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Reis MDDS, Veneziani LP, Porto FL, Lins MP, Mendes-da-Cruz DA, Savino W. Intrathymic somatotropic circuitry: consequences upon thymus involution. Front Immunol 2023; 14:1108630. [PMID: 37426675 PMCID: PMC10323194 DOI: 10.3389/fimmu.2023.1108630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 06/05/2023] [Indexed: 07/11/2023] Open
Abstract
Growth hormone (GH) is a classic pituitary-derived hormone crucial to body growth and metabolism. In the pituitary gland, GH production is stimulated by GH-releasing hormone and inhibited by somatostatin. GH secretion can also be induced by other peptides, such as ghrelin, which interacts with receptors present in somatotropic cells. It is well established that GH acts directly on target cells or indirectly by stimulating the production of insulin-like growth factors (IGFs), particularly IGF-1. Notably, such somatotropic circuitry is also involved in the development and function of immune cells and organs, including the thymus. Interestingly, GH, IGF-1, ghrelin, and somatostatin are expressed in the thymus in the lymphoid and microenvironmental compartments, where they stimulate the secretion of soluble factors and extracellular matrix molecules involved in the general process of intrathymic T-cell development. Clinical trials in which GH was used to treat immunocompromised patients successfully recovered thymic function. Additionally, there is evidence that the reduction in the function of the somatotropic axis is associated with age-related thymus atrophy. Treatment with GH, IGF-1 or ghrelin can restore thymopoiesis of old animals, thus in keeping with a clinical study showing that treatment with GH, associated with metformin and dehydroepiandrosterone, could induce thymus regeneration in healthy aged individuals. In conclusion, the molecules of the somatotrophic axis can be envisioned as potential therapeutic targets for thymus regeneration in age-related or pathological thymus involution.
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Affiliation(s)
- Maria Danielma dos Santos Reis
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Rio de Janeiro, Brazil
| | - Luciana Peixoto Veneziani
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Rio de Janeiro, Brazil
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- Rio de Janeiro Research Network on Neuroinflammation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- INOVA-IOC Network on Neuroimmunomodulation, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Felipe Lima Porto
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Rio de Janeiro, Brazil
| | - Marvin Paulo Lins
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Rio de Janeiro, Brazil
| | - Daniella Arêas Mendes-da-Cruz
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Rio de Janeiro, Brazil
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- Rio de Janeiro Research Network on Neuroinflammation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- INOVA-IOC Network on Neuroimmunomodulation, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Wilson Savino
- Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Rio de Janeiro, Brazil
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- Rio de Janeiro Research Network on Neuroinflammation, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
- INOVA-IOC Network on Neuroimmunomodulation, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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2
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Silva CS, Cerqueira MT, Reis RL, Martins A, Neves NM. Laminin-2 immobilized on a 3D fibrous structure impacts cortical thymic epithelial cells behaviour and their interaction with thymocytes. Int J Biol Macromol 2022; 222:3168-3177. [DOI: 10.1016/j.ijbiomac.2022.10.089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/15/2022] [Accepted: 10/10/2022] [Indexed: 11/05/2022]
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3
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Carter JA, Strömich L, Peacey M, Chapin SR, Velten L, Steinmetz LM, Brors B, Pinto S, Meyer HV. Transcriptomic diversity in human medullary thymic epithelial cells. Nat Commun 2022; 13:4296. [PMID: 35918316 PMCID: PMC9345899 DOI: 10.1038/s41467-022-31750-1] [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: 10/25/2021] [Accepted: 06/30/2022] [Indexed: 12/03/2022] Open
Abstract
The induction of central T cell tolerance in the thymus depends on the presentation of peripheral self-epitopes by medullary thymic epithelial cells (mTECs). This promiscuous gene expression (pGE) drives mTEC transcriptomic diversity, with non-canonical transcript initiation, alternative splicing, and expression of endogenous retroelements (EREs) representing important but incompletely understood contributors. Here we map the expression of genome-wide transcripts in immature and mature human mTECs using high-throughput 5' cap and RNA sequencing. Both mTEC populations show high splicing entropy, potentially driven by the expression of peripheral splicing factors. During mTEC maturation, rates of global transcript mis-initiation increase and EREs enriched in long terminal repeat retrotransposons are up-regulated, the latter often found in proximity to differentially expressed genes. As a resource, we provide an interactive public interface for exploring mTEC transcriptomic diversity. Our findings therefore help construct a map of transcriptomic diversity in the healthy human thymus and may ultimately facilitate the identification of those epitopes which contribute to autoimmunity and immune recognition of tumor antigens.
