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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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Santos JC, Dametto M, Masson AP, Faça VM, Bonacin R, Donadi EA, Passos GA. The AIRE G228W mutation disturbs the interaction of AIRE with its partner molecule SIRT1. Front Immunol 2022; 13:948419. [PMID: 36148232 PMCID: PMC9485725 DOI: 10.3389/fimmu.2022.948419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 08/11/2022] [Indexed: 12/02/2022] Open
Abstract
The autoimmune regulator (AIRE) protein functions as a tetramer, interacting with partner proteins to form the “AIRE complex,” which relieves RNA Pol II stalling in the chromatin of medullary thymic epithelial cells (mTECs). AIRE is the primary mTEC transcriptional controller, promoting the expression of a large set of peripheral tissue antigen genes implicated in the negative selection of self-reactive thymocytes. Under normal conditions, the SIRT1 protein temporarily interacts with AIRE and deacetylates K residues of the AIRE SAND domain. Once the AIRE SAND domain is deacetylated, the binding with SIRT1 is undone, allowing the AIRE complex to proceed downstream with the RNA Pol II to the elongation phase of transcription. Considering that the in silico and in vitro binding of the AIRE SAND domain with SIRT1 provides a powerful model system for studying the dominant SAND G228W mutation mechanism, which causes the autoimmune polyglandular syndrome-1, we integrated computational molecular modeling, docking, dynamics between the whole SAND domain with SIRT1, and surface plasmon resonance using a peptide harboring the 211 to 230 residues of the SAND domain, to compare the structure and energetics of binding/release between AIRE G228 (wild-type) and W228 (mutant) SAND domain to SIRT1. We observed that the G228W mutation in the SAND domain negatively influences the AIRE-SIRT1 interaction. The disturbed interaction might cause a disruption in the binding of the AIRE SAND domain with the SIRT1 catalytic site, impairing the AIRE complex to proceed downstream with RNA Pol II.
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Affiliation(s)
- Jadson C. Santos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Mariangela Dametto
- Renato Archer Information Technology Center (CTI Brazil), Ministry of Science, Technology and Innovation (MCTI), Campinas, SP, Brazil
| | - Ana Paula Masson
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Vitor M. Faça
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Rodrigo Bonacin
- Renato Archer Information Technology Center (CTI Brazil), Ministry of Science, Technology and Innovation (MCTI), Campinas, SP, Brazil
| | - Eduardo A. Donadi
- Division of Clinical Immunology, Department of Medicine, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Geraldo Aleixo Passos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
- Laboratory of Genetics and Molecular Biology, Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
- Center for Cell-Based Therapy in Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
- *Correspondence: Geraldo Aleixo Passos,
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Ma X, Ru Y, Luo Y, Kuai L, Chen QL, Bai Y, Liu YQ, Chen J, Luo Y, Song JK, Zhou M, Li B. Post-Translational Modifications in Atopic Dermatitis: Current Research and Clinical Relevance. Front Cell Dev Biol 2022; 10:942838. [PMID: 35874824 PMCID: PMC9301047 DOI: 10.3389/fcell.2022.942838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 06/16/2022] [Indexed: 11/20/2022] Open
Abstract
Atopic dermatitis (AD) is a chronic and relapsing cutaneous disorder characterized by compromised immune system, excessive inflammation, and skin barrier disruption. Post-translational modifications (PTMs) are covalent and enzymatic modifications of proteins after their translation, which have been reported to play roles in inflammatory and allergic diseases. However, less attention has been paid to the effect of PTMs on AD. This review summarized the knowledge of six major classes (including phosphorylation, acetylation, ubiquitination, SUMOylation, glycosylation, o-glycosylation, and glycation) of PTMs in AD pathogenesis and discussed the opportunities for disease management.
