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Povoleri GAM, Scottà C, Nova-Lamperti EA, John S, Lombardi G, Afzali B. Thymic versus induced regulatory T cells - who regulates the regulators? Front Immunol 2013; 4:169. [PMID: 23818888 PMCID: PMC3694260 DOI: 10.3389/fimmu.2013.00169] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 06/13/2013] [Indexed: 01/07/2023] Open
Abstract
Physiological health must balance immunological responsiveness against foreign pathogens with tolerance toward self-components and commensals. Disruption of this balance causes autoimmune diseases/chronic inflammation, in case of excessive immune responses, and persistent infection/immunodeficiency if regulatory components are overactive. This homeostasis occurs at two different levels: at a resting state to prevent autoimmune disease, as autoreactive effector T-cells (Teffs) are only partially deleted in the thymus, and during inflammation to prevent excessive tissue injury, contract the immune response, and enable tissue repair. Adaptive immune cells with regulatory function (“regulatory T-cells”) are essential to control Teffs. Two sets of regulatory T cell are required to achieve the desired control: those emerging de novo from embryonic/neonatal thymus (“thymic” or tTregs), whose function is to control autoreactive Teffs to prevent autoimmune diseases, and those induced in the periphery (“peripheral” or pTregs) to acquire regulatory phenotype in response to pathogens/inflammation. The differentiation mechanisms of these cells determine their commitment to lineage and plasticity toward other phenotypes. tTregs, expressing high levels of IL-2 receptor alpha chain (CD25), and the transcription factor Foxp3, are the most important, since mutations or deletions in these genes cause fatal autoimmune diseases in both mice and men. In the periphery, instead, Foxp3+ pTregs can be induced from naïve precursors in response to environmental signals. Here, we discuss molecular signatures and induction processes, mechanisms and sites of action, lineage stability, and differentiating characteristics of both Foxp3+ and Foxp3− populations of regulatory T cells, derived from the thymus or induced peripherally. We relate these predicates to programs of cell-based therapy for the treatment of autoimmune diseases and induction of tolerance to transplants.
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Affiliation(s)
- Giovanni Antonio Maria Povoleri
- Medical Research Council Centre for Transplantation, King's College London , London , UK ; National Institute for Health Research Biomedical Research Centre at Guy's and St Thomas' NHS Foundation Trust and King's College London , London , UK
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202
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Bacher P, Scheffold A. Flow-cytometric analysis of rare antigen-specific T cells. Cytometry A 2013; 83:692-701. [PMID: 23788442 DOI: 10.1002/cyto.a.22317] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/09/2013] [Accepted: 05/14/2013] [Indexed: 12/20/2022]
Abstract
The cytometric enumeration and characterization of antigen-specific lymphocytes, as introduced about 15 years ago, has contributed significantly to our understanding of adaptive immune responses in health and disease. Despite the development of several technologies, allowing to directly or indirectly analyze many aspects of lymphocyte specificity and function, several unresolved issues remain, due to the low frequency of certain antigen-specific lymphocyte subsets and the complexity of T cell antigen recognition. This is especially true for CD4(+) conventional as well as regulatory T cells, which bring major contributions to immune protection and pathology. Here we review the current technologies for the analysis of antigen specific T cells within the physiologic T cell repertoire and with a special focus on recent technologies addressing the analysis of rare antigen-specific T cell populations including naive and regulatory T cells.