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Affiliation(s)
- Jason A. Carter
- grid.225279.90000 0004 0387 3667Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA ,grid.36425.360000 0001 2216 9681Medical Scientist Training Program, Stony Brook University, Stony Brook, NY USA ,grid.34477.330000000122986657Department of Surgery, University of Washington, Seattle, WA USA
| | - Léonie Strömich
- grid.7497.d0000 0004 0492 0584German Cancer Research Center, Heidelberg, Germany ,grid.7445.20000 0001 2113 8111Present Address: Imperial College London, London, UK
| | - Matthew Peacey
- grid.225279.90000 0004 0387 3667School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
| | - Sarah R. Chapin
- grid.225279.90000 0004 0387 3667Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
| | - Lars Velten
- grid.473715.30000 0004 6475 7299Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain ,grid.5612.00000 0001 2172 2676Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Lars M. Steinmetz
- grid.4709.a0000 0004 0495 846XEuropean Molecular Biology Laboratory, Genome Biology Unit, Heidelberg, Germany ,grid.168010.e0000000419368956Department of Genetics, Stanford University School of Medicine, Stanford, CA USA ,grid.168010.e0000000419368956Stanford Genome Technology Center, Palo Alto, CA USA
| | - Benedikt Brors
- grid.7497.d0000 0004 0492 0584German Cancer Research Center, Heidelberg, Germany
| | - Sheena Pinto
- grid.7497.d0000 0004 0492 0584German Cancer Research Center, Heidelberg, Germany
| | - Hannah V. Meyer
- grid.225279.90000 0004 0387 3667Simons Center for Quantitative Biology, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY USA
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4
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CXCL12-driven thymocyte migration is increased by thymic epithelial cells treated with prolactin in vitro. J Biosci 2021. [PMID: 34815373 PMCID: PMC8608580 DOI: 10.1007/s12038-021-00229-4] [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] [Indexed: 11/16/2022]
Abstract
The prolactin hormone (PRL), in addition to its known effects on breast development and lactation, exerts effects on the immune system, including pleiotropic effects on the thymus. The aim of this study was to evaluate the influence of PRL on the epithelial compartment of the thymus. Thymic epithelial cells (TECs) (2BH4 cells) and fresh thymocytes were used. Immunofluorescence assay revealed that PRL treatment (10 ng/mL) increases the deposition of laminin and expression of the chemokine CXCL12 in 2BH4 cells. However, no change was observed in the deposition of fibronectin. Moreover, PRL altered F-actin polymerisation, allowing the formation of focal adhesion complexes in treated cells. When 2BH4 cells were pre-treated with PRL, thymocyte adhesion was not altered. However, in the cell migration assay, pre-treatment with PRL potentiated the chemotactic effect of CXCL12 on the migration of total, double-positive, CD4-positive, and CD8-positive thymocytes. Together, the results of this study demonstrate the effect of PRL on thymic epithelial cells, particularly on CXCL12-driven thymocyte migration, confirming that this hormone is a regulator of thymic physiology.
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5
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Silva CS, Reis RL, Martins A, Neves NM. Recapitulation of Thymic Function by Tissue Engineering Strategies. Adv Healthc Mater 2021; 10:e2100773. [PMID: 34197034 DOI: 10.1002/adhm.202100773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Indexed: 11/06/2022]
Abstract
The thymus is responsible for the development and selection of T lymphocytes, which in turn also participate in the maturation of thymic epithelial cells. These events occur through the close interactions between hematopoietic stem cells and developing thymocytes with the thymic stromal cells within an intricate 3D network. The complex thymic microenvironment and function, and the current therapies to induce thymic regeneration or to overcome the lack of a functional thymus are herein reviewed. The recapitulation of the thymic function using tissue engineering strategies has been explored as a way to control the body's tolerance to external grafts and to generate ex vivo T cells for transplantation. In this review, the main advances in the thymus tissue engineering field are disclosed, including both scaffold- and cell-based strategies. In light of the current gaps and limitations of the developed systems, the design of novel biomaterials for this purpose with unique features is also discussed.
