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Mercado MAB, Li Q, Quick CM, Kim Y, Palmer R, Huang L, Li LX. BHLHE40 drives protective polyfunctional CD4 T cell differentiation in the female reproductive tract against Chlamydia. PLoS Pathog 2024; 20:e1011983. [PMID: 38271477 PMCID: PMC10846703 DOI: 10.1371/journal.ppat.1011983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/06/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
The protein basic helix-loop-helix family member e40 (BHLHE40) is a transcription factor recently emerged as a key regulator of host immunity to infections, autoimmune diseases and cancer. In this study, we investigated the role of Bhlhe40 in protective T cell responses to the intracellular bacterium Chlamydia in the female reproductive tract (FRT). Mice deficient in Bhlhe40 exhibited severe defects in their ability to control Chlamydia muridarum shedding from the FRT. The heightened bacterial burdens in Bhlhe40-/- mice correlated with a marked increase in IL-10-producing T regulatory type 1 (Tr1) cells and decreased polyfunctional CD4 T cells co-producing IFN-γ, IL-17A and GM-CSF. Genetic ablation of IL-10 or functional blockade of IL-10R increased CD4 T cell polyfunctionality and partially rescued the defects in bacterial control in Bhlhe40-/- mice. Using single-cell RNA sequencing coupled with TCR profiling, we detected a significant enrichment of stem-like T cell signatures in Bhlhe40-deficient CD4 T cells, whereas WT CD4 T cells were further down on the differentiation trajectory with distinct effector functions beyond IFN-γ production by Th1 cells. Altogether, we identified Bhlhe40 as a key molecular driver of CD4 T cell differentiation and polyfunctional responses in the FRT against Chlamydia.
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Affiliation(s)
- Miguel A. B. Mercado
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Qiang Li
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Charles M. Quick
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Yejin Kim
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Rachel Palmer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Lu Huang
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Lin-Xi Li
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
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2
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Mercado MAB, Li Q, Quick CM, Kim Y, Palmer R, Huang L, Li LX. BHLHE40 drives protective polyfunctional CD4 T cell differentiation in the female reproductive tract against Chlamydia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.02.565369. [PMID: 37961221 PMCID: PMC10635079 DOI: 10.1101/2023.11.02.565369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The protein basic helix-loop-helix family member e40 (BHLHE40) is a transcription factor recently emerged as a key regulator of host immunity to infections, autoimmune diseases and cancer. In this study, we investigated the role of Bhlhe40 in protective T cell responses to the intracellular bacterium Chlamydia in the female reproductive tract (FRT). Mice deficient in Bhlhe40 exhibited severe defects in their ability to control Chlamydia muridarum shedding from the FRT. The heightened bacterial burdens in Bhlhe40-/- mice correlated with a marked increase in IL-10-producing T regulatory type 1 (Tr1) cells and decreased polyfunctional CD4 T cells co-producing IFN-γ, IL-17A and GM-CSF. Genetic ablation of IL-10 or functional blockade of IL-10R increased CD4 T cell polyfunctionality and partially rescued the defects in bacterial control in Bhlhe40-/- mice. Using single-cell RNA sequencing coupled with TCR profiling, we detected a significant enrichment of stem-like T cell signatures in Bhlhe40-deficient CD4 T cells, whereas WT CD4 T cells were further down on the differentiation trajectory with distinct effector functions beyond IFN-γ production by Th1 cells. Altogether, we identified Bhlhe40 as a key molecular driver of CD4 T cell differentiation and polyfunctional responses in the FRT against Chlamydia.
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Affiliation(s)
- Miguel A. B. Mercado
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Qiang Li
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Charles M. Quick
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Yejin Kim
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Rachel Palmer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Lu Huang
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Lin-Xi Li
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
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3
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Hsiung S, Egawa T. Population dynamics and gene regulation of T cells in response to chronic antigen stimulation. Int Immunol 2023; 35:67-77. [PMID: 36334059 DOI: 10.1093/intimm/dxac050] [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: 08/14/2022] [Accepted: 11/04/2022] [Indexed: 11/07/2022] Open
Abstract
T cells are activated by antigen and co-stimulatory receptor signaling and undergo robust proliferation and differentiation into effector cells with protective function. Such quantitatively and qualitatively amplified T cell responses are effective in controlling acute infection and are followed by contraction of the effector population and the formation of resting memory T cells for enhanced protection against previously experienced antigens. However, in the face of persistent antigen during chronic viral infection, in autoimmunity, or in the tumor microenvironment, T cells exhibit distinct responses relative to those in acute insult in several aspects, including reduced clonal expansion and impaired effector function associated with inhibitory receptor expression, a state known as exhaustion. Nevertheless, their responses to chronic infection and tumors are sustained through the establishment of hierarchical heterogeneity, which preserves the duration of the response by generating newly differentiated effector cells. In this review, we highlight recent findings on distinct dynamics of T cell responses under "exhausting" conditions and the roles of the transcription factors that support attenuated yet long-lasting T cell responses as well as the establishment of dysfunctional states.
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Affiliation(s)
- Sunnie Hsiung
- Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid Avenue, Saint Louis, MO 63110, USA
| | - Takeshi Egawa
- Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid Avenue, Saint Louis, MO 63110, USA
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4
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Elliot TAE, Jennings EK, Lecky DAJ, Rouvray S, Mackie GM, Scarfe L, Sheriff L, Ono M, Maslowski KM, Bending D. Nur77-Tempo mice reveal T cell steady state antigen recognition. DISCOVERY IMMUNOLOGY 2022; 1:kyac009. [PMID: 36704407 PMCID: PMC7614040 DOI: 10.1093/discim/kyac009] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In lymphocytes, Nr4a gene expression is specifically regulated by antigen receptor signalling, making them ideal targets for use as distal T cell receptor (TCR) reporters. Nr4a3-Timer of cell kinetics and activity (Tocky) mice are a ground-breaking tool to report TCR-driven Nr4a3 expression using Fluorescent Timer protein (FT). FT undergoes a time-dependent shift in its emission spectrum following translation, allowing for the temporal reporting of transcriptional events. Our recent work suggested that Nr4a1/Nur77 may be a more sensitive gene to distal TCR signals compared to Nr4a3, so we, therefore, generated Nur77-Timer-rapidly-expressed-in-lymphocytes (Tempo) mice that express FT under the regulation of Nur77. We validated the ability of Nur77-Tempo mice to report TCR and B cell receptor signals and investigated the signals regulating Nur77-FT expression. We found that Nur77-FT was sensitive to low-strength TCR signals, and its brightness was graded in response to TCR signal strength. Nur77-FT detected positive selection signals in the thymus, and analysis of FT expression revealed that positive selection signals are often persistent in nature, with most thymic Treg expressing FT Blue. We found that active TCR signals in the spleen are low frequency, but CD69+ lymphoid T cells are enriched for FT Blue+ Red+ T cells, suggesting frequent TCR signalling. In non-lymphoid tissue, we saw a dissociation of FT protein from CD69 expression, indicating that tissue residency is not associated with tonic TCR signals. Nur77-Tempo mice, therefore, combine the temporal dynamics from the Tocky innovation with increased sensitivity of Nr4a1 to lower TCR signal strengths.
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Affiliation(s)
- Thomas A. E. Elliot
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Emma K. Jennings
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - David A. J. Lecky
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Sophie Rouvray
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Gillian M. Mackie
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Lisa Scarfe
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Lozan Sheriff
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Masahiro Ono
- Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Kendle M. Maslowski
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - David Bending
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK,Correspondence: David Bending, Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK.
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5
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Biosensors for inflammation as a strategy to engineer regulatory T cells for cell therapy. Proc Natl Acad Sci U S A 2022; 119:e2208436119. [PMID: 36161919 PMCID: PMC9546553 DOI: 10.1073/pnas.2208436119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Engineered regulatory T cell (Treg cell) therapy is a promising strategy to treat patients suffering from inflammatory diseases, autoimmunity, and transplant rejection. However, in many cases, disease-related antigens that can be targeted by Treg cells are not available. In this study, we introduce a class of synthetic biosensors, named artificial immune receptors (AIRs), for murine and human Treg cells. AIRs consist of three domains: (a) extracellular binding domain of a tumor necrosis factor (TNF)-receptor superfamily member, (b) intracellular costimulatory signaling domain of CD28, and (c) T cell receptor signaling domain of CD3-ζ chain. These AIR receptors equip Treg cells with an inflammation-sensing machinery and translate this environmental information into a CD3-ζ chain-dependent TCR-activation program. Different AIRs were generated, recognizing the inflammatory ligands of the TNF-receptor superfamily, including LIGHT, TNFα, and TNF-like ligand 1A (TL1A), leading to activation, differentiation, and proliferation of AIR-Treg cells. In a graft-versus-host disease model, Treg cells expressing lymphotoxin β receptor-AIR, which can be activated by the ligand LIGHT, protect significantly better than control Treg cells. Expression and signaling of the corresponding human AIR in human Treg cells prove that this concept can be translated. Engineering Treg cells that target inflammatory ligands leading to TCR signaling and activation might be used as a Treg cell-based therapy approach for a broad range of inflammation-driven diseases.
