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Abusarah J, Khodayarian F, Cui Y, El-Kadiry AEH, Rafei M. Thymic Rejuvenation: Are We There Yet? Gerontology 2018. [DOI: 10.5772/intechopen.74048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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2
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Liang Z, Zhang L, Su H, Luan R, Na N, Sun L, Zhao Y, Zhang X, Zhang Q, Li J, Zhang L, Zhao Y. MTOR signaling is essential for the development of thymic epithelial cells and the induction of central immune tolerance. Autophagy 2018; 14:505-517. [PMID: 29099279 DOI: 10.1080/15548627.2017.1376161] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Thymic epithelial cells (TECs) are critical for the establishment and maintenance of appropriate microenvironment for the positive and negative selection of thymocytes and the induction of central immune tolerance. Yet, little about the molecular regulatory network on TEC development and function is understood. Here, we demonstrate that MTOR (mechanistic target of rapamycin [serine/threonine kinase]) is essential for proper development and functional maturation of TECs. Pharmacological inhibition of MTOR activity by rapamycin (RPM) causes severe thymic atrophy and reduction of TECs. TEC-specific deletion of Mtor causes the severe reduction of mTECs, the blockage of thymocyte differentiation and output, the reduced generation of thymic regulatory T (Treg) cells and the impaired expression of tissue-restricted antigens (TRAs) including Fabp2, Ins1, Tff3 and Chrna1 molecules. Importantly, specific deletion of Mtor in TECs causes autoimmune diseases characterized by enhanced tissue immune cell infiltration and the presence of autoreactive antibodies. Mechanistically, Mtor deletion causes overdegradation of CTNNB1/Beta-Catenin due to excessive autophagy and the attenuation of WNT (wingless-type MMTV integration site family) signaling in TECs. Selective inhibition of autophagy significantly rescued the poor mTEC development caused by Mtor deficiency. Altogether, MTOR is essential for TEC development and maturation by regulating proliferation and WNT signaling activity through autophagy. The present study also implies that long-term usage of RPM might increase the risk of autoimmunity by impairing TEC maturation and function.
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Affiliation(s)
- Zhanfeng Liang
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences, University of Chinese Academy of Sciences , Beijing , China
| | - Lianjun Zhang
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Huiting Su
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences, University of Chinese Academy of Sciences , Beijing , China
| | - Rong Luan
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Ning Na
- c Department of Kidney Transplantation , The Third Affiliated Hospital of Sun Yat-sen University , Guangzhou , Guangdong , China
| | - Lina Sun
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Yang Zhao
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences, University of Chinese Academy of Sciences , Beijing , China
| | - Xiaodong Zhang
- d Department of Urology , Beijing Chaoyang Hospital, Capital Medical University , Chaoyang District, Beijing , China
| | - Qian Zhang
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences, University of Chinese Academy of Sciences , Beijing , China
| | - Juan Li
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences, University of Chinese Academy of Sciences , Beijing , China
| | - Lianfeng Zhang
- e Key Laboratory of Human Diseases Comparative Medicine, Ministry of Health; Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing , China
| | - Yong Zhao
- a State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences , Beijing , China.,b College of Life Sciences, University of Chinese Academy of Sciences , Beijing , China
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Takahama Y, Ohigashi I, Baik S, Anderson G. Generation of diversity in thymic epithelial cells. Nat Rev Immunol 2017; 17:295-305. [PMID: 28317923 DOI: 10.1038/nri.2017.12] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In the thymus, diverse populations of thymic epithelial cells (TECs), including cortical and medullary TECs and their subpopulations, have distinct roles in coordinating the development and repertoire selection of functionally competent and self-tolerant T cells. Here, we review the expanding diversity in TEC subpopulations in relation to their functions in T cell development and selection as well as their origins and development.