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Affiliation(s)
- Catarina S. Silva
- 3B's Research Group I3Bs – Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine ICVS/3B's – PT Government Associate Laboratory AvePark, Parque da Ciência e Tecnologia, Zona Industrial da Gandra 4805‐017 Barco Guimarães Portugal
| | - Rui L. Reis
- 3B's Research Group I3Bs – Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine ICVS/3B's – PT Government Associate Laboratory AvePark, Parque da Ciência e Tecnologia, Zona Industrial da Gandra 4805‐017 Barco Guimarães Portugal
| | - Albino Martins
- 3B's Research Group I3Bs – Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine ICVS/3B's – PT Government Associate Laboratory AvePark, Parque da Ciência e Tecnologia, Zona Industrial da Gandra 4805‐017 Barco Guimarães Portugal
| | - Nuno M. Neves
- 3B's Research Group I3Bs – Research Institute on Biomaterials Biodegradables and Biomimetics University of Minho Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine ICVS/3B's – PT Government Associate Laboratory AvePark, Parque da Ciência e Tecnologia, Zona Industrial da Gandra 4805‐017 Barco Guimarães Portugal
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6
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Medeiros NC, Porto FL, de Menezes CA, dos Santos Reis MD, Smaniotto S, Lins MP. CXCL12-driven thymocyte migration is increased by thymic epithelial cells treated with prolactin in vitro. J Biosci 2021; 46:103. [PMID: 34815373 PMCID: PMC8608580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 10/21/2021] [Indexed: 02/27/2024]
Abstract
The prolactin hormone (PRL), in addition to its known effects on breast development and lactation, exerts effects on the immune system, including pleiotropic effects on the thymus. The aim of this study was to evaluate the influence of PRL on the epithelial compartment of the thymus. Thymic epithelial cells (TECs) (2BH4 cells) and fresh thymocytes were used. Immunofluorescence assay revealed that PRL treatment (10 ng/ mL) increases the deposition of laminin and expression of the chemokine CXCL12 in 2BH4 cells. However, no change was observed in the deposition of fibronectin. Moreover, PRL altered F-actin polymerisation, allowing the formation of focal adhesion complexes in treated cells. When 2BH4 cells were pre-treated with PRL, thymocyte adhesion was not altered. However, in the cell migration assay, pre-treatment with PRL potentiated the chemotactic effect of CXCL12 on the migration of total, double-positive, CD4-positive, and CD8-positive thymocytes. Together, the results of this study demonstrate the effect of PRL on thymic epithelial cells, particularly on CXCL12-driven thymocyte migration, confirming that this hormone is a regulator of thymic physiology.
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Affiliation(s)
- Návylla Candeia Medeiros
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
| | - Felipe Lima Porto
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
| | - Clarice Agudo de Menezes
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
| | - Maria Danielma dos Santos Reis
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Salete Smaniotto
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Marvin Paulo Lins
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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7
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Silva CS, Pinto RD, Amorim S, Pires RA, Correia-Neves M, Reis RL, Alves NL, Martins A, Neves NM. Fibronectin-Functionalized Fibrous Meshes as a Substrate to Support Cultures of Thymic Epithelial Cells. Biomacromolecules 2020; 21:4771-4780. [PMID: 33238090 DOI: 10.1021/acs.biomac.0c00933] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Thymic epithelial cells (TECs) are the main regulators of T lymphocyte development and selection, requiring a three-dimensional (3D) environment to properly perform these biological functions. The aim of this work was to develop a 3D culture substrate that allows the survival and proliferation of TECs. Thus, electrospun fibrous meshes (eFMs) were functionalized with fibronectin, one of the major extracellular matrix (ECM) proteins of the thymus. For that, highly porous eFMs were activated using oxygen plasma treatment followed by amine insertion, which allows the immobilization of fibronectin through EDC/NHS chemistry. The medullary TECs presented increased proliferation, viability, and protein synthesis when cultured on fibronectin-functionalized eFMs (FN-eFMs). These cells showed a spread morphology, with increased migration toward the inner layers of FN-eFMs and the production of thymic ECM proteins, such as collagen type IV and laminin. These results suggest that FN-eFMs are an effective substrate for supporting thymic cell cultures.
