1
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Anderson G, Cosway EJ, James KD, Ohigashi I, Takahama Y. Generation and repair of thymic epithelial cells. J Exp Med 2024; 221:e20230894. [PMID: 38980292 PMCID: PMC11232892 DOI: 10.1084/jem.20230894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 05/20/2024] [Accepted: 06/10/2024] [Indexed: 07/10/2024] Open
Abstract
In the vertebrate immune system, thymus stromal microenvironments support the generation of αβT cells from immature thymocytes. Thymic epithelial cells are of particular importance, and the generation of cortical and medullary epithelial lineages from progenitor stages controls the initiation and maintenance of thymus function. Here, we discuss the developmental pathways that regulate thymic epithelial cell diversity during both the embryonic and postnatal periods. We also examine how thymus microenvironments respond to injury, with particular focus on mechanisms that ensure regeneration of thymic epithelial cells for the restoration of thymus function.
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Affiliation(s)
- Graham Anderson
- Institute for Immunology and Immunotherapy, University of Birmingham , Birmingham, UK
| | - Emilie J Cosway
- Institute for Immunology and Immunotherapy, University of Birmingham , Birmingham, UK
| | - Kieran D James
- Institute for Immunology and Immunotherapy, University of Birmingham , Birmingham, UK
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima, Japan
| | - Yousuke Takahama
- Thymus Biology Section, Experimental Immunology Branch, National Cancer Institute, National Institutes of Health , Bethesda, MD, USA
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2
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Li L, Xu F, Han Y, Zeng J, Du S, Wang C. Thymic microenvironment's impact on immunosenescence. Immunol Res 2024:10.1007/s12026-024-09519-z. [PMID: 39042204 DOI: 10.1007/s12026-024-09519-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Accepted: 07/15/2024] [Indexed: 07/24/2024]
Abstract
Age-related thymic involution is characterized by the loss of T cell development and the supporting epithelial network, which are replaced by adipose tissue. We previously showed that aging functionally impairs lymphohematopoietic progenitor cells, including thymic early T cell progenitors (ETPs), contributing to thymic involution. Considering that the thymic microenvironment is essential for thymocyte incubation, we aimed to investigate its role in age-related thymic involution and the mechanisms underlying these changes. The challenge in studying these processes led us to transplant T cell-depleted fetal thymus tissue into the kidney capsule of aged mice. This model allowed us to identify the mechanisms driving age-related changes in the thymic microenvironment and to assess whether these changes could be reversed. Flow cytometry was used to detect naïve T cells (CD62L+CD44-), including CD4 CD8 double-negative, double-positive, and single-positive T cells. Real-time PCR was used to detect and quantify signal-joint T cell receptor excision circles. We rearranged δRec-ΨJα in murine peripheral blood leukocytes to evaluate the thymic output of newly developed naïve T cells in the mice and gene expression in the thymus. Age-related thymic involution decreased naïve T cells and increased memory T cells, while fetal thymus transplantation improved thymic output and T cell production and reversed the impairment of thymopoiesis due to thymic involution in aged mice. Furthermore, the expression of key cytokines was restored and ETPs in the aged mice showed normal thymic T cell development. Our study suggests that degenerative changes in the thymic microenvironment are the primary cause of thymic dysfunction, leading to immunosenescence associated with age-related thymic involution.
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Affiliation(s)
- Li Li
- Shenzhen Guangming District People's Hospital, 4253 Songbai Road, Matian Street, Guangming District, Shenzhen, 518106, Guangdong, China
| | - Feng Xu
- Shenzhen Guangming District People's Hospital, 4253 Songbai Road, Matian Street, Guangming District, Shenzhen, 518106, Guangdong, China
| | - Yi Han
- Shenzhen Guangming District People's Hospital, 4253 Songbai Road, Matian Street, Guangming District, Shenzhen, 518106, Guangdong, China
| | - Jun Zeng
- Shenzhen Guangming District People's Hospital, 4253 Songbai Road, Matian Street, Guangming District, Shenzhen, 518106, Guangdong, China
| | - Shan Du
- Shenzhen Guangming District People's Hospital, 4253 Songbai Road, Matian Street, Guangming District, Shenzhen, 518106, Guangdong, China
| | - Changshan Wang
- Shenzhen Guangming District People's Hospital, 4253 Songbai Road, Matian Street, Guangming District, Shenzhen, 518106, Guangdong, China.
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3
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Ma Z, Woo Kang S, Condie BG, Manley NR. Mechanisms underlying the direct programming of mouse embryonic fibroblasts to thymic epithelial cells by FOXN1. Development 2024; 151:dev202730. [PMID: 38958026 DOI: 10.1242/dev.202730] [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: 02/16/2024] [Accepted: 06/25/2024] [Indexed: 07/04/2024]
Abstract
Thymic epithelial cells (TECs) are crucial to the ability of the thymus to generate T cells for the adaptive immune system in vertebrates. However, no in vitro system for studying TEC function exists. Overexpressing the transcription factor FOXN1 initiates transdifferentiation of fibroblasts into TEC-like cells (iTECs) that support T-cell differentiation in culture or after transplant. In this study, we have characterized iTEC programming at the cellular and molecular level in mouse to determine how it proceeds, and have identified mechanisms that can be targeted for improving this process. These data show that iTEC programming consists of discrete gene expression changes that differ early and late in the process, and that iTECs upregulate markers of both cortical and medullary TEC (cTEC and mTEC) lineages. We demonstrate that promoting proliferation enhances iTEC generation, and that Notch inhibition allows the induction of mTEC differentiation. Finally, we show that MHCII expression is the major difference between iTECs and fetal TECs. MHCII expression was improved by co-culturing iTECs with fetal double-positive T-cells. This study supports future efforts to improve iTEC generation for both research and translational uses.
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Affiliation(s)
- Zhongyao Ma
- Department of Genetics, University of Georgia, Athens, GA 30621, USA
| | - Seung Woo Kang
- Department of Genetics, University of Georgia, Athens, GA 30621, USA
| | - Brian G Condie
- Department of Genetics, University of Georgia, Athens, GA 30621, USA
| | - Nancy R Manley
- Department of Genetics, University of Georgia, Athens, GA 30621, USA
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4
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Zhao J, Hu R, Lai KC, Zhang Z, Lai L. Recombinant FOXN1 fusion protein increases T cell generation in old mice. Front Immunol 2024; 15:1423488. [PMID: 39072332 PMCID: PMC11272594 DOI: 10.3389/fimmu.2024.1423488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Accepted: 07/02/2024] [Indexed: 07/30/2024] Open
Abstract
T cell development in the thymus is dependent on the thymic microenvironment, in which thymic epithelial cells (TECs) are the major component. However, TECs undergo both a qualitative and quantitative loss during aging, which is believed to be the major factor responsible for age-dependent thymic atrophy. FOXN1 plays a critical role in TEC development and adult TECs maintenance. We have previously reported that intrathymic injection of a recombinant (r) protein containing murine FOXN1 and a protein transduction domain increases the number of TECs in mice, leading to enhanced thymopoiesis. However, intrathymic injection may not be an ideal choice for clinical applications. In this study, we produced a rFOXN1 fusion protein containing the N-terminal of CCR9, human FOXN1 and a protein transduction domain. When injected intravenously into 14-month-old mice, the rFOXN1 fusion protein enters the thymus and TECs, and enhances thymopoiesis, resulting in increased T cell generation in the thymus and increased number of T cells in peripheral lymphoid organ. Our results suggest that the rFOXN1 fusion protein has the potential to be used in preventing and treating T cell immunodeficiency in older adults.
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Affiliation(s)
- Jin Zhao
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, United States
| | - Rong Hu
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, United States
| | - Kuan Chen Lai
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, United States
| | - Zhenzhen Zhang
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, United States
| | - Laijun Lai
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, United States
- Institute for Systems Genomics, University of Connecticut, Storrs, CT, United States
- University of Connecticut Stem Cell Institute, University of Connecticut, Storrs, CT, United States
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5
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Voss K, Bartkowiak T, Sewell AE, Chi C, Landis MD, Schaefer S, Pua HH, Connelly JA, Irish JM, Rathmell JC, Kaviany S. Peripheral T Cell Development and Immunophenotyping of Twins with Heterozygous FOXN1 Mutations. Immunohorizons 2024; 8:492-499. [PMID: 39008056 DOI: 10.4049/immunohorizons.2400006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/09/2024] [Indexed: 07/16/2024] Open
Abstract
The transcription factor FOXN1 plays an established role in thymic epithelial development to mediate selection of maturing thymocytes. Patients with heterozygous loss-of-function FOXN1 variants are associated with T cell lymphopenia at birth and low TCR excision circles that can ultimately recover. Although CD4+ T cell reconstitution in these patients is not completely understood, a lower proportion of naive T cells in adults has suggested a role for homeostatic proliferation. In this study, we present an immunophenotyping study of fraternal twins with low TCR excision circles at birth. Targeted primary immunodeficiency testing revealed a heterozygous variant of uncertain significance in FOXN1 (c.1205del, p.Pro402Leufs*148). We present the immune phenotypes of these two patients, as well as their father who carries the same FOXN1 variant, to demonstrate an evolving immune environment over time. While FOXN1 haploinsufficiency may contribute to thymic defects and T cell lymphopenia, we characterized the transcriptional activity and DNA binding of the heterozygous FOXN1 variant in 293T cells and found the FOXN1 variant to have different effects across several target genes. These data suggest multiple mechanisms for similar FOXN1 variants pathogenicity that may be mutation specific. Increased understanding of how these variants drive transcriptional regulation to impact immune cell populations will guide the potential need for therapeutics, risk for infection or autoimmunity over time, and help inform clinical decisions for other variants that might arise.
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Affiliation(s)
- Kelsey Voss
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Todd Bartkowiak
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | - Allison E Sewell
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Channing Chi
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Madelyn D Landis
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Samuel Schaefer
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Heather H Pua
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
- Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
- Human Immunology Discovery Initiative of the Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
| | - James A Connelly
- Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
- Human Immunology Discovery Initiative of the Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
| | - Jonathan M Irish
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
- Human Immunology Discovery Initiative of the Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
| | - Jeffrey C Rathmell
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
- Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
- Human Immunology Discovery Initiative of the Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
| | - Saara Kaviany
- Human Immunology Discovery Initiative of the Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN
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6
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Stankiewicz LN, Rossi FMV, Zandstra PW. Rebuilding and rebooting immunity with stem cells. Cell Stem Cell 2024; 31:597-616. [PMID: 38593798 DOI: 10.1016/j.stem.2024.03.012] [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: 01/08/2024] [Revised: 03/08/2024] [Accepted: 03/15/2024] [Indexed: 04/11/2024]
Abstract
Advances in modern medicine have enabled a rapid increase in lifespan and, consequently, have highlighted the immune system as a key driver of age-related disease. Immune regeneration therapies present exciting strategies to address age-related diseases by rebooting the host's primary lymphoid tissues or rebuilding the immune system directly via biomaterials or artificial tissue. Here, we identify important, unanswered questions regarding the safety and feasibility of these therapies. Further, we identify key design parameters that should be primary considerations guiding technology design, including timing of application, interaction with the host immune system, and functional characterization of the target patient population.