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Affiliation(s)
- Yousuke Takahama
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima 770-8503, Japan
| | - Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima 770-8503, Japan
| | - Song Baik
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
| | - Graham Anderson
- Institute for Immunology and Immunotherapy, Medical School, University of Birmingham, Birmingham B15 2TT, UK
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Shi Y, Wu W, Chai Q, Li Q, Hou Y, Xia H, Ren B, Xu H, Guo X, Jin C, Lv M, Wang Z, Fu YX, Zhu M. LTβR controls thymic portal endothelial cells for haematopoietic progenitor cell homing and T-cell regeneration. Nat Commun 2016; 7:12369. [PMID: 27493002 PMCID: PMC4980457 DOI: 10.1038/ncomms12369] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 06/27/2016] [Indexed: 12/19/2022] Open
Abstract
Continuous thymic homing of haematopoietic progenitor cells (HPCs) via the blood is critical for normal T-cell development. However, the nature and the differentiation programme of specialized thymic endothelial cells (ECs) controlling this process remain poorly understood. Here using conditional gene-deficient mice, we find that lymphotoxin beta receptor (LTβR) directly controls thymic ECs to guide HPC homing. Interestingly, T-cell deficiency or conditional ablation of T-cell-engaged LTβR signalling results in a defect in thymic HPC homing, suggesting the feedback regulation of thymic progenitor homing by thymic products. Furthermore, we identify and characterize a special thymic portal EC population with features that guide HPC homing. LTβR is essential for the differentiation and homeostasis of these thymic portal ECs. Finally, we show that LTβR is required for T-cell regeneration on irradiation-induced thymic injury. Together, these results uncover a cellular and molecular pathway that governs thymic EC differentiation for HPC homing. Lymphoid progenitors migrate from the bone marrow into the thymus to give rise to T and NK cell lineages. Here the authors characterize a lymphotoxin receptor beta-dependent population of thymic endothelial cells that guide lymphoid progenitor homing in the thymus.
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Affiliation(s)
- Yaoyao Shi
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weiwei Wu
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qian Chai
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Qingqing Li
- Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, Beijing 100871, China
| | - Yu Hou
- Biodynamic Optical Imaging Center, College of Life Sciences, Peking University, Beijing 100871, China
| | - Huan Xia
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Boyang Ren
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hairong Xu
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaohuan Guo
- School of Medicine, Tsinghua University, Beijing 100084 China
| | - Caiwei Jin
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengjie Lv
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhongnan Wang
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yang-Xin Fu
- Department of Pathology and Immunology, UT Southwestern Medical Center, Dallas, Texas 75235-9072, USA
| | - Mingzhao Zhu
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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Prolongevity hormone FGF21 protects against immune senescence by delaying age-related thymic involution. Proc Natl Acad Sci U S A 2016; 113:1026-31. [PMID: 26755598 DOI: 10.1073/pnas.1514511113] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Age-related thymic degeneration is associated with loss of naïve T cells, restriction of peripheral T-cell diversity, and reduced healthspan due to lower immune competence. The mechanistic basis of age-related thymic demise is unclear, but prior evidence suggests that caloric restriction (CR) can slow thymic aging by maintaining thymic epithelial cell integrity and reducing the generation of intrathymic lipid. Here we show that the prolongevity ketogenic hormone fibroblast growth factor 21 (FGF21), a member of the endocrine FGF subfamily, is expressed in thymic stromal cells along with FGF receptors and its obligate coreceptor, βKlotho. We found that FGF21 expression in thymus declines with age and is induced by CR. Genetic gain of FGF21 function in mice protects against age-related thymic involution with an increase in earliest thymocyte progenitors and cortical thymic epithelial cells. Importantly, FGF21 overexpression reduced intrathymic lipid, increased perithymic brown adipose tissue, and elevated thymic T-cell export and naïve T-cell frequencies in old mice. Conversely, loss of FGF21 function in middle-aged mice accelerated thymic aging, increased lethality, and delayed T-cell reconstitution postirradiation and hematopoietic stem cell transplantation (HSCT). Collectively, FGF21 integrates metabolic and immune systems to prevent thymic injury and may aid in the reestablishment of a diverse T-cell repertoire in cancer patients following HSCT.