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Affiliation(s)
- Catarina S Silva
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Rute D Pinto
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Sara Amorim
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Ricardo A Pires
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Margarida Correia-Neves
- ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal.,Life and Health Sciences Research Institute (ICVS), School of MedicineUniversity of Minho, 4710-057 Braga, Portugal
| | - Rui L Reis
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Nuno L Alves
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
| | - Albino Martins
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
| | - Nuno M Neves
- 3B's Research Group, I3Bs - Research Institute on Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal.,ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga, Portugal
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8
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Lins MP, Medeiros NC, Carmo J, Porto FL, dos Santos Reis MD, Smaniotto S. The Responsiveness of Thymic Stromal Cells to semaphorin-3A. Immunol Invest 2020; 51:395-410. [DOI: 10.1080/08820139.2020.1834578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Marvin Paulo Lins
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Návylla Candeia Medeiros
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
| | - Julianderson Carmo
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Felipe Lima Porto
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
| | - Maria Danielma dos Santos Reis
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Salete Smaniotto
- Laboratory of Cell Biology, Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Brazil
- Brazilian National Institute of Science and Technology on Neuroimmunomodulation (INCT-NIM), Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
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9
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Lee BJ, Mace EM. From stem cell to immune effector: how adhesion, migration, and polarity shape T-cell and natural killer cell lymphocyte development in vitro and in vivo. Mol Biol Cell 2020; 31:981-991. [PMID: 32352896 PMCID: PMC7346728 DOI: 10.1091/mbc.e19-08-0424] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/10/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Abstract
Lymphocyte development is a complex and coordinated pathway originating from pluripotent stem cells during embryogenesis and continuing even as matured lymphocytes are primed and educated in adult tissue. Hematopoietic stem cells develop in a specialized niche that includes extracellular matrix and supporting stromal and endothelial cells that both maintain stem cell pluripotency and enable the generation of differentiated cells. Cues for lymphocyte development include changes in integrin-dependent cell motility and adhesion which ultimately help to determine cell fate. The capacity of lymphocytes to adhere and migrate is important for modulating these developmental signals both by regulating the cues that the cell receives from the local microenvironment as well as facilitating the localization of precursors to tissue niches throughout the body. Here we consider how changing migratory and adhesive phenotypes contribute to human natural killer (NK)- and T-cell development as they undergo development from precursors to mature, circulating cells and how our understanding of this process is informed by in vitro models of T- and NK cell generation.
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Affiliation(s)
- Barclay J. Lee
- Department of Bioengineering, Rice University, Houston, TX 77005
- Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
| | - Emily M. Mace
- Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032
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Abstract
Previous work showed that the thymus can be infected by RNA viruses as HIV and HTLV-1. We thus hypothesized that the thymus might also be infected by the Zika virus (ZIKV). Herein we provide compelling evidence that ZIKV targets human thymic epithelial cells (TEC) in vivo and in vitro. ZIKV-infection enhances keratinization of TEC, with a decrease in proliferation and increase in cell death. Moreover, ZIKV modulates a high amount of coding RNAs with upregulation of genes related to cell adhesion and migration, as well as non-coding genes including miRNAs, circRNAs and lncRNAs. Moreover, we observed enhanced attachment of lymphoblastic T-cells to infected TEC, as well as virus transfer to those cells. Lastly, alterations in thymuses from babies congenitally infected were seen, with the presence of viral envelope protein in TEC. Taken together, our data reveals that the thymus, particularly the thymic epithelium, is a target for the ZIKV with changes in the expression of molecules that are relevant for interactions with developing thymocytes.
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11
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Cotrim-Sousa L, Freire-Assis A, Pezzi N, Tanaka PP, Oliveira EH, Passos GA. Adhesion between medullary thymic epithelial cells and thymocytes is regulated by miR-181b-5p and miR-30b. Mol Immunol 2019; 114:600-611. [PMID: 31539668 DOI: 10.1016/j.molimm.2019.09.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 09/03/2019] [Accepted: 09/05/2019] [Indexed: 12/16/2022]
Abstract
In this work, we demonstrate that adhesion between medullary thymic epithelial cells (mTECs) and thymocytes is controlled by miRNAs. Adhesion between mTECs and developing thymocytes is essential for triggering negative selection (NS) of autoreactive thymocytes that occurs in the thymus. Immune recognition is mediated by the MHC / TCR receptor, whereas adhesion molecules hold cell-cell interaction stability. Indeed, these processes must be finely controlled, if it is not, it may lead to aggressive autoimmunity. Conversely, the precise molecular genetic control of mTEC-thymocyte adhesion is largely unclear. Here, we asked whether miRNAs would be controlling this process through the posttranscriptional regulation of mRNAs that encode adhesion molecules. For this, we used small interfering RNA to knockdown (KD) Dicer mRNA in vitro in a murine mTEC line. A functional assay with fresh murine thymocytes co-cultured with mTECs showed that single-positive (SP) CD4 and CD8 thymocyte adhesion was increased after Dicer KD and most adherent subtype was CD8 SP cells. Analysis of broad mTEC transcriptional expression showed that Dicer KD led to the modulation of 114 miRNAs and 422 mRNAs, including those encoding cell adhesion or extracellular matrix proteins, such as Lgals9, Lgals3pb, Tnc and Cd47. Analysis of miRNA-mRNA networks followed by miRNA mimic transfection showed that these mRNAs are under the control of miR-181b-5p and miR-30b*, which may ultimately control mTEC-thymocyte adhesion. The expression of CD80 surface marker in mTECs was increased after Dicer KD following thymocyte adhesion. This indicates the existence of new mechanisms in mTECs that involve the synergistic action of thymocyte adhesion and regulatory miRNAs.