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Affiliation(s)
- Petra Bacher
- Miltenyi Biotec GmbH, Bergisch Gladbach, Germany
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203
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Goldstein JD, Pérol L, Zaragoza B, Baeyens A, Marodon G, Piaggio E. Role of cytokines in thymus- versus peripherally derived-regulatory T cell differentiation and function. Front Immunol 2013; 4:155. [PMID: 23801992 PMCID: PMC3685818 DOI: 10.3389/fimmu.2013.00155] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 06/06/2013] [Indexed: 12/22/2022] Open
Abstract
CD4+CD25+Foxp3+ regulatory T cells (Tregs) are essential players in the control of immune responses. Recently, accordingly to their origin, two main subsets of Tregs have been described: thymus-derived Tregs (tTregs) and peripherally derived Tregs (pTregs). Numerous signaling pathways including the IL-2/STAT5 or the TGF-β/Smad3 pathways play a crucial role in segregating the two lineages. Here, we review some of the information existing on the distinct requirements of IL-2, TGF-β, and TNF-α three major cytokines involved in tTreg and pTreg generation, homeostasis and function. Today it is clear that signaling via the IL-2Rβ chain (CD122) common to IL-2 and IL-15 is required for proper differentiation of tTregs and for tTreg and pTreg survival in the periphery. This notion has led to the development of promising therapeutic strategies based on low-dose IL-2 administration to boost the patients’ own Treg compartment and dampen autoimmunity and inflammation. Also, solid evidence points to TGF-β as the master regulator of pTreg differentiation and homeostasis. However, therapeutic administration of TGF-β is difficult to implement due to toxicity and safety issues. Knowledge on the role of TNF-α on the biology of Tregs is fragmentary and inconsistent between mice and humans. Moreover, emerging results from the clinical use of TNF-α inhibitors indicate that part of their anti-inflammatory effect may be dependent on their action on Tregs. Given the profusion of clinical trials testing cytokine administration or blocking to modulate inflammatory diseases, a better knowledge of the effects of cytokines on tTregs and pTregs biology is necessary to improve the efficiency of these immunotherapies.
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Affiliation(s)
- Jérémie David Goldstein
- Université Pierre et Marie Curie Univ Paris 06, INSERM U959 , Paris , France ; Centre National de la Recherche Scientifique, UMR 7211 , Paris , France ; Institut National de la Santé et de la Recherche Médicale (INSERM), U959, Immunology-Immunopathology-Immunotherapy (I3) , Paris , France
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204
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Shi Y, Zhu M. Medullary thymic epithelial cells, the indispensable player in central tolerance. SCIENCE CHINA. LIFE SCIENCES 2013; 56:392-8. [PMID: 23633070 DOI: 10.1007/s11427-013-4482-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 03/21/2013] [Indexed: 02/06/2023]
Abstract
Crosstalk between thymocytes and thymic epithelial cells is critical for T cell development and the establishment of central tolerance. Medullary thymic epithelial cells (mTECs) play important roles in the late stage of T cell development, especially negative selection and Treg generation. The function of mTECs is highly dependent on their characteristic features such as ectopic expression of peripheral tissue restricted antigens (TRAs) and their master regulator-autoimmune regulator (Aire), expression of various chemokines and cytokines. In this review, we summarize the current understanding of cellular and molecular mechanisms of mTEC development and its functions in T cell development and the establishment of central tolerance. The open questions in this field are also discussed. Understanding the function and underlying mechanisms of mTECs will contribute to the better control of autoimmune diseases and the improvement of immune reconstitution during aging or after infection, chemotherapy or radiotherapy.