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6
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Chanda MK, Shudde CE, Piper TL, Zheng Y, Courtney AH. Combined analysis of T cell activation and T cell-mediated cytotoxicity by imaging cytometry. J Immunol Methods 2022; 506:113290. [PMID: 35644255 PMCID: PMC9202232 DOI: 10.1016/j.jim.2022.113290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 04/28/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022]
Abstract
Immunotherapies for the treatment of cancer have spurred the development of new drugs that seek to harness the ability of T cells to recognize and kill malignant cells. There is a substantial need to evaluate how these experimental drugs influence T cell functional outputs in co-culture systems that contain cancerous cells. We describe an imaging cytometry-based platform that can simultaneously quantify activated T cells and the capacity of these T cells to kill cancer cells. Our platform was developed using the Nur77-GFP reporter system because GFP expression provides a direct readout of T cell activation that is induced by T cell antigen receptor (TCR) signaling. We combined the Nur77-GFP reporter system with a cancer cell line that displays a TCR-specific antigen and evaluated the relationship between T cell activation and cancer cell death. We demonstrate that imaging cytometry can be used to quantify the number of activated cytotoxic CD8+ T cells (CTLs) and the capacity of these CTLs to recognize and kill adherent MC38 cancer cells. We tested whether this platform could evaluate heterogenous lymphocyte populations by quantifying the proportion of antigen-specific activated T cells in co-cultures that contain unresponsive lymphocytes. The effects of a SRC family kinase inhibitor on CTL activation and MC38 cell death were also determined. Our findings demonstrate that the Nur77-GFP reporter system can be used to evaluate the effects of diverse treatment conditions on T cell-cancer co-cultures in a microtiter plate-based format by imaging cytometry. We anticipate the combined analysis of T cell activation with T cell-mediated cancer cell death can be used to rapidly assess immuno-oncology drug candidates and T cell-based therapeutics.
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7
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Boulet S, Odagiu L, Dong M, Lebel MÈ, Daudelin JF, Melichar HJ, Labrecque N. NR4A3 Mediates Thymic Negative Selection. THE JOURNAL OF IMMUNOLOGY 2021; 207:1055-1064. [PMID: 34312259 DOI: 10.4049/jimmunol.1901228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 06/16/2021] [Indexed: 11/19/2022]
Abstract
Central tolerance aims to limit the production of T lymphocytes bearing TCR with high affinity for self-peptide presented by MHC molecules. The accumulation of thymocytes with such receptors is limited by negative selection or by diversion into alternative differentiation, including T regulatory cell commitment. A role for the orphan nuclear receptor NR4A3 in negative selection has been suggested, but its function in this process has never been investigated. We find that Nr4a3 transcription is upregulated in postselection double-positive thymocytes, particularly those that have received a strong selecting signal and are destined for negative selection. Indeed, we found an accumulation of cells bearing a negative selection phenotype in NR4A3-deficient mice as compared with wild-type controls, suggesting that Nr4a3 transcriptional induction is necessary to limit accumulation of self-reactive thymocytes. This is consistent with a decrease of cleaved caspase-3+-signaled thymocytes and more T regulatory and CD4+Foxp3-HELIOS+ cells in the NR4A3-deficient thymus. We further tested the role for NR4A3 in negative selection by reconstituting transgenic mice expressing the OVA Ag under the control of the insulin promoter with bone marrow cells from OT-I Nr4a3 +/+ or OT-I Nr4a3 -/- mice. Accumulation of autoreactive CD8 thymocytes and autoimmune diabetes developed only in the absence of NR4A3. Overall, our results demonstrate an important role for NR4A3 in T cell development.
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Affiliation(s)
- Salix Boulet
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
| | - Livia Odagiu
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada; and
| | - Mengqi Dong
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada; and
| | - Marie-Ève Lebel
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada
| | | | - Heather J Melichar
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada.,Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
| | - Nathalie Labrecque
- Maisonneuve-Rosemont Hospital Research Center, Montreal, Quebec, Canada; .,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montreal, Quebec, Canada; and.,Département de Médecine, Université de Montréal, Montreal, Quebec, Canada
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8
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Srinivasan J, Lancaster JN, Singarapu N, Hale LP, Ehrlich LIR, Richie ER. Age-Related Changes in Thymic Central Tolerance. Front Immunol 2021; 12:676236. [PMID: 33968086 PMCID: PMC8100025 DOI: 10.3389/fimmu.2021.676236] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/06/2021] [Indexed: 01/03/2023] Open
Abstract
Thymic epithelial cells (TECs) and hematopoietic antigen presenting cells (HAPCs) in the thymus microenvironment provide essential signals to self-reactive thymocytes that induce either negative selection or generation of regulatory T cells (Treg), both of which are required to establish and maintain central tolerance throughout life. HAPCs and TECs are comprised of multiple subsets that play distinct and overlapping roles in central tolerance. Changes that occur in the composition and function of TEC and HAPC subsets across the lifespan have potential consequences for central tolerance. In keeping with this possibility, there are age-associated changes in the cellular composition and function of T cells and Treg. This review summarizes changes in T cell and Treg function during the perinatal to adult transition and in the course of normal aging, and relates these changes to age-associated alterations in thymic HAPC and TEC subsets.
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Affiliation(s)
- Jayashree Srinivasan
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States
| | | | - Nandini Singarapu
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Smithville, TX, United States
| | - Laura P Hale
- Department of Pathology, Duke University School of Medicine, Durham, NC, United States
| | - Lauren I R Ehrlich
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX, United States.,Livestrong Cancer Institutes, Dell Medical School, The University of Texas at Austin, Austin, TX, United States
| | - Ellen R Richie
- Department of Epigenetics and Molecular Carcinogenesis, The University of Texas M.D. Anderson Cancer Center, Smithville, TX, United States
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9
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Esen E, Sergin I, Jesudason R, Himmels P, Webster JD, Zhang H, Xu M, Piskol R, McNamara E, Gould S, Capietto AH, Delamarre L, Walsh K, Ye W. MAP4K4 negatively regulates CD8 T cell-mediated antitumor and antiviral immunity. Sci Immunol 2020; 5:5/45/eaay2245. [PMID: 32220977 DOI: 10.1126/sciimmunol.aay2245] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 11/01/2019] [Accepted: 02/27/2020] [Indexed: 12/28/2022]
Abstract
During cytotoxic T cell activation, lymphocyte function-associated antigen-1 (LFA-1) engages its ligands on antigen-presenting cells (APCs) or target cells to enhance T cell priming or lytic activity. Inhibiting LFA-1 dampens T cell-dependent symptoms in inflammation, autoimmune diseases, and graft-versus-host disease. However, the therapeutic potential of augmenting LFA-1 function is less explored. Here, we show that genetic deletion or inhibition of mitogen-activated protein kinase kinase kinase kinase 4 (MAP4K4) enhances LFA-1 activation on CD8 T cells and improves their adherence to APCs or LFA-1 ligand. In addition, loss of Map4k4 increases CD8 T cell priming, which culminates in enhanced antigen-dependent activation, proliferation, cytokine production, and cytotoxic activity, resulting in impaired tumor growth and improved response to viral infection. LFA-1 inhibition reverses these phenotypes. The ERM (ezrin, radixin, and moesin) proteins reportedly regulate T cell-APC conjugation, but the molecular regulator and effector of ERM proteins in T cells have not been defined. In this study, we demonstrate that the ERM proteins serve as mediators between MAP4K4 and LFA-1. Last, systematic analyses of many organs revealed that inducible whole-body deletion of Map4k4 in adult animals is tolerated under homeostatic conditions. Our results uncover MAP4K4 as a potential target to augment antitumor and antiviral immunity.
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Affiliation(s)
- Emel Esen
- Department of Molecular Oncology, Genentech, South San Francisco, CA, USA
| | - Ismail Sergin
- Department of Molecular Oncology, Genentech, South San Francisco, CA, USA
| | - Rajiv Jesudason
- Department of Molecular Oncology, Genentech, South San Francisco, CA, USA
| | - Patricia Himmels
- Department of Molecular Oncology, Genentech, South San Francisco, CA, USA
| | - Joshua D Webster
- Department of Research Pathology, Genentech, South San Francisco, CA, USA
| | - Hua Zhang
- Department of Translational Immunology, Genentech, South San Francisco, CA, USA
| | - Min Xu
- Department of Translational Immunology, Genentech, South San Francisco, CA, USA
| | - Robert Piskol
- Department of Bioinformatics, Genentech, South San Francisco, CA, USA
| | - Erin McNamara
- Department of Translational Oncology, Genentech, South San Francisco, CA, USA
| | - Stephen Gould
- Department of Translational Oncology, Genentech, South San Francisco, CA, USA
| | | | - Lélia Delamarre
- Department of Cancer Immunology, Genentech, South San Francisco, CA, USA
| | - Kevin Walsh
- Department of Molecular Oncology, Genentech, South San Francisco, CA, USA.
| | - Weilan Ye
- Department of Molecular Oncology, Genentech, South San Francisco, CA, USA.
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10
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Paprckova D, Stepanek O. Narcissistic T cells: reactivity to self makes a difference. FEBS J 2020; 288:1778-1788. [PMID: 32738029 DOI: 10.1111/febs.15498] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/22/2020] [Accepted: 07/25/2020] [Indexed: 12/15/2022]
Abstract
It has been appreciated for more than three decades that the interactions between the T-cell antigen receptor and self-antigens are the major determinants of the cell fates of developing thymocytes and the establishment of central tolerance. However, recent evidence shows that the level of self-reactivity substantially contributes to fate choices of positively selected mature T cells in homeostasis, as well as during immune responses. This implies that individual clones of peripheral T cells are predisposed to specific functional properties based on the self-reactivity of their antigen receptors. Overall, the relative difference in the self-reactivity among peripheral T cells is an important factor contributing to the diversity of T-cell responses to foreign antigens.
