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Guan Y, Cao M, Wu X, Yan J, Hao Y, Zhang C. CD28 null T cells in aging and diseases: From biology to assessment and intervention. Int Immunopharmacol 2024; 131:111807. [PMID: 38471362 DOI: 10.1016/j.intimp.2024.111807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/25/2024] [Accepted: 03/04/2024] [Indexed: 03/14/2024]
Abstract
CD28null T cells, an atypical subset characterized by the loss of CD28 costimulatory molecule expression, exhibit functional variants and progressively expand with age. Moreover, T cells with these phenotypes are found in both typical and atypical humoral immune responses. Consequently, they accumulate during infectious diseases, autoimmune disorders, cardiovascular conditions, and neurodegenerative ailments. To provide an in-depth review of the current knowledge regarding CD28null T cells, we specifically focus on their phenotypic and functional characteristics as well as their physiological roles in aging and diseases. While uncertainties regarding the clinical utility remains, we will review the following two crucial research perspectives to explore clinical translational applications of the research on this specific T cell subset: 1) addressing the potential utility of CD28null T cells as immunological markers for prognosis and adverse outcomes in both aging and disease, and 2) speculating on the potential of targeting CD28null T cells as an interventional strategy for preventing or delaying immune aging processes and disease progression.
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Affiliation(s)
- Yuqi Guan
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; Key Laboratory of Vascular Aging, Ministry of Education, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China
| | - Ming Cao
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; Key Laboratory of Vascular Aging, Ministry of Education, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China
| | - Xiaofen Wu
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; Key Laboratory of Vascular Aging, Ministry of Education, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China
| | - Jinhua Yan
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; Key Laboratory of Vascular Aging, Ministry of Education, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China
| | - Yi Hao
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; Key Laboratory of Vascular Aging, Ministry of Education, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
| | - Cuntai Zhang
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China; Key Laboratory of Vascular Aging, Ministry of Education, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, China.
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Lee DY, Song WH, Lim YS, Lee C, Rajbongshi L, Hwang SY, Kim BS, Lee D, Song YJ, Kim HG, Yoon S. Fish Collagen Peptides Enhance Thymopoietic Gene Expression, Cell Proliferation, Thymocyte Adherence, and Cytoprotection in Thymic Epithelial Cells via Activation of the Nuclear Factor-κB Pathway, Leading to Thymus Regeneration after Cyclophosphamide-Induced Injury. Mar Drugs 2023; 21:531. [PMID: 37888466 PMCID: PMC10608061 DOI: 10.3390/md21100531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 10/28/2023] Open
Abstract
Prolonged thymic involution results in decreased thymopoiesis and thymic output, leading to peripheral T-cell deficiency. Since the thymic-dependent pathway is the only means of generating fully mature T cells, the identification of strategies to enhance thymic regeneration is crucial in developing therapeutic interventions to revert immune suppression in immunocompromised patients. The present study clearly shows that fish collagen peptides (FCPs) stimulate activities of thymic epithelial cells (TECs), including cell proliferation, thymocyte adhesion, and the gene expression of thymopoietic factors such as FGF-7, IGF-1, BMP-4, VEGF-A, IL-7, IL-21, RANKL, LTβ, IL-22R, RANK, LTβR, SDF-1, CCL21, CCL25, CXCL5, Dll1, Dll4, Wnt4, CD40, CD80, CD86, ICAM-1, VCAM-1, FoxN1, leptin, cathepsin L, CK5, and CK8 through the NF-κB signal transduction pathway. Furthermore, our study also revealed the cytoprotective effects of FCPs on TECs against cyclophosphamide-induced cellular injury through the NF-κB signaling pathway. Importantly, FCPs exhibited a significant capability to facilitate thymic regeneration in mice after cyclophosphamide-induced damage via the NF-κB pathway. Taken together, this study sheds light on the role of FCPs in TEC function, thymopoiesis, and thymic regeneration, providing greater insight into the development of novel therapeutic strategies for effective thymus repopulation for numerous clinical conditions in which immune reconstitution is required.
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Affiliation(s)
- Do Young Lee
- Department of Anatomy and Convergence Medical Sciences, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Won Hoon Song
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Department of Urology, Pusan National University Yangsan Hospital and Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Ye Seon Lim
- Department of Anatomy and Convergence Medical Sciences, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Changyong Lee
- Department of Anatomy and Convergence Medical Sciences, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Lata Rajbongshi
- Department of Anatomy and Convergence Medical Sciences, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Seon Yeong Hwang
- Department of Anatomy and Convergence Medical Sciences, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Byoung Soo Kim
- School of Biomedical Convergence Engineering, Pusan National University, Yangsan 626-870, Republic of Korea
| | - Dongjun Lee
- Department of Convergence Medicine, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Yong Jung Song
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Department of Obstetrics and Gynecology, Pusan National University Yangsan Hospital and Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Hwi-Gon Kim
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Department of Obstetrics and Gynecology, Pusan National University Yangsan Hospital and Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
| | - Sik Yoon
- Department of Anatomy and Convergence Medical Sciences, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
- Immune Reconstitution Research Center of Medical Research Institute, Pusan National University College of Medicine, Yangsan 626-870, Republic of Korea
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Seymour F, Carmichael J, Taylor C, Parrish C, Cook G. Immune senescence in multiple myeloma-a role for mitochondrial dysfunction? Leukemia 2022; 36:2368-2373. [PMID: 35879358 DOI: 10.1038/s41375-022-01653-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 07/02/2022] [Accepted: 07/11/2022] [Indexed: 11/09/2022]
Abstract
Age-related immune dysfunction is primarily mediated by immunosenescence which results in ineffective clearance of infective pathogens, poor vaccine responses and increased susceptibility to multi-morbidities. Immunosenescence-related immunometabolic abnormalities are associated with accelerated aging, an inflammatory immune response (inflammaging) and ultimately frailty syndromes. In addition, several conditions can accelerate the development of immunosenescence, including cancer. This is a bi-directional interaction since inflammaging may create a permissive environment for tumour development. Multiple myeloma (MM) is a mature B-cell malignancy that presents in the older population. MM exemplifies the interaction of age- (Host Response Biology; HRB) and disease-related immunological dysfunction, contributing to the development of a frailty syndrome which impairs the therapeutic impact of recent advances in treatment strategies. Understanding the mechanisms by which accelerated immunological aging is induced and the ways in which a tumour such as MM influences this process is key to overcoming therapeutic barriers. A link between cellular mitochondrial dysfunction and the acquisition of an abnormal immune phenotype has recently been described and has widespread physiological consequence beyond the impact on the immune system. Here we outline our current understanding of normal immune aging, describe the mechanism of immunometabolic dysfunction in accelerating this process, and propose the role these processes are playing in the pathogenesis of MM.
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Affiliation(s)
- Frances Seymour
- Department of Haematology, Leeds Cancer Centre, Leeds Teaching Hospitals Trust, Leeds, UK.
| | - Jonathan Carmichael
- Department of Haematology, Leeds Cancer Centre, Leeds Teaching Hospitals Trust, Leeds, UK
- NIHR (Leeds) Medtech & In vitro Diagnostic Cooperative, Leeds, UK
| | - Claire Taylor
- Experimental Haematology, Leeds Institute of Medical Research, University of Leeds UK, Leeds, UK
| | - Christopher Parrish
- Department of Haematology, Leeds Cancer Centre, Leeds Teaching Hospitals Trust, Leeds, UK
- Cancer Research UK Clinical Trials Unit, Leeds Institute of Clinical Trial Research, University of Leeds UK, Leeds, UK
| | - Gordon Cook
- Department of Haematology, Leeds Cancer Centre, Leeds Teaching Hospitals Trust, Leeds, UK
- NIHR (Leeds) Medtech & In vitro Diagnostic Cooperative, Leeds, UK
- Cancer Research UK Clinical Trials Unit, Leeds Institute of Clinical Trial Research, University of Leeds UK, Leeds, UK
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Lewis ED, Wu D, Meydani SN. Age-associated alterations in immune function and inflammation. Prog Neuropsychopharmacol Biol Psychiatry 2022; 118:110576. [PMID: 35588939 DOI: 10.1016/j.pnpbp.2022.110576] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Immunosenescence is a term used to describe the age-related changes in the immune system. Immunosenescence is associated with complex alterations and dysregulation of immune function and inflammatory processes. Age-related changes in innate immune responses including alterations in chemotactic, phagocytic, and natural killing functions, impaired antigen presenting capacity, and dysregulated inflammatory response have been described. The most striking and best characterized feature of immunosenescence is the decline in both number and function of T cells. With age there is decreased proliferation, decreased number of antigen-naïve T cells, and increased number of antigen-experienced memory T cells. This decline in naïve T cell population is associated with impaired immunity and reduced response to new or mutated pathogens. While the absolute number of peripheral B cells appears constant with age, changes in B cell functions including reduced antibody production and response and cell memory have been described. However, the main alteration in cell-mediated function that has been reported across all species with aging is those observed in in T cell. These T cell mediated changes have been shown to contribute to increased susceptibility to infection and cancer in older adults. In addition to functional and phenotype alterations in immune cells, studies demonstrate that circulating concentrations of inflammatory mediators in older adults are higher than those of young. This low grade, chronic inflammatory state that occurs in the context of aging has been termed "inflammaging". This review will focus on age-related changes in the immune system including immunosenescence and inflammation as well as the functional consequences of these age-related alterations for the aged.