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Affiliation(s)
- Xin Ma
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
| | - Yi Ru
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, China
| | - Ying Luo
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, China
| | - Le Kuai
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, China
| | - Qi-Long Chen
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
| | - Yun Bai
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
| | - Ye-Qiang Liu
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
| | - Jia Chen
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
| | - Yue Luo
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
| | - Jian-Kun Song
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
| | - Mi Zhou
- Department of Dermatology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, China
- *Correspondence: Mi Zhou, ; Bin Li,
| | - Bin Li
- Shanghai Skin Disease Hospital of Tongji University, Shanghai, China
- Institute of Dermatology, Shanghai Academy of Traditional Chinese Medicine, Shanghai, China
- *Correspondence: Mi Zhou, ; Bin Li,
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Sun Z, Ma Y, Liu Y, Lv J, Wang D, You Z, Jiang C, Sheng Q, Nie Z. The Acetylation Modification of SP1 Regulates the Protein Stability in Silkworm. Appl Biochem Biotechnol 2021; 194:1621-1635. [PMID: 34826090 DOI: 10.1007/s12010-021-03757-9] [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: 05/29/2021] [Accepted: 11/08/2021] [Indexed: 12/01/2022]
Abstract
Acetylation is a highly conservative and reversible post-translational modification. Acetylation modification can regulate gene expression by altering protein function and is widely identified in an increasing number of species. Previously, the acetylated proteome of silkworm was identified by combining acetylated polypeptide enrichment with nano-HPLC/MS/MS; the identification revealed that the SP proteins (SPs) were high acetylated. In this study, the acetylation of SP1, one of the SPs, was further confirmed using immunoprecipitation (IP) and Western blotting. Then, we found the acetylation could upregulate SP1 protein expression by enhancing the protein stability. Further research found that the acetylation of SP1 protein can competitively inhibit its ubiquitination and thus improve the stability and cell accumulation of SP1 protein by inhibiting the ubiquitin-mediated proteasome degradation pathway. This result provides a basis for acetylation to regulate the nutrient storage and utilization of silkworm.
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Affiliation(s)
- Zihan Sun
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Yafei Ma
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Yue Liu
- Zhejiang Economic & Trade Polytechnic, Hangzhou, 310018, China
| | - Jiao Lv
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Dan Wang
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Zhengying You
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Caiying Jiang
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Qing Sheng
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Zuoming Nie
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou, 310018, China.
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Hu C, Zhang K, Jiang F, Wang H, Shao Q. Epigenetic modifications in thymic epithelial cells: an evolutionary perspective for thymus atrophy. Clin Epigenetics 2021; 13:210. [PMID: 34819170 PMCID: PMC8612001 DOI: 10.1186/s13148-021-01197-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/08/2021] [Indexed: 02/06/2023] Open
Abstract
Background The thymic microenvironment is mainly comprised of thymic epithelial cells, the cytokines, exosomes, surface molecules, and hormones from the cells, and plays a vital role in the development, differentiation, maturation and homeostasis of T lymphocytes. However, the thymus begins to degenerate as early as the second year of life and continues through aging in human beings, leading to a decreased output of naïve T cells, the limited TCR diversity and an expansion of monoclonal memory T cells in the periphery organs. These alternations will reduce the adaptive immune response to tumors and emerging infectious diseases, such as COVID-19, also it is easier to suffer from autoimmune diseases in older people. In the context of global aging, it is important to investigate and clarify the causes and mechanisms of thymus involution. Main body Epigenetics include histone modification, DNA methylation, non-coding RNA effects, and chromatin remodeling. In this review, we discuss how senescent thymic epithelial cells determine and control age-related thymic atrophy, how this process is altered by epigenetic modification. How the thymus adipose influences the dysfunctions of the thymic epithelial cells, and the prospects of targeting thymic epithelial cells for the treatment of thymus atrophy. Conclusion Epigenetic modifications are emerging as key regulators in governing the development and senescence of thymic epithelial cells. It is beneficial to re-establish effective thymopoiesis, identify the potential therapeutic strategy and rejuvenate the immune function in the elderly.
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Affiliation(s)
- Cexun Hu
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Keyu Zhang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Feng Jiang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China.,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China
| | - Hui Wang
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China.
| | - Qixiang Shao
- Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Department of Immunology, Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, No. 301 Xuefu Road, Zhenjiang, 212013, Jiangsu, People's Republic of China. .,Jiangsu College of Nursing, School of Medical Science and Laboratory Medicine, Huai'an, 223002, Jiangsu, People's Republic of China.