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Affiliation(s)
- Laura N Stankiewicz
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| | - Fabio M V Rossi
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| | - Peter W Zandstra
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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7
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Shirafkan F, Hensel L, Rattay K. Immune tolerance and the prevention of autoimmune diseases essentially depend on thymic tissue homeostasis. Front Immunol 2024; 15:1339714. [PMID: 38571951 PMCID: PMC10987875 DOI: 10.3389/fimmu.2024.1339714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 03/11/2024] [Indexed: 04/05/2024] Open
Abstract
The intricate balance of immune reactions towards invading pathogens and immune tolerance towards self is pivotal in preventing autoimmune diseases, with the thymus playing a central role in establishing and maintaining this equilibrium. The induction of central immune tolerance in the thymus involves the elimination of self-reactive T cells, a mechanism essential for averting autoimmunity. Disruption of the thymic T cell selection mechanisms can lead to the development of autoimmune diseases. In the dynamic microenvironment of the thymus, T cell migration and interactions with thymic stromal cells are critical for the selection processes that ensure self-tolerance. Thymic epithelial cells are particularly significant in this context, presenting self-antigens and inducing the negative selection of autoreactive T cells. Further, the synergistic roles of thymic fibroblasts, B cells, and dendritic cells in antigen presentation, selection and the development of regulatory T cells are pivotal in maintaining immune responses tightly regulated. This review article collates these insights, offering a comprehensive examination of the multifaceted role of thymic tissue homeostasis in the establishment of immune tolerance and its implications in the prevention of autoimmune diseases. Additionally, the developmental pathways of the thymus are explored, highlighting how genetic aberrations can disrupt thymic architecture and function, leading to autoimmune conditions. The impact of infections on immune tolerance is another critical area, with pathogens potentially triggering autoimmunity by altering thymic homeostasis. Overall, this review underscores the integral role of thymic tissue homeostasis in the prevention of autoimmune diseases, discussing insights into potential therapeutic strategies and examining putative avenues for future research on developing thymic-based therapies in treating and preventing autoimmune conditions.
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8
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Dinges SS, Amini K, Notarangelo LD, Delmonte OM. Primary and secondary defects of the thymus. Immunol Rev 2024; 322:178-211. [PMID: 38228406 PMCID: PMC10950553 DOI: 10.1111/imr.13306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The thymus is the primary site of T-cell development, enabling generation, and selection of a diverse repertoire of T cells that recognize non-self, whilst remaining tolerant to self- antigens. Severe congenital disorders of thymic development (athymia) can be fatal if left untreated due to infections, and thymic tissue implantation is the only cure. While newborn screening for severe combined immune deficiency has allowed improved detection at birth of congenital athymia, thymic disorders acquired later in life are still underrecognized and assessing the quality of thymic function in such conditions remains a challenge. The thymus is sensitive to injury elicited from a variety of endogenous and exogenous factors, and its self-renewal capacity decreases with age. Secondary and age-related forms of thymic dysfunction may lead to an increased risk of infections, malignancy, and autoimmunity. Promising results have been obtained in preclinical models and clinical trials upon administration of soluble factors promoting thymic regeneration, but to date no therapy is approved for clinical use. In this review we provide a background on thymus development, function, and age-related involution. We discuss disease mechanisms, diagnostic, and therapeutic approaches for primary and secondary thymic defects.
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Affiliation(s)
- Sarah S. Dinges
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité – Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Kayla Amini
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Luigi D. Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ottavia M. Delmonte
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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9
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Fujimori S, Ohigashi I. The role of thymic epithelium in thymus development and age-related thymic involution. THE JOURNAL OF MEDICAL INVESTIGATION 2024; 71:29-39. [PMID: 38735722 DOI: 10.2152/jmi.71.29] [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] [Indexed: 05/14/2024]
Abstract
The establishment of an adaptive immune system is critical for protecting our bodies from neoplastic cancers and invading pathogens such as viruses and bacteria. As a primary lymphoid organ, the thymus generates lymphoid T cells that play a major role in the adaptive immune system. T cell generation in the thymus is controlled by interactions between thymocytes and other thymic cells, primarily thymic epithelial cells. Thus, the normal development and function of thymic epithelial cells are important for the generation of immunocompetent and self-tolerant T cells. On the other hand, the degeneration of the thymic epithelium due to thymic aging causes thymic involution, which is associated with the decline of adaptive immune function. Herein we summarize basic and current knowledge of the development and function of thymic epithelial cells and the mechanism of thymic involution. J. Med. Invest. 71 : 29-39, February, 2024.
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Affiliation(s)
- Sayumi Fujimori
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
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10
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Yang J, Liu J, Liang J, Li F, Wang W, Chen H, Xie X. Epithelial-mesenchymal transition in age-associated thymic involution: Mechanisms and therapeutic implications. Ageing Res Rev 2023; 92:102115. [PMID: 37922996 DOI: 10.1016/j.arr.2023.102115] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/17/2023] [Accepted: 10/29/2023] [Indexed: 11/07/2023]
Abstract
The thymus is a critical immune organ with endocrine and immune functions that plays important roles in the physiological and pathological processes of the body. However, with aging, the thymus undergoes degenerative changes leading to decreased production and output of naive T cells and the secretion of thymic hormones and related cytokines, thereby promoting the occurrence and development of various age-associated diseases. Therefore, identifying essential processes that regulate age-associated thymic involution is crucial for long-term control of thymic involution and age-associated disease progression. Epithelial-mesenchymal transition (EMT) is a well-established process involved in organ aging and functional impairment through tissue fibrosis in several organs, such as the heart and kidney. In the thymus, EMT promotes fibrosis and potentially adipogenesis, leading to thymic involution. This review focuses on the factors involved in thymic involution, including oxidative stress, inflammation, and hormones, from the perspective of EMT. Furthermore, current interventions for reversing age-associated thymic involution by targeting EMT-associated processes are summarized. Understanding the key mechanisms of thymic involution through EMT as an entry point may promote the development of new therapies and clinical agents to reverse thymic involution and age-associated disease.
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Affiliation(s)
- Jiali Yang
- The School of Basic Medical Sciences, Southwest Medical University, Luzhou, China; Public Center of Experimental Technology, Model Animal and Human Disease Research of Luzhou Key Laboratory, Southwest Medical University, Luzhou, China
| | - Juan Liu
- The School of Basic Medical Sciences, Southwest Medical University, Luzhou, China; Public Center of Experimental Technology, Model Animal and Human Disease Research of Luzhou Key Laboratory, Southwest Medical University, Luzhou, China
| | - Jiayu Liang
- The School of Basic Medical Sciences, Southwest Medical University, Luzhou, China; Public Center of Experimental Technology, Model Animal and Human Disease Research of Luzhou Key Laboratory, Southwest Medical University, Luzhou, China
| | - Fan Li
- The School of Basic Medical Sciences, Southwest Medical University, Luzhou, China; Public Center of Experimental Technology, Model Animal and Human Disease Research of Luzhou Key Laboratory, Southwest Medical University, Luzhou, China
| | - Wenwen Wang
- The School of Basic Medical Sciences, Southwest Medical University, Luzhou, China; Public Center of Experimental Technology, Model Animal and Human Disease Research of Luzhou Key Laboratory, Southwest Medical University, Luzhou, China
| | - Huan Chen
- The School of Basic Medical Sciences, Southwest Medical University, Luzhou, China; Nucleic Acid Medicine of Luzhou Key Laboratory, Southwest Medical University, Luzhou, China.
| | - Xiang Xie
- The School of Basic Medical Sciences, Southwest Medical University, Luzhou, China; Public Center of Experimental Technology, Model Animal and Human Disease Research of Luzhou Key Laboratory, Southwest Medical University, Luzhou, China.
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11
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Li YR, Zúñiga-Pflücker JC. Thymus aging and immune reconstitution, progresses and challenges. Semin Immunol 2023; 70:101837. [PMID: 37659170 DOI: 10.1016/j.smim.2023.101837] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 08/25/2023] [Accepted: 08/25/2023] [Indexed: 09/04/2023]
Abstract
Thymus is a primary lymphoid organ essential for the development of T lymphocytes. Age-related thymic involution is a prominent feature of immune senescence. The thymus undergoes rapid growth during fetal and neonatal development, peaks in size before puberty and then begins to undergo a decrease in cellularity with age. Dramatic changes occur with age-associated thymic involution. The most prominent features of thymic involution include: (i) epithelial structure disruption, (ii) adipogenesis, and (iii) thymocyte development arrest. There is a sex disparity in thymus aging. It is a multifactorial process controlled and regulated by a series of molecules, including the transcription factor FOXN1, fibroblast and keratinocyte growth factors (FGF and KGF, respectively), sex steroids, Notch signaling, WNT signaling, and microRNAs. Nevertheless, there is still no satisfactory evolutionary or physiological explanation for age-associated thymic involution, and understanding the precise mechanism(s) for thymus aging remains challenging. Sustained thymic regeneration has yet to be achieved by sex steroid ablation. Recent preclinical studies indicate that long-term thymic reconstitution can be achieved via adoptive transfer of in vitro-generated progenitor T (proT) cells, and improvements in the methods for the generation of human proT cells make this an attractive approach. Future clinical applications may rely on new applications integrating proT cells, cytokine support and sex-steroid inhibition treatments.
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Affiliation(s)
- Yue Ru Li
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Juan Carlos Zúñiga-Pflücker
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada; Biological Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.
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12
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Xiao S, Zhang W, Li J, Manley NR. Lin28 regulates thymic growth and involution and correlates with MHCII expression in thymic epithelial cells. Front Immunol 2023; 14:1261081. [PMID: 37868985 PMCID: PMC10588642 DOI: 10.3389/fimmu.2023.1261081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/07/2023] [Indexed: 10/24/2023] Open
Abstract
Thymic epithelial cells (TECs) are essential for T cell development in the thymus, yet the mechanisms governing their differentiation are not well understood. Lin28, known for its roles in embryonic development, stem cell pluripotency, and regulating cell proliferation and differentiation, is expressed in endodermal epithelial cells during embryogenesis and persists in adult epithelia, implying postnatal functions. However, the detailed expression and function of Lin28 in TECs remain unknown. In this study, we examined the expression patterns of Lin28 and its target Let-7g in fetal and postnatal TECs and discovered opposing expression patterns during postnatal thymic growth, which correlated with FOXN1 and MHCII expression. Specifically, Lin28b showed high expression in MHCIIhi TECs, whereas Let-7g was expressed in MHCIIlo TECs. Deletion of Lin28a and Lin28b specifically in TECs resulted in reduced MHCII expression and overall TEC numbers. Conversely, overexpression of Lin28a increased total TEC and thymocyte numbers by promoting the proliferation of MHCIIlo TECs. Additionally, our data strongly suggest that Lin28 and Let-7g expression is reliant on FOXN1 to some extent. These findings suggest a critical role for Lin28 in regulating the development and differentiation of TECs by modulating MHCII expression and TEC proliferation throughout thymic ontogeny and involution. Our study provides insights into the mechanisms underlying TEC differentiation and highlights the significance of Lin28 in orchestrating these processes.
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Affiliation(s)
- Shiyun Xiao
- Department of Genetics, University of Georgia, Athens, GA, United States
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13
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Zhao J, Zhang Z, Lai KC, Lai L. Administration of recombinant FOXN1 protein attenuates Alzheimer's pathology in mice. Brain Behav Immun 2023; 113:341-352. [PMID: 37541395 PMCID: PMC10528256 DOI: 10.1016/j.bbi.2023.07.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 07/26/2023] [Accepted: 07/30/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND Alzheimer's disease (AD) is the most common cause of dementia in older adults and characterized by progressive loss of memory and cognitive functions that are associated with amyloid-beta (Aβ) plaques and neurofibrillary tangles. Immune cells play an important role in the clearance of Aβ deposits and neurofibrillary tangles. T cells are the major component of the immune system. The thymus is the primary organ for T cell generation. T cell development in the thymus depends on thymic epithelial cells (TECs). However, TECs undergo both qualitative and quantitative loss over time. We have previously reported that a recombinant (r) protein containing FOXN1 and a protein transduction domain can increase the number of TECs and subsequently increases the number of T cells in mice. In this study we determined the ability of rFOXN1 to affect cognitive performance and AD pathology in mice. METHODS Aged 3xTg-AD and APP/PS1 AD mice were injected with rFOXN1 or control protein. Cognitive performance, AD pathology, the thymic microenvironment and immune cells were then analyzed. RESULTS Administration of rFOXN1 into AD mice improves cognitive performance and reduces Aβ plaque load and phosphorylated tau in the brain. This is related to rejuvenating the aged thymic microenvironment, which results in enhanced T cell generation in the thymus, leading to increased number of T cells, especially IFNγ-producing T cells, in the spleen and the choroid plexus (CP), enhanced expression of immune cell trafficking molecules in the CP, and increased migration of monocyte-derived macrophages into the brain. Furthermore, the production of anti-Aβ antibodies in the serum and the brain, and the macrophage phagocytosis of Aβ are enhanced in rFOXN1-treated AD mice. CONCLUSIONS Our results suggest that rFOXN1 protein has the potential to provide a novel approach to treat AD patients.