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Affiliation(s)
- Erin Diane Lewis
- Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, United States of America
| | - Dayong Wu
- Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, United States of America
| | - Simin Nikbin Meydani
- Nutritional Immunology Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, United States of America.
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Abstract
Following periods of haematopoietic cell stress, such as after chemotherapy, radiotherapy, infection and transplantation, patient outcomes are linked to the degree of immune reconstitution, specifically of T cells. Delayed or defective recovery of the T cell pool has significant clinical consequences, including prolonged immunosuppression, poor vaccine responses and increased risks of infections and malignancies. Thus, strategies that restore thymic function and enhance T cell reconstitution can provide considerable benefit to individuals whose immune system has been decimated in various settings. In this Review, we focus on the causes and consequences of impaired adaptive immunity and discuss therapeutic strategies that can recover immune function, with a particular emphasis on approaches that can promote a diverse repertoire of T cells through de novo T cell formation.
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García-Ceca J, Montero-Herradón S, Zapata AG. Thymus aging in mice deficient in either EphB2 or EphB3, two master regulators of thymic epithelium development. Dev Dyn 2020; 249:1243-1258. [PMID: 32506584 DOI: 10.1002/dvdy.212] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The epithelial microenvironment is involved in thymus aging, but the possible role of EphB receptors that govern the thymic epithelium development has not been investigated. Herein, we study the changes undergone by the thymus of EphB-deficient mice throughout their life. RESULTS Immune alterations occurring throughout life were more severe in mutant than in wild-type (WT) mice. Mutant thymuses exhibit lower cellularity than WT ones, as well as lower proportions of early thymic progenitors cells and double-positive (CD4+ CD8+ ) thymocytes, but higher of double-negative (CD4- CD8- ) and single-positive (CD4+ CD8- , CD4- CD8+ ) cells. Throughout life, CD4+ naïve cells decreased particularly in mutant mice. In correlation, memory T cells, largely CD8+ cells, increased. Aged thymic epithelium undergoes changes including appearance of big epithelial free areas, decrease of K8+ K5- areas, which, however, contain higher proportions of Ly51+ UEA1- cortical epithelial cells, in correlation with reduced Aire+ medullary epithelial cells. Also, aged thymuses particularly those derived from mutant mice exhibited increased collagen IV, fat-storing cells, and connective cells. CONCLUSIONS The absence of EphB accelerates the alterations undergone throughout life by both thymic epithelium and thymocytes, and the proportions of peripheral naïve and memory T cells, all of which are hallmarks of immune aging.
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Affiliation(s)
- Javier García-Ceca
- Department of Cell Biology; Faculty of Biology, Complutense University of Madrid, Madrid, Spain.,Health Research Institute, Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Sara Montero-Herradón
- Department of Cell Biology; Faculty of Biology, Complutense University of Madrid, Madrid, Spain.,Health Research Institute, Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Agustín G Zapata
- Department of Cell Biology; Faculty of Biology, Complutense University of Madrid, Madrid, Spain.,Health Research Institute, Hospital 12 de Octubre (imas12), Madrid, Spain
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Abstract
The age-associated B cell subset has been the focus of increasing interest over the last decade. These cells have a unique cell surface phenotype and transcriptional signature, and they rely on TLR7 or TLR9 signals in the context of Th1 cytokines for their formation and activation. Most are antigen-experienced memory B cells that arise during responses to microbial infections and are key to pathogen clearance and control. Their increasing prevalence with age contributes to several well-established features of immunosenescence, including reduced B cell genesis and damped immune responses. In addition, they are elevated in autoimmune and autoinflammatory diseases, and in these settings they are enriched for characteristic autoantibody specificities. Together, these features identify age-associated B cells as a subset with pivotal roles in immunological health, disease, and aging. Accordingly, a detailed understanding of their origins, functions, and physiology should make them tractable translational targets in each of these settings.
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Affiliation(s)
- Michael P. Cancro
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Kasherman L, Siu DHW, Lee KWC, Lord S, Marschner I, Lewis CR, Friedlander M, Lee CK. Efficacy of immune checkpoint inhibitors in older adults with advanced stage cancers: A meta-analysis. J Geriatr Oncol 2020; 11:508-514. [DOI: 10.1016/j.jgo.2019.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/02/2019] [Accepted: 05/14/2019] [Indexed: 12/26/2022]
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El-Naseery NI, Mousa HSE, Noreldin AE, El-Far AH, Elewa YHA. Aging-associated immunosenescence via alterations in splenic immune cell populations in rat. Life Sci 2019; 241:117168. [PMID: 31838133 DOI: 10.1016/j.lfs.2019.117168] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 12/07/2019] [Accepted: 12/10/2019] [Indexed: 12/16/2022]
Abstract
AIM Immunosenescence is the decline of the host immune system due to aging, resulting in various complications. The splenic lymphoid nodule is the pivotal compartment involved in immunosenescence. In this study, we investigated the important changes in the splenic immune cell populations of aged rats (18-24 months) in comparison with young rats (3-5 months). MATERIALS AND METHODS We, also, studied the effects of aging on the activities of total superoxide dismutase (T-SOD) and malondialdehyde (MDA) levels in spleen of both groups, besides the changes of the splenic architecture. Furthermore, immunohistochemical staining was performed to detect the aging effects in T cells, B cells, macrophages, granulocytes, mast cells, proliferating cells, apoptotic cells, and cells positive for interleukin-1β (IL-1β), interleukin-6 (IL-6), and Toll-like receptor 4 (TLR4). KEY FINDINGS The aged rats had significantly lower spleen/body weight ratios and smaller splenic nodules, indicating a decline in general immunity in them. With aging, T-SOD activities were decreased, while MDA levels were increased, exhibiting that oxidative stress increases in spleens. In addition, the aged group also had significantly fewer T and B cells, macrophages, granulocytes, IL-6 and TLR4 immuno-positive cells, and proliferating cells in the periarterial lymphatic sheaths, marginal zone, and lymphoid follicles compared with the young group. On the other hand, the number of mast cells and apoptotic cells was significantly increased with age. Therefore, we can conclude that cellular immunity and humoral immunity were crumpled with age.
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Affiliation(s)
- Nesma I El-Naseery
- Histology and Cytology Department, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Hanaa S E Mousa
- Department of Histology and Cell Biology, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Ahmed E Noreldin
- Histology and Cytology Department, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, Egypt
| | - Ali H El-Far
- Department of Biochemistry, Faculty of Veterinary Medicine, Damanhour University, Damanhour 22511, Egypt
| | - Yaser H A Elewa
- Histology and Cytology Department, Faculty of Veterinary Medicine, Zagazig University, Zagazig 44519, Egypt; Laboratory of Anatomy, Faculty of Veterinary Medicine, Basic Veterinary Sciences, Hokkaido University, Sapporo 060-0818, Japan.
