603-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Functionally competent immune system includes a functionally competent T-cell repertoire that is reactive to foreign antigens but is tolerant to self-antigens. The repertoire of T cells is primarily formed in the thymus through positive and negative selection of developing thymocytes. Immature thymocytes that undergo V(D)J recombination of T-cell antigen receptor (TCR) genes and that express the virgin repertoire of TCRs are generated in thymic cortex. The recent discovery of thymoproteasomes, a molecular complex specifically expressed in cortical thymic epithelial cells (cTEC), has revealed a unique role of cTEC in cuing the further development of immature thymocytes in thymic cortex, possibly by displaying unique self-peptides that induce positive selection. Cortical thymocytes that receive TCR-mediated positive selection signals are destined to survive for further differentiation and are induced to express CCR7, a chemokine receptor. Being attracted to CCR7 ligands expressed by medullary thymic epithelial cells (mTEC), CCR7-expressing positively selected thymocytes relocate to thymic medulla. The medullary microenvironment displays another set of unique self-peptides for trimming positively selected T-cell repertoire to establish self-tolerance, via promiscuous expression of tissue-specific antigens by mTEC and efficient antigen presentation by dendritic cells. Recent results demonstrate that tumor necrosis factor (TNF) superfamily ligands, including receptor activating NF-kappaB ligand (RANKL), CD40L, and lymphotoxin, are produced by positively selected thymocytes and pivotally regulate mTEC development and thymic medulla formation.
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Affiliation(s)
- Takeshi Nitta
- Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima 770-8503, Japan
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41
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Dixit VD, Yang H, Sun Y, Weeraratna AT, Youm YH, Smith RG, Taub DD. Ghrelin promotes thymopoiesis during aging. J Clin Invest 2007; 117:2778-90. [PMID: 17823656 PMCID: PMC1964507 DOI: 10.1172/jci30248] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Accepted: 06/26/2007] [Indexed: 11/17/2022] Open
Abstract
The decline in adaptive immunity, T lymphocyte output, and the contraction of the TCR repertoire with age is largely attributable to thymic involution. The loss of thymic function with age may be due to diminished numbers of progenitors and the loss of critical cytokines and hormones from the thymic microenvironment. We have previously demonstrated that the orexigenic hormone ghrelin is expressed by immune cells and regulates T cell activation and inflammation. Here we report that ghrelin and ghrelin receptor expression within the thymus diminished with progressive aging. Infusion of ghrelin into 14-month-old mice significantly improved the age-associated changes in thymic architecture and thymocyte numbers, increasing recent thymic emigrants and improving TCR diversity of peripheral T cell subsets. Ghrelin-induced thymopoiesis during aging was associated with enhanced early thymocyte progenitors and bone marrow-derived Lin(-)Sca1(+)cKit(+) cells, while ghrelin- and growth hormone secretagogue receptor-deficient (GHS-R-deficient) mice displayed enhanced age-associated thymic involution. Leptin also enhanced thymopoiesis in aged but not young mice. Our findings demonstrate what we believe to be a novel role for ghrelin and its receptor in thymic biology and suggest a possible therapeutic benefit of harnessing this pathway in the reconstitution of thymic function in immunocompromised subjects.
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Affiliation(s)
- Vishwa Deep Dixit
- Clinical Immunology Section, Laboratory of Immunology, Intramural Research Program, National Institute on Aging, NIH, Baltimore, Maryland, USA.
Laboratory of Neuroendocrine Immunology, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
Roy M. and Phyllis Gough Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, USA
| | - Hyunwon Yang
- Clinical Immunology Section, Laboratory of Immunology, Intramural Research Program, National Institute on Aging, NIH, Baltimore, Maryland, USA.
Laboratory of Neuroendocrine Immunology, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
Roy M. and Phyllis Gough Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, USA
| | - Yuxiang Sun
- Clinical Immunology Section, Laboratory of Immunology, Intramural Research Program, National Institute on Aging, NIH, Baltimore, Maryland, USA.
Laboratory of Neuroendocrine Immunology, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
Roy M. and Phyllis Gough Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, USA
| | - Ashani T. Weeraratna
- Clinical Immunology Section, Laboratory of Immunology, Intramural Research Program, National Institute on Aging, NIH, Baltimore, Maryland, USA.
Laboratory of Neuroendocrine Immunology, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
Roy M. and Phyllis Gough Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, USA
| | - Yun-Hee Youm
- Clinical Immunology Section, Laboratory of Immunology, Intramural Research Program, National Institute on Aging, NIH, Baltimore, Maryland, USA.