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Affiliation(s)
- Darina Paprckova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
| | - Ondrej Stepanek
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics, Czech Academy of Sciences, Prague, Czech Republic
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11
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Mitra A, Shanthalingam S, Sherman HL, Singh K, Canakci M, Torres JA, Lawlor R, Ran Y, Golde TE, Miele L, Thayumanavan S, Minter LM, Osborne BA. CD28 Signaling Drives Notch Ligand Expression on CD4 T Cells. Front Immunol 2020; 11:735. [PMID: 32457739 PMCID: PMC7221189 DOI: 10.3389/fimmu.2020.00735] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/31/2020] [Indexed: 12/22/2022] Open
Abstract
Notch signaling provides an important cue in the mammalian developmental process. It is a key player in T cell development and function. Notch ligands such as Delta-like ligands (DLL) 1, 3, 4, and JAG1, 2 can impact Notch signaling positively or negatively, by trans-activation or cis-inhibition. Trans and cis interactions are receptor-ligand interaction on two adjacent cells and interaction on the same cell, respectively. The former sends an activation signal and the later, a signal for inhibition of Notch. However, earlier reports suggested that Notch is activated in the absence of Notch ligand-expressing APCs in a purified population of CD4 T cells. Thus, the role of ligands in Notch activation, in a purified population of CD4 T cells, remains obscure. In this study, we demonstrate that mature CD4 T cells are capable of expressing Notch ligands on their surface very early upon activation with soluble antibodies against CD3 and CD28. Moreover, signaling solely through CD28 induces Notch ligand expression and CD3 signaling inhibits ligand expression, in contrast to Notch which is induced by CD3 signaling. Additionally, by using decoys, mimicking the Notch extracellular domain, we demonstrated that DLL1, DLL4, and JAG1, expressed on the T cells, can cis-interact with the Notch receptor and inhibit activation of Notch. Thus, our data indicate a novel mechanism of the regulation of Notch ligand expression on CD4 T cells and its impact on activated Notch.
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Affiliation(s)
- Ankita Mitra
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States
| | - Sudarvili Shanthalingam
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States
| | - Heather L Sherman
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States
| | - Khushboo Singh
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, United States
| | - Mine Canakci
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States.,Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, United States
| | - Joe A Torres
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States
| | - Rebecca Lawlor
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States
| | - Yong Ran
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
| | - Todd E Golde
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL, United States
| | - Lucio Miele
- School of Medicine, Department of Genetics, LSU Health Sciences Center, New Orleans, LA, United States
| | - Sankaran Thayumanavan
- Department of Chemistry, University of Massachusetts Amherst, Amherst, MA, United States
| | - Lisa M Minter
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States
| | - Barbara A Osborne
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, Amherst, MA, United States
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12
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Mittelstadt PR, Taves MD, Ashwell JD. Glucocorticoids Oppose Thymocyte Negative Selection by Inhibiting Helios and Nur77. THE JOURNAL OF IMMUNOLOGY 2019; 203:2163-2170. [PMID: 31527196 DOI: 10.4049/jimmunol.1900559] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/15/2019] [Indexed: 12/18/2022]
Abstract
Glucocorticoid (GC) signaling in thymocytes shapes the TCR repertoire by antagonizing thymocyte negative selection. The transcription factors Nur77 and Helios, which are upregulated in TCR-signaled thymocytes, have been implicated in negative selection. In this study, we found that GCs inhibited Helios and, to a lesser extent, Nur77 upregulation in TCR-stimulated mouse thymocytes. Inhibition was increased by GC preincubation, and reductions in mRNA were prevented by a protein synthesis inhibitor, suggesting that GCs suppress indirectly via an intermediary factor. Upregulation of Helios in TCR-stimulated thymocytes was unaffected by deletion of Nur77, indicating Nur77 and Helios are regulated independently. Whereas CD4+ thymocytes are positively selected in wild-type AND TCR-transgenic B6 mice, loss of GC receptor expression resulted in increased negative selection. Correspondingly, Helios and Nur77 levels were elevated in TCRhiCD4+CD8+ (TCR-signaled) thymocytes. Notably, deletion of Helios fully reversed this negative selection, whereas deletion of Nur77 had no effect on CD4+CD8+ cell numbers but reversed the loss of mature CD4+ thymocytes. Thus, Nur77 and Helios are GC targets that play nonredundant roles in setting the signaling threshold for thymocyte negative selection.
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Affiliation(s)
- Paul R Mittelstadt
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Matthew D Taves
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Jonathan D Ashwell
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
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13
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Cheng L, Deng N, Yang N, Zhao X, Lin X. Malt1 Protease Is Critical in Maintaining Function of Regulatory T Cells and May Be a Therapeutic Target for Antitumor Immunity. THE JOURNAL OF IMMUNOLOGY 2019; 202:3008-3019. [DOI: 10.4049/jimmunol.1801614] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 03/14/2019] [Indexed: 01/17/2023]
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14
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Kimura T, Tse K, McArdle S, Gerhardt T, Miller J, Mikulski Z, Sidney J, Sette A, Wolf D, Ley K. Atheroprotective vaccination with MHC-II-restricted ApoB peptides induces peritoneal IL-10-producing CD4 T cells. Am J Physiol Heart Circ Physiol 2017; 312:H781-H790. [PMID: 28087520 DOI: 10.1152/ajpheart.00798.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/09/2017] [Accepted: 01/09/2017] [Indexed: 12/14/2022]
Abstract
Although immunization with major histocompatibility complex (MHC) class II-restricted apolipoprotein B (ApoB) peptides has been shown to be atheroprotective, the mechanism is unclear. Here, we investigated CD4+ T cell populations in immunized atherosclerotic mice. Peptides (16-mers) from mouse ApoB, the core protein of low-density lipoprotein (LDL), were screened for binding to I-Ab by computer prediction and confirmed by radiolabeled peptide competition. Three new peptides, P101 (FGKQGFFPDSVNKALY, 5.5 nM IC50), P102 (TLYALSHAVNSYFDVD, 6.8 nM), and P103 (LYYKEDKTSLSASAAS, 95 nM), were tested in an atherosclerosis model (Apoe-/- mice on Western diet). Immunization with each of the three peptides (1 time in complete Freund's adjuvant subcuntaneously and 4 time in incomplete Freund's adjuvant intraperitoneally) but not with adjuvant alone showed significantly reduced atherosclerotic plaques in the aortic root by serial sections and in the whole aorta by en face staining. There were no differences in body weight, LDL cholesterol, or triglycerides. Peritoneal leukocytes from ApoB peptide-immunized mice, but not control mice, secreted significant amounts of IL-10 (150 pg/ml). Flow cytometry showed that peptide immunization induced IL-10 in 10% of peritoneal CD4+ T cells, some of which also expressed chemokine (C-C motif) receptor 5 (CCR5). Vaccination with ApoB peptides expanded peritoneal FoxP3+ regulatory CD4+ T cells and more than tripled the number of CCR5+FoxP3+ cells. Similar trends were also seen in the draining mediastinal lymph nodes but not in the nondraining inguinal lymph nodes. We conclude that vaccination with MHC class II-restricted autologous ApoB peptides induces regulatory T cells (Tregs) and IL-10, suggesting a plausible mechanism for atheroprotection.NEW & NOTEWORTHY Vaccination against apolipoprotein B (ApoB), the protein of LDL, attracts attention as a novel approach to prevent atherosclerosis. We discovered major histocompatibility complex class II-restricted ApoB peptides, which reduce atherosclerosis and induce IL-10-producing CD4+ T cells and chemokine (C-C motif) receptor 5 expression on regulatory T cells, suggesting that immunization with ApoB peptides inhibits atherosclerosis by inducing anti-inflammatory cytokines.
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Affiliation(s)
- Takayuki Kimura
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
| | - Kevin Tse
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
| | - Sara McArdle
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
| | - Teresa Gerhardt
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
| | - Jacqueline Miller
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
| | - Zbigniew Mikulski
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
| | - John Sidney
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, California
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, California
| | - Dennis Wolf
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
| | - Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California; and
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15
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Nowyhed HN, Huynh TR, Thomas GD, Blatchley A, Hedrick CC. Cutting Edge: The Orphan Nuclear Receptor Nr4a1 Regulates CD8+ T Cell Expansion and Effector Function through Direct Repression of Irf4. THE JOURNAL OF IMMUNOLOGY 2015; 195:3515-9. [PMID: 26363057 DOI: 10.4049/jimmunol.1403027] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 08/11/2015] [Indexed: 11/19/2022]
Abstract
The transcription factor IFN regulatory factor (IRF)4 was shown to play a crucial role in the protective CD8(+) T cell response; however, regulation of IRF4 expression in CD8(+) T cells remains unclear. In this article, we report a critical role for Nr4a1 in regulating the expansion, differentiation, and function of CD8(+) T cells through direct transcriptional repression of Irf4. Without Nr4a1, the regulation of IRF4 is lost, driving an increase in Irf4 expression and, in turn, resulting in a faster rate of CD8 T cell proliferation and expansion. Nr4a1-deficient mice show increases in CD8 T cell effector responses with improved clearance of Listeria monocytogenes. Our data support a novel and critical role for Nr4a1 in the regulation of CD8(+) T cell expansion and effector function through transcriptional repression of Irf4.
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Affiliation(s)
- Heba N Nowyhed
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
| | - Tridu R Huynh
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
| | - Graham D Thomas
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
| | - Amy Blatchley
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
| | - Catherine C Hedrick
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037
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16
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Bajoghli B, Kuri P, Inoue D, Aghaallaei N, Hanelt M, Thumberger T, Rauzi M, Wittbrodt J, Leptin M. Noninvasive In Toto Imaging of the Thymus Reveals Heterogeneous Migratory Behavior of Developing T Cells. THE JOURNAL OF IMMUNOLOGY 2015; 195:2177-86. [PMID: 26188059 DOI: 10.4049/jimmunol.1500361] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 06/23/2015] [Indexed: 01/21/2023]
Abstract
The migration of developing T cells (thymocytes) between distinct thymic microenvironments is crucial for their development. Ex vivo studies of thymus tissue explants suggest two distinct migratory behaviors of thymocytes in the thymus. In the cortex, thymocytes exhibit a stochastic migration, whereas medullary thymocytes show confined migratory behavior. Thus far, it has been difficult to follow all thymocytes in an entire thymus and relate their differentiation steps to their migratory dynamics. To understand the spatial organization of the migratory behavior and development of thymocytes in a fully functional thymus, we developed transgenic reporter lines for the chemokine receptors ccr9a and ccr9b, as well as for rag2, and used them for noninvasive live imaging of the entire thymus in medaka (Oryzias latipes). We found that the expression of these two chemokine receptors in the medaka juvenile thymus defined two spatially distinct subpopulations of thymocytes. Landmark events of T cell development including proliferation, somatic recombination, and thymic selection can be mapped to subregions of the thymus. The migratory behavior of thymocytes within each of the subpopulations is equally heterogeneous, and specific migratory behaviors are not associated with particular domains in the thymus. During the period when thymocytes express rag2 their migratory behavior was more homogeneous. Therefore, the migratory behavior of thymocytes is partly correlated with their developmental stage rather than being defined by their spatial localization.