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Affiliation(s)
- Jin Zhao
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, USA
| | - Zhenzhen Zhang
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, USA
| | - Kuan Chen Lai
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, USA
| | - Laijun Lai
- Department of Allied Health Sciences, University of Connecticut, Storrs, CT, USA; University of Connecticut Stem Cell Institute, University of Connecticut, Storrs, CT, USA.
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14
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Li D, Yao H, Han X, Cao X, Du X, Meng F, Bu G, Kong F, Song T, Zeng X. Active immunization against gonadotropin-releasing hormone affects thymic T cell production, migration, and colonization in male rat lymphoid tissue. J Reprod Immunol 2023; 159:104132. [PMID: 37591181 DOI: 10.1016/j.jri.2023.104132] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/19/2023] [Accepted: 08/08/2023] [Indexed: 08/19/2023]
Abstract
Active immunization against gonadotropin-releasing hormone (GnRH) inhibits animal reproduction and has become a friendly alternative to surgical castration, which has been reported to affect the proportion of thymic T cell subpopulations. The effects of active immunization against GnRH on T cell migration from the thymus to the periphery and T cell distribution in lymphoid tissues remain unclear. Here, we showed that active immunization against GnRH increased thymic size and weight, enlarged the number of thymocytes, and enhanced CD4+ recent thymic emigrants (RTEs) and CD8+ RTEs migration to the blood and spleen. Active immunization against GnRH had no significant effect on naïve CD4+, naïve CD8+, CD4+ memory/activated, or CD8+ memory/activated T cells. In addition, active immunization against GnRH increased the proportion of CD3+ T cells in the spleen and lymph nodes. The percentages of CD3+CD4+ and CD3+CD8+ T cells in the blood, spleen, and lymph nodes were not significantly affected by GnRH immunization. Overall, these results enhance our understanding of thymic T cell production, migration, and colonization in rat lymphoid tissues affected by GnRH immunization.
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Affiliation(s)
- Dong Li
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Huan Yao
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Xinfa Han
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Xiaohan Cao
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Xiaogang Du
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Fengyan Meng
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Guixian Bu
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Fanli Kong
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China
| | - Tianzeng Song
- Institute of animal science, Tibet academy of Agricultural and Animal Husbandry Science, Lhasa 850009, Xizang, PR China.
| | - Xianyin Zeng
- College of Life Science, Sichuan Agricultural University, Ya'an 625014, Sichuan, PR China.
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15
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Carter EB, Pugh-Toole M, Kabil A, Boudreau JE, Nersesian S. The Canadian Society for Immunology's 34th annual meeting 2022: symposia minireview. J Leukoc Biol 2023; 114:79-83. [PMID: 36805942 DOI: 10.1093/jleuko/qiad002] [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: 10/29/2022] [Indexed: 01/22/2023] Open
Abstract
The Canadian Society for Immunology 2022 Annual Meeting (June 17-20, 2022) brought together immunologists from across the country to discuss current topics and cutting-edge research in immunology. Here we highlight the published work presented during three thematic symposia (1) Immune Development and Layered Immunity; (2) Primary Immune Deficiencies from Thymic Developmental Defects to Dysregulation and Inflammation; and (3) Opposing Inflammatory and Suppressive Regulation of Anti-Tumor Immunity.
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Affiliation(s)
- Emily B Carter
- The Trainee Engagement Committee, Canadian Society for Immunology, Canada
- Department of Microbiology and Immunology, Dalhousie University, 5850 College St, Halifax, NS B3H 4R5, Canada
- Beatrice Hunter Cancer Research Institute, 5850 College St, Halifax, NS B3H 4R5, Canada
| | - Morgan Pugh-Toole
- The Trainee Engagement Committee, Canadian Society for Immunology, Canada
- Beatrice Hunter Cancer Research Institute, 5850 College St, Halifax, NS B3H 4R5, Canada
- Department of Pathology, Dalhousie University, 5850 College St, Halifax, NS B3H 4R5, Canada
| | - Ahmed Kabil
- Department of Medical Genetics, University of British Columbia, 2222 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Jeanette E Boudreau
- Department of Microbiology and Immunology, Dalhousie University, 5850 College St, Halifax, NS B3H 4R5, Canada
- Beatrice Hunter Cancer Research Institute, 5850 College St, Halifax, NS B3H 4R5, Canada
- Department of Pathology, Dalhousie University, 5850 College St, Halifax, NS B3H 4R5, Canada
| | - Sarah Nersesian
- The Trainee Engagement Committee, Canadian Society for Immunology, Canada
- Department of Microbiology and Immunology, Dalhousie University, 5850 College St, Halifax, NS B3H 4R5, Canada
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16
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Li J, Wachsmuth LP, Xiao S, Condie BG, Manley NR. Foxn1 overexpression promotes thymic epithelial progenitor cell proliferation and mTEC maintenance, but does not prevent thymic involution. Development 2023; 150:dev200995. [PMID: 36975725 PMCID: PMC10263147 DOI: 10.1242/dev.200995] [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: 06/01/2022] [Accepted: 03/21/2023] [Indexed: 03/29/2023]
Abstract
The transcription factor FOXN1 is essential for fetal thymic epithelial cell (TEC) differentiation and proliferation. Postnatally, Foxn1 levels vary widely between TEC subsets, from low/undetectable in putative TEC progenitors to highest in differentiated TEC subsets. Correct Foxn1 expression is required to maintain the postnatal microenvironment; premature downregulation of Foxn1 causes a rapid involution-like phenotype, and transgenic overexpression can cause thymic hyperplasia and/or delayed involution. We investigated a K5.Foxn1 transgene that drives overexpression in mouse TECs, but causes neither hyperplasia nor delay or prevention of aging-related involution. Similarly, this transgene cannot rescue thymus size in Foxn1lacZ/lacZ mice, which undergo premature involution as a result of reduced Foxn1 levels. However, TEC differentiation and cortico-medullary organization are maintained with aging in both K5.Foxn1 and Foxn1lacZ/lacZ mice. Analysis of candidate TEC markers showed co-expression of progenitor and differentiation markers as well as increased proliferation in Plet1+ TECs associated with Foxn1 expression. These results demonstrate that the functions of FOXN1 in promoting TEC proliferation and differentiation are separable and context dependent, and suggest that modulating Foxn1 levels can regulate the balance of proliferation and differentiation in TEC progenitors.
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Affiliation(s)
- Jie Li
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | | | - Shiyun Xiao
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Brian G. Condie
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Nancy R. Manley
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
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17
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Chiu H, Linsley PS, Ziegler SF. Investigating Thymic Epithelial Cell Diversity Using Systems Biology. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 210:888-894. [PMID: 36947816 PMCID: PMC10037528 DOI: 10.4049/jimmunol.2200610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/12/2022] [Indexed: 03/24/2023]
Abstract
The thymus is an intricate organ consisting of a diverse population of thymic epithelial cells (TECs). Cortical and medullary TECs and their subpopulations have distinct roles in coordinating the development and selection of functionally competent and self-tolerant T cells. Recent advances made in technologies such as single-cell RNA sequencing have made it possible to investigate and resolve the heterogeneity in TECs. These findings have provided further understanding of the molecular mechanisms regulating TEC function and expression of tissue-restricted Ags. In this brief review, we focus on the newly characterized subsets of TECs and their diversity in relation to their functions in supporting T cell development. We also discuss recent discoveries in expression of self-antigens in the context of TEC development as well as the cellular and molecular changes occurring during embryonic development to thymic involution.
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18
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Bosticardo M, Notarangelo LD. Human thymus in health and disease: Recent advances in diagnosis and biology. Semin Immunol 2023; 66:101732. [PMID: 36863139 PMCID: PMC10134747 DOI: 10.1016/j.smim.2023.101732] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/30/2023] [Accepted: 02/14/2023] [Indexed: 03/04/2023]
Abstract
The thymus is the crucial tissue where thymocytes develop from hematopoietic precursors that originate from the bone marrow and differentiate to generate a repertoire of mature T cells able to respond to foreign antigens while remaining tolerant to self-antigens. Until recently, most of the knowledge on thymus biology and its cellular and molecular complexity have been obtained through studies in animal models, because of the difficulty to gain access to thymic tissue in humans and the lack of in vitro models able to faithfully recapitulate the thymic microenvironment. This review focuses on recent advances in the understanding of human thymus biology in health and disease obtained through the use of innovative experimental techniques (eg. single cell RNA sequencing, scRNAseq), diagnostic tools (eg. next generation sequencing), and in vitro models of T-cell differentiation (artificial thymic organoids) and thymus development (eg. thymic epithelial cell differentiation from embryonic stem cells or induced pluripotent stem cells).
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Affiliation(s)
- Marita Bosticardo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Luigi D Notarangelo
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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19
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Thymus transplantation regulates blood pressure and alleviates hypertension-associated heart and kidney damage via transcription factors FoxN1 pathway. Int Immunopharmacol 2023; 116:109798. [PMID: 36738681 DOI: 10.1016/j.intimp.2023.109798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/15/2023] [Accepted: 01/25/2023] [Indexed: 02/05/2023]
Abstract
Previous studies have found that thymus is involved in the process of hypertension. However, whether thymus transplantation alleviates target organ damage in hypertensive mice remains unknown. The aim of this study was to evaluate the effects of thymus transplantation on blood pressure and target organ changes in mice with hypertension. Mice were randomly divided into normal control group (Con), hypertensive group (HTN) and thymus transplantation group (HTN + Trans). Thymus of neonatal mice was transplanted into the renal capsule of the transplantation group. After transplantation, the mouse tail noninvasive pressure was measured and heart function was evaluated weekly. Then mice were euthanized and organs or tissues were harvested at 4 weeks post-transplantation. The blood pressure of HTN + Trans group was lower than that in the HTN group. The expression of FoxN1, Aire, ATRAP, thymosin β4 and the content of sjTREC in thymus of HTN group was decreased and the number of naïve T cells in HTN group was lower compared with other two groups. The ratio of cTEC/mTEC in HTN group was higher than that in Con group and lower than that in HTN + Trans group. Cardiac pathology showed cardiac hypertrophy and fibrosis in HTN group whereas thymus transplantation improved heart function and structure. Altogether, our findings demonstrated thymus transplantation could improve thymus function of hypertensive mice, which increased the expression of thymus transcription factor FoxN1, affected the proportion of T cell subsets, and increased thymosin β4 thereby reducing blood pressure and reversing the progression of target organ damage.