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Hu J, Xia X, Zhao Q, Li S. Lysine acetylation of NKG2D ligand Rae-1 stabilizes the protein and sensitizes tumor cells to NKG2D immune surveillance. Cancer Lett 2021; 502:143-153. [PMID: 33279621 PMCID: PMC10142196 DOI: 10.1016/j.canlet.2020.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 11/23/2020] [Accepted: 12/01/2020] [Indexed: 02/08/2023]
Abstract
Shedding, loss of expression, or internalization of natural killer group 2, member D (NKG2D) ligands from the tumor cell surface leads to immune evasion, which is associated with poor prognosis in patients with cancer. In many cancers, matrix metalloproteinases cause the proteolytic shedding of NKG2D ligands. However, it remained unclear how to protect NKG2D ligands from shedding. Here, we showed that the shedding of the mouse NKG2D ligand Rae-1 can be prevented by two critical acetyltransferases, GCN5 and PCAF, which acetylate the lysine residues of Rae-1 to avoid shedding both in vitro and in vivo. In contrast, mutations at lysines 80 and 87 of Rae-1 abrogated this acetylation and thereby desensitized tumor cells to NKG2D-dependent immune surveillance. Notably, the protein levels of GCN5 correlated with the expression levels of the human NKG2D ligand ULPB1 in a human tumor tissue microarray and, more importantly, with prolonged overall survival in many cancers. Our results suggest that the acetylation of Rae-1 protein at lysines 80 and 87 by GCN5 and PCAF protects Rae-1 from shedding so as to activate NKG2D-dependent immune surveillance. This discovery may shed light on new targets for NKG2D immunotherapy in cancer treatment.
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Affiliation(s)
- Jiemiao Hu
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA
| | - Xueqing Xia
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA
| | - Qingnan Zhao
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA
| | - Shulin Li
- Division of Pediatrics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 853, Houston, TX, 77030, USA.
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Oliveira EH, Assis AF, Speck-Hernandez CA, Duarte MJ, Passos GA. Aire Gene Influences the Length of the 3' UTR of mRNAs in Medullary Thymic Epithelial Cells. Front Immunol 2020; 11:1039. [PMID: 32547551 PMCID: PMC7270294 DOI: 10.3389/fimmu.2020.01039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
Aire is a transcriptional controller in medullary thymic epithelial cells (mTECs) modulating a set of peripheral tissue antigens (PTAs) and non-PTA mRNAs as well as miRNAs. Even miRNAs exerting posttranscriptional control of mRNAs in mTECs, the composition of miRNA-mRNA networks may differ. Under reduction in Aire expression, networks exhibited greater miRNA diversity controlling mRNAs. Variations in the number of 3'UTR binding sites of Aire-dependent mRNAs may represent a crucial factor that influence the miRNA interaction. To test this hypothesis, we analyzed through bioinformatics the length of 3'UTRs of a large set of Aire-dependent mRNAs. The data were obtained from existing RNA-seq of mTECs of wild type or Aire-knockout (KO) mice. We used computational algorithms as FASTQC, STAR and HTSEQ for sequence alignment and counting reads, DESEQ2 for the differential expression, 3USS for the alternative 3'UTRs and TAPAS for the alternative polyadenylation sites. We identified 152 differentially expressed mRNAs between these samples comprising those that encode PTAs as well as transcription regulators. In Aire KO mTECs, most of these mRNAs featured an increase in the length of their 3'UTRs originating additional miRNA binding sites and new miRNA controllers. Results from the in silico analysis were statistically significant and the predicted miRNA-mRNA interactions were thermodynamically stable. Even with no in vivo or in vitro experiments, they were adequate to show that lack of Aire in mTECs might favor the downregulation of PTA mRNAs and transcription regulators via miRNA control. This could unbalance the overall transcriptional activity in mTECs and thus the self-representation.