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Wu H, Qin X, Dai H, Zhang Y. Time-course transcriptome analysis of medullary thymic epithelial cells in the early phase of thymic involution. Mol Immunol 2018; 99:87-94. [DOI: 10.1016/j.molimm.2018.04.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/24/2018] [Accepted: 04/19/2018] [Indexed: 12/13/2022]
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Williams KM, Moore AR, Lucas PJ, Wang J, Bare CV, Gress RE. FLT3 ligand regulates thymic precursor cells and hematopoietic stem cells through interactions with CXCR4 and the marrow niche. Exp Hematol 2017; 52:40-49. [PMID: 28552733 DOI: 10.1016/j.exphem.2017.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 05/05/2017] [Accepted: 05/06/2017] [Indexed: 01/07/2023]
Abstract
Impaired immune reconstitution after hematopoietic stem cell transplantation (HSCT) is attributed in part to impaired thymopoiesis. Recent data suggest that precursor input may be a point of regulation for the thymus. We hypothesized that administration of FLT3 ligand (FLT3L) would enhance thymopoiesis after adoptive transfer of aged, FLT3L-treated bone marrow (BM) to aged, Lupron-treated hosts by increasing murine HSC (Lin[minus]Sca1+c-Kit+ [LSK] cells) trafficking and survival. In murine models of aged and young hosts, we show that FLT3L enhances thymopoiesis in aged, Lupron-treated hosts through increased survival and export of LSK cells via CXCR4 regulation. In addition, we elucidate an underlying mechanism of FLT3L action on BM LSK cells-FLT3L drives LSK cells into the stromal niche using Hoescht (Ho) dye perimortem. In summary, we show that FLT3L administration leads to: (1) increased LSK cells and early thymocyte progenitor precursors that can enhance thymopoiesis after transplantation and androgen withdrawal, (2) mobilization of LSK cells through downregulation of CXCR4, (3) enhanced BM stem cell survival associated with Bcl-2 upregulation, and (4) BM stem cell enrichment through increased trafficking to the BM niche. Therefore, we show a mechanism by which FLT3L activity on hematopoeitic and thymic progenitor cells may contribute to thymic recovery. These data have potential clinical relevance to enhance thymic reconstitution after cytoreductive therapy.
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Affiliation(s)
- Kirsten M Williams
- Children's Research Institute, Children's National Medical Institutes, Washington, DC.
| | - Amber R Moore
- Stanford Immunology, Stanford University School of Medicine, Stanford, CA
| | - Philip J Lucas
- Experimental Transplantation and Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Juin Wang
- Experimental Transplantation and Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Catherine V Bare
- Experimental Transplantation and Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Ronald E Gress
- Experimental Transplantation and Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD
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Abstract
Intrathymic T cell development is a complex process that depends upon continuous guidance from thymus stromal cell microenvironments. The thymic epithelium within the thymic stroma comprises highly specialized cells with a high degree of anatomic, phenotypic, and functional heterogeneity. These properties are collectively required to bias thymocyte development toward production of self-tolerant and functionally competent T cells. The importance of thymic epithelial cells (TECs) is evidenced by clear links between their dysfunction and multiple diseases where autoimmunity and immunodeficiency are major components. Consequently, TECs are an attractive target for cell therapies to restore effective immune system function. The pathways and molecular regulators that control TEC development are becoming clearer, as are their influences on particular stages of T cell development. Here, we review both historical and the most recent advances in our understanding of the cellular and molecular mechanisms controlling TEC development, function, dysfunction, and regeneration.
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Affiliation(s)
- Jakub Abramson
- Department of Immunology, Weizmann Institute of Science, Rehovot 76100, Israel;
| | - Graham Anderson
- MRC Centre for Immune Regulation, Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham B15 2TT, United Kingdom;
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13
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Scalea JR, Hickman JB, Moore DJ, Brayman KL. An overview of the necessary thymic contributions to tolerance in transplantation. Clin Immunol 2016; 173:S1521-6616(16)30382-5. [PMID: 27989896 DOI: 10.1016/j.clim.2016.10.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/04/2016] [Accepted: 10/22/2016] [Indexed: 02/08/2023]
Abstract
The thymus is important for the development of the immune system. However, aging leads to predictable involution of the thymus and immunodeficiency. These immunodeficiencies may be rectified with thymic rejuvenation. Atrophy of the thymus is governed by a complex interplay of molecular, cytokine and hormonal factors. Herein we review the interaction of these factors across age and how they may be targeted for thymic rejuvenation. We further discuss the growing pre-clinical evidence defining the necessary and sufficient contributions of the thymus to successful tolerance induction in transplantation.
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Affiliation(s)
- Joseph R Scalea
- Division of Transplantation, Department of Surgery, University of Maryland, United States.
| | - John B Hickman
- School of Medicine, University of Virginia, United States
| | - Daniel J Moore
- Division of Endocrinology, Department of Pediatrics, Department of Pathology, Microbiology and Immunology, Vanderbilt University, United States
| | - Kenneth L Brayman
- School of Medicine, University of Virginia, United States; Division of Transplantation, Department of Surgery, University of Virginia, United States
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Kyoizumi S, Kubo Y, Misumi M, Kajimura J, Yoshida K, Hayashi T, Imai K, Ohishi W, Nakachi K, Young LF, Shieh JH, Moore MA, van den Brink MRM, Kusunoki Y. Circulating Hematopoietic Stem and Progenitor Cells in Aging Atomic Bomb Survivors. Radiat Res 2016; 185:69-76. [PMID: 26720799 PMCID: PMC5015444 DOI: 10.1667/rr14209.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It is not yet known whether hematopoietic stem and progenitor cells (HSPCs) are compromised in the aging population of atomic bomb (A-bomb) survivors after their exposure nearly 70 years ago. To address this, we evaluated age- and radiation-related changes in different subtypes of circulating HSPCs among the CD34-positive/lineage marker-negative (CD34(+)Lin(-)) cell population in 231 Hiroshima A-bomb survivors. We enumerated functional HSPC subtypes, including: cobblestone area-forming cells; long-term culture-initiating cells; erythroid burst-forming units; granulocyte and macrophage colony-forming units; and T-cell and natural killer cell progenitors using cell culture. We obtained the count of each HSPC subtype per unit volume of blood and the proportion of each HSPC subtype in CD34(+)Lin(-) cells to represent the lineage commitment trend. Multivariate analyses, using sex, age and radiation dose as variables, showed significantly decreased counts with age in the total CD34(+)Lin(-) cell population and all HSPC subtypes. As for the proportion, only T-cell progenitors decreased significantly with age, suggesting that the commitment to the T-cell lineage in HSPCs continuously declines with age throughout the lifetime. However, neither the CD34(+)Lin(-) cell population, nor HSPC subtypes showed significant radiation-induced dose-dependent changes in counts or proportions. Moreover, the correlations of the proportions among HSPC subtypes in the survivors properly revealed the hierarchy of lineage commitments. Taken together, our findings suggest that many years after exposure to radiation and with advancing age, the number and function of HSPCs in living survivors as a whole may have recovered to normal levels.
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Affiliation(s)
- Seishi Kyoizumi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Yoshiko Kubo
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Munechika Misumi
- Department of Statistics, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Junko Kajimura
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Kengo Yoshida
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Tomonori Hayashi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Kazue Imai
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Waka Ohishi
- Department of Clinical Studies, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Kei Nakachi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
| | - Lauren F. Young
- Department of Medicine and Immunology, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Jae-Hung Shieh
- Cell Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York
| | - Malcolm A. Moore
- Cell Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York
| | | | - Yoichiro Kusunoki
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima, Japan
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15
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Genetic and Epigenetic Mechanisms That Maintain Hematopoietic Stem Cell Function. Stem Cells Int 2015; 2016:5178965. [PMID: 26798358 PMCID: PMC4699043 DOI: 10.1155/2016/5178965] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 09/03/2015] [Accepted: 09/09/2015] [Indexed: 01/15/2023] Open
Abstract
All hematopoiesis cells develop from multipotent progenitor cells. Hematopoietic stem cells (HSC) have the ability to develop into all blood lineages but also maintain their stemness. Different molecular mechanisms have been identified that are crucial for regulating quiescence and self-renewal to maintain the stem cell pool and for inducing proliferation and lineage differentiation. The stem cell niche provides the microenvironment to keep HSC in a quiescent state. Furthermore, several transcription factors and epigenetic modifiers are involved in this process. These create modifications that regulate the cell fate in a more or less reversible and dynamic way and contribute to HSC homeostasis. In addition, HSC respond in a unique way to DNA damage. These mechanisms also contribute to the regulation of HSC function and are essential to ensure viability after DNA damage. How HSC maintain their quiescent stage during the entire life is still matter of ongoing research. Here we will focus on the molecular mechanisms that regulate HSC function.
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Naradikian MS, Hao Y, Cancro MP. Age-associated B cells: key mediators of both protective and autoreactive humoral responses. Immunol Rev 2015; 269:118-29. [DOI: 10.1111/imr.12380] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Martin S. Naradikian
- Department of Pathology and Laboratory Medicine; Perelman School of Medicine at the University of Pennsylvania; Philadelphia PA USA
| | - Yi Hao
- Department of Microbiology; Tongji Medical College; Huazhong University of Science and Technology, Wuhan, China
| | - Michael P. Cancro
- Department of Pathology and Laboratory Medicine; Perelman School of Medicine at the University of Pennsylvania; Philadelphia PA USA
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Rubtsova K, Rubtsov AV, Cancro MP, Marrack P. Age-Associated B Cells: A T-bet-Dependent Effector with Roles in Protective and Pathogenic Immunity. THE JOURNAL OF IMMUNOLOGY 2015; 195:1933-7. [PMID: 26297793 DOI: 10.4049/jimmunol.1501209] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
A newly discovered B cell subset, age-associated B cells, expresses the transcription factor T-bet, has a unique surface phenotype, and accumulates progressively with age. Moreover, B cells with these general features are associated with viral infections and autoimmunity in both mice and humans. In this article, we review current understanding of the characteristics, origins, and functions of these cells. We also suggest that the protective versus pathogenic actions of these cells reflect appropriate versus aberrant engagement of regulatory mechanisms that control the Ab responses to nucleic acid-containing Ags.