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20
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Zhao J, Zhang Z, Lai KC, Lai L. Recombinant FOXN1 fusion protein increases T cell generation in aged mice. RESEARCH SQUARE 2023:rs.3.rs-2557067. [PMID: 36798162 PMCID: PMC9934747 DOI: 10.21203/rs.3.rs-2557067/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Background Although the thymus continues to export T cells throughout life, it undergoes a profound involution/atrophy with age, resulting in decreased numbers of T cells in the older adult, which has direct etiological linkages with many diseases. T cell development in the thymus is dependent on the thymic microenvironment, in which thymic epithelial cells (TECs) are the major component. However, TECs undergo both a qualitative and quantitative loss during aging, which is believed to be the major factor responsible for age-dependent thymic atrophy. FOXN1 plays a critical role in TEC development and adult TECs maintenance. We have previously reported that intrathymic injection of a recombinant (r) protein containing FOXN1 and a protein transduction domain increases the number of TECs in mice, leading to enhanced thymopoiesis. However, intrathymic injection may not be an ideal choice for clinical applications. In this study, we produce a rFOXN1 fusion protein containing the N-terminal of CCR9, FOXN1 and a protein transduction domain. Results We show here that, when injected intravenously into aged mice, the rFOXN1 fusion protein migrates into the thymus and enhances thymopoiesis, resulting in increased T cell generation in the thymus and increased number of T cells in peripheral lymphoid organ. Conclusions Our results suggest that the rFOXN1 fusion protein has the potential to be used in preventing and treating T cell immunodeficiency in the older adult.
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21
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Hino C, Xu Y, Xiao J, Baylink DJ, Reeves ME, Cao H. The potential role of the thymus in immunotherapies for acute myeloid leukemia. Front Immunol 2023; 14:1102517. [PMID: 36814919 PMCID: PMC9940763 DOI: 10.3389/fimmu.2023.1102517] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 01/20/2023] [Indexed: 02/09/2023] Open
Abstract
Understanding the factors which shape T-lymphocyte immunity is critical for the development and application of future immunotherapeutic strategies in treating hematological malignancies. The thymus, a specialized central lymphoid organ, plays important roles in generating a diverse T lymphocyte repertoire during the infantile and juvenile stages of humans. However, age-associated thymic involution and diseases or treatment associated injury result in a decline in its continuous role in the maintenance of T cell-mediated anti-tumor/virus immunity. Acute myeloid leukemia (AML) is an aggressive hematologic malignancy that mainly affects older adults, and the disease's progression is known to consist of an impaired immune surveillance including a reduction in naïve T cell output, a restriction in T cell receptor repertoire, and an increase in frequencies of regulatory T cells. As one of the most successful immunotherapies thus far developed for malignancy, T-cell-based adoptive cell therapies could be essential for the development of a durable effective treatment to eliminate residue leukemic cells (blasts) and prevent AML relapse. Thus, a detailed cellular and molecular landscape of how the adult thymus functions within the context of the AML microenvironment will provide new insights into both the immune-related pathogenesis and the regeneration of a functional immune system against leukemia in AML patients. Herein, we review the available evidence supporting the potential correlation between thymic dysfunction and T-lymphocyte impairment with the ontogeny of AML (II-VI). We then discuss how the thymus could impact current and future therapeutic approaches in AML (VII). Finally, we review various strategies to rejuvenate thymic function to improve the precision and efficacy of cancer immunotherapy (VIII).
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Affiliation(s)
- Christopher Hino
- Department of Internal Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Yi Xu
- Division of Hematology and Oncology, Department of Medicine, Loma Linda University, Loma Linda, CA, United States.,Division of Regenerative Medicine, Department of Medicine, Loma Linda University, Loma Linda, CA, United States.,Loma Linda University Cancer Center, Loma Linda, CA, United States
| | - Jeffrey Xiao
- Division of Regenerative Medicine, Department of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - David J Baylink
- Division of Regenerative Medicine, Department of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Mark E Reeves
- Division of Hematology and Oncology, Department of Medicine, Loma Linda University, Loma Linda, CA, United States.,Loma Linda University Cancer Center, Loma Linda, CA, United States
| | - Huynh Cao
- Division of Hematology and Oncology, Department of Medicine, Loma Linda University, Loma Linda, CA, United States.,Loma Linda University Cancer Center, Loma Linda, CA, United States
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22
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Muacevic A, Adler JR. FOXN1 Gene Considerations in Severe Combined Immunodeficiency Treatment in Children. Cureus 2022; 14:e32040. [PMID: 36600823 PMCID: PMC9800850 DOI: 10.7759/cureus.32040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2022] [Indexed: 12/05/2022] Open
Abstract
Forkheadbox N1 (FOXN1) gene mutation in humans is a rare cause of thymic hypoplasia and T cell immunodeficiency. This gene is the master transcriptional regulator of thymic epithelial cells and disruptions have been described in consequence to a variety of antepartum complications. FOXN1 mutation-mediated immune deficiency is typically associated with severe combined immunodeficiency and alopecia universalis (SCID/NUDE phenotypes) with homozygous alterations in human animal models. Less common, however, FOXN1 alterations can occur in a heterozygous form and provide a distinct phenotype of severe combined immunodeficiency (SCID) without alopecia. Here, we present one such case of a Caucasian child born with heterozygous FOXN1 mutation, first presenting with undetectable T cell levels at newborn screen. He was confirmed to have FOXN1 immunodeficiency in the heterozygous form through genetic testing. Early identification and initiation of appropriate interventions are crucial to reduce mortality from opportunistic pathogens associated with immunodeficiency. Furthermore, we need to appreciate the less common presentations of established diseases among young patients.
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23
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The unilateral involution in the thymus of a 96-year-old male leads to the preservation of structural integrity in one thymic lobe, as assessed by the expression of medullar and cortical antigens and the presence of CD3+ cells. Heliyon 2022; 8:e11734. [PMID: 36411931 PMCID: PMC9674545 DOI: 10.1016/j.heliyon.2022.e11734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/20/2022] [Accepted: 11/11/2022] [Indexed: 11/18/2022] Open
Abstract
The process of thymic involution begins soon after birth and continues through adult life. Although evolutionary conserved in all vertebrates, the thymic involution has no defined kinetics. Little is known about the pace of its regression in humans, except that there is a marked increase of thymic involution after puberty. This report describes the unusual structural findings in the thymus of a 96-year-old male. The morphological parameters of the organ were evaluated using H&E and immunohistochemistry (IHC) techniques. The macroscopic examination showed a typical organ's weight and size, except that the right thymic lobe presented a well-preserved organ and the left lobe was significantly adiposed. The H&E staining of the thymic sections from the left and right lobes confirmed advanced thymic adiposity in the left lobe and preserved thymic epithelial space containing hematoxylin-stained cells in the right lobe. The multiplex immunostaining of the right lobe sections with antibodies specific to cytokeratins -14 and -8, CD3, and CD4 revealed the presence of medullar and cortical epithelium and mix population of CD3+/CD4+ and CD3+/CD4- T cells. The T cells were associated with the medulla but not with the cortex of the thymus. The immunostaining with an antibody to FoxN1 showed that the protein was expressed in the thymic epithelium. Taken together, we provide evidence that the thymus of a 96-year-old man involuted different kinetics in each of the two thymic lobes. Furthermore, the presence of CD3+/CD4+ and CD3+/CD4-cells gives a hand to the hypothesis that a pool of T-cells may associate with this primary lymphatic organ for as long as there is the available thymic epithelium and be a source of lymphocytes aiding adaptive immune responses to old age.
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24
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Provin N, Giraud M. Differentiation of Pluripotent Stem Cells Into Thymic Epithelial Cells and Generation of Thymic Organoids: Applications for Therapeutic Strategies Against APECED. Front Immunol 2022; 13:930963. [PMID: 35844523 PMCID: PMC9277542 DOI: 10.3389/fimmu.2022.930963] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 05/26/2022] [Indexed: 01/01/2023] Open
Abstract
The thymus is a primary lymphoid organ essential for the induction of central immune tolerance. Maturing T cells undergo several steps of expansion and selection mediated by thymic epithelial cells (TECs). In APECED and other congenital pathologies, a deficiency in genes that regulate TEC development or their ability to select non auto-reactive thymocytes results in a defective immune balance, and consequently in a general autoimmune syndrome. Restoration of thymic function is thus crucial for the emergence of curative treatments. The last decade has seen remarkable progress in both gene editing and pluripotent stem cell differentiation, with the emergence of CRISPR-based gene correction, the trivialization of reprogramming of somatic cells to induced pluripotent stem cells (iPSc) and their subsequent differentiation into multiple cellular fates. The combination of these two approaches has paved the way to the generation of genetically corrected thymic organoids and their use to control thymic genetic pathologies affecting self-tolerance. Here we review the recent advances in differentiation of iPSc into TECs and the ability of the latter to support a proper and efficient maturation of thymocytes into functional and non-autoreactive T cells. A special focus is given on thymus organogenesis and pathway modulation during iPSc differentiation, on the impact of the 2/3D structure on the generated TECs, and on perspectives for therapeutic strategies in APECED based on patient-derived iPSc corrected for AIRE gene mutations.
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25
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Bhalla P, Su DM, van Oers NSC. Thymus Functionality Needs More Than a Few TECs. Front Immunol 2022; 13:864777. [PMID: 35757725 PMCID: PMC9229346 DOI: 10.3389/fimmu.2022.864777] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/03/2022] [Indexed: 12/18/2022] Open
Abstract
The thymus, a primary lymphoid organ, produces the T cells of the immune system. Originating from the 3rd pharyngeal pouch during embryogenesis, this organ functions throughout life. Yet, thymopoiesis can be transiently or permanently damaged contingent on the types of systemic stresses encountered. The thymus also undergoes a functional decline during aging, resulting in a progressive reduction in naïve T cell output. This atrophy is evidenced by a deteriorating thymic microenvironment, including, but not limited, epithelial-to-mesenchymal transitions, fibrosis and adipogenesis. An exploration of cellular changes in the thymus at various stages of life, including mouse models of in-born errors of immunity and with single cell RNA sequencing, is revealing an expanding number of distinct cell types influencing thymus functions. The thymus microenvironment, established through interactions between immature and mature thymocytes with thymus epithelial cells (TEC), is well known. Less well appreciated are the contributions of neural crest cell-derived mesenchymal cells, endothelial cells, diverse hematopoietic cell populations, adipocytes, and fibroblasts in the thymic microenvironment. In the current review, we will explore the contributions of the many stromal cell types participating in the formation, expansion, and contraction of the thymus under normal and pathophysiological processes. Such information will better inform approaches for restoring thymus functionality, including thymus organoid technologies, beneficial when an individuals’ own tissue is congenitally, clinically, or accidentally rendered non-functional.
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Affiliation(s)
- Pratibha Bhalla
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Dong-Ming Su
- Department of Microbiology, Immunology & Genetics, The University of North Texas Health Sciences Center, Fort Worth, TX, United States
| | - Nicolai S C van Oers
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, United States.,Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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26
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García-León MJ, Mosquera M, Cela C, Alcain J, Zuklys S, Holländer G, Toribio ML. Abrogation of Notch Signaling in Embryonic TECs Impacts Postnatal mTEC Homeostasis and Thymic Involution. Front Immunol 2022; 13:867302. [PMID: 35707539 PMCID: PMC9189879 DOI: 10.3389/fimmu.2022.867302] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/29/2022] [Indexed: 11/18/2022] Open
Abstract
Notch signaling is crucial for fate specification and maturation of thymus-seeding progenitors along the T-cell lineage. Recent studies have extended the role of Notch signaling to thymic epithelial cells (TECs), showing that Notch regulates TEC progenitor maintenance and emergence of medullary TECs (mTECs) in fetal thymopoiesis. Based on immunohistochemistry studies of spatiotemporal regulation of Notch activation in the postnatal thymus, we show that in vivo Notch activation is not confined to fetal TECs. Rather, Notch signaling, likely mediated through the Notch1 receptor, is induced in postnatal cortical and medullary TECs, and increases significantly with age in the latter, in both humans and mice, suggesting a conserved role for Notch signaling in TEC homeostasis during thymus aging. To investigate the functional impact of Notch activation in postnatal TEC biology, we used a mouse model in which RPBJκ, the transcriptional effector of canonical Notch signaling, is deleted in epithelial cells, including TECs, under the control of the transcription factor Foxn1. Immunohistochemistry and flow cytometry analyses revealed no significant differences in TEC composition in mutant (RPBJκ-KOTEC) and wild-type (WT) littermate mice at early postnatal ages. However, a significant reduction of the medullary region was observed in mutant compared to WT older thymi, which was accompanied by an accelerated decrease of postnatal mTEC numbers. Also, we found that organization and integrity of the postnatal thymic medulla critically depends on activation of the canonical Notch signaling pathway, as abrogation of Notch signaling in TECs led to the disruption of the medullary thymic microenvironment and to an accelerated thymus atrophy. These features paralleled a significant increase in the proportion of intrathymic non-T lineage cells, mostly B cells, and a slight decrease of DP thymocyte numbers compatible with a compromised thymic function in mutant mice. Therefore, impaired Notch signaling induced in embryonic development impacts postnatal TECs and leads to an accelerated mTEC degeneration and a premature thymus involution. Collectively, our data have uncovered a new role for Notch1 signaling in the control of adult mTEC homeostasis, and point toward Notch signaling manipulation as a novel strategy for thymus regeneration and functional recovery from immunosenescence.