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Passos GA, Mendes-da-Cruz DA, Oliveira EH. The Thymic Orchestration Involving Aire, miRNAs, and Cell-Cell Interactions during the Induction of Central Tolerance. Front Immunol 2015; 6:352. [PMID: 26236310 PMCID: PMC4500981 DOI: 10.3389/fimmu.2015.00352] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 06/29/2015] [Indexed: 01/23/2023] Open
Abstract
Developing thymocytes interact sequentially with two distinct structures within the thymus: the cortex and medulla. Surviving single-positive and double-positive thymocytes from the cortex migrate into the medulla, where they interact with medullary thymic epithelial cells (mTECs). These cells ectopically express a vast set of peripheral tissue antigens (PTAs), a property termed promiscuous gene expression that is associated with the presentation of PTAs by mTECs to thymocytes. Thymocyte clones that have a high affinity for PTAs are eliminated by apoptosis in a process termed negative selection, which is essential for tolerance induction. The Aire gene is an important factor that controls the expression of a large set of PTAs. In addition to PTAs, Aire also controls the expression of miRNAs in mTECs. These miRNAs are important in the organization of the thymic architecture and act as posttranscriptional controllers of PTAs. Herein, we discuss recent discoveries and highlight open questions regarding the migration and interaction of developing thymocytes with thymic stroma, the ectopic expression of PTAs by mTECs, the association between Aire and miRNAs and its effects on central tolerance.
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Affiliation(s)
- Geraldo Aleixo Passos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil ; Disciplines of Genetics and Molecular Biology, Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, University of São Paulo , Ribeirão Preto, São Paulo , Brazil
| | - Daniella Arêas Mendes-da-Cruz
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation , Rio de Janeiro, Rio de Janeiro , Brazil
| | - Ernna Hérida Oliveira
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo , Ribeirão Preto, São Paulo , Brazil
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Fan Y, Tajima A, Goh SK, Geng X, Gualtierotti G, Grupillo M, Coppola A, Bertera S, Rudert WA, Banerjee I, Bottino R, Trucco M. Bioengineering Thymus Organoids to Restore Thymic Function and Induce Donor-Specific Immune Tolerance to Allografts. Mol Ther 2015; 23:1262-1277. [PMID: 25903472 DOI: 10.1038/mt.2015.77] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 04/05/2015] [Indexed: 02/07/2023] Open
Abstract
One of the major obstacles in organ transplantation is to establish immune tolerance of allografts. Although immunosuppressive drugs can prevent graft rejection to a certain degree, their efficacies are limited, transient, and associated with severe side effects. Induction of thymic central tolerance to allografts remains challenging, largely because of the difficulty of maintaining donor thymic epithelial cells in vitro to allow successful bioengineering. Here, the authors show that three-dimensional scaffolds generated from decellularized mouse thymus can support thymic epithelial cell survival in culture and maintain their unique molecular properties. When transplanted into athymic nude mice, the bioengineered thymus organoids effectively promoted homing of lymphocyte progenitors and supported thymopoiesis. Nude mice transplanted with thymus organoids promptly rejected skin allografts and were able to mount antigen-specific humoral responses against ovalbumin on immunization. Notably, tolerance to skin allografts was achieved by transplanting thymus organoids constructed with either thymic epithelial cells coexpressing both syngeneic and allogenic major histocompatibility complexes, or mixtures of donor and recipient thymic epithelial cells. Our results demonstrate the technical feasibility of restoring thymic function with bioengineered thymus organoids and highlight the clinical implications of this thymus reconstruction technique in organ transplantation and regenerative medicine.
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Affiliation(s)
- Yong Fan
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Asako Tajima
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Saik Kia Goh
- Department of Chemical and Petroleum Engineering, University of Pittsburgh School of Engineering, Pittsburgh, Pennsylvania, USA
| | - Xuehui Geng
- Division of Immunogenetics, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Giulio Gualtierotti
- Division of Immunogenetics, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Maria Grupillo
- Division of Immunogenetics, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Antonina Coppola
- Division of Immunogenetics, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA; Current address: Section of Endocrinology, Dipartimento Biomedico di Medicina Interna e Specialistica (DIBIMIS), University of Palermo, Palermo, Italy
| | - Suzanne Bertera
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - William A Rudert
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Ipsita Banerjee
- Department of Chemical and Petroleum Engineering, University of Pittsburgh School of Engineering, Pittsburgh, Pennsylvania, USA
| | - Rita Bottino
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, Pennsylvania, USA
| | - Massimo Trucco
- Institute of Cellular Therapeutics, Allegheny Health Network, Pittsburgh, Pennsylvania, USA.