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Affiliation(s)
- Kira Rubtsova
- Howard Hughes Medical Institute, National Jewish Health, Denver, CO 80206; Department of Biomedical Science, National Jewish Health, Denver, CO 80206; Department of Immunology and Microbiology, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045;
| | - Anatoly V Rubtsov
- Howard Hughes Medical Institute, National Jewish Health, Denver, CO 80206; Department of Biomedical Science, National Jewish Health, Denver, CO 80206; Department of Immunology and Microbiology, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045
| | - Michael P Cancro
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Philippa Marrack
- Howard Hughes Medical Institute, National Jewish Health, Denver, CO 80206; Department of Biomedical Science, National Jewish Health, Denver, CO 80206; Department of Immunology and Microbiology, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045; Department of Medicine, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045; and Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045
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18
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WEI TIANLI, ZHANG NANNAN, GUO ZHIBIN, CHI FENG, SONG YAN, ZHU XIKE. Wnt4 signaling is associated with the decrease of proliferation and increase of apoptosis during age-related thymic involution. Mol Med Rep 2015; 12:7568-76. [DOI: 10.3892/mmr.2015.4343] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 09/01/2015] [Indexed: 11/06/2022] Open
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19
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Kim MJ, Miller CM, Shadrach JL, Wagers AJ, Serwold T. Young, proliferative thymic epithelial cells engraft and function in aging thymuses. THE JOURNAL OF IMMUNOLOGY 2015; 194:4784-95. [PMID: 25870244 DOI: 10.4049/jimmunol.1403158] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/09/2015] [Indexed: 01/17/2023]
Abstract
The thymus reaches its maximum size early in life and then begins to shrink, producing fewer T cells with increasing age. This thymic decline is thought to contribute to age-related T cell lymphopenias and hinder T cell recovery after bone marrow transplantation. Although several cellular and molecular processes have been implicated in age-related thymic involution, their relative contributions are not known. Using heterochronic parabiosis, we observe that young circulating factors are not sufficient to drive regeneration of the aged thymus. In contrast, we find that resupplying young, engraftable thymic epithelial cells (TECs) to a middle-aged or defective thymus leads to thymic growth and increased T cell production. Intrathymic transplantation and in vitro colony-forming assays reveal that the engraftment and proliferative capacities of TECs diminish early in life, whereas the receptivity of the thymus to TEC engraftment remains relatively constant with age. These results support a model in which thymic growth and subsequent involution are driven by cell-intrinsic changes in the proliferative capacity of TECs, and further show that young TECs can engraft and directly drive the growth of involuted thymuses.
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Affiliation(s)
- Mi-Jeong Kim
- Joslin Diabetes Center, Boston, MA 02215; Harvard Stem Cell Institute, Cambridge, MA 02138
| | - Christine M Miller
- Joslin Diabetes Center, Boston, MA 02215; Harvard Stem Cell Institute, Cambridge, MA 02138; Howard Hughes Medical Institute, Cambridge, MA 02138; and Department of Stem Cell and Regenerative Biology, Paul F. Glenn Laboratories for the Biological Mechanisms of Aging, Harvard Medical School, Harvard University, Cambridge, MA 02138
| | - Jennifer L Shadrach
- Joslin Diabetes Center, Boston, MA 02215; Harvard Stem Cell Institute, Cambridge, MA 02138; Howard Hughes Medical Institute, Cambridge, MA 02138; and Department of Stem Cell and Regenerative Biology, Paul F. Glenn Laboratories for the Biological Mechanisms of Aging, Harvard Medical School, Harvard University, Cambridge, MA 02138
| | - Amy J Wagers
- Joslin Diabetes Center, Boston, MA 02215; Harvard Stem Cell Institute, Cambridge, MA 02138; Howard Hughes Medical Institute, Cambridge, MA 02138; and Department of Stem Cell and Regenerative Biology, Paul F. Glenn Laboratories for the Biological Mechanisms of Aging, Harvard Medical School, Harvard University, Cambridge, MA 02138
| | - Thomas Serwold
- Joslin Diabetes Center, Boston, MA 02215; Harvard Stem Cell Institute, Cambridge, MA 02138;
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20
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Yang YM, Li P, Cui DC, Dang RJ, Zhang L, Wen N, Jiang XX. Effect of aged bone marrow microenvironment on mesenchymal stem cell migration. AGE (DORDRECHT, NETHERLANDS) 2015; 37:16. [PMID: 25693923 PMCID: PMC4332889 DOI: 10.1007/s11357-014-9743-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 12/26/2014] [Indexed: 06/04/2023]
Abstract
Mesenchymal stem cells (MSCs) are known to have many notable features, especially their multiple differentiation ability and immunoregulatory capacity. MSCs are important stem cells in the bone marrow (BM), and their characteristics are affected by the BM microenvironment. However, effects of the BM microenvironment on the properties of MSCs are not well understood. In this study, we found that BM from aged mice decreased MSC colony formation. Flow cytometry data showed that the proportion of B220(+) cells in BM from aged mice was significantly lower than that in BM from young mice, while the proportion of CD11b(+), CD3(+), Gr-1(+), or F4/80(+) cells are on the contrary. CD11b(+), B220(+), and Ter119(+) cells from aged mice were not the subsets that decreased MSC colony formation. We further demonstrated that both BM from aged mice and young mice exhibited similar effects on the proliferation of murine MSC cell line C3H10T1/2. However, when cocultured with BM from aged mice, C3H10T1/2 showed slower migration ability. In addition, we found that phosphorylation of JNK (c-Jun N-terminal kinases) in C3H10T1/2 cocultured with BM from aged mice was lower than that in C3H10T1/2 cocultured with BM from young mice. Collectively, our data revealed that BM from aged mice could decrease the migration of MSCs from their niche through regulating the JNK pathway.
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Affiliation(s)
- Yan-Mei Yang
- Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100850 People’s Republic of China
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Science, 27 Taiping Road, Haidian District, Beijing, 100850 People’s Republic of China
| | - Ping Li
- Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100850 People’s Republic of China
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Science, 27 Taiping Road, Haidian District, Beijing, 100850 People’s Republic of China
| | - Dian-Chao Cui
- Beijing Aiyuhua Hospital for Children and Women, 2 South Street, Beijing Economic and Technological Development Zone, Beijing, 100176, People’s Republic of China
| | - Rui-Jie Dang
- Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100850 People’s Republic of China
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Science, 27 Taiping Road, Haidian District, Beijing, 100850 People’s Republic of China
| | - Lei Zhang
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Science, 27 Taiping Road, Haidian District, Beijing, 100850 People’s Republic of China
| | - Ning Wen
- Chinese PLA General Hospital, 28 Fuxing Road, Haidian District, Beijing, 100850 People’s Republic of China
| | - Xiao-Xia Jiang
- Department of Advanced Interdisciplinary Studies, Institute of Basic Medical Science, 27 Taiping Road, Haidian District, Beijing, 100850 People’s Republic of China
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21
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Martinet KZ, Bloquet S, Bourgeois C. Ageing combines CD4 T cell lymphopenia in secondary lymphoid organs and T cell accumulation in gut associated lymphoid tissue. IMMUNITY & AGEING 2014; 11:8. [PMID: 24829607 PMCID: PMC4020584 DOI: 10.1186/1742-4933-11-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 04/29/2014] [Indexed: 12/11/2022]
Abstract
Background CD4 T cell lymphopenia is an important T cell defect associated to ageing. Higher susceptibility to infections, cancer, or autoimmune pathologies described in aged individuals is thought to partly rely on T cell lymphopenia. We hypothesize that such diverse effects may reflect anatomical heterogeneity of age related T cell lymphopenia. Indeed, no data are currently available on the impact of ageing on T cell pool recovered from gut associated lymphoid tissue (GALT), a crucial site of CD4 T cell accumulation. Results Primary, secondary and tertiary lymphoid organs of C57BL/6 animals were analysed at three intervals of ages: 2 to 6 months (young), 10 to 14 months (middle-aged) and 22 to 26 months (old). We confirmed that ageing preferentially impacted CD4 T cell compartment in secondary lymphoid organs. Importantly, a different picture emerged from gut associated mucosal sites: during ageing, CD4 T cell accumulation was progressively developing in colon and small intestine lamina propria and Peyer’s patches. Similar trend was also observed in middle-aged SJL/B6 F1 mice. Interestingly, an inverse correlation was detected between CD4 T cell numbers in secondary lymphoid organs and colonic lamina propria of C57BL/6 mice whereas no increase in proliferation rate of GALT CD4 T cells was detected. In contrast to GALT, no CD4 T cell accumulation was detected in lungs and liver in middle-aged animals. Finally, the concomitant accumulation of CD4 T cell in GALT and depletion in secondary lymphoid organs during ageing was detected both in male and female animals. Conclusions Our data thus demonstrate that T cell lymphopenia in secondary lymphoid organs currently associated to ageing is not sustained in gut or lung mucosa associated lymphoid tissues or non-lymphoid sites such as the liver. The inverse correlation between CD4 T cell numbers in secondary lymphoid organs and colonic lamina propria and the absence of overt proliferation in GALT suggest that marked CD4 T cell decay in secondary lymphoid organs during ageing reflect redistribution of CD4 T cells rather than generalized CD4 T cell decay. Such anatomical heterogeneity may provide an important rationale for the diversity of immune defects observed during ageing.