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Affiliation(s)
- Larissa Cotrim-Sousa
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Amanda Freire-Assis
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil; State University of Minas Gerais, Passos, MG, Brazil
| | - Nicole Pezzi
- Graduate Program in Basic and Applied Immunology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Pedro Paranhos Tanaka
- Molecular Immunogenetics Group, Department of Genetics, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Ernna Hérida Oliveira
- Molecular Immunogenetics Group, Department of Genetics, 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; Graduate Program in Basic and Applied Immunology, 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, USP, Ribeirão Preto, SP, Brazil.
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12
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Speck-Hernandez CA, Assis AF, Felicio RF, Cotrim-Sousa L, Pezzi N, Lopes GS, Bombonato-Prado KF, Giuliatti S, Passos GA. Aire Disruption Influences the Medullary Thymic Epithelial Cell Transcriptome and Interaction With Thymocytes. Front Immunol 2018; 9:964. [PMID: 29867946 PMCID: PMC5949327 DOI: 10.3389/fimmu.2018.00964] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 04/18/2018] [Indexed: 11/13/2022] Open
Abstract
The function of medullary thymic epithelial cells (mTECs) is associated with thymocyte adhesion, which is crucial for the negative selection of autoreactive thymocytes in the thymus. This process represents the root of central tolerance of self-components and prevents the onset of autoimmune diseases. Since thymic epithelia correspond to an important target of donor T cells during the onset of chronic graft-vs-host-disease, mTEC-thymocyte adhesion may have implications for alloimmunity. The Aire and Fezf2 genes function as transcriptome controllers in mTECs. The central question of this study is whether there is a mutual relationship between mTEC-thymocyte adhesion and the control of the mTEC transcriptome and whether Aire is involved in this process. Here, we show that in vitro mTEC-thymocyte adhesion causes transcriptome changes in mTECs and upregulates the transcriptional expression of Aire and Fezf2, as well as cell adhesion-related genes such as Cd80 or Tcf7, among others. Crispr-Cas9-mediated Aire gene disruption demonstrated that this gene plays a role in the process of mTEC-thymocyte adhesion. Consistent with the nuclear localization signal (NLS) encoded by Aire exon 3, which was targeted, we demonstrate that Aire KO-/- mTECs impair AIRE protein localization in the nucleus. Consequently, the loss of function of Aire reduced the ability of these cells to adhere to thymocytes. Their transcriptomes differed from their wild-type Aire+/+ counterparts, even during thymocyte adhesion. A set of mRNA isoforms that encode proteins involved in cell adhesion were also modulated during this process. This demonstrates that both thymocyte interactions and Aire influence transcriptome profiling of mTEC cells.
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Affiliation(s)
- Cesar A. Speck-Hernandez
- Graduate Programme in Basic and Applied Immunology, Universidade de São Paulo, São Paulo, Brazil
| | - Amanda F. Assis
- Molecular Immunogenetics Group, Genetics, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Rafaela F. Felicio
- Graduate Programme in Basic and Applied Immunology, Universidade de São Paulo, São Paulo, Brazil
| | - Larissa Cotrim-Sousa
- Molecular Immunogenetics Group, Genetics, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Nicole Pezzi
- Graduate Programme in Basic and Applied Immunology, Universidade de São Paulo, São Paulo, Brazil
| | - Gabriel S. Lopes
- Graduate Programme in Cellular and Molecular Biology, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Karina F. Bombonato-Prado
- Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Silvana Giuliatti
- Genetics, Bioinformatics Group, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
| | - Geraldo A. Passos
- Molecular Immunogenetics Group, Genetics, Ribeirão Preto Medical School, Universidade de São Paulo, São Paulo, Brazil
- Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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Golbert DCF, Santana-Van-Vliet E, Ribeiro-Alves M, Fonsêca MMBD, Lepletier A, Mendes-da-Cruz DA, Loss G, Cotta-de-Almeida V, Vasconcelos ATR, Savino W. Small interference ITGA6 gene targeting in the human thymic epithelium differentially regulates the expression of immunological synapse-related genes. Cell Adh Migr 2018; 12:152-167. [PMID: 28494186 DOI: 10.1080/19336918.2017.1327513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The thymus supports differentiation of T cell precursors. This process requires relocation of developing thymocytes throughout multiple microenvironments of the organ, mainly with thymic epithelial cells (TEC), which control intrathymic T cell differentiation influencing the formation and maintenance of the immunological synapse. In addition to the proteins of the major histocompatibility complex (MHC), this structure is supported by several adhesion molecules. During the process of thymopoiesis, we previously showed that laminin-mediated interactions are involved in the entrance of T-cell precursors into the thymus, as well as migration of differentiating thymocytes within the organ. Using small interference RNA strategy, we knocked-down the ITGA6 gene (which encodes the CD49f integrin α-chain) in cultured human TEC, generating a decrease in the expression of the corresponding CD49f subunit, in addition to modulation in several other genes related to cell adhesion and migration. Thymocyte adhesion to TEC was significantly impaired, comprising both immature and mature thymocyte subsets. Moreover, we found a modulation of the MHC, with a decrease in membrane expression of HLA-ABC, in contrast with increase in the expression of HLA-DR. Interestingly, the knockdown of the B2M gene (encoding the β-2 microglobulin of the HLA-ABC complex) increased CD49f expression levels, thus unraveling the existence of a cross-talk event in the reciprocal control of CD49f and HLA-ABC. Our data suggest that the expression levels of CD49f may be relevant in the general control of MHC expression by TEC and consequently the corresponding synapse with developing thymocytes mediated by the T-cell receptor.