Laboratory of Neuroendocrine Immunology, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
Roy M. and Phyllis Gough Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, USA
| | - Roy G. Smith
- Clinical Immunology Section, Laboratory of Immunology, Intramural Research Program, National Institute on Aging, NIH, Baltimore, Maryland, USA.
Laboratory of Neuroendocrine Immunology, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
Roy M. and Phyllis Gough Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, USA
| | - Dennis D. Taub
- Clinical Immunology Section, Laboratory of Immunology, Intramural Research Program, National Institute on Aging, NIH, Baltimore, Maryland, USA.
Laboratory of Neuroendocrine Immunology, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, USA.
Roy M. and Phyllis Gough Huffington Center on Aging, Baylor College of Medicine, Houston, Texas, USA
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Cai AQ, Landman KA, Hughes BD, Witt CM. T cell development in the thymus: From periodic seeding to constant output. J Theor Biol 2007; 249:384-94. [PMID: 17869276 DOI: 10.1016/j.jtbi.2007.07.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 07/27/2007] [Accepted: 07/27/2007] [Indexed: 11/15/2022]
Abstract
T cell development occurs in the thymus throughout life. Recent experimental findings show that the seeding of the thymus by multi-potent stem cells from the bone marrow is periodic rather than continuous, as previously assumed. However it is well known that the output rate of cells from the thymus is relatively constant. A quantitative model is used to verify the current hypotheses regarding T cell development in the steady state mouse thymus. The results show that the thymus could be at a periodic steady state with out-of-phase thymocyte populations. Experiments to examine possible periodic fluctuations in the thymus are proposed and methods for further analysis are outlined.
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Affiliation(s)
- Anna Q Cai
- Department of Mathematics and Statistics, The University of Melbourne, Vic. 3010, Australia
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Rossi SW, Chidgey AP, Parnell SM, Jenkinson WE, Scott HS, Boyd RL, Jenkinson EJ, Anderson G. Redefining epithelial progenitor potential in the developing thymus. Eur J Immunol 2007; 37:2411-8. [PMID: 17694573 DOI: 10.1002/eji.200737275] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Cortical and medullary epithelium represent specialised cell types that play key roles in thymocyte development, including positive and negative selection of the T cell repertoire. While recent evidence shows that these epithelial lineages share a common embryonic origin, the phenotype and possible persistence of such progenitor cells in the thymus at later stages of development remain controversial. Through use of a panel of reagents including the putative progenitor marker Mts24, we set out to redefine the stages in the development of thymic epithelium. In the early embryonic day (E)12 thymus anlagen we find that almost all epithelial cells are uniformly positive for Mts24 expression. In addition, while the thymus at later stages of development was found to contain distinct Mts24(+) and Mts24(-) epithelial subsets, thymus grafting experiments show that both Mts24(+) and Mts24(-) epithelial subsets share the ability to form organised cortical and medullary thymic microenvironments that support T cell development, a function shown previously to be lost in the Mts24(-) cells by E15 when lower cell doses were used. Our data help to clarify stages in thymic epithelial development and provide important information in relation to currently used markers of epithelial progenitors.
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Affiliation(s)
- Simona W Rossi
- MRC Centre for Immune Regulation, Institute for Biomedical Research, University of Birmingham Medical School, Birmingham, UK
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44
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Unbiased analysis, enrichment and purification of thymic stromal cells. J Immunol Methods 2007; 329:56-66. [PMID: 17988680 DOI: 10.1016/j.jim.2007.09.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 09/21/2007] [Accepted: 09/24/2007] [Indexed: 11/23/2022]
Abstract
The microenvironment of the thymus consists of functionally discrete niches composed of distinct stromal cell subsets. Clinically relevant changes affecting T-cell differentiation occur within these niches with age and injury caused by irradiation and chemotherapy treatments. The study of thymic stromal cells has been hampered by the technical difficulty in isolating significant numbers of this important population. Here we present an improved protocol for enzymatic isolation of stromal cells that enables comparative flow cytometric analyses and their purification for downstream cellular or molecular analysis. Fractions analyzed throughout enzymatic digestion of the thymus revealed that various stromal subsets are isolated at characteristic intervals. This highlights the importance of pooling all cells isolated from the thymus for numerical and phenotypic analysis to avoid biased representation of subpopulations. We also describe refined magnetic bead separation techniques that yield almost pure preparations of CD45(-) stroma. Sorting of these suspensions using defined markers enabled purification of the major epithelial subsets, confirmed by keratin staining and PCR analysis. This three-step procedure represents a rapid, reproducible method for the unbiased purification of the stromal cells that direct thymic T-cell differentiation.