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Affiliation(s)
- Kim Zita Martinet
- INSERM U1012, Faculté de Médecine Paris-Sud, 63 rue Gabriel Péri, 94276 Le Kremlin-Bicêtre, France ; Univ Paris-Sud, UMR-S1012, Le Kremlin-Bicêtre, France
| | - Stéphane Bloquet
- Univ Paris-Sud, UMR-S1012, Le Kremlin-Bicêtre, France ; Animalerie centrale, Faculté de Médecine Paris-Sud, Univ Paris-Sud, Le Kremlin-Bicêtre, France
| | - Christine Bourgeois
- INSERM U1012, Faculté de Médecine Paris-Sud, 63 rue Gabriel Péri, 94276 Le Kremlin-Bicêtre, France ; Univ Paris-Sud, UMR-S1012, Le Kremlin-Bicêtre, France
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22
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Zook EC, Zhang S, Gerstein RM, Witte PL, Le PT. Enhancing T lineage production in aged mice: a novel function of Foxn1 in the bone marrow niche. THE JOURNAL OF IMMUNOLOGY 2013; 191:5583-93. [PMID: 24184560 DOI: 10.4049/jimmunol.1202278] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Foxn1 is essential for thymic organogenesis and T lymphopoiesis. Whereas reduced Foxn1 expression results in a decline in T lymphopoiesis, overexpression of Foxn1 in the thymus of a transgenic mouse model (Foxn1Tg) attenuates the age-associated decline in T lymphopoiesis. T lymphopoiesis begins with early T cell progenitors (ETP), derived from multipotent progenitors (MPP) in the bone marrow (BM). A decline in MPP and ETP numbers with age is thought to contribute to reduced T lymphopoiesis. Previously, we showed that reduced ETP number with age is attenuated in Foxn1 transgenic (Tg); whether the effect is initiated in the BM with MPP is not known. In this study, we report that Foxn1 is expressed in wild-type BM and overexpressed in Foxn1Tg. With age, the number of MPP in Foxn1Tg was not reduced, and Foxn1Tg also have a larger pool of hematopoietic stem cells. Furthermore, the Foxn1Tg BM is more efficient in generating MPP. In contrast to MPP, common lymphoid progenitors and B lineage cell numbers were significantly lower in both young and aged Foxn1Tg compared with wild type. We identified a novel population of lineage(neg/low), CD45(pos) EpCAM(pos), SCA1(pos), CD117(neg), CD138(neg), MHCII(neg) cells as Foxn1-expressing BM cells that also express Delta-like 4. Thus, Foxn1 affects both T lymphopoiesis and hematopoiesis, and the Foxn1 BM niche may function in skewing MPP development toward T lineage progenitors.
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Affiliation(s)
- Erin C Zook
- Cell Biology, Neurobiology, and Anatomy Graduate Program, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153
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23
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Interleukin-21 accelerates thymic recovery from glucocorticoïd-induced atrophy. PLoS One 2013; 8:e72801. [PMID: 24023776 PMCID: PMC3759406 DOI: 10.1371/journal.pone.0072801] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 07/11/2013] [Indexed: 12/20/2022] Open
Abstract
Both physiological and psychological stress cause thymic atrophy via glucocorticoïd (GC)-dependent apoptosis of double-positive (DP) thymocytes. Given the pervasiveness of stress, GC-induced thymic atrophy is arguably the most common type of acquired immunodeficiency. We recently reported that interleukin-21 (IL-21) has a unique ability to expand the small subset of DP thymocytes (CD69(+)) which are ongoing positive selection, and that administration of IL-21 increases thymic output in aged mice. The goal of this study was to evaluate whether IL-21 could mitigate GC-induced thymic atrophy. In contrast to double-negative (DN) and single-positive (SP) thymocytes, most DP thymocytes (CD69(-)) do not constitutively express the IL-21 receptor (IL-21R). Accordingly, CD69(-) DP thymocytes from PBS-treated mice were unresponsive to IL-21 administration. However, following GC injection, surviving CD69(-) DP thymocytes up-regulated IL-21R and responded to IL-21 treatment as evidenced by enhancement of Bcl6 expression and phosphorylation of STAT1, STAT3 and STAT5. Consequently, IL-21 administration to GC-treated mice accelerated thymic recovery by expanding considerably DP thymocytes and, to a lesser extent, DN thymocytes. However, IL-21-induced expansion of DN/DP thymocytes did not alter the diversity of the intrathymic or peripheral T-cell receptor (TCR) repertoire. We conclude that IL-21 dramatically accelerates recovery from GC-induced thymic atrophy.
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24
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A simple model system enabling human CD34(+) cells to undertake differentiation towards T cells. PLoS One 2013; 8:e69572. [PMID: 23894504 PMCID: PMC3720953 DOI: 10.1371/journal.pone.0069572] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/14/2013] [Indexed: 12/20/2022] Open
Abstract
Background Channelling the development of haematopoietic progenitor cells into T lymphocytes is dependent upon a series of extrinsic prompts whose temporal and spatial sequence is critical for a productive outcome. Simple models of human progenitor cells development depend in the main on the use of xenogeneic systems which may provide some limitations to development. Methods and Findings Here we provide evidence that a simple model system which utilises both human keratinocyte and fibroblast cell lines arrayed on a synthetic tantalum coated matrix provides a permissive environment for the development of human CD34⁺ haematopoietic cells into mature CD4⁺ or CD8⁺ T lymphocytes in the presence of Interleukin 7 (IL-7), Interleukin 15 (IL-15) and the Fms-like tyrosine kinase 3 ligand (Flt-3L). This system was used to compare the ability of CD34+ cells to produce mature thymocytes and showed that whilst these cells derived from cord blood were able to productively differentiate into thymocytes the system was not permissive for the development of CD34+ cells from adult peripheral blood. Conclusions/Significance Our study provides direct evidence for the capacity of human cord blood CD34+ cells to differentiate along the T lineage in a simple human model system. Productive commitment of the CD34⁺ cells to generate T cells was found to be dependent on a three-dimensional matrix which induced the up-regulation of the Notch delta-like ligand 4 (Dll-4) by epithelial cells.
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25
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Kyoizumi S, Kubo Y, Kajimura J, Yoshida K, Imai K, Hayashi T, Nakachi K, Young LF, Moore MA, van den Brink MRM, Kusunoki Y. Age-associated changes in the differentiation potentials of human circulating hematopoietic progenitors to T- or NK-lineage cells. THE JOURNAL OF IMMUNOLOGY 2013; 190:6164-72. [PMID: 23670190 DOI: 10.4049/jimmunol.1203189] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Age-associated changes of T and NK cell (T/NK) potential of human hematopoietic stem cells are unknown. In this study, we enumerate and characterize T/NK precursors among CD34(+)Lin(-) cell populations circulating in normal human adult peripheral blood (PB) by a limiting-dilution assay using coculture with OP9-DL1 stroma cells expressing Notch 1 ligand, Delta-like 1. The frequency of T cell precursors in CD34(+)Lin(-) cells was found to decrease with donor age, whereas the ratio of NK to T cell precursor frequency (NK/T ratio) increased with age, suggesting that lymphoid differentiation potential of PB progenitors shifts from T to NK cell lineage with aging. Clonal analyses of CD34(+)Lin(-) cells showed that differences in the NK/T ratio were attributable to different distributions of single- and dual-lineage T/NK precursor clones. Because nearly all of the clones retained monocyte and/or granulocyte differentiation potentials in coculture with OP9-DL1 cells, T/NK precursors in PB are considered to be contained in the pool of T/NK/myeloid multipotent progenitors. The age-associated increase in NK over T cell commitment might occur in precursor cells with T/NK/myeloid potential.