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Affiliation(s)
- Ernna H. Oliveira
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | | | - Cesar A. Speck-Hernandez
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Max Jordan Duarte
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
| | - Geraldo A. Passos
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, Brazil
- Laboratory of Genetics and Molecular Biology, Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, USP, Ribeirão Preto, Brazil
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8
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Pellegrino M, Bellacchio E, Dhamo R, Frasca F, Betterle C, Fierabracci A. A Novel Homozygous Mutation of the AIRE Gene in an APECED Patient From Pakistan: Case Report and Review of the Literature. Front Immunol 2018; 9:1835. [PMID: 30150985 PMCID: PMC6099424 DOI: 10.3389/fimmu.2018.01835] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 07/25/2018] [Indexed: 11/13/2022] Open
Abstract
Autoimmune-poly-endocrinopathy-candidiasis-ectodermal-dystrophy syndrome (APECED) is a rare monogenic recessive disorder caused by mutations in the autoimmune regulator (AIRE) gene. Criteria for the diagnosis of APECED are the presence of two of the following disorders: chronic mucocutaneous candidiasis (CMC), chronic hypoparathyroidism (CHP), and Addison's disease. APECED develops at high incidence in Finns, Sardinians, and Iranian Jews and presents with a wide range of clinical phenotypes and genotypes. In this manuscript, we report the clinical, endocrinological, and molecular features of a 16-year-old female patient from Pakistan living in Italy and presenting the major APECED clinical manifestations CMC, CHP, and primary adrenal insufficiency. Premature ovarian failure, chronic bronchopneumopathy, vitiligo, Hashimoto's thyroiditis emerged as associated diseases. In our patient, AIRE gene screening revealed the novel c.396G>C (p.Arg132Ser; p.R132S) mutation in homozygosity thus confirming APECED diagnosis. This is the first reported mutation within the nuclear localization signal (NLS) that is associated with APECED. The NLS mutation affects the nuclear import of classical transcription factors through nuclear pore by recognition of nuclear import receptors, the importin α molecules. By displaying crystal structures of the peptide containing the KRK basic residue cluster bound to α importins, we show that p.R132S replacement in 131-KRK-133 does not reproduce these interactions. Thus, we propose that the novel mutation exerts its pathogenetic effect by impairing the nuclear import of the Aire protein. The present case report is added to a limited series of Pakistani APECED patients who we reviewed from the scientific literature, mostly diagnosed on clinical findings.
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Affiliation(s)
- Marsha Pellegrino
- Infectivology and Clinical Trials Research Division, Bambino Gesù Children’s Hospital, Rome, Italy
| | - Emanuele Bellacchio
- Molecular Genetics and Functional Genomics, Genetics and Rare Diseases Research Division, Bambino Gesù Children’s Hospital, Rome, Italy
| | | | - Federica Frasca
- Infectivology and Clinical Trials Research Division, Bambino Gesù Children’s Hospital, Rome, Italy
| | - Corrado Betterle
- Endocrine Unit, Department of Medicine (DIMED), University of Padua, Padua, Italy
| | - Alessandra Fierabracci
- Infectivology and Clinical Trials Research Division, Bambino Gesù Children’s Hospital, Rome, Italy
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Abstract
About two decades ago, cloning of the autoimmune regulator (AIRE) gene materialized one of the most important actors on the scene of self-tolerance. Thymic transcription of genes encoding tissue-specific antigens (ts-ags) is activated by AIRE protein and embodies the essence of thymic self-representation. Pathogenic AIRE variants cause the autoimmune polyglandular syndrome type 1, which is a rare and complex disease that is gaining attention in research on autoimmunity. The animal models of disease, although not identically reproducing the human picture, supply fundamental information on mechanisms and extent of AIRE action: thanks to its multidomain structure, AIRE localizes to chromatin enclosing the target genes, binds to histones, and offers an anchorage to multimolecular complexes involved in initiation and post-initiation events of gene transcription. In addition, AIRE enhances mRNA diversity by favoring alternative mRNA splicing. Once synthesized, ts-ags are presented to, and cause deletion of the self-reactive thymocyte clones. However, AIRE function is not restricted to the activation of gene transcription. AIRE would control presentation and transfer of self-antigens for thymic cellular interplay: such mechanism is aimed at increasing the likelihood of engagement of the thymocytes that carry the corresponding T-cell receptors. Another fundamental role of AIRE in promoting self-tolerance is related to the development of thymocyte anergy, as thymic self-representation shapes at the same time the repertoire of regulatory T cells. Finally, AIRE seems to replicate its action in the secondary lymphoid organs, albeit the cell lineage detaining such property has not been fully characterized. Delineation of AIRE functions adds interesting data to the knowledge of the mechanisms of self-tolerance and introduces exciting perspectives of therapeutic interventions against the related diseases.