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Zöller M, Rajasagi M, Vitacolonna M, Luft T. Thymus repopulation after allogeneic reconstitution in hematological malignancies. Exp Hematol 2007; 35:1891-905. [PMID: 17920753 DOI: 10.1016/j.exphem.2007.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2007] [Revised: 06/05/2007] [Accepted: 08/02/2007] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Active vaccination in the allogeneically reconstituted tumor-bearing host essentially requires donor T-cell tolerance. To create a basis for vaccination in the allogeneically reconstituted, lymphoma-bearing host, we elaborate a reconstitution protocol that supports thymus repopulation and tolerance induction. METHODS Myeloreductively conditioned, lymphoma-bearing mice were vaccinated after reconstitution with hematopoietic progenitor cells. Readout systems included recovery of donor-derived T cells, graft vs host disease (GVHD), anti-host and anti-lymphoma cytotoxicity, as well as tumor growth rate and tumor rejection. RESULTS In tumor-free mice, myeloreductive conditioning, together with natural killer cell depletion of the host and transfer of T cell-depleted bone marrow cells, allows reconstitution without severe GVHD. However, in hematological malignancies, donor-derived T-progenitor cells hardly immigrated into the thymus. As a consequence, the frequency of severe GVHD was significantly increased, which prohibited active vaccination. Thymus repopulation became improved by strengthening myeloreductive conditioning; by supporting thymocyte expansion via interleukin-7; and, most strongly, by a small dose of donor-derived CD4(+)CD8(+) thymocytes, which preferentially homed into the thymus. Active vaccination, in combination with this reconstitution protocol, did not strengthen GVHD, but significantly improved survival time and survival rate of lymphoma-bearing mice. CONCLUSION The negative impact of hematological malignancies on thymus repopulation and central tolerance induction can, at least in part, be corrected by application of a small number of donor-derived T-progenitor cells.
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Affiliation(s)
- Margot Zöller
- Department of Tumor Progression and Tumor Defense, German Cancer Research Center, Heidelberg, Germany.
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Legrand N, Dontje W, van Lent AU, Spits H, Blom B. Human thymus regeneration and T cell reconstitution. Semin Immunol 2007; 19:280-8. [DOI: 10.1016/j.smim.2007.10.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Accepted: 10/02/2007] [Indexed: 01/12/2023]
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Li J, Iwanami N, Hoa VQ, Furutani-Seiki M, Takahama Y. Noninvasive intravital imaging of thymocyte dynamics in medaka. THE JOURNAL OF IMMUNOLOGY 2007; 179:1605-15. [PMID: 17641027 DOI: 10.4049/jimmunol.179.3.1605] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In vivo imaging of thymocytes has not been accomplished due to their localization deep within opaque body and high susceptibility to surgical stress. To overcome these problems, medaka is useful because of transparency and ex-uterine development. We report the noninvasive detection of thymocytes in transgenic medaka that express fluorescent protein under the control of immature-lymphocyte-specific rag1. We show that lymphoid progenitor cells colonize the thymus primordium in an anterior-to-posterior orientation-specific manner, revealing that extrathymic anterior components guide prevascular thymus colonization. We also show that developing thymocytes acquire "random walk motility" along with the expression of Ag receptors and coreceptors, suggesting that thymocyte walking is initiated at the developmental stage for repertoire selection. Thus, transgenic medaka enables real-time intravital imaging of thymocytes without surgical invasion.
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Affiliation(s)
- Jie Li
- Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, Tokushima, Japan
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48
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Gray DHD, Tull D, Ueno T, Seach N, Classon BJ, Chidgey A, McConville MJ, Boyd RL. A unique thymic fibroblast population revealed by the monoclonal antibody MTS-15. THE JOURNAL OF IMMUNOLOGY 2007; 178:4956-65. [PMID: 17404277 DOI: 10.4049/jimmunol.178.8.4956] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T cell differentiation in the thymus is dependent upon signals from thymic stromal cells. Most studies into the nature of these signals have focused only on the support provided by the thymic epithelium, but there is an emerging view that other stromal cells such as mesenchymal fibroblasts may also be involved. Study of the latter has been hindered by a lack of appropriate markers, particularly those allowing their isolation. In this study, we describe a new surface marker of thymic stroma, MTS-15, and demonstrate its specificity for fibroblasts and a subset of endothelial cells. Coculture experiments showed that the determinant could be transferred between cells. Extensive biochemical analysis demonstrated that the Ag bound by MTS-15 was the glycosphingolipid Forssman determinant, consistent with the distribution observed. Transcriptional analysis of purified MTS-15(+) thymic fibroblasts revealed a unique expression profile for a number of chemokines and growth factors important to thymocyte and epithelial cell development. In a model of cyclophosphamide-induced thymic involution and regeneration, fibroblasts were found to expand extensively and express growth factors important to epithelial proliferation and increased T cell production just before thymic regeneration. Overall, this study identifies a useful marker of thymic fibroblasts and highlights this subpopulation as a key player in thymic function by virtue of their support of both thymocytes and epithelial cells.