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Affiliation(s)
- María Jesús García-León
- Immune System Development and Function Unit, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Marta Mosquera
- Immune System Development and Function Unit, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Carmela Cela
- Immune System Development and Function Unit, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Juan Alcain
- Immune System Development and Function Unit, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
| | - Saulius Zuklys
- Department of Biomedicine and University Children's Hospital of Basel, University of Basel, Basel, Switzerland
| | - Georg Holländer
- Department of Biomedicine and University Children's Hospital of Basel, University of Basel, Basel, Switzerland.,Department of Paediatrics and the Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - María L Toribio
- Immune System Development and Function Unit, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
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Nusser A, Sagar, Swann JB, Krauth B, Diekhoff D, Calderon L, Happe C, Grün D, Boehm T. Developmental dynamics of two bipotent thymic epithelial progenitor types. Nature 2022; 606:165-171. [PMID: 35614226 PMCID: PMC9159946 DOI: 10.1038/s41586-022-04752-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 04/11/2022] [Indexed: 12/18/2022]
Abstract
T cell development in the thymus is essential for cellular immunity and depends on the organotypic thymic epithelial microenvironment. In comparison with other organs, the size and cellular composition of the thymus are unusually dynamic, as exemplified by rapid growth and high T cell output during early stages of development, followed by a gradual loss of functional thymic epithelial cells and diminished naive T cell production with age1-10. Single-cell RNA sequencing (scRNA-seq) has uncovered an unexpected heterogeneity of cell types in the thymic epithelium of young and aged adult mice11-18; however, the identities and developmental dynamics of putative pre- and postnatal epithelial progenitors have remained unresolved1,12,16,17,19-27. Here we combine scRNA-seq and a new CRISPR-Cas9-based cellular barcoding system in mice to determine qualitative and quantitative changes in the thymic epithelium over time. This dual approach enabled us to identify two principal progenitor populations: an early bipotent progenitor type biased towards cortical epithelium and a postnatal bipotent progenitor population biased towards medullary epithelium. We further demonstrate that continuous autocrine provision of Fgf7 leads to sustained expansion of thymic microenvironments without exhausting the epithelial progenitor pools, suggesting a strategy to modulate the extent of thymopoietic activity.
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Affiliation(s)
- Anja Nusser
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Sagar
- Quantitative Single Cell Biology Group, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- Department of Medicine II, University Hospital Freiburg, Freiburg, Germany
| | - Jeremy B Swann
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Brigitte Krauth
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Dagmar Diekhoff
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Lesly Calderon
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- Institute of Molecular Pathology, Vienna, Austria
| | - Christiane Happe
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Dominic Grün
- Quantitative Single Cell Biology Group, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
- Würzburg Institute of Systems Immunology, Max Planck Research Group at the Julius-Maximilians-Universität Würzburg, Würzburg, Germany.
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany.
| | - Thomas Boehm
- Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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28
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Gulla S, Reddy MC, Reddy VC, Chitta S, Bhanoori M, Lomada D. Role of thymus in health and disease. Int Rev Immunol 2022; 42:347-363. [PMID: 35593192 DOI: 10.1080/08830185.2022.2064461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/26/2022] [Accepted: 04/04/2022] [Indexed: 01/04/2023]
Abstract
The thymus is a primary lymphoid organ, essential for the development of T-cells that will protect from invading pathogens, immune disorders, and cancer. The thymus decreases in size and cellularity with age referred to as thymus involution or atrophy. This involution causes decreased T-cell development and decreased naive T-cell emigration to the periphery, increased proportion of memory T cells, and a restricted, altered T-cell receptor (TCR) repertoire. The changes in composition and function of the circulating T cell pool as a result of thymic involution led to increased susceptibility to infectious diseases including the recent COVID and a higher risk for autoimmune disorders and cancers. Thymic involution consisting of both structural and functional loss of the thymus has a deleterious effect on T cell development, T cell selection, and tolerance. The mechanisms which act on the structural (cortex and medulla) matrix of the thymus, the gradual accumulation of genetic mutations, and altered gene expressions may lead to immunosenescence as a result of thymus involution. Understanding the molecular mechanisms behind thymic involution is critical for identifying diagnostic biomarkers and targets for treatment help to develop strategies to mitigate thymic involution-associated complications. This review is focused on the consequences of thymic involution in infections, immune disorders, and diseases, identifying potential checkpoints and potential approaches to sustain or restore the function of the thymus particularly in elderly and immune-compromised individuals.
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Affiliation(s)
- Surendra Gulla
- Department of Biotechnology and Bioinformatics, Yogi Vemana University, Kadapa, Andhra Pradesh, India
| | - Madhava C Reddy
- Department of Biotechnology and Bioinformatics, Yogi Vemana University, Kadapa, Andhra Pradesh, India
| | - Vajra C Reddy
- Katuri Medical College and Hospital, Chinnakondrupadu, Guntur, India
| | | | - Manjula Bhanoori
- Department of Biochemistry, Osmania University, Hyderabad, Telangana State, India
| | - Dakshayani Lomada
- Department of Genetics and Genomics, Yogi Vemana University, Kadapa, Andhra Pradesh, India
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29
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Rota IA, Handel AE, Maio S, Klein F, Dhalla F, Deadman ME, Cheuk S, Newman JA, Michaels YS, Zuklys S, Prevot N, Hublitz P, Charles PD, Gkazi AS, Adamopoulou E, Qasim W, Davies EG, Hanson I, Pagnamenta AT, Camps C, Dreau HM, White A, James K, Fischer R, Gileadi O, Taylor JC, Fulga T, Lagerholm BC, Anderson G, Sezgin E, Holländer GA. FOXN1 forms higher-order nuclear condensates displaced by mutations causing immunodeficiency. SCIENCE ADVANCES 2021; 7:eabj9247. [PMID: 34860543 PMCID: PMC8641933 DOI: 10.1126/sciadv.abj9247] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 10/15/2021] [Indexed: 05/04/2023]
Abstract
The transcription factor FOXN1 is a master regulator of thymic epithelial cell (TEC) development and function. Here, we demonstrate that FOXN1 expression is differentially regulated during organogenesis and participates in multimolecular nuclear condensates essential for the factor’s transcriptional activity. FOXN1’s C-terminal sequence regulates the diffusion velocity within these aggregates and modulates the binding to proximal gene regulatory regions. These dynamics are altered in a patient with a mutant FOXN1 that is modified in its C-terminal sequence. This mutant is transcriptionally inactive and acts as a dominant negative factor displacing wild-type FOXN1 from condensates and causing athymia and severe lymphopenia in heterozygotes. Expression of the mutated mouse ortholog selectively impairs mouse TEC differentiation, revealing a gene dose dependency for individual TEC subtypes. We have therefore identified the cause for a primary immunodeficiency disease and determined the mechanism by which this FOXN1 gain-of-function mutant mediates its dominant negative effect.
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Affiliation(s)
- Ioanna A. Rota
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Adam E. Handel
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Stefano Maio
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Fabian Klein
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Fatima Dhalla
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Mary E. Deadman
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Stanley Cheuk
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Joseph A. Newman
- Structural Genomics Consortium, University of Oxford, ORCRB, Roosevelt Drive, Oxford, UK
| | - Yale S. Michaels
- Genome Engineering and Synthetic Biology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Saulius Zuklys
- Paediatric Immunology, Department of Biomedicine, University of Basel and University Children’s Hospital Basel, Basel, Switzerland
| | - Nicolas Prevot
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Philip Hublitz
- MRC Weatherall Institute of Molecular Medicine, Genome engineering services, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Philip D. Charles
- Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK
| | - Athina Soragia Gkazi
- Great Ormond Street Hospital and Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Eleni Adamopoulou
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Waseem Qasim
- Great Ormond Street Hospital and Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Edward Graham Davies
- Great Ormond Street Hospital and Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| | - Imelda Hanson
- Department of Pediatrics, Section of Pediatric Immunology, Allergy, and Retrovirology, Baylor College of Medicine, Houston, TX, USA
| | - Alistair T. Pagnamenta
- National Institute for Health Research Biomedical Research Centre, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Carme Camps
- National Institute for Health Research Biomedical Research Centre, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Helene M. Dreau
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Andrea White
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Kieran James
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Roman Fischer
- Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK
| | - Opher Gileadi
- Structural Genomics Consortium, University of Oxford, ORCRB, Roosevelt Drive, Oxford, UK
| | - Jenny C. Taylor
- National Institute for Health Research Biomedical Research Centre, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Tudor Fulga
- Genome Engineering and Synthetic Biology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - B. Christoffer Lagerholm
- Wolfson Imaging Centre Oxford, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, UK
| | - Graham Anderson
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Erdinc Sezgin
- Paediatric Immunology, Department of Biomedicine, University of Basel and University Children’s Hospital Basel, Basel, Switzerland
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Georg A. Holländer
- Department of Paediatrics and the MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Paediatric Immunology, Department of Biomedicine, University of Basel and University Children’s Hospital Basel, Basel, Switzerland
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
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30
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Graft-versus-host disease: a disorder of tissue regeneration and repair. Blood 2021; 138:1657-1665. [PMID: 34370823 DOI: 10.1182/blood.2021011867] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 07/27/2021] [Indexed: 11/20/2022] Open
Abstract
Regenerative failure at barrier surfaces and maladaptive repair leading to fibrosis are hallmarks of graft-versus-host disease (GVHD). Although immunosuppressive treatment can control inflammation, impaired tissue homeostasis leads to prolonged organ damage and impaired quality of life. In this Spotlight article, we review recent research that addresses the critical failures in tissue regeneration and repair that underpin treatment-resistant GVHD. We highlight current interventions designed to overcome these defects and provide our assessment of the future therapeutic landscape.
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31
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Sharma H, Moroni L. Recent Advancements in Regenerative Approaches for Thymus Rejuvenation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2100543. [PMID: 34306981 PMCID: PMC8292900 DOI: 10.1002/advs.202100543] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 04/04/2021] [Indexed: 05/29/2023]
Abstract
The thymus plays a key role in adaptive immunity by generating a diverse population of T cells that defend the body against pathogens. Various factors from disease and toxic insults contribute to the degeneration of the thymus resulting in a fewer output of T cells. Consequently, the body is prone to a wide host of diseases and infections. In this review, first, the relevance of the thymus is discussed, followed by thymic embryological organogenesis and anatomy as well as the development and functionality of T cells. Attempts to regenerate the thymus include in vitro methods, such as forming thymic organoids aided by biofabrication techniques that are transplantable. Ex vivo methods that have shown promise in enhancing thymic regeneration are also discussed. Current regenerative technologies have not yet matched the complexity and functionality of the thymus. Therefore, emerging techniques that have shown promise and the challenges that lie ahead are explored.