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Affiliation(s)
- Roberto Perniola
- Department of Pediatrics, Neonatal Intensive Care, Vito Fazzi Regional Hospital, Lecce, Italy
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Passos GA, Speck‐Hernandez CA, Assis AF, Mendes‐da‐Cruz DA. Update on Aire and thymic negative selection. Immunology 2018; 153:10-20. [PMID: 28871661 PMCID: PMC5721245 DOI: 10.1111/imm.12831] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/24/2017] [Accepted: 08/31/2017] [Indexed: 12/17/2022] Open
Abstract
Twenty years ago, the autoimmune regulator (Aire) gene was associated with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy, and was cloned and sequenced. Its importance goes beyond its abstract link with human autoimmune disease. Aire identification opened new perspectives to better understand the molecular basis of central tolerance and self-non-self distinction, the main properties of the immune system. Since 1997, a growing number of immunologists and molecular geneticists have made important discoveries about the function of Aire, which is essentially a pleiotropic gene. Aire is one of the functional markers in medullary thymic epithelial cells (mTECs), controlling their differentiation and expression of peripheral tissue antigens (PTAs), mTEC-thymocyte adhesion and the expression of microRNAs, among other functions. With Aire, the immunological tolerance became even more apparent from the molecular genetics point of view. Currently, mTECs represent the most unusual cells because they express almost the entire functional genome but still maintain their identity. Due to the enormous diversity of PTAs, this uncommon gene expression pattern was termed promiscuous gene expression, the interpretation of which is essentially immunological - i.e. it is related to self-representation in the thymus. Therefore, this knowledge is strongly linked to the negative selection of autoreactive thymocytes. In this update, we focus on the most relevant results of Aire as a transcriptional and post-transcriptional controller of PTAs in mTECs, its mechanism of action, and its influence on the negative selection of autoreactive thymocytes as the bases of the induction of central tolerance and prevention of autoimmune diseases.
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Affiliation(s)
- Geraldo A. Passos
- Molecular Immunogenetics GroupDepartment of GeneticsRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
- Discipline of Genetics and Molecular BiologyDepartment of Morphology, Physiology and Basic PathologySchool of Dentistry of Ribeirão PretoUniversity of São PauloRibeirão PretoSPBrazil
| | - Cesar A. Speck‐Hernandez
- Graduate Programme in Basic and Applied ImmunologyRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
| | - Amanda F. Assis
- Molecular Immunogenetics GroupDepartment of GeneticsRibeirão Preto Medical SchoolUniversity of São PauloRibeirão PretoSPBrazil
| | - Daniella A. Mendes‐da‐Cruz
- Laboratory on Thymus ResearchOswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
- National Institute of Science and Technology on NeuroimmunomodulationRio de JaneiroRJBrazil
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11
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Flici H, Schnitzler CE, Millane RC, Govinden G, Houlihan A, Boomkamp SD, Shen S, Baxevanis AD, Frank U. An Evolutionarily Conserved SoxB-Hdac2 Crosstalk Regulates Neurogenesis in a Cnidarian. Cell Rep 2017; 18:1395-1409. [PMID: 28178518 PMCID: PMC5312794 DOI: 10.1016/j.celrep.2017.01.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/09/2016] [Accepted: 01/10/2017] [Indexed: 10/20/2022] Open
Abstract
SoxB transcription factors and histone deacetylases (HDACs) are each major players in the regulation of neurogenesis, but a functional link between them has not been previously demonstrated. Here, we show that SoxB2 and Hdac2 act together to regulate neurogenesis in the cnidarian Hydractinia echinata during tissue homeostasis and head regeneration. We find that misexpression of SoxB genes modifies the number of neural cells in all life stages and interferes with head regeneration. Hdac2 was co-expressed with SoxB2, and its downregulation phenocopied SoxB2 knockdown. We also show that SoxB2 and Hdac2 promote each other's transcript levels, but Hdac2 counteracts this amplification cycle by deacetylating and destabilizing SoxB2 protein. Finally, we present evidence for conservation of these interactions in human neural progenitors. We hypothesize that crosstalk between SoxB transcription factors and Hdac2 is an ancient feature of metazoan neurogenesis and functions to stabilize the correct levels of these multifunctional proteins.
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Affiliation(s)
- Hakima Flici
- Centre for Chromosome Biology (CCB), School of Natural Sciences, National University of Ireland, Galway H91 CF50, Ireland
| | - Christine E Schnitzler
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080, USA; Department of Biology, University of Florida, Gainesville, FL 32611, USA; Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-8002, USA
| | - R Cathriona Millane
- Centre for Chromosome Biology (CCB), School of Natural Sciences, National University of Ireland, Galway H91 CF50, Ireland
| | - Graham Govinden
- Centre for Chromosome Biology (CCB), School of Natural Sciences, National University of Ireland, Galway H91 CF50, Ireland
| | - Amy Houlihan
- Centre for Chromosome Biology (CCB), School of Natural Sciences, National University of Ireland, Galway H91 CF50, Ireland
| | - Stephanie D Boomkamp
- Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Galway H91 CF50, Ireland
| | - Sanbing Shen
- Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Galway H91 CF50, Ireland
| | - Andreas D Baxevanis
- Computational and Statistical Genomics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-8002, USA
| | - Uri Frank
- Centre for Chromosome Biology (CCB), School of Natural Sciences, National University of Ireland, Galway H91 CF50, Ireland.