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Affiliation(s)
- Seishi Kyoizumi
- Department of Radiobiology/Molecular Epidemiology, Radiation Effects Research Foundation, Hiroshima 732-0815, Japan.
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Sun L, Brown R, Chen S, Zhuge Q, Su DM. Aging induced decline in T-lymphopoiesis is primarily dependent on status of progenitor niches in the bone marrow and thymus. Aging (Albany NY) 2013; 4:606-19. [PMID: 23047952 PMCID: PMC3492225 DOI: 10.18632/aging.100487] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Age-related decline in the generation of T cells is associated with two primary lymphoid organs, the bone marrow (BM) and thymus. Both organs contain lympho-hematopoietic progenitor/stem cells (LPCs) and non-hematopoietic stromal/niche cells. Murine model showed this decline is not due to reduced quantities of LPCs, nor autonomous defects in LPCs, but rather defects in their niche cells. However, this viewpoint is challenged by the fact that aged BM progenitors have a myeloid skew. By grafting young wild-type (WT) BM progenitors into aged IL-7R−/− hosts, which possess WT-equivalent niches although LPCs are defect, we demonstrated that these young BM progenitors also exhibited a myeloid skew. We, further, demonstrated that aged BM progenitors, recruited by a grafted fetal thymus in the in vivo microenvironment, were able to compete with their young counterparts, although the in vitro manipulated old BM cells were not able to do so in conventional BM transplantation. Both LPCs and their niche cells inevitably get old with increasing organismal age, but aging in niche cells occurred much earlier than in LPCs by an observation in thymic T-lymphopoiesis. Therefore, the aging induced decline in competence to generate T cells is primarily dependent on status of the progenitor niche cells in the BM and thymus.
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Affiliation(s)
- Liguang Sun
- Department of Molecular Biology and Immunology, University of North Texas Health Science Center at Fort Worth, Fort Worth, TX 76107, USA
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27
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Ringhoffer S, Rojewski M, Döhner H, Bunjes D, Ringhoffer M. T-cell reconstitution after allogeneic stem cell transplantation: assessment by measurement of the sjTREC/βTREC ratio and thymic naive T cells. Haematologica 2013; 98:1600-8. [PMID: 23585532 DOI: 10.3324/haematol.2012.072264] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The immune reconstitution after allogeneic hematopoietic stem cell transplantation comprises thymus-dependent and thymus-independent pathways. We wanted to improve the understanding of this complex process using two different measurements at definite checkpoints of T-cell neogenesis. We therefore assessed the thymus-dependent pathway by combining measurements of single joint T-cell receptor excision circles (sjTREC) and β T-cell receptor excision circles (βTREC) in an improved quantitative light-cycler hybridization polymerase chain reaction assay. In a subgroup of patients, we additionally assessed the proliferation kinetics of the CD31(+) thymic naïve cell population, which corresponds to recent thymic emigrants by six-color immunostaining. After the establishment of normal values in 22 healthy volunteers, we applied our polymerase chain reaction to 66 patients undergoing allogeneic hematopoietic stem cell transplantation at a median age of 44 years. It took more than 2 years after transplant to restore the pre-transplant thymic proliferation capacity. Only one third of the patients in our longitudinal study reached age-adjusted normal values for both sjTREC and βTREC at a median follow-up of 558 days, with acute graft-versus-host disease being the most prominent negative factor by univariate analysis. We observed several patterns of sjTREC and βTREC recovery suggesting different mechanisms of thymic damage in individual patients. In a comparison of CD31(+) thymic naïve cells between volunteers and patients after transplant we found a significantly higher peak proliferation rate within the latter population in the first year after transplantation. The combination of measurements of sjTREC and βTREC by our simplified polymerase chain reaction assay provides insight about the stage of T-cell development affected by different types of damage and may help to choose the correct therapeutic intervention. Besides the sole thymic T-cell neogenesis, proliferation within the CD31(+) thymic naïve cell compartment contributed to the replenishment of the naïve T-cell pool after transplantation.
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28
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Montecino-Rodriguez E, Berent-Maoz B, Dorshkind K. Causes, consequences, and reversal of immune system aging. J Clin Invest 2013; 123:958-65. [PMID: 23454758 DOI: 10.1172/jci64096] [Citation(s) in RCA: 518] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The effects of aging on the immune system are manifest at multiple levels that include reduced production of B and T cells in bone marrow and thymus and diminished function of mature lymphocytes in secondary lymphoid tissues. As a result, elderly individuals do not respond to immune challenge as robustly as the young. An important goal of aging research is to define the cellular changes that occur in the immune system and the molecular events that underlie them. Considerable progress has been made in this regard, and this information has provided the rationale for clinical trials to rejuvenate the aging immune system.
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Affiliation(s)
- Encarnacion Montecino-Rodriguez
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA
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29
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Abstract
The continuous production of T lymphocytes requires that hematopoietic progenitors developing in the bone marrow migrate to the thymus. Rare progenitors egress from the bone marrow into the circulation, then traffic via the blood to the thymus. It is now evident that thymic settling is tightly regulated by selectin ligands, chemokine receptors, and integrins, among other factors. Identification of these signals has enabled progress in identifying specific populations of hematopoietic progenitors that can settle the thymus. Understanding the nature of progenitor cells and the molecular mechanisms involved in thymic settling may allow for therapeutic manipulation of this process, and improve regeneration of the T lineage in patients with impaired T cell numbers.
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Affiliation(s)
- Shirley L Zhang
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 264 John Morgan Building 3620 Hamilton Walk, Philadelphia, PA, USA
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30
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Notch signals contribute to preserve the multipotentiality of human CD34+CD38−CD45RA−CD90+ hematopoietic progenitors by maintaining T cell lineage differentiation potential. Exp Hematol 2012; 40:983-993.e4. [DOI: 10.1016/j.exphem.2012.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 08/15/2012] [Accepted: 08/21/2012] [Indexed: 01/09/2023]
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Huang J, Nguyen-McCarty M, Hexner EO, Danet-Desnoyers G, Klein PS. Maintenance of hematopoietic stem cells through regulation of Wnt and mTOR pathways. Nat Med 2012; 18:1778-85. [PMID: 23142822 PMCID: PMC3518679 DOI: 10.1038/nm.2984] [Citation(s) in RCA: 181] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 09/27/2012] [Indexed: 12/14/2022]
Abstract
Hematopoietic stem cell (HSC) self renewal and lineage commitment depend on complex interactions with the microenvironment. The ability to maintain or expand HSCs for clinical applications or basic research has been substantially limited because these interactions are not well defined. Recent evidence suggests that HSCs reside in a low-perfusion, reduced-nutrient niche and that nutrient-sensing pathways contribute to HSC homeostasis. Here we report that suppression of the mTOR pathway, an established nutrient sensor, combined with activation of canonical Wnt-β-catenin signaling, allows for the ex vivo maintenance of human and mouse long-term HSCs under cytokine-free conditions. We also show that the combination of two clinically approved medications that together activate Wnt-β-catenin and inhibit mTOR signaling increases the number (but not the proportion) of long-term HSCs in vivo.
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Affiliation(s)
- Jian Huang
- Department of Medicine (Hematology-Oncology), University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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Fibroblast growth factor-7 partially reverses murine thymocyte progenitor aging by repression of Ink4a. Blood 2012; 119:5715-21. [PMID: 22555975 DOI: 10.1182/blood-2011-12-400002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Involution of the thymus results in reduced production of naive T cells, and this in turn is thought to contribute to impaired immunity in the elderly. Early T-cell progenitors (ETPs), the most immature intrathymic T-cell precursors, harvested from the involuted thymus exhibit a diminished proliferative potential and increased rate of apoptosis and as a result their number is significantly reduced. In the present study, we show that these age-induced alterations result in part from increased expression of the Ink4a tumor-suppressor gene in ETPs. We also show that repression of Ink4a in aged ETPs results in their partial rejuvenation and that this can be accomplished by in vivo fibroblast growth factor 7 administration. These results define a genetic basis for thymocyte progenitor aging and demonstrate that the senescence-associated gene Ink4a can be pharmacologically repressed in ETPs to partially reverse the effects of aging.