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Affiliation(s)
- Yaoyao Shi
- Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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205
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Coquet JM, Ribot JC, Bąbała N, Middendorp S, van der Horst G, Xiao Y, Neves JF, Fonseca-Pereira D, Jacobs H, Pennington DJ, Silva-Santos B, Borst J. Epithelial and dendritic cells in the thymic medulla promote CD4+Foxp3+ regulatory T cell development via the CD27-CD70 pathway. J Exp Med 2013; 210:715-28. [PMID: 23547099 PMCID: PMC3620350 DOI: 10.1084/jem.20112061] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 02/15/2013] [Indexed: 01/02/2023] Open
Abstract
CD4(+)Foxp3(+) regulatory T cells (Treg cells) are largely autoreactive yet escape clonal deletion in the thymus. We demonstrate here that CD27-CD70 co-stimulation in the thymus rescues developing Treg cells from apoptosis and thereby promotes Treg cell generation. Genetic ablation of CD27 or its ligand CD70 reduced Treg cell numbers in the thymus and peripheral lymphoid organs, whereas it did not alter conventional CD4(+)Foxp3(-) T cell numbers. The CD27-CD70 pathway was not required for pre-Treg cell generation, Foxp3 induction, or mature Treg cell function. Rather, CD27 signaling enhanced positive selection of Treg cells within the thymus in a cell-intrinsic manner. CD27 signals promoted the survival of thymic Treg cells by inhibiting the mitochondrial apoptosis pathway. CD70 was expressed on Aire(-) and Aire(+) medullary thymic epithelial cells (mTECs) and on dendritic cells (DCs) in the thymic medulla. CD70 on both mTECs and DCs contributed to Treg cell development as shown in BM chimera experiments with CD70-deficient mice. In vitro experiments indicated that CD70 on the CD8α(+) subset of thymic DCs promoted Treg cell development. Our data suggest that mTECs and DCs form dedicated niches in the thymic medulla, in which CD27-CD70 co-stimulation rescues developing Treg cells from apoptosis, subsequent to Foxp3 induction by TCR and CD28 signals.
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Affiliation(s)
- Jonathan M. Coquet
- Division of Immunology and Division of Biological Stress Responses, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Julie C. Ribot
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Nikolina Bąbała
- Division of Immunology and Division of Biological Stress Responses, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Sabine Middendorp
- Division of Immunology and Division of Biological Stress Responses, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Gerda van der Horst
- Division of Immunology and Division of Biological Stress Responses, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Yanling Xiao
- Division of Immunology and Division of Biological Stress Responses, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Joana F. Neves
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, England, UK
- Programa Doutoral de Biologia Experimental e Biomedicina, Centro de Neurociências e Biologia Celular, Universidade de Coimbra, 3000-214 Coimbra, Portugal
| | - Diogo Fonseca-Pereira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Heinz Jacobs
- Division of Immunology and Division of Biological Stress Responses, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
| | - Daniel J. Pennington
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, England, UK
| | - Bruno Silva-Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - Jannie Borst
- Division of Immunology and Division of Biological Stress Responses, The Netherlands Cancer Institute, 1066 CX Amsterdam, Netherlands
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206
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Recent thymic emigrants are the preferential precursors of regulatory T cells differentiated in the periphery. Proc Natl Acad Sci U S A 2013; 110:6494-9. [PMID: 23576744 DOI: 10.1073/pnas.1221955110] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Most Forkhead box P3(+) (Foxp3(+)) CD4 regulatory T cell (Treg) precursors are newly formed thymocytes that acquire Foxp3 expression on antigen encounter in the thymus. Differentiation of Treg, however, can also occur in the periphery. What limits this second layer of self- and nonself-reactive Treg production in physiological conditions remains to be understood. In this work, we tested the hypothesis that, similarly to thymic Treg, the precursors of peripheral Treg are immature T cells. We show that CD4(+)CD8(-)Foxp3(-) thymocytes and recent thymic emigrants (RTEs), contrarily to peripheral naïve mature cells, efficiently differentiate into Treg on transfer into lymphopenic mice. By varying donor and recipient mice and conducting ex vivo assays, we document that the preferential conversion of newly formed T cells does not require intrathymic preactivation, is cell-intrinsic, and correlates with low and high sensitivity to natural inhibitors and inducers of Foxp3 expression, such as IL-6, T-cell receptor triggering, and TGF-β. Finally, ex vivo analysis of human thymocytes and peripheral blood T cells revealed that human RTE and newly developed T cells share an increased potential to acquire a FOXP3(bright)CD25(high) Treg phenotype. Our findings indicating that RTEs are the precursors of Tregs differentiated in the periphery should guide the design of Treg-based therapies.