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12
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Abstract
More than 15 years ago, mutations in the autoimmune regulator (AIRE) gene were identified as the cause of autoimmune polyglandular syndrome type 1 (APS1). It is now clear that this transcription factor has a crucial role in promoting self-tolerance in the thymus by regulating the expression of a wide array of self-antigens that have the commonality of being tissue-restricted in their expression pattern in the periphery. In this Review, we highlight many of the recent advances in our understanding of the complex biology that is related to AIRE, with a particular focus on advances in genetics, molecular interactions and the effect of AIRE on thymic selection of regulatory T cells. Furthermore, we highlight new areas of biology that are potentially affected by this key regulator of immune tolerance.
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Affiliation(s)
- Maureen A. Su
- Department of Pediatrics, School of Medicine, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
- Department of Microbiology/Immunology, School of Medicine, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
| | - Mark S. Anderson
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143
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13
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Ghosh S, Padmanabhan B, Anand C, Nagaraja V. Lysine acetylation of the Mycobacterium tuberculosis HU protein modulates its DNA binding and genome organization. Mol Microbiol 2016; 100:577-88. [PMID: 26817737 DOI: 10.1111/mmi.13339] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/23/2016] [Indexed: 12/20/2022]
Abstract
Nucleoid-associated protein HU, a conserved protein across eubacteria is necessary for maintaining the nucleoid organization and global regulation of gene expression. Mycobacterium tuberculosis HU (MtHU) is distinct from the other orthologues having 114 amino acid long carboxyl terminal extensions with a high degree of sequence similarity to eukaryotic histones. In this study, we demonstrate that the DNA binding property of MtHU is regulated by posttranslational modifications akin to eukaryotic histones. MtHU purified from M. tuberculosis cells is found to be acetylated on multiple lysine residues unlike the E. coli expressed recombinant protein. Using coimmunoprecipitation assay, we identified Eis as one of the acetyl transferases that interacts with MtHU and modifies it. Although Eis is known to acetylate aminoglycosides, the kinetics of acetylation showed that its protein acetylation activity on MtHU is robust. In vitro Eis modified MtHU at various lysine residues, primarily those located at the carboxyl terminal domain. Acetylation of MtHU caused reduced DNA interaction and alteration in DNA compaction ability of the NAP. Over-expression of the Eis leads to hyperacetylation of HU and decompaction of genome. These results provide first insights into the modulation of the nucleoid structure by lysine acetylation in bacteria.
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Affiliation(s)
- Soumitra Ghosh
- Department of Microbiology and Cell biology, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Bhavna Padmanabhan
- Department of Microbiology and Cell biology, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Chinmay Anand
- Department of Microbiology and Cell biology, Indian Institute of Science, Bangalore, Karnataka, 560012, India
| | - Valakunja Nagaraja
- Department of Microbiology and Cell biology, Indian Institute of Science, Bangalore, Karnataka, 560012, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, Karnataka, 560064, India
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14
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De Martino L, Capalbo D, Improda N, Lorello P, Ungaro C, Di Mase R, Cirillo E, Pignata C, Salerno M. Novel Findings into AIRE Genetics and Functioning: Clinical Implications. Front Pediatr 2016; 4:86. [PMID: 27597936 PMCID: PMC4992815 DOI: 10.3389/fped.2016.00086] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/02/2016] [Indexed: 01/22/2023] Open
Abstract
Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), formerly known as autoimmune polyendocrine syndrome type 1, is a paradigm of a monogenic autoimmune disease caused by mutations of a gene, named autoimmune regulator (AIRE). AIRE acts as a transcription regulator that promotes immunological central tolerance by inducing the ectopic thymic expression of many tissue-specific antigens. Although the syndrome is a monogenic disease, it is characterized by a wide variability of the clinical expression with no significant correlation between genotype and phenotype. Indeed, many aspects regarding the exact role of AIRE and APECED pathogenesis still remain unraveled. In the last decades, several studies in APECED and in its mouse experimental counterpart have revealed new insights on how immune system learns self-tolerance. Moreover, novel interesting findings have extended our understanding of AIRE's function and regulation thus improving our knowledge on the pathogenesis of APECED. In this review, we will summarize recent novelties on molecular mechanisms underlying the development of APECED and their clinical implications.