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Affiliation(s)
- Baubak Bajoghli
- European Molecular Biology Laboratory, Directors' Research Unit, 69117-Heidelberg, Germany; and
| | - Paola Kuri
- European Molecular Biology Laboratory, Directors' Research Unit, 69117-Heidelberg, Germany; and
| | - Daigo Inoue
- Center for Organismal Studies, Heidelberg University, 69120-Heidelberg, Germany
| | - Narges Aghaallaei
- Center for Organismal Studies, Heidelberg University, 69120-Heidelberg, Germany
| | - Marleen Hanelt
- European Molecular Biology Laboratory, Directors' Research Unit, 69117-Heidelberg, Germany; and
| | - Thomas Thumberger
- Center for Organismal Studies, Heidelberg University, 69120-Heidelberg, Germany
| | - Matteo Rauzi
- European Molecular Biology Laboratory, Directors' Research Unit, 69117-Heidelberg, Germany; and
| | - Joachim Wittbrodt
- Center for Organismal Studies, Heidelberg University, 69120-Heidelberg, Germany
| | - Maria Leptin
- European Molecular Biology Laboratory, Directors' Research Unit, 69117-Heidelberg, Germany; and
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17
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O'Hagan KL, Choi J, Pryshchep O, Chernoff J, Phee H. Pak2 Links TCR Signaling Strength to the Development of Regulatory T Cells and Maintains Peripheral Tolerance. THE JOURNAL OF IMMUNOLOGY 2015; 195:1564-77. [PMID: 26157175 DOI: 10.4049/jimmunol.1500843] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 06/10/2015] [Indexed: 01/01/2023]
Abstract
Although significant effort has been devoted to understanding the thymic development of Foxp3(+) regulatory T cells (Tregs), the precise signaling pathways that govern their lineage commitment still remain enigmatic. Our findings show a novel role for the actin cytoskeletal remodeling protein, p21-activated kinase 2 (Pak2), in Treg development and homeostasis. The absence of Pak2 in T cells resulted in a marked reduction in both thymus- and peripherally derived Tregs, accompanied by the development of spontaneous colitis in Pak2-deficient mice. Additionally, Pak2 was required for the proper differentiation of in vitro-induced Tregs as well as maintenance of Tregs. Interestingly, Pak2 was necessary for generating the high-affinity TCR- and IL-2-mediated signals that are required by developing Tregs for their lineage commitment. These findings provide novel insight into how developing thymocytes translate lineage-specific high-affinity TCR signals to adopt the Treg fate, and they further posit Pak2 as an essential regulator for this process.
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Affiliation(s)
- Kyle Leonard O'Hagan
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611; and
| | - Jinyong Choi
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611; and
| | - Olga Pryshchep
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611; and
| | - Jonathan Chernoff
- Cancer Biology Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Hyewon Phee
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611; and
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18
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The nuclear receptor nr4a1 controls CD8 T cell development through transcriptional suppression of runx3. Sci Rep 2015; 5:9059. [PMID: 25762306 PMCID: PMC4356985 DOI: 10.1038/srep09059] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/09/2015] [Indexed: 12/23/2022] Open
Abstract
The NR4A nuclear receptor family member Nr4a1 is strongly induced in thymocytes undergoing selection, and has been shown to control the development of Treg cells; however the role of Nr4a1 in CD8+ T cells remains undefined. Here we report a novel role for Nr4a1 in regulating the development and frequency of CD8+ T cells through direct transcriptional control of Runx3. We discovered that Nr4a1 recruits the corepressor, CoREST to suppress Runx3 expression in CD8+ T cells. Loss of Nr4a1 results in increased Runx3 expression in thymocytes which consequently causes a 2-fold increase in the frequency and total number of intrathymic and peripheral CD8+ T cells. Our findings establish Nr4a1 as a novel and critical player in the regulation of CD8 T cell development through the direct suppression of Runx3.
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19
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Sinclair C, Seddon B. Overlapping and asymmetric functions of TCR signaling during thymic selection of CD4 and CD8 lineages. THE JOURNAL OF IMMUNOLOGY 2014; 192:5151-9. [PMID: 24771853 DOI: 10.4049/jimmunol.1303085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
TCR signaling plays a central role in directing developmental fates of thymocytes. Current models suggest TCR signal duration directs CD4 versus CD8 lineage development. To investigate the role of TCR signaling during positive selection directly, we switched signaling off in a cohort of selecting thymocytes and followed, in time, their subsequent fate. We did this using an inducible Zap70 transgenic mouse model that allowed Zap70-dependent signaling to be turned on and then off again. Surprisingly, loss of TCR signaling in CD4(+)CD8(lo) thymocytes did not prevent their development into committed CD4 single positives (SPs), nor their continued maturation to HSA(lo) SPs. However, numbers of CD4 SPs underwent a substantial decline following loss of Zap70 expression, suggesting an essential survival role for the kinase. Termination of TCR signaling is considered an essential step in CD8 lineage development. Loss of Zap70 expression, however, resulted in the rapid death of CD8 lineage precursor thymocytes and a failure to generate CD8 SPs. Significantly, extending the window of Zap70 expression was sufficient for generation and export of both CD4 and CD8 T cells. These data reveal a parallel requirement for TCR-mediated survival signaling, but an asymmetric requirement for TCR-mediated maturation signals.
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Affiliation(s)
- Charles Sinclair
- Division of Immune Cell Biology, Medical Research Council National Institute for Medical Research, London NW7 1AA, United Kingdom
| | - Benedict Seddon
- Division of Immune Cell Biology, Medical Research Council National Institute for Medical Research, London NW7 1AA, United Kingdom
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20
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Wencker M, Turchinovich G, Di Marco Barros R, Deban L, Jandke A, Cope A, Hayday AC. Innate-like T cells straddle innate and adaptive immunity by altering antigen-receptor responsiveness. Nat Immunol 2014; 15:80-7. [PMID: 24241693 PMCID: PMC6485477 DOI: 10.1038/ni.2773] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 10/24/2013] [Indexed: 12/14/2022]
Abstract
The subclassification of immunology into innate and adaptive immunity is challenged by innate-like T lymphocytes that use innate receptors to respond rapidly to stress despite expressing T cell antigen receptors (TCRs), a hallmark of adaptive immunity. In studies that explain how such cells can straddle innate and adaptive immunity, we found that signaling via antigen receptors, whose conventional role is to facilitate clonal T cell activation, was critical for the development of innate-like T cells but then was rapidly attenuated, which accommodated the cells' innate responsiveness. These findings permitted the identification of a previously unknown innate-like T cell subset and indicate that T cell hyporesponsiveness, a state traditionally linked to tolerance, may be fundamental to T cells entering the innate compartment and thereby providing lymphoid stress surveillance.
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MESH Headings
- Adaptive Immunity/immunology
- Animals
- Animals, Newborn
- Cells, Cultured
- Flow Cytometry
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Immunity, Innate/immunology
- Interleukin-17/immunology
- Interleukin-17/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- Nuclear Receptor Subfamily 4, Group A, Member 1/genetics
- Nuclear Receptor Subfamily 4, Group A, Member 1/immunology
- Nuclear Receptor Subfamily 4, Group A, Member 1/metabolism
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Signal Transduction/immunology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- ZAP-70 Protein-Tyrosine Kinase/immunology
- ZAP-70 Protein-Tyrosine Kinase/metabolism
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Affiliation(s)
- Melanie Wencker
- London Research Institute, Cancer Research UK, UK
- Peter Gorer Dept of Immunobiology, King’s College London, UK
| | - Gleb Turchinovich
- London Research Institute, Cancer Research UK, UK
- Peter Gorer Dept of Immunobiology, King’s College London, UK
| | | | - Livija Deban
- London Research Institute, Cancer Research UK, UK
| | - Anett Jandke
- London Research Institute, Cancer Research UK, UK
| | - Andrew Cope
- Centre for the Molecular and Cell Biology of Inflammation, King’s College London, UK
| | - Adrian C Hayday
- London Research Institute, Cancer Research UK, UK
- Peter Gorer Dept of Immunobiology, King’s College London, UK
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21
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Schmidt AM, Zou T, Joshi RP, Leichner TM, Pimentel MA, Sommers CL, Kambayashi T. Diacylglycerol kinase ζ limits the generation of natural regulatory T cells. Sci Signal 2013; 6:ra101. [PMID: 24280042 DOI: 10.1126/scisignal.2004411] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Natural regulatory T (nT(reg)) cells are important for maintaining tolerance to self- and foreign antigens, and they are thought to develop from thymocytes that receive strong T cell receptor (TCR)-mediated signals in the thymus. TCR engagement leads to the activation of phospholipase C-γ1, which generates the lipid second messenger diacylglycerol (DAG) from phosphatidylinositol 4,5-bisphosphate. We used mice that lack the ζ isoform of DAG kinase (DGKζ), which metabolizes DAG to terminate its signaling, to enhance TCR-mediated signaling and identify critical signaling events in nT(reg) cell development. Loss of DGKζ resulted in increased numbers of thymic CD25(+)Foxp3(-)CD4(+) nT(reg) cell precursors and Foxp3(+)CD4(+) nT(reg) cells in a cell-autonomous manner. DGKζ-deficient T cells exhibited increased nuclear translocation of the nuclear factor κB subunit c-Rel, as well as enhanced extracellular signal-regulated kinase (ERK) phosphorylation in response to TCR stimulation, suggesting that these downstream pathways may contribute to nT(reg) cell development. Indeed, reducing c-Rel abundance or blocking ERK phosphorylation abrogated the increased generation of nTreg cells by DGKζ-deficient thymocytes. The extent of ERK phosphorylation correlated with TCR-mediated acquisition of Foxp3 in immature thymocytes in vitro. Furthermore, the development of nT(reg) cells was augmented in mice in which ERK activation was selectively enhanced in T cells. Together, these data suggest that DGKζ regulates the development of nT(reg) cells by limiting the extent of activation of the ERK and c-Rel signaling pathways.