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Affiliation(s)
- Himal Sharma
- MERLN Institute for Technology‐Inspired Regenerative MedicineDepartment of Complex Tissue RegenerationMaastricht UniversityMaastricht6229 ERNetherlands
| | - Lorenzo Moroni
- MERLN Institute for Technology‐Inspired Regenerative MedicineDepartment of Complex Tissue RegenerationMaastricht UniversityMaastricht6229 ERNetherlands
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32
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Pinheiro RGR, Alves NL. The Early Postnatal Life: A Dynamic Period in Thymic Epithelial Cell Differentiation. Front Immunol 2021; 12:668528. [PMID: 34220815 PMCID: PMC8250140 DOI: 10.3389/fimmu.2021.668528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/04/2021] [Indexed: 11/20/2022] Open
Abstract
The microenvironments formed by cortical (c) and medullary (m) thymic epithelial cells (TECs) play a non-redundant role in the generation of functionally diverse and self-tolerant T cells. The role of TECs during the first weeks of the murine postnatal life is particularly challenging due to the significant augment in T cell production. Here, we critically review recent studies centered on the timely coordination between the expansion and maturation of TECs during this period and their specialized role in T cell development and selection. We further discuss how aging impacts on the pool of TEC progenitors and maintenance of functionally thymic epithelial microenvironments, and the implications of these chances in the capacity of the thymus to sustain regular thymopoiesis throughout life.
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Affiliation(s)
- Ruben G R Pinheiro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Doctoral Program in Cell and Molecular Biology, Instituto de Ciências Biomédicas, Universidade do Porto, Porto, Portugal
| | - Nuno L Alves
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
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33
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Hashimoto D, Colet JGR, Murashima A, Fujimoto K, Ueda Y, Suzuki K, Hyuga T, Hemmi H, Kaisho T, Takahashi S, Takahama Y, Yamada G. Radiation inducible MafB gene is required for thymic regeneration. Sci Rep 2021; 11:10439. [PMID: 34001954 PMCID: PMC8129107 DOI: 10.1038/s41598-021-89836-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 04/23/2021] [Indexed: 11/28/2022] Open
Abstract
The thymus facilitates mature T cell production by providing a suitable stromal microenvironment. This microenvironment is impaired by radiation and aging which lead to immune system disturbances known as thymic involution. Young adult thymus shows thymic recovery after such involution. Although various genes have been reported for thymocytes and thymic epithelial cells in such processes, the roles of stromal transcription factors in these remain incompletely understood. MafB (v-maf musculoaponeurotic fibrosarcoma oncogene homolog B) is a transcription factor expressed in thymic stroma and its expression was induced a day after radiation exposure. Hence, the roles of mesenchymal MafB in the process of thymic regeneration offers an intriguing research topic also for radiation biology. The current study investigated whether MafB plays roles in the adult thymus. MafB/green fluorescent protein knock-in mutant (MafB+/GFP) mice showed impaired thymic regeneration after the sublethal irradiation, judged by reduced thymus size, total thymocyte number and medullary complexity. Furthermore, IL4 was induced after irradiation and such induction was reduced in mutant mice. The mutants also displayed signs of accelerated age-related thymic involution. Altogether, these results suggest possible functions of MafB in the processes of thymic recovery after irradiation, and maintenance during aging.
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Affiliation(s)
- Daiki Hashimoto
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Jose Gabriel R Colet
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan.,Experimental Therapeutics Laboratory, University of South Australia Cancer Research Institute, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Aki Murashima
- Department of Anatomy, Iwate Medical University, Yahaba, Iwate, Japan.
| | - Kota Fujimoto
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Yuko Ueda
- Department of Urology, Wakayama Medical University, Wakayama, Japan
| | - Kentaro Suzuki
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Taiju Hyuga
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan
| | - Hiroaki Hemmi
- Laboratory of Immunology, Faculty of Veterinary Medicine, Okayama University of Science, Imabari, Ehime, Japan
| | - Tsuneyasu Kaisho
- Department of Immunology, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera, Wakayama, Japan
| | - Satoru Takahashi
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tennodai, Japan
| | - Yousuke Takahama
- Experimental Immunology Branch, National Cancer Institute, NIH, Bethesda, MD, 20892, USA
| | - Gen Yamada
- Department of Developmental Genetics, Institute of Advanced Medicine, Wakayama Medical University, Kimiidera 811-1, Wakayama City, Wakayama, 641-8509, Japan.
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34
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Srinivasan J, Lancaster JN, Singarapu N, Hale LP, Ehrlich LIR, Richie ER. Age-Related Changes in Thymic Central Tolerance. Front Immunol 2021; 12:676236. [PMID: 33968086 PMCID: PMC8100025 DOI: 10.3389/fimmu.2021.676236] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/06/2021] [Indexed: 01/03/2023] Open
Abstract
Thymic epithelial cells (TECs) and hematopoietic antigen presenting cells (HAPCs) in the thymus microenvironment provide essential signals to self-reactive thymocytes that induce either negative selection or generation of regulatory T cells (Treg), both of which are required to establish and maintain central tolerance throughout life. HAPCs and TECs are comprised of multiple subsets that play distinct and overlapping roles in central tolerance. Changes that occur in the composition and function of TEC and HAPC subsets across the lifespan have potential consequences for central tolerance. In keeping with this possibility, there are age-associated changes in the cellular composition and function of T cells and Treg. This review summarizes changes in T cell and Treg function during the perinatal to adult transition and in the course of normal aging, and relates these changes to age-associated alterations in thymic HAPC and TEC subsets.
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Affiliation(s)
- Jayashree Srinivasan
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | | | - Nandini Singarapu
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Smithville, TX, United States
| | - Laura P Hale
- Department of Pathology, Duke University School of Medicine, Durham, NC, United States
| | - Lauren I R Ehrlich
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, United States
| | - Ellen R Richie
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Smithville, TX, United States
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35
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Kreins AY, Bonfanti P, Davies EG. Current and Future Therapeutic Approaches for Thymic Stromal Cell Defects. Front Immunol 2021; 12:655354. [PMID: 33815417 PMCID: PMC8012524 DOI: 10.3389/fimmu.2021.655354] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/03/2021] [Indexed: 12/14/2022] Open
Abstract
Inborn errors of thymic stromal cell development and function lead to impaired T-cell development resulting in a susceptibility to opportunistic infections and autoimmunity. In their most severe form, congenital athymia, these disorders are life-threatening if left untreated. Athymia is rare and is typically associated with complete DiGeorge syndrome, which has multiple genetic and environmental etiologies. It is also found in rare cases of T-cell lymphopenia due to Nude SCID and Otofaciocervical Syndrome type 2, or in the context of genetically undefined defects. This group of disorders cannot be corrected by hematopoietic stem cell transplantation, but upon timely recognition as thymic defects, can successfully be treated by thymus transplantation using cultured postnatal thymic tissue with the generation of naïve T-cells showing a diverse repertoire. Mortality after this treatment usually occurs before immune reconstitution and is mainly associated with infections most often acquired pre-transplantation. In this review, we will discuss the current approaches to the diagnosis and management of thymic stromal cell defects, in particular those resulting in athymia. We will discuss the impact of the expanding implementation of newborn screening for T-cell lymphopenia, in combination with next generation sequencing, as well as the role of novel diagnostic tools distinguishing between hematopoietic and thymic stromal cell defects in facilitating the early consideration for thymus transplantation of an increasing number of patients and disorders. Immune reconstitution after the current treatment is usually incomplete with relatively common inflammatory and autoimmune complications, emphasizing the importance for improving strategies for thymus replacement therapy by optimizing the current use of postnatal thymus tissue and developing new approaches using engineered thymus tissue.
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Affiliation(s)
- Alexandra Y. Kreins
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
- Department of Immunology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - Paola Bonfanti
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
- Epithelial Stem Cell Biology & Regenerative Medicine Laboratory, The Francis Crick Institute, London, United Kingdom
- Institute of Immunity & Transplantation, University College London, London, United Kingdom
| | - E. Graham Davies
- Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
- Department of Immunology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
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36
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Thymic Aging May Be Associated with COVID-19 Pathophysiology in the Elderly. Cells 2021; 10:cells10030628. [PMID: 33808998 PMCID: PMC8001029 DOI: 10.3390/cells10030628] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/01/2021] [Accepted: 03/10/2021] [Indexed: 02/06/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the global pandemic of coronavirus disease 2019 (COVID-19) and particularly exhibits severe symptoms and mortality in elderly individuals. Mounting evidence shows that the characteristics of the age-related clinical severity of COVID-19 are attributed to insufficient antiviral immune function and excessive self-damaging immune reaction, involving T cell immunity and associated with pre-existing basal inflammation in the elderly. Age-related changes to T cell immunosenescence is characterized by not only restricted T cell receptor (TCR) repertoire diversity, accumulation of exhausted and/or senescent memory T cells, but also by increased self-reactive T cell- and innate immune cell-induced chronic inflammation, and accumulated and functionally enhanced polyclonal regulatory T (Treg) cells. Many of these changes can be traced back to age-related thymic involution/degeneration. How these changes contribute to differences in COVID-19 disease severity between young and aged patients is an urgent area of investigation. Therefore, we attempt to connect various clues in this field by reviewing and discussing recent research on the role of the thymus and T cells in COVID-19 immunity during aging (a synergistic effect of diminished responses to pathogens and enhanced responses to self) impacting age-related clinical severity of COVID-19. We also address potential combinational strategies to rejuvenate multiple aging-impacted immune system checkpoints by revival of aged thymic function, boosting peripheral T cell responses, and alleviating chronic, basal inflammation to improve the efficiency of anti-SARS-CoV-2 immunity and vaccination in the elderly.
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37
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Nagatake T, Zhao YC, Ito T, Itoh M, Kometani K, Furuse M, Saika A, Node E, Kunisawa J, Minato N, Hamazaki Y. Selective expression of claudin-5 in thymic endothelial cells regulates the blood-thymus barrier and T-cell export. Int Immunol 2021; 33:171-182. [PMID: 33038259 PMCID: PMC7936066 DOI: 10.1093/intimm/dxaa069] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 10/08/2020] [Indexed: 12/15/2022] Open
Abstract
T-cell development depends on the thymic microenvironment, in which endothelial cells (ECs) play a vital role. Interestingly, vascular permeability of the thymic cortex is lower than in other organs, suggesting the existence of a blood-thymus barrier (BTB). On the other hand, blood-borne molecules and dendritic cells bearing self-antigens are accessible to the medulla, facilitating central tolerance induction, and continuous T-precursor immigration and mature thymocyte egress occur through the vessels at the cortico-medullary junction (CMJ). We found that claudin-5 (Cld5), a membrane protein of tight junctions, was expressed in essentially all ECs of the cortical vasculatures, whereas approximately half of the ECs of the medulla and CMJ lacked Cld5 expression. An intravenously (i.v.) injected biotin tracer hardly penetrated cortical Cld5+ vessels, but it leaked into the medullary parenchyma through Cld5- vessels. Cld5 expression in an EC cell line caused a remarkable increase in trans-endothelial resistance in vitro, and the biotin tracer leaked from the cortical vasculatures in Cldn5-/- mice. Furthermore, i.v.-injected sphingosine-1 phosphate distributed selectively into the medulla through the Cld5- vessels, probably ensuring the egress of CD3high mature thymocytes from Cld5- vessels at the CMJ. These results suggest that distinct Cld5 expression profiles in the cortex and medulla may control the BTB and the T-cell gateway to blood circulation, respectively.