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207
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Murine thymic selection quantified using a unique method to capture deleted T cells. Proc Natl Acad Sci U S A 2013; 110:4679-84. [PMID: 23487759 DOI: 10.1073/pnas.1217532110] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Thymic positive and negative selection events generate a T-cell repertoire that is MHC restricted and self-tolerant. The number of T cells undergoing positive and negative selection in normal mice has never been firmly established. We generated mice that lack the proapoptotic molecule Bim (bcl2l11) together with a Nur77(GFP) transgene, which allowed the identification and enumeration of T cells that would normally undergo clonal deletion. Using this method, we report the striking observation that six times more cells undergo negative selection than complete positive selection. Seventy-five percent of the negatively selected cells are deleted at the double positive stage in the thymic cortex, compared with 25% at the single positive stage in the medulla. The fact that more thymocytes are highly reactive to MHC than are weakly reactive is inconsistent with a random model of recognition and suggests that T-cell recognition is MHC biased. Furthermore, Bim(-/-) mice had an increased number of GFP(hi) cells in the peripheral lymphoid tissue and a corresponding increase in antigen experienced or anergic cell phenotype. Our data also show that the CD4+ T cells that are clonally deleted experienced only slightly stronger T-cell receptor signaling than those that developed into regulatory T cells.
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208
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Guo Z, Khattar M, Schroder PM, Miyahara Y, Wang G, He X, Chen W, Stepkowski SM. A dynamic dual role of IL-2 signaling in the two-step differentiation process of adaptive regulatory T cells. THE JOURNAL OF IMMUNOLOGY 2013; 190:3153-62. [PMID: 23427250 DOI: 10.4049/jimmunol.1200751] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The molecular mechanism of the extrathymic generation of adaptive, or inducible, CD4(+)Foxp3(+) regulatory T cells (iTregs) remains incompletely defined. We show that exposure of splenic CD4(+)CD25(+)Foxp3(-) cells to IL-2, but not other common γ-chain cytokines, resulted in Stat5 phosphorylation and induced Foxp3 expression in ∼10% of the cells. Thus, IL-2/Stat5 signaling may be critical for Foxp3 induction in peripheral CD4(+)CD25(+)Foxp3(-) iTreg precursors. In this study, to further define the role of IL-2 in the formation of iTreg precursors as well as their subsequent Foxp3 expression, we designed a two-step iTreg differentiation model. During the initial "conditioning" step, CD4(+)CD25(-)Foxp3(-) naive T cells were activated by TCR stimulation. Inhibition of IL-2 signaling via Jak3-Stat5 was required during this step to generate CD4(+)CD25(+)Foxp3(-) cells containing iTreg precursors. During the subsequent Foxp3-induction step driven by cytokines, IL-2 was the most potent cytokine to induce Foxp3 expression in these iTreg precursors. This two-step method generated a large number of iTregs with relatively stable expression of Foxp3, which were able to prevent CD4(+)CD45RB(high) cell-mediated colitis in Rag1(-/-) mice. In consideration of this information, whereas initial inhibition of IL-2 signaling upon T cell priming generates iTreg precursors, subsequent activation of IL-2 signaling in these precursors induces the expression of Foxp3. These findings advance the understanding of iTreg differentiation and may facilitate the therapeutic use of iTregs in immune disorders.