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Affiliation(s)
- Amanda M Schmidt
- 1Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 10194, USA
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22
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Nuclear receptor Nr4a1 modulates both regulatory T-cell (Treg) differentiation and clonal deletion. Proc Natl Acad Sci U S A 2012; 109:3891-6. [PMID: 22345564 DOI: 10.1073/pnas.1200090109] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Immature thymocytes expressing autoreactive T-cell receptors (TCR) can adopt differing cell fates: clonal deletion by apoptosis or deviation into alternative lineages such as FoxP3(+) regulatory T cells (Treg). We revisited the role of the transcription factor Nr4a1 (Nur77), an immediate-early response gene induced by TCR engagement. Nr4a1KO mice show clear quantitative defects in antigen-induced clonal deletion. The impact of the Nr4a1 deletion is not enhanced by deletion of the proapoptotic factor Bim. In addition, Nr4a1 curtails initial differentiation into the Treg lineage in TCR transgenic mice and in nontransgenic mice. Transcriptional profiling of Nr4a1KO thymocytes under selection conditions reveals that Nr4a1 activates the transcription of several targets, consistent with these diverse actions: (i) Nr4a1 partakes in the induction of Bim after TCR triggering; (ii) perhaps paradoxically, Nr4a1 positively controls several transcripts of the Treg signature, in particular Ikzf2 and Tnfrsf9; (iii) consistent with its prosurvival and metabolic role in the liver, Nr4a1 is also required for the induction by TCR of a coordinated set of enzymes of the glycolytic and Krebs cycle pathways, which we propose may antagonize Treg selection as does activation of mTOR/Akt. Thus, Nr4a1 appears to act as a balancing molecule in fate determination at a critical juncture of T-cell differentiation.
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23
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Moran AE, Holzapfel KL, Xing Y, Cunningham NR, Maltzman JS, Punt J, Hogquist KA. T cell receptor signal strength in Treg and iNKT cell development demonstrated by a novel fluorescent reporter mouse. ACTA ACUST UNITED AC 2011; 208:1279-89. [PMID: 21606508 PMCID: PMC3173240 DOI: 10.1084/jem.20110308] [Citation(s) in RCA: 771] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The ability of antigen receptors to engage self-ligands with varying affinity is crucial for lymphocyte development. To further explore this concept, we generated transgenic mice expressing GFP from the immediate early gene Nr4a1 (Nur77) locus. GFP was up-regulated in lymphocytes by antigen receptor stimulation but not by inflammatory stimuli. In T cells, GFP was induced during positive selection, required major histocompatibility complex for maintenance, and directly correlated with the strength of T cell receptor (TCR) stimulus. Thus, our results define a novel tool for studying antigen receptor activation in vivo. Using this model, we show that regulatory T cells (T(reg) cells) and invariant NKT cells (iNKT cells) perceived stronger TCR signals than conventional T cells during development. However, although T(reg) cells continued to perceive strong TCR signals in the periphery, iNKT cells did not. Finally, we show that T(reg) cell progenitors compete for recognition of rare stimulatory TCR self-ligands.
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Affiliation(s)
- Amy E Moran
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55414, USA
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24
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Misumi I, Yada T, Leong JAC, Schreck CB. The effect of in vitro exposure to tributyltin on the immune competence of Chinook salmon (Oncorhynchus tshawytscha) leukocytes. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2009; 56:229-237. [PMID: 18629429 DOI: 10.1007/s00244-008-9187-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Accepted: 05/31/2008] [Indexed: 05/26/2023]
Abstract
We evaluated the direct effects of in vitro exposures to tributyltin (TBT), a widely used biocide, on the cell-mediated immune system of Chinook salmon (Oncorhynchus tshawytscha). Splenic and pronephric leukocytes isolated from juvenile Chinook salmon were exposed to TBT (0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mg/l) in cell cultures for 24 h. Effects of TBT on cell viability, induction of apoptosis, and mitogenic responses were measured by flow cytometry. Splenic and pronephric leukocytes in the presence of TBT experienced a concentration-dependent decrease in viability in cell cultures. Apoptosis was detected as one of the mechanisms of cell death after TBT exposure. In addition, pronephric lymphocytes exhibited a greater sensitivity to TBT exposure than pronephric granulocytes. The functional ability of splenic B-cells to undergo blastogenesis upon lipopolysaccharide stimulation was also significantly inhibited in the presence of 0.05, 0.07, or 0.10 mg/l of TBT in the cell cultures. Flow cytometric assay using a fluorescent conjugated monoclonal antibody against salmon surface immunoglobulin was employed for the conclusive identification of B-cells in the Chinook salmon leukocytes. Our findings suggest that adverse effects of TBT on the function or development of fish immune systems could lead to an increase in disease susceptibility and its subsequent ecological implications.
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Affiliation(s)
- Ichiro Misumi
- Department of Microbiology, Oregon State University, Corvallis, OR 97331, USA.
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25
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Abstract
A functional immune system requires the selection of T lymphocytes expressing receptors that are major histocompatibility complex restricted but tolerant to self-antigens. This selection occurs predominantly in the thymus, where lymphocyte precursors first assemble a surface receptor. In this review we summarize the current state of the field regarding the natural ligands and molecular factors required for positive and negative selection and discuss a model for how these disparate outcomes can be signaled via the same receptor. We also discuss emerging data on the selection of regulatory T cells. Such cells require a high-affinity interaction with self-antigens, yet differentiate into regulatory cells instead of being eliminated.
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Affiliation(s)
- Timothy K Starr
- Center for Immunology and the Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455, USA.
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26
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Huettenbrenner S, Maier S, Leisser C, Polgar D, Strasser S, Grusch M, Krupitza G. The evolution of cell death programs as prerequisites of multicellularity. Mutat Res 2003; 543:235-49. [PMID: 12787815 DOI: 10.1016/s1383-5742(02)00110-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
One of the hallmarks of multicellularity is that the individual cellular fate is sacrificed for the benefit of a higher order of life-the organism. The accidental death of cells in a multicellular organism results in swelling and membrane-rupture and inevitably spills cell contents into the surrounding tissue with deleterious effects for the organism. To avoid this form of necrotic death the cells of metazoans have developed complex self-destruction mechanisms, collectively called programmed cell death, which see to an orderly removal of superfluous cells. Since evolution never invents new genes but plays variations on old themes by DNA mutations, it is not surprising, that some of the genes involved in metazoan death pathways apparently have evolved from homologues in unicellular organisms, where they originally had different functions. Interestingly some unicellular protozoans have developed a primitive form of non-necrotic cell death themselves, which could mean that the idea of an altruistic death for the benefit of genetically identical cells predated the invention of multicellularity. The cell death pathways of protozoans, however, show no homology to those in metazoans, where several death pathways seem to have evolved in parallel. Mitochondria stands at the beginning of several death pathways and also determines, whether a cell has sufficient energy to complete a death program. However, the endosymbiotic bacterial ancestors of mitochondria are unlikely to have contributed to the recent mitochondrial death machinery and therefore, these components may derive from mutated eukaryotic precursors and might have invaded the respective mitochondrial compartments. Although there is no direct evidence, it seems that the prokaryotic-eukaryotic symbiosis created the space necessary for sophisticated death mechanisms on command, which in their distinct forms are major factors for the evolution of multicellular organisms.
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Affiliation(s)
- Simone Huettenbrenner
- Institute of Clinical Pathology, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria
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27
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Vugmeyster Y, Borodovsky A, Maurice MM, Maehr R, Furman MH, Ploegh HL. The ubiquitin-proteasome pathway in thymocyte apoptosis: caspase-dependent processing of the deubiquitinating enzyme USP7 (HAUSP). Mol Immunol 2002; 39:431-41. [PMID: 12413694 DOI: 10.1016/s0161-5890(02)00123-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Programmed cell death (apoptosis) is crucial for thymocyte development. We analyzed the role of the ubiquitin (Ub)-proteasome pathway in dexamethasone-triggered and TCR-mediated apoptosis in fetal thymic organ culture (FTOC). Proteasome activity was increased in apoptotic thymocytes, as visualized by active-site labeling of proteasomal beta subunits. The activity of deubiquitinating enzymes in murine apoptotic thymocytes was likewise examined by active-site labeling. We show that the deubiquitinating enzyme USP7 (HAUSP) is proteolytically processed upon dexamethasone-, gamma-irradiation-, and antigen-induced cell death. Such processing of HAUSP does not occur in caspase 3-/- thymocytes, or upon pretreatment of wild type thymocytes with the general caspase inhibitor ZVAD-fmk. Thus, our results suggest that thymocyte apoptosis leads to modification of deubiquitinating enzymes by caspase activity and may provide an additional link between the ubiquitin-proteasome pathway and the caspase cascade during programmed cell death.