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Affiliation(s)
- Lucia De Martino
- Pediatric Section, Department of Translational Medical Sciences, Federico II University , Naples , Italy
| | | | - Nicola Improda
- Pediatric Section, Department of Translational Medical Sciences, Federico II University , Naples , Italy
| | - Paola Lorello
- Pediatric Section, Department of Translational Medical Sciences, Federico II University , Naples , Italy
| | - Carla Ungaro
- Department of Pediatrics, Federico II University , Naples , Italy
| | | | - Emilia Cirillo
- Pediatric Section, Department of Translational Medical Sciences, Federico II University , Naples , Italy
| | - Claudio Pignata
- Pediatric Section, Department of Translational Medical Sciences, Federico II University , Naples , Italy
| | - Mariacarolina Salerno
- Pediatric Section, Department of Translational Medical Sciences, Federico II University , Naples , Italy
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15
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Barr MP, O'Byrne KJ, Al-Sarraf N, Gray SG. VEGF-mediated cell survival in non-small-cell lung cancer: implications for epigenetic targeting of VEGF receptors as a therapeutic approach. Epigenomics 2015; 7:897-910. [DOI: 10.2217/epi.15.51] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aims: To evaluate the potential therapeutic utility of histone deacetylase inhibitors (HDACi) in targeting VEGF receptors in non-small-cell lung cancer. Materials & methods: Non-small-cell lung cancer cells were screened for the VEGF receptors at the mRNA and protein levels, while cellular responses to various HDACi were examined. Results: Significant effects on the regulation of the VEGF receptors were observed in response to HDACi. These were associated with decreased secretion of VEGF, decreased cellular proliferation and increased apoptosis which could not be rescued by addition of exogenous recombinant VEGF. Direct remodeling of the VEGFR1 and VEGFR2 promoters was observed. In contrast, HDACi treatments resulted in significant downregulation of the Neuropilin receptors. Conclusion: Epigenetic targeting of the Neuropilin receptors may offer an effective treatment for lung cancer patients in the clinical setting.
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Affiliation(s)
- Martin P Barr
- Thoracic Oncology Research Group, School of Clinical Medicine, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St James's Hospital & Trinity College Dublin, Dublin 8, Ireland
| | - Kenneth J O'Byrne
- Thoracic Oncology Research Group, School of Clinical Medicine, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St James's Hospital & Trinity College Dublin, Dublin 8, Ireland
- Cancer & Ageing Research Program, Queensland University of Technology, Brisbane, Australia
| | - Nael Al-Sarraf
- Thoracic Oncology Research Group, School of Clinical Medicine, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St James's Hospital & Trinity College Dublin, Dublin 8, Ireland
| | - Steven G Gray
- Thoracic Oncology Research Group, School of Clinical Medicine, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St James's Hospital & Trinity College Dublin, Dublin 8, Ireland
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16
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Yoshida H, Bansal K, Schaefer U, Chapman T, Rioja I, Proekt I, Anderson MS, Prinjha RK, Tarakhovsky A, Benoist C, Mathis D. Brd4 bridges the transcriptional regulators, Aire and P-TEFb, to promote elongation of peripheral-tissue antigen transcripts in thymic stromal cells. Proc Natl Acad Sci U S A 2015; 112:E4448-57. [PMID: 26216992 PMCID: PMC4538633 DOI: 10.1073/pnas.1512081112] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Aire controls immunologic tolerance by inducing a battery of thymic transcripts encoding proteins characteristic of peripheral tissues. Its unusually broad effect is achieved by releasing RNA polymerase II paused just downstream of transcriptional start sites. We explored Aire's collaboration with the bromodomain-containing protein, Brd4, uncovering an astonishing correspondence between those genes induced by Aire and those inhibited by a small-molecule bromodomain blocker. Aire:Brd4 binding depended on an orchestrated series of posttranslational modifications within Aire's caspase activation and recruitment domain. This interaction attracted P-TEFb, thereby mobilizing downstream transcriptional elongation and splicing machineries. Aire:Brd4 association was critical for tolerance induction, and its disruption could account for certain point mutations that provoke human autoimmune disease. Our findings evoke the possibility of unanticipated immunologic mechanisms subtending the potent antitumor effects of bromodomain blockers.