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Affiliation(s)
- Zhiyong Guo
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine, Toledo, OH 43614, USA
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209
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Toker A, Engelbert D, Garg G, Polansky JK, Floess S, Miyao T, Baron U, Düber S, Geffers R, Giehr P, Schallenberg S, Kretschmer K, Olek S, Walter J, Weiss S, Hori S, Hamann A, Huehn J. Active demethylation of the Foxp3 locus leads to the generation of stable regulatory T cells within the thymus. THE JOURNAL OF IMMUNOLOGY 2013; 190:3180-8. [PMID: 23420886 DOI: 10.4049/jimmunol.1203473] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Stable expression of Foxp3 in regulatory T cells (Tregs) depends on DNA demethylation at the Treg-specific demethylated region (TSDR), a conserved, CpG-rich region within the Foxp3 locus. The TSDR is selectively demethylated in ex vivo Tregs purified from secondary lymphoid organs, but it is unclear at which stage of Treg development demethylation takes place. In this study, we show that commitment to a stable lineage occurred during early stages of murine thymic Treg development by engraving of lineage-specific epigenetic marks in parallel with establishment of a Treg-specific gene expression profile. TSDR demethylation was achieved through an active mechanism and involved enzymes of the ten-eleven-translocation family and hydroxylation of methylated cytosines, a modification that is implicated as an initiating step of mitosis-independent DNA demethylation pathways and has not yet been observed at specific loci during immune cell differentiation. Together, our results demonstrate that initiating TSDR demethylation during early stages of thymic Treg development commences stabilization of Foxp3 expression and guarantees full functionality and long-term lineage stability of Tregs.
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Affiliation(s)
- Aras Toker
- Helmholtz Centre for Infection Research, Braunschweig 38124, Germany
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210
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Cheng G, Yu A, Dee MJ, Malek TR. IL-2R signaling is essential for functional maturation of regulatory T cells during thymic development. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2013; 190:1567-75. [PMID: 23315074 PMCID: PMC3563871 DOI: 10.4049/jimmunol.1201218] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
CD4(+) Foxp3(+) regulatory T cells (Tregs) are an independent cell lineage, and their developmental progression during thymic development depends on IL-2R signaling. However, the role of IL-2R signaling during thymic Treg development remains only partially understood. The current study assessed the contribution of IL-2 to the expansion and functional programming of developing Tregs. In the absence of IL-2Rβ signaling, predominantly CD4(+) CD25(-) Foxp3(lo) T cells were found, and these cells exhibited somewhat lower expression of the proliferative marker Ki67. These immature Tregs, which represent products of failed development, were also found in normal mice and were characterized by markedly lower expression of several Treg functional molecules. Therefore, IL-2R is required for the progression, functional programming, and expansion of Tregs during thymic development. An IL-2R-signaling mutant that lowers STAT5 activation readily supported Treg functional programming, but Treg proliferation remained somewhat impaired. The requirement for IL-2 during thymic Treg expansion was best illustrated in mixed chimeras where the Tregs with mutant IL-2Rs were forced to compete with wild-type Tregs during their development. Tregs with impaired IL-2R signaling were more prevalent in the thymus than spleen in these competitive experiments. The general effectiveness of mutant IL-2Rs to support thymic Treg development is partially accounted for by a heightened capacity of thymic Tregs to respond to IL-2. Overall, our data support a model in which limiting IL-2R signaling is amplified by thymic Tregs to readily support their development and functional programming, whereas these same conditions are not sufficient to support peripheral Treg homeostasis.
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Affiliation(s)
- Guoyan Cheng
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33101, USA
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211
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Abstract
The transcription factor Signal Tranducer and Activator of Transcription 5 (STAT5) plays an important role in many biological processes. To study STAT5 biology, several different constructs have been designed that render STAT5 constitutively active. These constructs have now been used to generate animal models that allow for targeted expression of constitutively active STAT5 including a model where STAT5 is expressed in developing B and T cells. Herein we briefly describe the design of constitutively active STAT5 constructs and recent advances in their use.
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Affiliation(s)
- Lynn M Heltemes-Harris
- Center for Immunology, Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA
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212
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Abstract
Forkhead box P3 positive (Foxp3(+)) regulatory T (Treg) cells suppress immune responses and regulate peripheral tolerance. Here we show that the atypical inhibitor of NFκB (IκB) IκB(NS) drives Foxp3 expression via association with the promoter and the conserved noncoding sequence 3 (CNS3) of the Foxp3 locus. Consequently, IκB(NS) deficiency leads to a substantial reduction of Foxp3(+) Treg cells in vivo and impaired Foxp3 induction upon transforming growth factor-β (TGF-β) treatment in vitro. Moreover, fewer Foxp3(+) Treg cells developed from IκB(NS)-deficient CD25(-)CD4(+) T cells adoptively transferred into immunodeficient recipients. Importantly, IκB(NS) was required for the transition of immature GITR(+)CD25(+)Foxp3(-) thymic Treg cell precursors into Foxp3(+) cells. In contrast to mice lacking c-Rel or Carma1, IκB(NS)-deficient mice do not show reduced Treg precursor cells. Our results demonstrate that IκB(NS) critically regulates Treg cell development in the thymus and during gut inflammation, indicating that strategies targeting IκB(NS) could modulate the Treg cell compartment.