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Inhibins tune the thymocyte selection process by regulating thymic stromal cell differentiation. J Immunol Res 2015; 2015:837859. [PMID: 25973437 PMCID: PMC4418002 DOI: 10.1155/2015/837859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/15/2015] [Accepted: 01/20/2015] [Indexed: 01/01/2023] Open
Abstract
Inhibins and Activins are members of the TGF-β superfamily that regulate the differentiation of several cell types. These ligands were initially identified as hormones that regulate the hypothalamus-pituitary-gonadal axis; however, increasing evidence has demonstrated that they are key regulators in the immune system. We have previously demonstrated that Inhibins are the main Activin ligands expressed in the murine thymus and that they regulate thymocyte differentiation, promoting the DN3-DN4 transition and the selection of SP thymocytes. As Inhibins are mainly produced by thymic stromal cells, which also express Activin receptors and Smad proteins, we hypothesized that Inhibins might play a role in stromal cell differentiation and function. Here, we demonstrate that, in the absence of Inhibins, thymic conventional dendritic cells display reduced levels of MHC Class II (MHCII) and CD86. In addition, the ratio between cTECs and mTECs was affected, indicating that mTEC differentiation was favoured and cTEC diminished in the absence of Inhibins. These changes appeared to impact thymocyte selection leading to a decreased selection of CD4SP thymocytes and increased generation of natural regulatory T cells. These findings demonstrate that Inhibins tune the T cell selection process by regulating both thymocyte and stromal cell differentiation.
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Sawicka M, Stritesky GL, Reynolds J, Abourashchi N, Lythe G, Molina-París C, Hogquist KA. From pre-DP, post-DP, SP4, and SP8 Thymocyte Cell Counts to a Dynamical Model of Cortical and Medullary Selection. Front Immunol 2014; 5:19. [PMID: 24592261 PMCID: PMC3924582 DOI: 10.3389/fimmu.2014.00019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 01/15/2014] [Indexed: 01/15/2023] Open
Abstract
Cells of the mature αβ T cell repertoire arise from the development in the thymus of bone marrow precursors (thymocytes). αβ T cell maturation is characterized by the expression of thousands of copies of identical αβ T cell receptors and the CD4 and/or CD8 co-receptors on the surface of thymocytes. The maturation stages of a thymocyte are: (1) double negative (DN) (TCR−, CD4− and CD8−), (2) double positive (DP) (TCR+, CD4+ and CD8+), and (3) single positive (SP) (TCR+, CD4+ or CD8+). Thymic antigen presenting cells provide the appropriate micro-architecture for the maturation of thymocytes, which “sense” the signaling environment via their randomly generated TCRs. Thymic development is characterized by (i) an extremely low success rate, and (ii) the selection of a functional and self-tolerant T cell repertoire. In this paper, we combine recent experimental data and mathematical modeling to study the selection events that take place in the thymus after the DN stage. The stable steady state of the model for the pre-DP, post-DP, and SP populations is identified with the experimentally measured cell counts from 5.5- to 17-week-old mice. We make use of residence times in the cortex and the medulla for the different populations, as well as recently reported asymmetric death rates for CD4 and CD8 SP thymocytes. We estimate that 65.8% of pre-DP thymocytes undergo death by neglect. In the post-DP compartment, 91.7% undergo death by negative selection, 4.7% become CD4 SP, and 3.6% become CD8 SP. Death by negative selection in the medulla removes 8.6% of CD4 SP and 32.1% of CD8 SP thymocytes. Approximately 46.3% of CD4 SP and 27% of CD8 SP thymocytes divide before dying or exiting the thymus.
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Affiliation(s)
- Maria Sawicka
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Gretta L Stritesky
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota , Minneapolis, MN , USA
| | - Joseph Reynolds
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Niloufar Abourashchi
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Grant Lythe
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Carmen Molina-París
- Department of Applied Mathematics, School of Mathematics, University of Leeds , Leeds , UK
| | - Kristin A Hogquist
- Department of Laboratory Medicine and Pathology, Center for Immunology, University of Minnesota , Minneapolis, MN , USA
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