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Berent-Maoz B, Montecino-Rodriguez E, Dorshkind K. Genetic regulation of thymocyte progenitor aging. Semin Immunol 2012; 24:303-8. [PMID: 22559986 DOI: 10.1016/j.smim.2012.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 03/27/2012] [Accepted: 04/09/2012] [Indexed: 02/06/2023]
Abstract
The number of T cell progenitors is significantly reduced in the involuted thymus, and the growth and developmental potential of the few cells that are present is severely attenuated. This review provides an overview of how aging affects T cell precursors before and following entry into the thymus and discusses the age-related genetic changes that may occur in them. Finally, interventions that rejuvenate thymopoiesis in the elderly by targeting T cell progenitors are discussed.
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Affiliation(s)
- Beata Berent-Maoz
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
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34
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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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Henry CJ, Marusyk A, DeGregori J. Aging-associated changes in hematopoiesis and leukemogenesis: what's the connection? Aging (Albany NY) 2011; 3:643-56. [PMID: 21765201 PMCID: PMC3164372 DOI: 10.18632/aging.100351] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Aging is associated with a marked increase in a number of diseases, including many types of cancer. Due to the complex and multi-factorial nature of both aging and cancer, accurate deciphering of causative links between aging and cancer remains a major challenge. It is generally accepted that initiation and progression of cancers are driven by a process of clonal evolution. In principle, this somatic evolution should follow the same Darwinian logic as evolutionary processes in populations in nature: diverse heritable types arising as a result of mutations are subjected to selection, resulting in expansion of the fittest clones. However, prevalent paradigms focus primarily on mutational aspects in linking aging and cancer. In this review, we will argue that age-related changes in selective pressures are likely to be equally important. We will focus on aging-related changes in the hematopoietic system, where age-associated alterations are relatively well studied, and discuss the impact of these changes on the development of leukemias and other malignancies.
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Affiliation(s)
- Curtis J Henry
- Department of Biochemistry and Molecular Genetics, Integrated Department of Immunology, Program in Molecular Biology, University of Colorado Denver School of Medicine, Aurora, Colorado, USA
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Keren Z, Averbuch D, Shahaf G, Zisman-Rozen S, Golan K, Itkin T, Lapidot T, Mehr R, Melamed D. Chronic B Cell Deficiency from Birth Prevents Age-Related Alterations in the B Lineage. THE JOURNAL OF IMMUNOLOGY 2011; 187:2140-7. [DOI: 10.4049/jimmunol.1100999] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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B-cell depletion reactivates B lymphopoiesis in the BM and rejuvenates the B lineage in aging. Blood 2011; 117:3104-12. [PMID: 21228330 DOI: 10.1182/blood-2010-09-307983] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Aging is associated with a decline in B-lymphopoiesis in the bone marrow and accumulation of long-lived B cells in the periphery. These changes decrease the body's ability to mount protective antibody responses. We show here that age-related changes in the B lineage are mediated by the accumulating long-lived B cells. Thus, depletion of B cells in old mice was followed by expansion of multipotent primitive progenitors and common lymphoid progenitors, a revival of B-lymphopoiesis in the bone marrow, and generation of a rejuvenated peripheral compartment that enhanced the animal's immune responsiveness to antigenic stimulation. Collectively, our results suggest that immunosenescence in the B-lineage is not irreversible and that depletion of the long-lived B cells in old mice rejuvenates the B-lineage and enhances immune competence.
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Abstract
Although most hematopoietic lineages develop in the bone marrow (BM), T cells uniquely complete their development in the specialized environment of the thymus. Hematopoietic stem cells with long-term self-renewal capacity are not present in the thymus. As a result, continuous T cell development requires that BM-derived progenitors be imported into the thymus throughout adult life. The process of thymic homing begins with the mobilization of progenitors out of the BM, continues with their circulation in the bloodstream, and concludes with their settling in the thymus. This review will discuss each of these steps as they occur in the unirradiated and postirradiation scenarios, focusing on the molecular mechanisms of regulation. Improved knowledge about these early steps in T cell generation may accelerate the development of new therapeutic options in patients with impaired T cell number or function.
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Affiliation(s)
- Daniel A Zlotoff
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
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39
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Thymic fatness and approaches to enhance thymopoietic fitness in aging. Curr Opin Immunol 2010; 22:521-8. [PMID: 20650623 DOI: 10.1016/j.coi.2010.06.010] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 06/18/2010] [Accepted: 06/29/2010] [Indexed: 12/19/2022]
Abstract
With advancing age, the thymus undergoes striking fibrotic and fatty changes that culminate in its transformation into adipose tissue. As the thymus involutes, reduction in thymocytes and thymic epithelial cells precede the emergence of mature lipid-laden adipocytes. Dogma dictates that adipocytes are 'passive' cells that occupy non-epithelial thymic space or 'infiltrate' the non-cellular thymic niches. The provenance and purpose of ectopic thymic adipocytes during aging in an organ that is required for establishment and maintenance of T cell repertoire remains an unsolved puzzle. Nonetheless, tantalizing clues about elaborate reciprocal relationship between thymic fatness and thymopoietic fitness are emerging. Blocking or bypassing the route toward thymic adiposity may complement the approaches to rejuvenate thymopoiesis and immunity in elderly.
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40
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Sun L, Guo J, Brown R, Amagai T, Zhao Y, Su DM. Declining expression of a single epithelial cell-autonomous gene accelerates age-related thymic involution. Aging Cell 2010; 9:347-57. [PMID: 20156205 DOI: 10.1111/j.1474-9726.2010.00559.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Age-related thymic involution may be triggered by gene expression changes in lymphohematopoietic and/or nonhematopoietic thymic epithelial cells (TECs). The role of epithelial cell-autonomous gene FoxN1 may be involved in the process, but it is still a puzzle because of the shortage of evidence from gradual loss-of-function and exogenous gain-of-function studies. Using our recently generated loxP-floxed-FoxN1(fx) mouse carrying the ubiquitous CreER(T) (uCreER(T)) transgene with a low dose of spontaneous activation, which causes gradual FoxN1 deletion with age, we found that the uCreER(T)-fx/fx mice showed an accelerated age-related thymic involution owing to progressive loss of FoxN1(+) TECs. The thymic aging phenotypes were clearly observable as early as at 3-6 months of age, resembling the naturally aged (18-22-month-old) murine thymus. By intrathymically supplying aged wild-type mice with exogenous FoxN1-cDNA, thymic involution and defective peripheral CD4(+) T-cell function could be partially rescued. The results support the notion that decline of a single epithelial cell-autonomous gene FoxN1 levels with age causes primary deterioration in TECs followed by impairment of the total postnatal thymic microenvironment, and potentially triggers age-related thymic involution in mice.
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Affiliation(s)
- Liguang Sun
- Department of Biomedical Research, University of Texas Health Science Center at Tyler, 75708, USA
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41
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Feeding the fire: the role of defective bone marrow function in exacerbating thymic involution. Trends Immunol 2010; 31:191-8. [DOI: 10.1016/j.it.2010.02.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 02/02/2010] [Accepted: 02/25/2010] [Indexed: 12/28/2022]
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Preferential effects of leptin on CD4 T cells in central and peripheral immune system are critically linked to the expression of leptin receptor. Biochem Biophys Res Commun 2010; 394:562-8. [PMID: 20227394 DOI: 10.1016/j.bbrc.2010.03.019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Accepted: 03/03/2010] [Indexed: 11/22/2022]
Abstract
Leptin can enhance thymopoiesis and modulate the T-cell immune response. However, it remains controversial whether these effects correlate with the expression of leptin receptor, ObR. We herein addressed this issue by using in vivo animal models and in vitro culture systems. Leptin treatment in both ob/ob mice and normal young mice induced increases of CD4 SP thymocytes in thymus and CD4 T cells in the periphery. Interestingly, expression of the long form ObR was significantly restricted to DN, DP and CD4 SP, but not CD8 SP thymocytes. Moreover, in the reaggregated DP thymocyte cultures with leptin plus TSCs, leptin profoundly induced differentiation of CD4 SP but not CD8 SP thymocytes, suggesting that the effects of leptin on thymocyte differentiation might be closely related to the expression of leptin receptor in developing thymocytes. Surprisingly, ObR expression was markedly higher in peripheral CD4 T cells than that in CD8 T cells. Furthermore, leptin treatment with or without IL-2 and PHA had preferential effects on cell proliferation of CD4 T cells compared to that of CD8 T cells. Collectively, these data provide evidence that the effects of leptin on differentiation and proliferation of CD4 T cells might be closely related to the expression of leptin receptor.