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213
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Legoux FP, Moon JJ. Peptide:MHC tetramer-based enrichment of epitope-specific T cells. J Vis Exp 2012:4420. [PMID: 23117190 DOI: 10.3791/4420] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
A basic necessity for researchers studying adaptive immunity with in vivo experimental models is an ability to identify T cells based on their T cell antigen receptor (TCR) specificity. Many indirect methods are available in which a bulk population of T cells is stimulated in vitro with a specific antigen and epitope-specific T cells are identified through the measurement of a functional response such as proliferation, cytokine production, or expression of activation markers(1). However, these methods only identify epitope-specific T cells exhibiting one of many possible functions, and they are not sensitive enough to detect epitope-specific T cells at naive precursor frequencies. A popular alternative is the TCR transgenic adoptive transfer model, in which monoclonal T cells from a TCR transgenic mouse are seeded into histocompatible hosts to create a large precursor population of epitope-specific T cells that can be easily tracked with the use of a congenic marker antibody(2,3). While powerful, this method suffers from experimental artifacts associated with the unphysiological frequency of T cells with specificity for a single epitope(4,5). Moreover, this system cannot be used to investigate the functional heterogeneity of epitope-specific T cell clones within a polyclonal population. The ideal way to study adaptive immunity should involve the direct detection of epitope-specific T cells from the endogenous T cell repertoire using a method that distinguishes TCR specificity solely by its binding to cognate peptide:MHC (pMHC) complexes. The use of pMHC tetramers and flow cytometry accomplishes this(6), but is limited to the detection of high frequency populations of epitope-specific T cells only found following antigen-induced clonal expansion. In this protocol, we describe a method that coordinates the use of pMHC tetramers and magnetic cell enrichment technology to enable detection of extremely low frequency epitope-specific T cells from mouse lymphoid tissues(3,7). With this technique, one can comprehensively track entire epitope-specific populations of endogenous T cells in mice at all stages of the immune response.
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Affiliation(s)
- Francois P Legoux
- Center for Immunology and Inflammatory Diseases, and Pulmonary and Critical Care Unit, Massachusetts General Hospital and Harvard Medical School, USA
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214
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Yamane H, Paul WE. Cytokines of the γ(c) family control CD4+ T cell differentiation and function. Nat Immunol 2012; 13:1037-44. [PMID: 23080204 DOI: 10.1038/ni.2431] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Naive CD4(+) T cells undergo massive proliferation and differentiation into at least four distinct helper T cell subsets after recognition of foreign antigen-derived peptides presented by dendritic cells. Each helper T cell subset expresses a distinct set of genes that encode unique transcription factor(s), as well as hallmark cytokines. The cytokine environment created by activated CD4(+) T cells, dendritic cells and/or other cell types during the course of differentiation is a major determinant for the helper T cell fate. This Review focuses on the role of cytokines of the common γ-chain (γ(c)) family in the determination of the effector helper T cell phenotype that naive CD4(+) T cells adopt after being activated and in the function of these helper T cells.