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Affiliation(s)
- Yulia Vugmeyster
- Department of Pathology, Harvard Medical School, Building D2, Room 137, 200 Longwood Avenue, Boston, MA 02115, USA
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Shiraishi J, Tatsumi T, Keira N, Akashi K, Mano A, Yamanaka S, Matoba S, Asayama J, Yaoi T, Fushiki S, Fliss H, Nakagawa M. Important role of energy-dependent mitochondrial pathways in cultured rat cardiac myocyte apoptosis. Am J Physiol Heart Circ Physiol 2001; 281:H1637-47. [PMID: 11557554 DOI: 10.1152/ajpheart.2001.281.4.h1637] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent studies have suggested that apoptosis and necrosis share common features in their signaling pathway and that apoptosis requires intracellular ATP for its mitochondrial/apoptotic protease-activating factor-1 suicide cascade. The present study was, therefore, designed to examine the role of intracellular energy levels in determining the form of cell death in cardiac myocytes. Neonatal rat cardiac myocytes were first incubated for 1 h in glucose-free medium containing oligomycin to achieve metabolic inhibition. The cells were then incubated for another 4 h in similar medium containing staurosporine and graded concentrations of glucose to manipulate intracellular ATP levels. Under ATP-depleting conditions, the cell death caused by staurosporine was primarily necrotic, as determined by creatine kinase release and nuclear staining with ethidium homodimer-1. However, under ATP-replenishing conditions, staurosporine increased the percentage of apoptotic cells, as determined by nuclear morphology and DNA fragmentation. Caspase-3 activation by staurosporine was also ATP dependent. However, loss of mitochondrial transmembrane potential (DeltaPsi(m)), Bax translocation, and cytochrome c release were observed in both apoptotic and necrotic cells. Moreover, cyclosporin A, an inhibitor of mitochondrial permeability transition, attenuated staurosporine-induced apoptosis and necrosis through the inhibition of DeltaPsi(m) reduction, cytochrome c release, and caspase-3 activation. Our data therefore suggest that staurosporine induces cell demise through a mitochondrial death signaling pathway and that the presence of intracellular ATP favors a shift from necrosis to apoptosis through caspase activation.
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Affiliation(s)
- J Shiraishi
- Second Department of Medicine, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
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29
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Di Sabatino A, D'Alò S, Millimaggi D, Ciccocioppo R, Parroni R, Sciarra G, Cifone MG, Corazza GR. Apoptosis and peripheral blood lymphocyte depletion in coeliac disease. Immunology 2001; 103:435-40. [PMID: 11529933 PMCID: PMC1783265 DOI: 10.1046/j.1365-2567.2001.01245.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In coeliac disease (CD) immunological abnormalities are not confined to the small bowel and it has been suggested that changes in peripheral blood lymphocytes (PBL), such as lymphopenia and increased T-cell activation, may predispose to malignant or autoimmune complications of this condition. In the light of the recent findings about the Fas-Fas ligand (FasL) system in regulating lymphocyte homeostasis, the aim of the present study was to investigate peripheral lymphocyte Fas-mediated apoptosis in CD to establish whether the homeostatic role of apoptosis in peripheral T-cell selection is maintained. Moreover, because a soluble form of Fas has been described to be functionally implicated in the Fas signalling system, suggesting a relationship between some disorders and soluble Fas function, we measured levels of soluble Fas in sera of coeliac patients and analysed the relationship between these levels and the proportions of apoptotic and Fas(+) PBL to further explore the function of the Fas-FasL pathway in this condition. Finally, we evaluated whether the increased prevalence of anticardiolipin antibodies, recently described in CD, could be related to PBL apoptosis in this condition. We demonstrated an increased apoptosis and higher levels of Fas and FasL expression in PBL isolated from untreated coeliac patients when compared to treated coeliac patients and controls. In addition, low levels of soluble Fas and a significant positive correlation between anticardiolipin antibodies and PBL apoptosis were found in untreated CD. Then, our results showed an increased susceptibility of PBL to undergo Fas-mediated apoptosis in active CD. This increased apoptosis could be responsible for both lymphopenia and immunogenic exposure of phospholipids with subsequent production of autoantibodies.
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Affiliation(s)
- A Di Sabatino
- Gastroenterology Unit, IRCCS Policlinico S. Matteo, University of Pavia, Pavia, Italy
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30
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Ferri KF, Jacotot E, Blanco J, Esté JA, Kroemer G. Mitochondrial control of cell death induced by HIV-1-encoded proteins. Ann N Y Acad Sci 2001; 926:149-64. [PMID: 11193032 DOI: 10.1111/j.1749-6632.2000.tb05609.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In most examples of physiological or pathological cell death, mitochondrial membrane permeabilization (MMP) constitutes an early critical event of the lethal process. Signs of MMP that precede nuclear apoptosis include the translocation of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria to an extra-mitochondrial localization, as well as the dissipation of the mitochondrial transmembrane potential. MMP also occurs in HIV-1-induced apoptosis. Different HIV-1 encoded proteins (Env, Vpr, Tat, PR) can directly or indirectly trigger MMP, thereby causing cell death. The gp120/gp41 Env complex constitutes an example for an indirect MMP inducer. Env expressed on the plasma membrane of HIV-1 infected (or Env-transfected) cells mediates cell fusion with CD4/CXCR4-expressing uninfected cells. After a cell type-dependent latency period, syncytia then undergo MMP and apoptosis. Vpr exemplifies a direct MMP inducer. Vpr binds to the adenine nucleotide translocator (ANT), a mitochondrial inner membrane protein which also interacts with apoptosis-regulatory proteins from the Bcl-2/Bax family. Binding of Vpr to ANT favors formation of a non-specific pore leading to MMP. The structural motifs of the Vpr protein involved in MMP are conserved among most pathogenic HIV-1 isolates and determine the cytotoxic effect of Vpr. These data suggest the possibility that viruses employ multiple strategies to regulate host cell apoptosis by targeting mitochondria.
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Affiliation(s)
- K F Ferri
- Centre National de la Recherche Scientifique, UMR1599, Institut Gustave Roussy, 39 rue Camille-Desmoulins, F-94805 Villejuif, France
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31
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Szegezdi E, Szondy Z, Nagy L, Nemes Z, Friis RR, Davies PJ, Fésüs L. Apoptosis-linked in vivo regulation of the tissue transglutaminase gene promoter. Cell Death Differ 2000; 7:1225-33. [PMID: 11175260 DOI: 10.1038/sj.cdd.4400751] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Tissue transglutaminase (tTG) is upregulated in various cells undergoing apoptosis. To investigate the transcriptional regulation of tTG a mouse strain carrying a beta-galactosidase reporter gene under the control of a 3.8 kilobase fragment of the tTG promoter was characterised. The transgene construct was shown to be expressed in the apoptotic regions of the mouse embryo. Here we report that the regulation of the transgene is also apoptosis-linked in adult animals. The transgene is induced in endocrine apoptosis involving mammary gland involution and corpus luteum regression. Induction of the reporter gene is detectable during in vivo but not in vitro apoptosis of thymocytes induced by the glucocorticoid receptor, the nur77, p53 and the retinoid receptor gamma mediated pathways. Additionally, the lacZ expression mimics the activation of the endogenous promoter in tissues characterised by high apoptotic turnover. These results suggest that the apoptosis-specific transcriptional regulation of tTG is mediated through elements of a 3.8 kb promoter and may require cosignals available only in tissue environment. Cell Death and Differentiation (2000) 7, 1225 - 1233.
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Affiliation(s)
- E Szegezdi
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
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32
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Ofir R, Zhang LC, Kyne AP, Houtzager V, O'Connor L, Adams JM. Gamma-radiation-induced growth arrest and apoptosis in p53-null lymphoma cells is accompanied by modest transcriptional changes in many genes. DNA Cell Biol 2000; 19:29-37. [PMID: 10668789 DOI: 10.1089/104454900314681] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Damage to DNA produces cell cycle arrest, apoptosis, or both. The response in cells with p53 tumor suppressor function involves transcriptional changes, but whether that holds for cells lacking active p53, as in most tumors, is not known. Better characterization of the DNA damage response in tumors lacking p53 function is relevant to cytotoxic therapy. We have explored whether gamma-irradiated p53-null mouse T lymphoma cells undergo marked changes in transcription. Their arrest in G2/M prior to apoptosis required transcription. Transcripts whose abundance altered on irradiation were sought by subtractive hybridization, and 1010 candidate clones from two oppositely enriched cDNA populations were sequenced. Hybridization revealed small (<3-fold) increases or decreases in the transcripts of more than 15 genes, including some implicated in cell cycle control (e.g., BTG, Bap1) or apoptosis (e.g., STAT1, calpain), but no marked changes like those associated with other forms of T-cell death. Moreover, the expression of some critical apoptosis regulators, such as Bcl-2 family members, did not change. Hence, the G2/M arrest and apoptosis in the irradiated p53-null lymphoma appears to involve modest expression changes for many genes, but post-transcriptional alterations may be more critical.
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Affiliation(s)
- R Ofir
- Molecular Genetics of Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
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33
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Abstract
The Fas/FasL system mediates apoptosis in several different cell types, including T lymphocytes. Fas ligand (FasL), a 40-kD type II membrane protein also expressed in activated T cells, belongs to the tumor necrosis factor ligand family. We describe a new alternative splicing of mouse FasL, named FasL short (FasLs), cloned by reverse transcriptase-polymerase chain reaction. FasLs is encoded by part of exon 1 and part of exon 4 of FasL gene. The protein encoded by FasLs mRNA has a putative initiation code at position 756 and preserves the same reading frame as FasL, resulting in a short molecule lacking the intracellular, the transmembrane, and part of the extracellular domains. RNase protection and immunoprecipitation analysis showed that FasLs is expressed in nonactivated normal spleen cells and in hybridoma T cells and that it is upregulated upon activation by anti-CD3 monoclonal antibody (MoAb). Moreover, FasLs-transfected cells expressed soluble FasLs in the supernatant and became resistant to apoptosis induced by agonist anti-Fas MoAb. Thus, FasLs, a new alternative splicing of FasL, is involved in the regulation of Fas/FasL-mediated cell death.