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43
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The aging immune system and its relationship to the development of chronic obstructive pulmonary disease. Ann Am Thorac Soc 2010; 6:573-80. [PMID: 19934352 DOI: 10.1513/pats.200904-022rm] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease of the lungs that usually manifests late in life. Physiologic and immunologic changes that occur in COPD often mimic changes seen in the aging lung. This has led some to characterize COPD as an "accelerated aging phenotype." At the molecular level, COPD and aging share common mechanisms and are associated with significant dysregulation of the immune systems. Aging and COPD are characterized by increases in proinflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha, which are implicated in aging-related inflammatory diseases and correlate with degree of obstruction in COPD. There is an age-dependent decline in naïve T cells with oligoclonal expansion of CD8(+) CD28(null) T cells from chronic antigenic stimulation. The increase in CD8(+) CD28 (null) T regulatory cells inhibits antigen-specific CD4(+) T cell responses, leading to a decline in adaptive immune response. To compensate for the decline in the adaptive immune function there is a paradoxical up-regulation of innate immune system resulting in a proinflammatory state. The dysregulated adaptive immune system with activated innate immune responses seen with aging results in recruitment and retention of neutrophils, macrophages, and CD4(+) and CD8(+) T cells in the lungs of smokers with COPD. Once the inflammation is triggered, there is a self-perpetuating cascade of inflammation and lung parenchymal damage. This review will focus on how the aging immune system may contribute to COPD development later in life in susceptible individuals.
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44
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Abstract
T lymphopoiesis requires settling of the thymus by bone marrow-derived precursors throughout adult life. Progenitor entry into the thymus is selective, but the molecular basis of this selectivity is incompletely understood. The chemokine receptor CCR9 has been demonstrated to be important in this process. However, progenitors lacking CCR9 can still enter the thymus, suggesting a role for additional molecules. Here we report that the chemokine receptor CCR7 is also required for efficient thymic settling. CCR7 is selectively expressed on bone marrow progenitors previously shown to have the capacity to settle the thymus, and CCR7(-/-) progenitors are defective in settling the thymus. We further demonstrate that CCR7 sustains thymic settling in the absence of CCR9. Mice deficient for both CCR7 and CCR9 have severe reductions in the number of early thymic progenitors, and in competitive assays CCR7(-/-)CCR9(-/-) double knockout progenitors are almost completely restricted from thymic settling. However, these mice possess near-normal thymic cellularity. Compensatory expansion of intrathymic populations can account for at least a part of this recovery. Together our results illustrate the critical role of chemokine receptor signaling in thymic settling and help to clarify the cellular identity of the physiologic thymic settling progenitors.
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45
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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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46
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Yang H, Youm YH, Sun Y, Rim JS, Galbán CJ, Vandanmagsar B, Dixit VD. Axin expression in thymic stromal cells contributes to an age-related increase in thymic adiposity and is associated with reduced thymopoiesis independently of ghrelin signaling. J Leukoc Biol 2009; 85:928-38. [PMID: 19299626 DOI: 10.1189/jlb.1008621] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The adipocytes are the predominant cell types that constitute the bulk of the thymic microenvironment by the fifth decade of life in healthy humans. An age-related increase in thymic adiposity is associated with reduced thymopoiesis and compromised immune surveillance in the elderly. However, the mechanisms regulating the generation of intrathymic adipocytes during aging remain to be elucidated. Here, we report that the CD45- thymic stromal cells (TSCs) are amenable to adipogenesis. We identified that the Wnt inhibitor axin is expressed in the lymphoid as well as stromal cells of the thymus with increased expression in CD45- TSCs of older mice. Knockdown of axin by RNA interference in CD45- primary TSCs led to a marked reduction in adipogenesis with significantly lower expression of adipogenic transcripts peroxisome proliferator-activated receptor 2 (PPAR), adipocyte fatty acid-binding protein (aP2), and perilipin. Age-related elevated axin expression was increased specifically in thymic fibroblasts and medullary thymic epithelial cells (TECs) but not in the cortical TEC or CD45+ cells. Consistent with a role of axin in promoting thymic adipogenesis, axin expression was also colocalized with lipid-expressing adipogenic cells in aging thymus. The prolongevity intervention, caloric restriction (CR), prevented the age-related increase in axin and the adipogenic cell in the thymus together with increase in thymic output. We have recently demonstrated that CR induces ghrelin, which can partially reverse thymic involution. Here, we show that axin expression is not affected by ablation of ghrelin receptors in aging mice, suggesting a ghrelin-independent mechanism for regulation of axin. Our data are consistent with the hypothesis that blocking the specific proadipogenic signals in the thymus may complement the present approaches to rejuvenate thymic function during aging.
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Affiliation(s)
- Hyunwon Yang
- Laboratory of Neuroendocrine-Immunology, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
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47
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Cell intrinsic and extrinsic mechanisms of stem cell aging depend on telomere status. Exp Gerontol 2009; 44:75-82. [DOI: 10.1016/j.exger.2008.06.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Revised: 06/24/2008] [Accepted: 06/25/2008] [Indexed: 12/16/2022]
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48
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Kumar R, Fossati V, Israel M, Snoeck HW. Lin-Sca1+kit- bone marrow cells contain early lymphoid-committed precursors that are distinct from common lymphoid progenitors. THE JOURNAL OF IMMUNOLOGY 2008; 181:7507-13. [PMID: 19017940 DOI: 10.4049/jimmunol.181.11.7507] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The significance of a population in mouse bone marrow of lineage-negative (Lin(-)), Sca1-positive, c-kit-negative (LSK(-)) cells, which is reported to be devoid of long-term repopulation capacity or myeloid potential, is unknown. In this study, we show that the LSK(-) population is composed of several subsets defined by the expression of flt3, CD25, and IL-7Ralpha. The first subset was CD25(-) and more than 90% expressed either flt3, IL-7Ralpha, or both. The CD25(-)LSK(-) population had T cell, B cell, and NK cell potential in vivo, and most of this activity was localized in the flt3(+) subset, irrespective of the expression of IL-7Ralpha. Although lymphoid potential of flt3(+)LSK(-) cells in vivo was 3-fold lower than that of lin(-)Sca1(low)kit(low)IL7Ralpha(+) common lymphoid progenitors (CLPs), their cloning efficiency in vitro was 10-fold lower than that of CLPs. Furthermore, although the myeloid potential of flt3(+)LSK(-) cells was 10-fold lower than that of CLPs in the absence of M-CSF, the relative myeloid potential of both populations was similar in its presence. These observations suggest differential growth factor requirements of both populations. The second subset of LSK(-) cells was homogeneously CD25(+)flt3(-)IL7Ralpha(+) and could be generated from both CD25(-)LSK(-) cells and from CLPs, but did not engraft in immunodeficient Rag1(-/-) or Rag1(-/-)gamma(c)(-/-) hosts. This population, of which the significance is unclear, was increased in Rag1(-/-) mice and in old mice. Thus, the LSK(-) population is phenotypically and functionally heterogeneous and contains early lymphoid-committed precursors. Our findings imply that the early stages of lymphoid commitment are more complex than was thus far assumed.
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Affiliation(s)
- Ritu Kumar
- Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA
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49
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Youm YH, Yang H, Sun Y, Smith RG, Manley NR, Vandanmagsar B, Dixit VD. Deficient ghrelin receptor-mediated signaling compromises thymic stromal cell microenvironment by accelerating thymic adiposity. J Biol Chem 2008; 284:7068-77. [PMID: 19054770 DOI: 10.1074/jbc.m808302200] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
With progressive aging, adipocytes are the major cell types that constitute the bulk of thymic microenvironment. Understanding the origin of thymic adipocytes and mechanisms responsible for age-related thymic adiposity is thus germane for the design of long lasting thymic rejuvenation strategies. We have recently identified that ghrelin, an orexigenic anti-inflammatory peptide, can partially reverse age-related thymic involution. Here we demonstrate that Ghrl and ghrelin receptor (growth hormone secretagogue receptor (GHSR)) are expressed in thymic stromal cells and that their expression declines with physiological aging. Genetic ablation of ghrelin and GHSR leads to loss of thymic epithelial cells (TEC) and an increase in adipogenic fibroblasts in the thymus, suggesting potential cellular transitions. Using FoxN1Cre;R26RstopLacZ double transgenic mice, we provide qualitative evidence that thymic epithelial cells can transition to mesenchymal cells that express proadipogenic regulators in the thymus. We found that loss of functional Ghrl-GHSR interactions facilitates EMT and induces thymic adipogenesis with age. In addition, the compromised thymic stromal microenvironment due to lack of Ghrl-GHSR interactions is associated with reduced number of naive T cells. These data suggest that Ghrl may be a novel regulator of EMT and preserves thymic stromal cell microenvironment by controlling age-related adipocyte development within the thymus.
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Affiliation(s)
- Yun-Hee Youm
- Laboratory of Neuroendocrine-Immunology, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana 70808, USA
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50
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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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