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Affiliation(s)
- Hideyuki Yoshida
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Kushagra Bansal
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Uwe Schaefer
- Laboratory of Immune Cell Epigenetics and Signaling, The Rockefeller University, New York, NY 10065
| | - Trevor Chapman
- Epinova Discovery Performance Unit, Immuno-Inflammation Therapy Area, Medicines Research Centre, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
| | - Inmaculada Rioja
- Epinova Discovery Performance Unit, Immuno-Inflammation Therapy Area, Medicines Research Centre, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
| | - Irina Proekt
- Department of Microbiology and Immunology, University of California, San Francisco, CA 94143
| | - Mark S Anderson
- Diabetes Center, University of California, San Francisco, CA 94143
| | - Rab K Prinjha
- Epinova Discovery Performance Unit, Immuno-Inflammation Therapy Area, Medicines Research Centre, GlaxoSmithKline, Stevenage SG1 2NY, United Kingdom
| | - Alexander Tarakhovsky
- Laboratory of Immune Cell Epigenetics and Signaling, The Rockefeller University, New York, NY 10065
| | - Christophe Benoist
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115; Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
| | - Diane Mathis
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115; Evergrande Center for Immunologic Diseases, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02115
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17
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Rattay K, Claude J, Rezavandy E, Matt S, Hofmann TG, Kyewski B, Derbinski J. Homeodomain-interacting protein kinase 2, a novel autoimmune regulator interaction partner, modulates promiscuous gene expression in medullary thymic epithelial cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 194:921-8. [PMID: 25552543 DOI: 10.4049/jimmunol.1402694] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Promiscuous expression of a plethora of tissue-restricted Ags (TRAs) by medullary thymic epithelial cells (mTECs) plays an essential role in T cell tolerance. Although the cellular mechanisms by which promiscuous gene expression (pGE) imposes T cell tolerance have been well characterized, the underlying molecular mechanisms remain poorly understood. The autoimmune regulator (AIRE) is to date the only validated molecule known to regulate pGE. AIRE is part of higher-order multiprotein complexes, which promote transcription, elongation, and splicing of a wide range of target genes. How AIRE and its partners mediate these various effects at the molecular level is still largely unclear. Using a yeast two-hybrid screen, we searched for novel AIRE-interacting proteins and identified the homeodomain-interacting protein kinase 2 (HIPK2) as a novel partner. HIPK2 partially colocalized with AIRE in nuclear bodies upon cotransfection and in human mTECs in situ. Moreover, HIPK2 phosphorylated AIRE in vitro and suppressed the coactivator activity of AIRE in a kinase-dependent manner. To evaluate the role of Hipk2 in modulating the function of AIRE in vivo, we compared whole-genome gene signatures of purified mTEC subsets from TEC-specific Hipk2 knockout mice with control mice and identified a small set of differentially expressed genes. Unexpectedly, most differentially expressed genes were confined to the CD80(lo) mTEC subset and preferentially included AIRE-independent TRAs. Thus, although it modulates gene expression in mTECs and in addition affects the size of the medullary compartment, TEC-specific HIPK2 deletion only mildly affects AIRE-directed pGE in vivo.
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Affiliation(s)
- Kristin Rattay
- Division of Developmental Immunobiology, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany; and
| | - Janine Claude
- Division of Developmental Immunobiology, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany; and
| | - Esmail Rezavandy
- Division of Developmental Immunobiology, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany; and
| | - Sonja Matt
- Zelluläre Seneszenz-Gruppe, Deutsches Krebsforschungszentrum-Zentrum für Molekulare Biologie Allianz, Deutsches Krebsforschungszentrum, 69120 Heidelberg, Germany
| | - Thomas G Hofmann
- Zelluläre Seneszenz-Gruppe, Deutsches Krebsforschungszentrum-Zentrum für Molekulare Biologie Allianz, Deutsches Krebsforschungszentrum, 69120 Heidelberg, Germany
| | - Bruno Kyewski
- Division of Developmental Immunobiology, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany; and
| | - Jens Derbinski
- Division of Developmental Immunobiology, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany; and
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