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34
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Abstract
During development of T cells in the thymus, T-cell receptor (TCR)-mediated recognition of self-MHC/self-peptide complexes on thymic stroma dictates the developmental fate of immature CD4+CD8+ (double positive) thymocytes. Intriguingly, TCR-generated intracellular signals can elicit two entirely different cellular responses in such thymocytes: apoptosis or further differentiation. The critical issue in understanding end-stage T-cell development is how TCR occupancy can be perceived in such markedly different ways by the TCR. Here, we review the cytoplasmic and nuclear events that result from TCR signaling during thymocyte selection. Studies aimed at distinguishing molecular components involved in positive selection (resulting in signals for further differentiation) and negative selection (resulting in apoptosis) will help solve this fascinating feature of T-lymphocyte biology. We also discuss how non-TCR-derived signaling might serve to fine tune the TCR-driven selection events in thymocytes. Central to this aspect of the conceptual framework needed to explain thymocyte selection is the observation that thymic antigen-presenting cells appear to be specialized in the induction of either positive or negative selection. Finally, we suggest a hypothesis that integrates the facts currently available on developing thymocytes, and which may serve to refine our exploration of unresolved issues in thymocyte selection. This hypothesis expands our focus to include signals from receptors other than TCRs as modulating and amplifying factors in thymocyte signaling.
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Affiliation(s)
- D Amsen
- Division of Immunology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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35
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Abstract
Aging is a complex physiological phenomenon and several different theories have been elaborated about its origin. Among such theories, the 'mitochondrial theory of aging', which has gained a large support, indicates the accumulation of somatic mutations of mitochondrial DNA leading to the decline of mitochondrial functionality as one of the driving forces for the process itself. In this review data on rat and man from our laboratory and from recent literature have been thoroughly examined and compared in order to provide the 'state-of-the-art' on the role of mitochondria in aging. Alterations of structure and expression of mitochondrial genome with aging, to find out the eventual relevant changes of mitochondrial biogenesis, have been studied in rat whereas the relationship between cytochrome c oxidase activity and 'common deletion' has been studied in man. Results on the effect of acetyl-L-carnitine on the mitochondrial functionality are also reported.
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Affiliation(s)
- M N Gadaleta
- Department of Biochemistry and Molecular Biology, University of Bari, Italy
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36
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Ibrahim MM, Razmara M, Nguyen D, Donahue RJ, Wubah JA, Knudsen TB. Altered expression of mitochondrial 16S ribosomal RNA in p53-deficient mouse embryos revealed by differential display. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1403:254-64. [PMID: 9685670 DOI: 10.1016/s0167-4889(98)00066-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Inactivation of the tumor suppressor p53 is associated with neural tube defects and altered teratogenicity in early embryos. To gain insight into the function of p53 during early embryogenesis, RNA profiles of wild-type p53(+/+) and p53(-/-) null mutant mouse embryos were compared at the head-fold stage (day 8 post coitum) using HPLC-based mRNA differential display. The results of this screen revealed a deficiency of mitochondrial 16S ribosomal RNA in p53(-/-) embryos. RT-PCR showed abnormalities in 16S rRNA levels relative to some representative nuclear (COIV, beta-actin) and mitochondrial (COIII) transcripts in p53(-/-) embryos, and that 16S rRNA expression increased with development of p53(+/+) embryos during neurulation. Embryos that lack p53 also displayed weakened cytochrome c oxidase staining and reduced ATP content. During neurulation, the mouse embryo switches from an anaerobic (glycolytic) to an aerobic (oxidative) metabolism. The preliminary results of the present study suggest that p53 may be involved, directly or indirectly, in this transition.
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Affiliation(s)
- M M Ibrahim
- Department of Pathology, Anatomy and Cell Biology, Jefferson Medical College, 1020 Locust Street, Philadelphia, PA 19107, USA
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37
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Kyaw H, Zeng Z, Su K, Fan P, Shell BK, Carter KC, Li Y. Cloning, characterization, and mapping of human homolog of mouse T-cell death-associated gene. DNA Cell Biol 1998; 17:493-500. [PMID: 9655242 DOI: 10.1089/dna.1998.17.493] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
To establish immunologic autotolerance, self-reactive immature thymocytes are eliminated by negative selection during T-cell development in the thymus. Self-reactive clones undergo apoptosis after stimulation via the T-cell receptor (TCR). The process of cell selection is determined by the dedication of the TCR for tolerogenic antigen/major histocompatibility complex. We have cloned a novel human gene that is highly homologous in the transmembrane and G protein-coupling domains to mouse T-cell death-associated gene 8 (TDAG8). The gene, human TDAG8 (hTDAG8), which belongs to the G protein-couple receptor superfamily, encodes a protein of 337 amino acids. An expressed sequence tag (EST) corresponding to hTDAG8 was identified from a human thyroid cDNA library and subsequently used to isolate a full-length genomic clone. Northern blot analysis revealed that the hTDAG8 gene is expressed predominantly in lymphoid tissues, including peripheral blood leukocytes, spleen, lymph nodes, and thymus. Stably transfected mammalian CHO cells were generated, and heterologous expression of hTDAG8 was confirmed by Northern blot analysis. Fluorescent in situ hybridization (FISH) revealed that hTDAG8 maps to human chromosome 14q31-32.1, a region in which abnormalities associated with human T-cell lymphoma or leukemia are found. Taken together, these data implicate the hTDAG8 gene in T-cell-associated diseases in humans, but its actual physiological and pathological role in the human immune system needs further investigation.
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Affiliation(s)
- H Kyaw
- Human Genome Sciences, Inc., Rockville, MD 20850, USA
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38
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39
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Compton MM, Waldrip HM. Endogenous activation of apoptosis in bursal lymphocytes: inhibition by phorbol esters and protein synthesis inhibitors. Cell Immunol 1998; 184:143-52. [PMID: 9630840 DOI: 10.1006/cimm.1998.1265] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The bursa of Fabricius represents the primary immune organ where immature B cells undergo maturational changes in avian species. Isolation of bursal lymphocytes for analysis in cell culture results in the rapid endogenous activation of apoptosis. After 2 h of incubation, over 45% of the lymphocytes were shown to be undergoing apoptosis and by 6 h 80% were undergoing apoptosis as demonstrated by a terminal deoxynucleotidyltransferase-mediated dUTP-fluorescein isothiocynate nick end-labeling flow-cytometric analysis. These results were corroborated by a propidium iodide-staining flow-cytometric assay and by an agarose gel electrophoresis DNA fragmentation assay that demonstrated internucleosomal DNA cleavage of genomic DNA in apoptotic bursal lymphocytes. Endogenous activation of apoptosis in bursal lymphocytes could be inhibited in a dose-dependent fashion with the phorbol ester, phorbol 12-myristate 13-acetate, but not the phorbol ester antagonist 4 alpha-phorbol 12,13-didecanoate. In addition, apoptosis could be inhibited in a dose-dependent fashion with inhibitors of protein translation, cycloheximide, and puromycin, as well as the transcriptional inhibitor actinomycin D. These results suggest that endogenous activation of bursal lymphocyte apoptosis may be mediated by the protein kinase C signal transduction pathway and activation of this process appears to be dependent upon de novo protein biosynthesis.
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Affiliation(s)
- M M Compton
- Department of Poultry Science, University of Georgia, Athens 30602-2772, USA
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40
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Szondy Z, Reichert U, Bernardon JM, Michel S, Tóth R, Ancian P, Ajzner E, Fesus L. Induction of apoptosis by retinoids and retinoic acid receptor gamma-selective compounds in mouse thymocytes through a novel apoptosis pathway. Mol Pharmacol 1997; 51:972-82. [PMID: 9187263 DOI: 10.1124/mol.51.6.972] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Retinoic acids are morphogenic signaling molecules that are derived from vitamin A and involved in a variety of tissue functions. Two groups of their nuclear receptors have been identified: retinoic acid receptors (RARs) and retinoic acid X receptors (RXRs). All-trans retinoic acid is the high affinity ligand for RARs, and 9-cis retinoic acid also binds to RXRs with high affinity. In cells at high concentrations, all-trans retinoic acid can be converted to 9-cis retinoic acid via unknown mechanisms. It was previously shown that retinoic acids prevents activation-induced death of thymocytes. Here, we report that both all-trans and 9-cis retinoic acid induce apoptosis of mouse thymocytes and purified CD4+CD8+ cells in ex vivo cultures, with 9-cis retinoic acid being 50 times more effective. The induction of apoptosis by retinoic acids is mediated by RARgamma because (a) the phenomenon can be reproduced only by RARgamma-selective retinoic acid analogs, (b) the cell death induced by either retinoic acids or RARgamma analogs can be inhibited by RARgamma-specific antagonists, and (c) CD4+CD8+ thymocytes express RARgamma. In vivo administration of an RARgamma analog resulted in thymus involution with the concomitant activation of the apoptosis-related endonuclease and induction of tissue transglutaminase. The RARgamma pathway of apoptosis is RNA and protein synthesis dependent, affects the CD4+CD8+ double positive thymocytes, and can be inhibited by the addition of either Ca2+ chelators or protease inhibitors. Using various RAR- and RXR-specific analogs and antagonists, it was demonstrated that stimulation of RAR alpha inhibits the RARgamma-specific death pathway (which explains the lack of apoptosis stimulatory effects of all-trans retinoic acid at physiological concentrations) and that costimulation of the RXR receptors (in the case of 9-cis retinoic acid) can neutralize this inhibitory effect. It is suggested that formation of 9-cis retinoic acid may be a critical element in regulating both the positive selection and the "default cell death pathway" of thymocytes.