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Affiliation(s)
- Daniel H D Gray
- Monash Immunology and Stem Cell Laboratories, Monash University, Clayton, Victoria, Australia
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49
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Parmo-Cabañas M, García-Bernal D, García-Verdugo R, Kremer L, Márquez G, Teixidó J. Intracellular signaling required for CCL25-stimulated T cell adhesion mediated by the integrin alpha4beta1. J Leukoc Biol 2007; 82:380-91. [PMID: 17510295 DOI: 10.1189/jlb.1206726] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The alpha4beta1 integrin is expressed on thymocytes and mediates cell attachment to its ligands CS-1/fibronectin (CS-1/FN) and VCAM-1 in the thymus. The chemokine CCL25 is highly expressed in the thymus, where it binds to its receptor CCR9 on thymocytes promoting migration and activation. We show here that alpha4beta1 and CCR9 are coexpressed mainly on double- and single-positive thymocytes and that CCL25 strongly stimulates CD4(+)CD8(+) and CD4(+)CD8(-) adhesion to CS-1/FN and VCAM-1. CCL25 rapidly activated the GTPases Rac and Rap1 on thymocytes, and this activation was required for stimulation of adhesion, as detected using the CCR9(+)/alpha4beta1(+) human T cell line Molt-4. To study the role on CCL25-stimulated adhesion of the Rac downstream effector Wiskott-Aldrich syndrome protein family verproline-homologous protein 2 (WAVE2) as well as of Rap1-GTP-interacting proteins, regulator of adhesion and cell polarization enriched in lymphoid tissues (RAPL) and Rap1-GTP-interacting adapter molecule (RIAM), we knocked down their expression and tested transfectant attachment to alpha4beta1 ligands. We found that WAVE2 and RAPL but not RIAM were required for efficient triggering by CCL25 of T cell adhesion to CS-1/FN and VCAM-1. Although Rac and Rap1 activation was required during early steps of T cell adhesion stimulated by CCL25, WAVE2 was needed for the development of actin-dependent T cell spreading subsequent to adhesion strengthening but not during initial alpha4beta1-ligand interactions. These results suggest that regulation by CCL25 of adhesion of thymocyte subpopulations mediated by alpha4beta1 could contribute to control their trafficking in the thymus during maturation, and identify Rac-WAVE2 and Rap1-RAPL as pathways whose activation is required in inside-out signaling, leading to stimulated adhesion.
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Affiliation(s)
- Marisa Parmo-Cabañas
- Department of Molecular and Cellular Physiopathology, Centro de Investigaciones Biológicas (CSIC), Madrid, Spain
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Ohi H, Mishima Y, Kamimura K, Maruyama M, Sasai K, Kominami R. Multi-step lymphomagenesis deduced from DNA changes in thymic lymphomas and atrophic thymuses at various times after gamma-irradiation. Oncogene 2007; 26:5280-9. [PMID: 17325664 DOI: 10.1038/sj.onc.1210325] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Whole-body gamma-irradiation to mice causes thymic atrophy where a population of precancerous cells with mutation can be found. Thus, clonal growth and DNA changes at Bcl11b, Ikaros, Pten, Notch1 and Myc were examined in not only thymic lymphomas but also in atrophic thymuses at various times after irradiation. Clonal expansion was detected from the distinct patterns of rearrangements at the TCRbeta receptor locus in a fraction of atrophic thymuses at as early as 30 days after irradiation. This expansion may be in part owing to the rearranged TCRbeta signaling because the transfer of bone marrow cells with the rearrangement and the wild-type locus into severe-combined immunodeficiency mice showed preferential growth of the rearranged thymocytes in atrophic thymus. Loss of heterozygosity (LOH) at Bcl11b and trisomy of Myc were found at high frequencies in both lymphomas and atrophic thymuses, and in contrast, LOH at Ikaros and Pten were rare in atrophic thymuses but prevalent in lymphomas. Notch1 activation was detected in lymphomas and in atrophic thymuses only at a late stage. Similar patterns of DNA changes were found in atrophic thymuses induced in Bcl11b(+/-) mice. These results suggest the order of genetic changes during lymphomagenesis, Bcl11b and Myc being at the early stage; whereas Ikaros, Pten and Notch1 at the late stage.
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Affiliation(s)
- H Ohi
- Department of Molecular Genetics, Graduate School of Medical and Dental Sciences, Niigata University, Asahimachi, Niigata, Japan
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