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Affiliation(s)
- Daiane Cristina F Golbert
- a Laboratory on Thymus Research, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil.,b National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil.,c Bioinformatics Laboratory, National Laboratory of Scientific Computation, Petrópolis , Rio de Janeiro , Brazil
| | - Eliane Santana-Van-Vliet
- a Laboratory on Thymus Research, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil.,b National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
| | - Marcelo Ribeiro-Alves
- d Evandro Chagas Research Institute, Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
| | - Marbella Maria B da Fonsêca
- e Nuffield Department of Clinical Medicine, Structural Genomics Consortium , University of Oxford, UK, Structural Genomics Consortium , Old Road Campus, Headington , Oxford , England
| | - Ailin Lepletier
- a Laboratory on Thymus Research, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil.,b National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
| | - Daniella Arêas Mendes-da-Cruz
- a Laboratory on Thymus Research, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil.,b National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
| | - Guilherme Loss
- c Bioinformatics Laboratory, National Laboratory of Scientific Computation, Petrópolis , Rio de Janeiro , Brazil
| | - Vinícius Cotta-de-Almeida
- a Laboratory on Thymus Research, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil.,b National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
| | - Ana Tereza R Vasconcelos
- c Bioinformatics Laboratory, National Laboratory of Scientific Computation, Petrópolis , Rio de Janeiro , Brazil
| | - Wilson Savino
- a Laboratory on Thymus Research, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil.,b National Institute of Science and Technology on Neuroimmunomodulation, Oswaldo Cruz Institute , Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
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14
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Bertoni A, Alabiso O, Galetto AS, Baldanzi G. Integrins in T Cell Physiology. Int J Mol Sci 2018; 19:E485. [PMID: 29415483 PMCID: PMC5855707 DOI: 10.3390/ijms19020485] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 01/19/2018] [Accepted: 02/02/2018] [Indexed: 11/16/2022] Open
Abstract
From the thymus to the peripheral lymph nodes, integrin-mediated interactions with neighbor cells and the extracellular matrix tune T cell behavior by organizing cytoskeletal remodeling and modulating receptor signaling. LFA-1 (αLβ2 integrin) and VLA-4 (α4β1 integrin) play a key role throughout the T cell lifecycle from thymocyte differentiation to lymphocyte extravasation and finally play a fundamental role in organizing immune synapse, providing an essential costimulatory signal for the T cell receptor. Apart from tuning T cell signaling, integrins also contribute to homing to specific target organs as exemplified by the importance of α4β7 in maintaining the gut immune system. However, apart from those well-characterized examples, the physiological significance of the other integrin dimers expressed by T cells is far less understood. Thus, integrin-mediated cell-to-cell and cell-to-matrix interactions during the T cell lifespan still represent an open field of research.
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Affiliation(s)
- Alessandra Bertoni
- Department of Translational Medicine and Institute for Research and Cure of Autoimmune Diseases, University of Piemonte Orientale, 28100 Novara, Italy.
| | - Oscar Alabiso
- Department of Translational Medicine, University of Eastern Piedmont, Novara-Italy and Oncology Division, University Hospital "Maggiore della Carità", 28100 Novara, Italy.
| | - Alessandra Silvia Galetto
- Department of Translational Medicine, University of Eastern Piedmont, Novara 28100-Italy and Palliative Care Division, A.S.L., 13100 Vercelli, Italy.
| | - Gianluca Baldanzi
- Department of Translational Medicine and Institute for Research and Cure of Autoimmune Diseases, University of Piemonte Orientale, 28100 Novara, Italy.