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Affiliation(s)
- Z Szondy
- Department of Biochemistry, University Medical School of Debrecen, Hungary
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41
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Zamzami N, Hirsch T, Dallaporta B, Petit PX, Kroemer G. Mitochondrial implication in accidental and programmed cell death: apoptosis and necrosis. J Bioenerg Biomembr 1997; 29:185-93. [PMID: 9239543 DOI: 10.1023/a:1022694131572] [Citation(s) in RCA: 251] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Both physiological cell death (apoptosis) and at least some cases of accidental cell death (necrosis) involve a two-step-process. At first level, numerous physiological or pathological stimuli can trigger mitochondrial permeability transition which constitutes a rate-limiting event and initiates the common phase of the death process. Mitochondrial permeability transition (PT) involves the formation of proteaceous, regulated pores, probably by apposition of inner and outer mitochondrial membrane proteins which cooperate to form the mitochondrial PT pore complex. Inhibition of PT by pharmacological intervention on mitochondrial structures or mitochondrial expression of the apoptosis-inhibitory oncoprotein Bcl-2 thus can prevent cell death. At a second level, the consequences of mitochondrial dysfunction (collapse of the mitochondrial transmembrane potential, uncoupling of the respiratory chain, hyperproduction of superoxide anions, disruption of mitochondrial biogenesis, outflow of matrix calcium and glutathione, and release of soluble intermembrane proteins) can entail a biogenetic catastrophe culminating in the disruption of plasma membrane integrity (necrosis) and/or the activation and action of apoptogenic proteases with secondary endonuclease activation and consequent oligonucleosomal DNA fragmentation (apoptosis). The acquisition of the biochemical and ultrastructural features of apoptosis critically relies on the liberation of apoptogenic proteases or protease activators from the mitochondrial intermembrane space. This scenario applies to very different models of cell death. The notion that mitochondrial events control cell death has major implications for the development of death-inhibitory drugs.
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Affiliation(s)
- N Zamzami
- Centre National de la Recherche Scientifique-UPR420, Villejuif, France
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42
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Crawford DR, Lauzon RJ, Wang Y, Mazurkiewicz JE, Schools GP, Davies KJ. 16S mitochondrial ribosomal RNA degradation is associated with apoptosis. Free Radic Biol Med 1997; 22:1295-300. [PMID: 9098105 DOI: 10.1016/s0891-5849(96)00544-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The use of mitochondrial RNA as an indicator of apoptosis was investigated. Exposure of HA-1 fibroblastic cells to 10 micromol H(2)O(2) per 10(7) cells induced nuclear fragmentation, cell shrinkage, and internucleosomal DNA fragmentation, all characteristics of apoptosis. RNA extracted from control and apoptotic cultures, and analyzed by Northern blot hybridization, revealed a significant increase in the degradation of mitochondrial 16S ribosomal RNA (rRNA) that was associated with apoptosis. Conversely, minimal, if any, degradation of glyceraldehyde-3-phosphate dehydrogenase or actin mRNAs was observed. Similar results were obtained for HA-1 cells treated with the protein kinase inhibitor staurosporine, and for HT-2 T-lymphocytes induced to undergo apoptosis by interleukin-2 withdrawal. In addition, 16S rRNA degradation was an early event that was discernable well before chromatin condensation in hydrogen peroxide-treated HA-1 cells. These observations suggest that degradation of mitochondrial 16S ribosomal RNA is a new marker of mammalian cell apoptosis.
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Affiliation(s)
- D R Crawford
- Department of Biochemistry and Molecular Biology, The Albany Medical College, NY 12208, USA
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44
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45
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Fesus L, Madi A, Balajthy Z, Nemes Z, Szondy Z. Transglutaminase induction by various cell death and apoptosis pathways. EXPERIENTIA 1996; 52:942-9. [PMID: 8917724 DOI: 10.1007/bf01920102] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Clarification of the molecular details of forms of natural cell death, including apoptosis, has become one of the most challenging issues of contemporary biomedical sciences. One of the effector elements of various cell death pathways is the covalent cross-linking of cellular proteins by transglutaminases. This review will discuss the accumulating data related to the induction and regulation of these enzymes, particularly of tissue type transglutaminase, in the molecular program of cell death. A wide range of signalling pathways can lead to the parallel induction of apoptosis and transglutaminase, providing a handle for better understanding the exact molecular interactions responsible for the mechanism of regulated cell death.
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Affiliation(s)
- L Fesus
- Department of Biochemistry, University Medical School of Debrecen, Hungary
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46
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47
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Abstract
Signals generated by T cell receptor (TCR) cross-linking (or phorbol 12-myristate-13-acetate + Ca2+ ionophore), glucocorticoids or ionizing radiation all stimulate apoptotic cell death in thymocytes by signals that are initially distinct from each other. However, when these stimuli were administered to thymocyte cultures that were maintained under an atmosphere containing less than 20 ppm oxygen as opposed to one that contained 18.5% molecular oxygen, cell death was inhibited or abrogated, suggesting that the induction of death by all three different stimuli depend on the presence of molecular oxygen. Studies of the effects of the cysteine analog N-acetyl cysteine (NAC) with normal thymocytes demonstrated that this antioxidant inhibited the induction of death by each of the different stimuli in a manner the paralleled anaerobiosis. Furthermore, studies with thymocytes demonstrated that the induction of nur77, a gene shown to be involved in thymocyte apoptosis signaled through the TCR or its surrogates, is not inhibited by NAC or dependent upon molecular oxygen. The possible implications for negative selection of NAC-mediated inhibition of TCR-signaled thymocyte cell death was examined in thymic organ culture. Treatment of these cultures with NAC provided significant protection against staphylococcal enterotoxin B-mediated deletion of V beta 8-expressing thymocytes.
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Affiliation(s)
- K A McLaughlin
- Program in Molecular and Cellular Biology, University of Massachusetts, Amherst 01002, USA
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48
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Zamzami N, Marchetti P, Castedo M, Hirsch T, Susin SA, Masse B, Kroemer G. Inhibitors of permeability transition interfere with the disruption of the mitochondrial transmembrane potential during apoptosis. FEBS Lett 1996; 384:53-7. [PMID: 8797802 DOI: 10.1016/0014-5793(96)00280-3] [Citation(s) in RCA: 316] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In a number of experimental systems, the early stage of the apoptotic process, i.e. the stage which precedes nuclear disintegration, is characterized by the breakdown of the inner mitochondrial transmembrane potential (delta psi m). Here we address the question as to whether mitochondrial permeability transition (PT) pores may account for the delta psi m dissipation in lymphocyte apoptosis. Drugs known for their PT-inhibitory potential (bongkrekic acid, cyclosporin A, and the non-immunosuppressive cyclosporin A analogue N-methyl-Val-4-cyclosporin A) are capable of preventing the apoptotic delta psi m disruption. Moreover, pharmacological modulation of PT-mediated delta psi m dissipation can prevent apoptosis. Thus, while suppressing the delta psi m disruption, bongkrekic acid also inhibits the apoptotic chromatinolysis. In conclusion, these data are compatible with the hypothesis that apoptotic delta psi m disruption is mediated by the formation of PT pores and that PT-mediated delta psi m disruption is a critical event of the apoptotic cascade.
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Abstract
The regulation of cell proliferation and the selection against autoreactive cells in the lymphoid system both occur through the induction of apoptosis. Many of the signals that induce apoptosis in lymphocytes are now well defined. Interactions between Fas and its ligand have emerged as a major mechanism for the deletion of activated peripheral T cells and autoreactive B cells. Although the signal-transduction pathway leading from engagement of Fas to apoptosis is not entirely clear, significant advances have been made recently. There has also been progress in the elucidation of the mechanisms that regulate apoptosis in the immune system.
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Affiliation(s)
- B A Osborne
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst 01003, USA.
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Zamzami N, Marchetti P, Castedo M, Decaudin D, Macho A, Hirsch T, Susin SA, Petit PX, Mignotte B, Kroemer G. Sequential reduction of mitochondrial transmembrane potential and generation of reactive oxygen species in early programmed cell death. J Exp Med 1995; 182:367-77. [PMID: 7629499 PMCID: PMC2192111 DOI: 10.1084/jem.182.2.367] [Citation(s) in RCA: 1237] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Programmed cell death (PCD) is a physiological process commonly defined by alterations in nuclear morphology (apoptosis) and/or characteristic stepwise degradation of chromosomal DNA occurring before cytolysis. However, determined characteristics of PCD such as loss in mitochondrial reductase activity or cytolysis can be induced in enucleated cells, indicating cytoplasmic PCD control. Here we report a sequential disregulation of mitochondrial function that precedes cell shrinkage and nuclear fragmentation. A first cyclosporin A-inhibitable step of ongoing PCD is characterized by a reduction of mitochondrial transmembrane potential, as determined by specific fluorochromes (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine++ + iodide; 3,3'dihexyloxacarbocyanine iodide). Cytofluorometrically purified cells with reduced mitochondrial transmembrane potential are initially incapable of oxidizing hydroethidine (HE) into ethidium. Upon short-term in vitro culture, such cells acquire the capacity of HE oxidation, thus revealing a second step of PCD marked by mitochondrial generation of reactive oxygen species (ROS). This step can be selectively inhibited by rotenone and ruthenium red yet is not affected by cyclosporin A. Finally, cells reduce their volume, a step that is delayed by radical scavengers, indicating the implication of ROS in the apoptotic process. This sequence of alterations accompanying early PCD is found in very different models of apoptosis induction: glucocorticoid-induced death of lymphocytes, activation-induced PCD of T cell hybridomas, and tumor necrosis factor-induced death of U937 cells. Transfection with the antiapoptotic protooncogene Bcl-2 simultaneously inhibits mitochondrial alterations and apoptotic cell death triggered by steroids or ceramide. In vivo injection of fluorochromes such as 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide; 3,3'dihexyloxacarbocyanine iodide; or HE allows for the detection of cells that are programmed for death but still lack nuclear DNA fragmentation. In particular, assessment of mitochondrial ROS generation provides an accurate picture of PCD-mediated lymphocyte depletion. In conclusion, alterations of mitochondrial function constitute an important feature of early PCD.
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Affiliation(s)
- N Zamzami
- Centre National de la Recherche Scientifique, Unité Propre de Recherche 420, Villejuif, France
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