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Affiliation(s)
- Takahiro Nagatake
- Department of Immunology and Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Laboratory of Vaccine Materials, Center for Vaccine and Adjuvant Research and Laboratory of Gut Environmental System, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
| | - Yan-Chun Zhao
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Takeshi Ito
- Department of Immunology and Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Laboratory of Immunobiology, Graduate School of Medicine, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Masahiko Itoh
- Department of Biochemistry, School of Medicine, Dokkyo Medical University, Tochigi, Japan
| | - Kohei Kometani
- Laboratory of Immunobiology, Graduate School of Medicine, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Mikio Furuse
- Division of Cell Structure, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
- Department of Physiological Sciences, SOKENDAI, The Graduate University for Advanced Studies, Okazaki, Aichi, Japan
| | - Azusa Saika
- Laboratory of Vaccine Materials, Center for Vaccine and Adjuvant Research and Laboratory of Gut Environmental System, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Eri Node
- Laboratory of Vaccine Materials, Center for Vaccine and Adjuvant Research and Laboratory of Gut Environmental System, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
| | - Jun Kunisawa
- Laboratory of Vaccine Materials, Center for Vaccine and Adjuvant Research and Laboratory of Gut Environmental System, National Institutes of Biomedical Innovation, Health and Nutrition (NIBIOHN), Osaka, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Nagahiro Minato
- Department of Immunology and Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Medical Innovation Center, Kyoto University, Kyoto, Japan
| | - Yoko Hamazaki
- Department of Immunology and Cell Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Laboratory of Immunobiology, Graduate School of Medicine, Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
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38
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Gautam DK, Chimata AV, Gutti RK, Paddibhatla I. Comparative hematopoiesis and signal transduction in model organisms. J Cell Physiol 2021; 236:5592-5619. [PMID: 33492678 DOI: 10.1002/jcp.30287] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 12/24/2020] [Accepted: 01/08/2021] [Indexed: 12/21/2022]
Abstract
Hematopoiesis is a continuous phenomenon involving the formation of hematopoietic stem cells (HSCs) giving rise to diverse functional blood cells. This developmental process of hematopoiesis is evolutionarily conserved, yet comparably different in various model organisms. Vertebrate HSCs give rise to all types of mature cells of both the myeloid and the lymphoid lineages sequentially colonizing in different anatomical tissues. Signal transduction in HSCs facilitates their potency and specifies branching of lineages. Understanding the hematopoietic signaling pathways is crucial to gain insights into their deregulation in several blood-related disorders. The focus of the review is on hematopoiesis corresponding to different model organisms and pivotal role of indispensable hematopoietic pathways. We summarize and discuss the fundamentals of blood formation in both invertebrate and vertebrates, examining the requirement of key signaling nexus in hematopoiesis. Knowledge obtained from such comparative studies associated with developmental dynamics of hematopoiesis is beneficial to explore the therapeutic options for hematopoietic diseases.
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Affiliation(s)
- Dushyant Kumar Gautam
- Department of Biochemistry, School of Life Sciences (SLS), University of Hyderabad, Hyderabad, Telangana, India
| | | | - Ravi Kumar Gutti
- Department of Biochemistry, School of Life Sciences (SLS), University of Hyderabad, Hyderabad, Telangana, India
| | - Indira Paddibhatla
- Department of Biochemistry, School of Life Sciences (SLS), University of Hyderabad, Hyderabad, Telangana, India
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Elyahu Y, Monsonego A. Thymus involution sets the clock of the aging T-cell landscape: Implications for declined immunity and tissue repair. Ageing Res Rev 2021; 65:101231. [PMID: 33248315 DOI: 10.1016/j.arr.2020.101231] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/15/2020] [Accepted: 11/20/2020] [Indexed: 12/11/2022]
Abstract
Aging is generally characterized as a gradual increase in tissue damage, which is associated with senescence and chronic systemic inflammation and is evident in a variety of age-related diseases. The extent to which such tissue damage is a result of a gradual decline in immune regulation, which consequently compromises the capacity of the body to repair damages, has not been fully explored. Whereas CD4 T lymphocytes play a critical role in the orchestration of immunity, thymus involution initiates gradual changes in the CD4 T-cell landscape, which may significantly compromise tissue repair. In this review, we describe the lifespan accumulation of specific dysregulated CD4 T-cell subsets and their coevolution with systemic inflammation in the process of declined immunity and tissue repair capacity with age. Then, we discuss the process of thymus involution-which appears to be most pronounced around puberty-as a possible driver of the aging T-cell landscape. Finally, we identify individualized T cell-based early diagnostic biomarkers and therapeutic strategies for age-related diseases.
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Affiliation(s)
- Yehezqel Elyahu
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Zlotowski Neuroscience Center and Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel; National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Alon Monsonego
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Zlotowski Neuroscience Center and Regenerative Medicine and Stem Cell Research Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel; National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
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40
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Li J, Lee YK, Fu W, Whalen AM, Estable MC, Raftery LA, White K, Weiner L, Brissette JL. Modeling by disruption and a selected-for partner for the nude locus. EMBO Rep 2020; 22:e49804. [PMID: 33369874 PMCID: PMC7926259 DOI: 10.15252/embr.201949804] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 11/03/2020] [Accepted: 11/20/2020] [Indexed: 12/25/2022] Open
Abstract
A long‐standing problem in biology is how to dissect traits for which no tractable model exists. Here, we screen for genes like the nude locus (Foxn1)—genes central to mammalian hair and thymus development—using animals that never evolved hair, thymi, or Foxn1. Fruit flies are morphologically disrupted by the FOXN1 transcription factor and rescued by weak reductions in fly gene function, revealing molecules that potently synergize with FOXN1 to effect dramatic, chaotic change. Strong synergy/effectivity in flies is expected to reflect strong selection/functionality (purpose) in mammals; the more disruptive a molecular interaction is in alien contexts (flies), the more beneficial it will be in its natural, formative contexts (mammals). The approach identifies Aff4 as the first nude‐like locus, as murine AFF4 and FOXN1 cooperatively induce similar cutaneous/thymic phenotypes, similar gene expression programs, and the same step of transcription, pre‐initiation complex formation. These AFF4 functions are unexpected, as AFF4 also serves as a scaffold in common transcriptional‐elongation complexes. Most likely, the approach works because an interaction's power to disrupt is the inevitable consequence of its selected‐for power to benefit.
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Affiliation(s)
- Jian Li
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Yun-Kyoung Lee
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA
| | - Wenyu Fu
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Anne M Whalen
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Mario C Estable
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
| | - Laurel A Raftery
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Kristin White
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Lorin Weiner
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Janice L Brissette
- Department of Cell Biology, State University of New York Downstate Health Sciences University, Brooklyn, NY, USA.,Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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41
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Kreins AY, Maio S, Dhalla F. Inborn errors of thymic stromal cell development and function. Semin Immunopathol 2020; 43:85-100. [PMID: 33257998 PMCID: PMC7925491 DOI: 10.1007/s00281-020-00826-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/09/2020] [Indexed: 12/31/2022]
Abstract
As the primary site for T cell development, the thymus is responsible for the production and selection of a functional, yet self-tolerant T cell repertoire. This critically depends on thymic stromal cells, derived from the pharyngeal apparatus during embryogenesis. Thymic epithelial cells, mesenchymal and vascular elements together form the unique and highly specialised microenvironment required to support all aspects of thymopoiesis and T cell central tolerance induction. Although rare, inborn errors of thymic stromal cells constitute a clinically important group of conditions because their immunological consequences, which include autoimmune disease and T cell immunodeficiency, can be life-threatening if unrecognised and untreated. In this review, we describe the molecular and environmental aetiologies of the thymic stromal cell defects known to cause disease in humans, placing particular emphasis on those with a propensity to cause thymic hypoplasia or aplasia and consequently severe congenital immunodeficiency. We discuss the principles underpinning their diagnosis and management, including the use of novel tools to aid in their identification and strategies for curative treatment, principally transplantation of allogeneic thymus tissue.
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Affiliation(s)
- Alexandra Y Kreins
- UCL Great Ormond Street Institute of Child Health, London, UK.,Department of Immunology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Stefano Maio
- Developmental Immunology, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Fatima Dhalla
- Developmental Immunology, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK. .,Department of Clinical Immunology, Oxford University Hospitals, Oxford, UK.
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42
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de Barros SC, Suterwala BT, He C, Ge S, Chick B, Blumberg GK, Kim K, Klein S, Zhu Y, Wang X, Casero D, Crooks GM. Pleiotropic Roles of VEGF in the Microenvironment of the Developing Thymus. THE JOURNAL OF IMMUNOLOGY 2020; 205:2423-2436. [PMID: 32989093 DOI: 10.4049/jimmunol.1901519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 08/27/2020] [Indexed: 01/04/2023]
Abstract
Neonatal life marks the apogee of murine thymic growth. Over the first few days after birth, growth slows and the murine thymus switches from fetal to adult morphology and function; little is known about the cues driving this dramatic transition. In this study, we show for the first time (to our knowledge) the critical role of vascular endothelial growth factor (VEGF) on thymic morphogenesis beyond its well-known role in angiogenesis. During a brief window a few days after birth, VEGF inhibition induced rapid and profound remodeling of the endothelial, mesenchymal and epithelial thymic stromal compartments, mimicking changes seen during early adult maturation. Rapid transcriptional changes were seen in each compartment after VEGF inhibition, including genes involved in migration, chemotaxis, and cell adhesion as well as induction of a proinflammatory and proadipogenic signature in endothelium, pericytes, and mesenchyme. Thymocyte numbers fell subsequent to the stromal changes. Expression patterns and functional blockade of the receptors VEGFR2 and NRP1 demonstrated that VEGF mediates its pleiotropic effects through distinct receptors on each microenvironmental compartment of the developing mouse thymus.
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Affiliation(s)
- Stephanie C de Barros
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Batul T Suterwala
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Chongbin He
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Shundi Ge
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Brent Chick
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Garrett K Blumberg
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Kenneth Kim
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Sam Klein
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Yuhua Zhu
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Xiaoyan Wang
- Department of General Internal Medicine and Health Services Research, University of California Los Angeles, Los Angeles, CA 90095
| | - David Casero
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095
| | - Gay M Crooks
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA 90095; .,Department of Pediatrics, University of California Los Angeles, Los Angeles, CA 90095; and.,Broad Stem Cell Research Center, University of California Los Angeles, Los Angeles, CA 90095
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43
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Lavaert M, Valcke B, Vandekerckhove B, Leclercq G, Liang KL, Taghon T. Conventional and Computational Flow Cytometry Analyses Reveal Sustained Human Intrathymic T Cell Development From Birth Until Puberty. Front Immunol 2020; 11:1659. [PMID: 32849574 PMCID: PMC7417369 DOI: 10.3389/fimmu.2020.01659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 06/22/2020] [Indexed: 11/13/2022] Open
Abstract
The thymus is the organ where subsets of mature T cells are generated which subsequently egress to function as central mediators in the immune system. While continuously generating T cells even into adulthood, the thymus does undergo involution during life. This is characterized by an initial rapid decrease in thymic cellularity during early life and by a second age-dependent decline in adulthood. The thymic cellularity of neonates remains low during the first month after birth and the tissue reaches a maximum in cellularity at 6 months of age. In order to study the effect that this first phase of thymic involution has on thymic immune subset frequencies, we performed multi-color flow cytometry on thymic samples collected from birth to 14 years of age. In consideration of the inherent limitations posed by conventional flow cytometry analysis, we established a novel computational analysis pipeline that is adapted from single-cell transcriptome sequencing data analysis. This allowed us to overcome technical effects by batch correction, analyze multiple samples simultaneously, limit computational cost by subsampling, and to rely on KNN-graphs for graph-based clustering. As a result, we successfully identified rare, distinct and gradually developing immune subsets within the human thymus tissues. Although the thymus undergoes early involution from infanthood onwards, our data suggests that this does not affect human T-cell development as we did not observe significant alterations in the proportions of T-lineage developmental intermediates from birth to puberty. Thus, in addition to providing an interesting novel strategy to analyze conventional flow cytometry data for the thymus, our work shows that the early phase of human thymic involution mainly limits the overall T cell output since no obvious changes in thymocyte subsets could be observed.