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Somaiah C, Kumar A, Mawrie D, Sharma A, Patil SD, Bhattacharyya J, Swaminathan R, Jaganathan BG. Collagen Promotes Higher Adhesion, Survival and Proliferation of Mesenchymal Stem Cells. PLoS One 2015; 10:e0145068. [PMID: 26661657 PMCID: PMC4678765 DOI: 10.1371/journal.pone.0145068] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/29/2015] [Indexed: 12/25/2022] Open
Abstract
Mesenchymal stem cells (MSC) can differentiate into several cell types and are desirable candidates for cell therapy and tissue engineering. However, due to poor cell survival, proliferation and differentiation in the patient, the therapy outcomes have not been satisfactory. Although several studies have been done to understand the conditions that promote proliferation, differentiation and migration of MSC in vitro and in vivo, still there is no clear understanding on the effect of non-cellular bio molecules. Of the many factors that influence the cell behavior, the immediate cell microenvironment plays a major role. In this context, we studied the effect of extracellular matrix (ECM) proteins in controlling cell survival, proliferation, migration and directed MSC differentiation. We found that collagen promoted cell proliferation, cell survival under stress and promoted high cell adhesion to the cell culture surface. Increased osteogenic differentiation accompanied by high active RHOA (Ras homology gene family member A) levels was exhibited by MSC cultured on collagen. In conclusion, our study shows that collagen will be a suitable matrix for large scale production of MSC with high survival rate and to obtain high osteogenic differentiation for therapy.
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Affiliation(s)
- Chinnapaka Somaiah
- Stem Cell Biology Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Atul Kumar
- Stem Cell Biology Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Darilang Mawrie
- Stem Cell Biology Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Amit Sharma
- Stem Cell Biology Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Suraj Dasharath Patil
- Stem Cell Biology Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Jina Bhattacharyya
- Department of Hematology, Gauhati Medical College Hospital, Assam, India
| | - Rajaram Swaminathan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Bithiah Grace Jaganathan
- Stem Cell Biology Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
- * E-mail:
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16
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Savino W, Mendes-da-Cruz DA, Golbert DCF, Riederer I, Cotta-de-Almeida V. Laminin-Mediated Interactions in Thymocyte Migration and Development. Front Immunol 2015; 6:579. [PMID: 26635793 PMCID: PMC4648024 DOI: 10.3389/fimmu.2015.00579] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2015] [Accepted: 10/29/2015] [Indexed: 11/30/2022] Open
Abstract
Intrathymic T-cell differentiation is a key process for the development and maintenance of cell-mediated immunity, and occurs concomitantly to highly regulated migratory events. We have proposed a multivectorial model for describing intrathymic thymocyte migration. One of the individual vectors comprises interactions mediated by laminins (LMs), a heterotrimeric protein family of the extracellular matrix. Several LMs are expressed in the thymus, being produced by microenvironmental cells, particularly thymic epithelial cells (TECs). Also, thymocytes and epithelial cells express integrin-type LM receptors. Functionally, it has been reported that the dy/dy mutant mouse (lacking the LM isoform 211) exhibits defective thymocyte differentiation. Several data show haptotactic effects of LMs upon thymocytes, as well as their adhesion on TECs; both effects being prevented by anti-LM or anti-LM receptor antibodies. Interestingly, LM synergizes with chemokines to enhance thymocyte migration, whereas classe-3 semaphorins and B ephrins, which exhibit chemorepulsive effects in the thymus, downregulate LM-mediated migratory responses of thymocytes. More recently, we showed that knocking down the ITGA6 gene (which encodes the α6 integrin chain of LM receptors) in human TECs modulates a large number of cell migration-related genes and results in changes of adhesion pattern of thymocytes onto the thymic epithelium. Overall, LM-mediated interactions can be placed at the cross-road of the multivectorial process of thymocyte migration, with a direct influence per se, as well as by modulating other molecular interactions associated with the intrathymic-trafficking events.
