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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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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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Symmank D, Richter FC, Rendeiro AF. Navigating the thymic landscape through development: from cellular atlas to tissue cartography. Genes Immun 2024; 25:102-104. [PMID: 38341523 PMCID: PMC11023925 DOI: 10.1038/s41435-024-00257-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/22/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024]
Affiliation(s)
- Dörte Symmank
- Department of Dermatology, Medical University of Vienna, Vienna, 1090, Austria.
| | - Felix Clemens Richter
- Institute of Hygiene and Applied Immunology, Department of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, 1090, Austria
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
| | - André F Rendeiro
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, 1090, Austria
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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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James EA, Joglekar AV, Linnemann AK, Russ HA, Kent SC. The beta cell-immune cell interface in type 1 diabetes (T1D). Mol Metab 2023; 78:101809. [PMID: 37734713 PMCID: PMC10622886 DOI: 10.1016/j.molmet.2023.101809] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 09/01/2023] [Accepted: 09/15/2023] [Indexed: 09/23/2023] Open
Abstract
BACKGROUND T1D is an autoimmune disease in which pancreatic islets of Langerhans are infiltrated by immune cells resulting in the specific destruction of insulin-producing islet beta cells. Our understanding of the factors leading to islet infiltration and the interplay of the immune cells with target beta cells is incomplete, especially in human disease. While murine models of T1D have provided crucial information for both beta cell and autoimmune cell function, the translation of successful therapies in the murine model to human disease has been a challenge. SCOPE OF REVIEW Here, we discuss current state of the art and consider knowledge gaps concerning the interface of the islet beta cell with immune infiltrates, with a focus on T cells. We discuss pancreatic and immune cell phenotypes and their impact on cell function in health and disease, which we deem important to investigate further to attain a more comprehensive understanding of human T1D disease etiology. MAJOR CONCLUSIONS The last years have seen accelerated development of approaches that allow comprehensive study of human T1D. Critically, recent studies have contributed to our revised understanding that the pancreatic beta cell assumes an active role, rather than a passive position, during autoimmune disease progression. The T cell-beta cell interface is a critical axis that dictates beta cell fate and shapes autoimmune responses. This includes the state of the beta cell after processing internal and external cues (e.g., stress, inflammation, genetic risk) that that contributes to the breaking of tolerance by hyperexpression of human leukocyte antigen (HLA) class I with presentation of native and neoepitopes and secretion of chemotactic factors to attract immune cells. We anticipate that emerging insights about the molecular and cellular aspects of disease initiation and progression processes will catalyze the development of novel and innovative intervention points to provide additional therapies to individuals affected by T1D.
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Affiliation(s)
- Eddie A James
- Center for Translational Immunology, Benaroya Research Institute, Seattle, WA, USA
| | - Alok V Joglekar
- Center for Systems Immunology and Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Amelia K Linnemann
- Center for Diabetes and Metabolic Diseases, and Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Holger A Russ
- Diabetes Institute, University of Florida, Gainesville, FL, USA; Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Sally C Kent
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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