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Affiliation(s)
- Marieke Lavaert
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Brecht Valcke
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Bart Vandekerckhove
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Georges Leclercq
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Kai Ling Liang
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Tom Taghon
- Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
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Lepletier A, Hun ML, Hammett MV, Wong K, Naeem H, Hedger M, Loveland K, Chidgey AP. Interplay between Follistatin, Activin A, and BMP4 Signaling Regulates Postnatal Thymic Epithelial Progenitor Cell Differentiation during Aging. Cell Rep 2020; 27:3887-3901.e4. [PMID: 31242421 DOI: 10.1016/j.celrep.2019.05.045] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/06/2019] [Accepted: 05/14/2019] [Indexed: 12/24/2022] Open
Abstract
A key feature of immune functional impairment with age is the progressive involution of thymic tissue responsible for naive T cell production. In this study, we identify two major phases of thymic epithelial cell (TEC) loss during aging: a block in mature TEC differentiation from the pool of immature precursors, occurring at the onset of puberty, followed by impaired bipotent TEC progenitor differentiation and depletion of Sca-1lo cTEC and mTEC lineage-specific precursors. We reveal that an increase in follistatin production by aging TECs contributes to their own demise. TEC loss occurs primarily through the antagonism of activin A signaling, which we show is required for TEC maturation and acts in dissonance to BMP4, which promotes the maintenance of TEC progenitors. These results support a model in which an imbalance of activin A and BMP4 signaling underpins the degeneration of postnatal TEC maintenance during aging, and its reversal enables the transient replenishment of mature TECs.
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Affiliation(s)
- Ailin Lepletier
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Michael L Hun
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Maree V Hammett
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Kahlia Wong
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Haroon Naeem
- Monash Bioinformatics Platform, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Mark Hedger
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, Melbourne, VIC 3168, Australia
| | - Kate Loveland
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Melbourne, VIC 3800, Australia; Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, Melbourne, VIC 3168, Australia; Department of Molecular and Translational Sciences, School of Clinical Sciences, Monash University, Clayton, Melbourne, VIC 3800, Australia
| | - Ann P Chidgey
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Melbourne, VIC 3800, Australia.
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45
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Cowan JE, Takahama Y, Bhandoola A, Ohigashi I. Postnatal Involution and Counter-Involution of the Thymus. Front Immunol 2020; 11:897. [PMID: 32477366 PMCID: PMC7235445 DOI: 10.3389/fimmu.2020.00897] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 04/17/2020] [Indexed: 11/15/2022] Open
Abstract
Thymus involution occurs in all vertebrates. It is thought to impact on immune responses in the aged, and in other clinical circumstances such as bone marrow transplantation. Determinants of thymus growth and size are beginning to be identified. Ectopic expression of factors like cyclin D1 and Myc in thymic epithelial cells (TEC)s results in considerable increase in thymus size. These models provide useful experimental tools that allow thymus function to be understood. In future, understanding TEC-specific controllers of growth will provide new approaches to thymus regeneration.
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Affiliation(s)
- Jennifer E Cowan
- Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Yousuke Takahama
- Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Avinash Bhandoola
- Laboratory of Genome Integrity, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima, Japan
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46
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Alawam AS, Anderson G, Lucas B. Generation and Regeneration of Thymic Epithelial Cells. Front Immunol 2020; 11:858. [PMID: 32457758 PMCID: PMC7221188 DOI: 10.3389/fimmu.2020.00858] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/15/2020] [Indexed: 01/04/2023] Open
Abstract
The thymus is unique in its ability to support the maturation of phenotypically and functionally distinct T cell sub-lineages. Through its combined production of MHC-restricted conventional CD4+ and CD8+, and Foxp3+ regulatory T cells, as well as non-conventional CD1d-restricted iNKT cells and invariant γδT cells, the thymus represents an important orchestrator of immune system development and control. It is now clear that thymus function is largely determined by the availability of stromal microenvironments. These specialized areas emerge during thymus organogenesis and are maintained throughout life. They are formed from both epithelial and mesenchymal components, and collectively they support a stepwise program of thymocyte development. Of these stromal cells, cortical, and medullary thymic epithelial cells represent functional components of thymic microenvironments in both the cortex and medulla. Importantly, a key feature of thymus function is that levels of T cell production are not constant throughout life. Here, multiple physiological factors including aging, stress and pregnancy can have either short- or long-term detrimental impact on rates of thymus function. Here, we summarize our current understanding of the development and function of thymic epithelial cells, and relate this to strategies to protect and/or restore thymic epithelial cell function for therapeutic benefit.
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Affiliation(s)
- Abdullah S Alawam
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Graham Anderson
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Beth Lucas
- Institute for Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
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47
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Bhalla P, Wysocki CA, van Oers NSC. Molecular Insights Into the Causes of Human Thymic Hypoplasia With Animal Models. Front Immunol 2020; 11:830. [PMID: 32431714 PMCID: PMC7214791 DOI: 10.3389/fimmu.2020.00830] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/14/2020] [Indexed: 12/30/2022] Open
Abstract
22q11.2 deletion syndrome (DiGeorge), CHARGE syndrome, Nude/SCID and otofaciocervical syndrome type 2 (OTFCS2) are distinct clinical conditions in humans that can result in hypoplasia and occasionally, aplasia of the thymus. Thymic hypoplasia/aplasia is first suggested by absence or significantly reduced numbers of recent thymic emigrants, revealed in standard-of-care newborn screens for T cell receptor excision circles (TRECs). Subsequent clinical assessments will often indicate whether genetic mutations are causal to the low T cell output from the thymus. However, the molecular mechanisms leading to the thymic hypoplasia/aplasia in diverse human syndromes are not fully understood, partly because the problems of the thymus originate during embryogenesis. Rodent and Zebrafish models of these clinical syndromes have been used to better define the underlying basis of the clinical presentations. Results from these animal models are uncovering contributions of different cell types in the specification, differentiation, and expansion of the thymus. Cell populations such as epithelial cells, mesenchymal cells, endothelial cells, and thymocytes are variably affected depending on the human syndrome responsible for the thymic hypoplasia. In the current review, findings from the diverse animal models will be described in relation to the clinical phenotypes. Importantly, these results are suggesting new strategies for regenerating thymic tissue in patients with distinct congenital disorders.
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Affiliation(s)
- Pratibha Bhalla
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Christian A. Wysocki
- Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Nicolai S. C. van Oers
- Department of Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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Sznajder ŁJ, Scotti MM, Shin J, Taylor K, Ivankovic F, Nutter CA, Aslam FN, Subramony SH, Ranum LPW, Swanson MS. Loss of MBNL1 induces RNA misprocessing in the thymus and peripheral blood. Nat Commun 2020; 11:2022. [PMID: 32332745 PMCID: PMC7181699 DOI: 10.1038/s41467-020-15962-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/03/2020] [Indexed: 12/25/2022] Open
Abstract
The thymus is a primary lymphoid organ that plays an essential role in T lymphocyte maturation and selection during development of one arm of the mammalian adaptive immune response. Although transcriptional mechanisms have been well documented in thymocyte development, co-/post-transcriptional modifications are also important but have received less attention. Here we demonstrate that the RNA alternative splicing factor MBNL1, which is sequestered in nuclear RNA foci by C(C)UG microsatellite expansions in myotonic dystrophy (DM), is essential for normal thymus development and function. Mbnl1 129S1 knockout mice develop postnatal thymic hyperplasia with thymocyte accumulation. Transcriptome analysis indicates numerous gene expression and RNA mis-splicing events, including transcription factors from the TCF/LEF family. CNBP, the gene containing an intronic CCTG microsatellite expansion in DM type 2 (DM2), is coordinately expressed with MBNL1 in the developing thymus and DM2 CCTG expansions induce similar transcriptome alterations in DM2 blood, which thus serve as disease-specific biomarkers.
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Affiliation(s)
- Łukasz J Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA.
| | - Marina M Scotti
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Jihae Shin
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA.,Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School and Rutgers Cancer Institute of New Jersey, Newark, NJ, 07103, USA
| | - Katarzyna Taylor
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA.,Laboratory of Gene Therapy, Department of Gene Expression, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland
| | - Franjo Ivankovic
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Curtis A Nutter
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Faaiq N Aslam
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - S H Subramony
- Department of Neurology, Center for NeuroGenetics, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Laura P W Ranum
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA.
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Dumont-Lagacé M, Daouda T, Depoërs L, Zumer J, Benslimane Y, Brochu S, Harrington L, Lemieux S, Perreault C. Qualitative Changes in Cortical Thymic Epithelial Cells Drive Postpartum Thymic Regeneration. Front Immunol 2020; 10:3118. [PMID: 32010151 PMCID: PMC6974522 DOI: 10.3389/fimmu.2019.03118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 12/20/2019] [Indexed: 12/05/2022] Open
Abstract
During gestation, sex hormones cause a significant thymic involution which enhances fertility. This thymic involution is rapidly corrected following parturition. As thymic epithelial cells (TECs) are responsible for the regulation of thymopoiesis, we analyzed the sequential phenotypic and transcriptomic changes in TECs during the postpartum period in order to identify mechanisms triggering postpartum thymic regeneration. In particular, we performed flow cytometry analyses and deep RNA-sequencing on purified TEC subsets at several time points before and after parturition. We report that pregnancy-induced involution is not caused by loss of TECs since their number does not change during or after pregnancy. However, during pregnancy, we observed a significant depletion of all thymocyte subsets downstream of the double-negative 1 (DN1) differentiation stage. Variations in thymocyte numbers correlated with conspicuous changes in the transcriptome of cortical TECs (cTECs). The transcriptomic changes affected predominantly cTEC expression of Foxn1, its targets and several genes that are essential for thymopoiesis. By contrast, medullary TECs (mTECs) showed very little transcriptomic changes in the early postpartum regenerative phase, but seemed to respond to the expansion of single-positive (SP) thymocytes in the late phase of regeneration. Together, these results show that postpartum thymic regeneration is orchestrated by variations in expression of a well-defined subset of cTEC genes, that occur very early after parturition.
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Affiliation(s)
- Maude Dumont-Lagacé
- Immunobiology Research Unit, Department of Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Tariq Daouda
- Immunobiology Research Unit, Department of Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada.,Functional and Structural Bioinformatics Research Unit, Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Lucyle Depoërs
- Immunobiology Research Unit, Department of Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Jérémie Zumer
- Functional and Structural Bioinformatics Research Unit, Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Yahya Benslimane
- Telomere Length Homeostasis and Genomic Instability Research Unit, Department of Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Sylvie Brochu
- Immunobiology Research Unit, Department of Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Lea Harrington
- Telomere Length Homeostasis and Genomic Instability Research Unit, Department of Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Sébastien Lemieux
- Functional and Structural Bioinformatics Research Unit, Department of Biochemistry and Molecular Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
| | - Claude Perreault
- Immunobiology Research Unit, Department of Medicine, Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC, Canada
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50
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Guo L, Cao JH, Wei TT, Li JH, Feng YK, Wang LP, Sun Y, Chai YR. Gallic acid attenuates thymic involution in the d-galactose induced accelerated aging mice. Immunobiology 2020; 225:151870. [DOI: 10.1016/j.imbio.2019.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 11/09/2019] [Accepted: 11/16/2019] [Indexed: 10/25/2022]
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