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Affiliation(s)
- Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
| | | | | | - Ingo Riederer
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
| | - Vinicius Cotta-de-Almeida
- Laboratory on Thymus Research, Oswaldo Cruz Institute, Oswaldo Cruz Foundation , Rio de Janeiro , Brazil
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Golbert DCF, Correa-de-Santana E, Ribeiro-Alves M, de Vasconcelos ATR, Savino W. ITGA6 gene silencing by RNA interference modulates the expression of a large number of cell migration-related genes in human thymic epithelial cells. BMC Genomics 2013; 14 Suppl 6:S3. [PMID: 24564203 PMCID: PMC3909006 DOI: 10.1186/1471-2164-14-s6-s3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background The thymic epithelium is the major microenvironmental component of the thymus, the primary lymphoid organ responsible for the generation of T lymphocytes. Thymic epithelial cells (TEC) control intrathymic T cell differentiation by means of distinct types of interactions. TEC constitutively produce chemokines and extracellular matrix ligands (such as laminin and fibronectin) and express corresponding receptors, which allow thymocytes to migrate in a very ordered fashion. We previously showed that laminin mediates TEC/thymocyte interactions in both mice and humans. More recently, we used RNAi technology to knock-down the ITGA5 gene (which encodes CD49e, the integrin α-chain subunit of the fibronectin receptor VLA-5) in cultured human TEC. Using a similar strategy, herein we knocked-down the ITGA6 gene, which encodes CD49f, the α-chain of two integrin-type laminin receptors, namely VLA-6 (α6β1) and α6β4. Results We first confirmed that RNAi-induced knock-down of the ITGA6 gene was successful, at both transcription and translational levels, with a significant decrease in the membrane expression of CD49f, apart from CD49b, CD49c and CD49d, ascertained by cytofluorometry on living TEC. We also demonstrated that such knock-down promotes a decrease in cell adhesion to laminin. Using quantitative PCR, we demonstrated that gene expression of other integrin α-chains were concomitantly down-regulated, particularly those which form other laminin receptors, including ITGA1, ITGA2 and ITGA7. Interestingly enough, LAMA1 gene expression (whose corresponding protein chain is part of laminin-111) was largely increased in ITGA6 knocked-down TEC cultures. Lastly, the network complexity of gene expression under ITGA6 influence is much broader, since we found that other cell migration-related genes, namely those coding for various chemokines, are also modulated when IGTA6 is knocked-down. Conclusion The data presented herein clearly show that down regulation of ITGA6 gene in the human thymic epithelium triggers a complex cascade of effects upon the expression levels of several other cell migration-related genes, including extracellular matrix and chemokine ligands and receptors. Taken together, these data unravel the concept that the expression of genes involved in controlling of thymocyte migration by the thymic microenvironment should be regarded as complex networks, so that a defect in the expression of one single gene may reflect in an amplified cascade with functional consequences for TEC adhesion onto the natural ligand and potential consequences upon the normal patterns of TEC/thymocyte interactions.
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Rusu M, Pop F, Mănoiu V, Lupuşoru M, Didilescu A. Zipper-like series of desmosomes supported by subplasmalemmal actin belts in thymic epithelial reticular cells in the rat. Ann Anat 2013; 195:359-364. [DOI: 10.1016/j.aanat.2013.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 02/06/2013] [Accepted: 02/12/2013] [Indexed: 11/26/2022]
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19
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Mendes-da-Cruz DA, Linhares-Lacerda L, Smaniotto S, Dardenne M, Savino W. Semaphorins and neuropilins: new players in the neuroendocrine control of the intrathymic T-cell migration in humans. Exp Physiol 2012; 97:1146-50. [PMID: 22327328 DOI: 10.1113/expphysiol.2011.061515] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cell migration is a key event for proper intrathymic T-cell differentiation, and several ligand-receptor interactions contribute to the well-co ordinated movement of developing thymocytes within the thymic lobules. Herein we summarize recent data that place semaphorin 3A (Sema3A) and its receptor neuropilin 1 (NRP1) as further players in the physiological process of cell migration in the human thymus. These molecules, as well as class A plexins (necessary for the intracellular signalling transduction triggered by Sema3A-NRP1 ligation), are constitutively expressed by both developing thymocytes and components of the thymic microenvironment, including epithelial and dendritic cells. Functionally, Sema3A decreases the adhesion of human thymocytes on thymic epithelial cell monolayers and exerts per se a dose-dependent chemorepulsive effect on human thymocytes. Moreover, Sema3A inhibits chemoattractant migratory responses induced by other ligands, including fibronectin, laminin and CXCL12 (chemokine CXC motif ligand 12). These data should be placed in the context of the concept that migration of developing T cells is a multivectorial system, in which the resulting migration vector derives from a balance of several simultaneous and/or sequential ligand-receptor pair interactions. Accordingly, semaphorins and neuropilins can be considered as further players in the system.
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