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Affiliation(s)
- Hidehiro Yamane
- Cytokine Biology Unit, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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215
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Fu W, Ergun A, Lu T, Hill JA, Haxhinasto S, Fassett MS, Gazit R, Adoro S, Glimcher L, Chan S, Kastner P, Rossi D, Collins JJ, Mathis D, Benoist C. A multiply redundant genetic switch 'locks in' the transcriptional signature of regulatory T cells. Nat Immunol 2012; 13:972-80. [PMID: 22961053 PMCID: PMC3698954 DOI: 10.1038/ni.2420] [Citation(s) in RCA: 214] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 08/13/2012] [Indexed: 12/13/2022]
Abstract
The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg signature. Computational network inference and experimental testing assessed the contribution of other transcription factors (TF). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability.
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Affiliation(s)
- Wenxian Fu
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
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216
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Akiyama T, Shinzawa M, Akiyama N. TNF receptor family signaling in the development and functions of medullary thymic epithelial cells. Front Immunol 2012; 3:278. [PMID: 22969770 PMCID: PMC3432834 DOI: 10.3389/fimmu.2012.00278] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 08/16/2012] [Indexed: 11/25/2022] Open
Abstract
Thymic epithelial cells (TECs) provide the microenvironment required for the development of T cells in the thymus. A unique property of medullary thymic epithelial cells (mTECs) is their expression of a wide range of tissue-restricted self-antigens, critically regulated by the nuclear protein AIRE, which contributes to the selection of the self-tolerant T cell repertoire, thereby suppressing the onset of autoimmune diseases. The TNF receptor family (TNFRF) protein receptor activator of NF-κB (RANK), CD40 and lymphotoxin β receptor (LtβR) regulate the development and functions of mTECs. The engagement of these receptors with their specific ligands results in the activation of the NF-κB family of transcription factors. Two NF-κB activation pathways, the classical and non-classical pathways, promote the development of mature mTECs induced by these receptors. Consistently, TNF receptor-associated factor (TRAF6), the signal transducer of the classical pathway, and NF-κB inducing kinase (NIK), the signal transducer of the non-classical pathway, are essential for the development of mature mTECs. This review summarizes the current understanding of how the signaling by the TNF receptor family controls the development and functions of mTEC.
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Affiliation(s)
- Taishin Akiyama
- Division of Cellular and Molecular Biology, Department of Cancer Biology, Institute of Medical Science, University of Tokyo Tokyo, Japan
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217
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Abstract
Regulatory T cells expressing the FoxP3 transcription factor have a profound and nonredundant role in several aspects of immunological tolerance. We will review here the specification of this lineage, its population dynamics, and the diversity of subphenotypes that correlate with their diverse roles in controlling inflammation in a variety of settings.
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Affiliation(s)
- Christophe Benoist
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts 02115, USA
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218
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Yuan X, Malek TR. Cellular and molecular determinants for the development of natural and induced regulatory T cells. Hum Immunol 2012; 73:773-82. [PMID: 22659217 PMCID: PMC3410644 DOI: 10.1016/j.humimm.2012.05.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 04/10/2012] [Accepted: 05/10/2012] [Indexed: 02/06/2023]
Abstract
Regulation of immune responses to self and foreign antigens is critically dependent on suppressive CD4(+) T cells characterized by expression of Foxp3. The large majority of regulatory T (Treg) cells develop in the thymus as a stable suppressive lineage. However, under the proper physiological conditions, conventional peripheral CD4(+) T lymphocytes also develop into Treg cells, particularly in the gut mucosa and inflammatory tissue sites. This review will focus on our current understanding of the immunological and molecular signals controlling the development of thymic derived natural (n)Treg and peripheral converted induced (i)Treg cells. Given the importance of Foxp3 in the development of these cells, particular attention is placed on how such signals are integrated to induce and maintain the expression of this signature transcriptional regulator of Treg cells.
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Affiliation(s)
- Xiaomei Yuan
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, FL 33136, United States
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219
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Gerondakis S, Banerjee A, Grigoriadis G, Vasanthakumar A, Gugasyan R, Sidwell T, Grumont RJ. NF-κB subunit specificity in hemopoiesis. Immunol Rev 2012; 246:272-85. [PMID: 22435561 DOI: 10.1111/j.1600-065x.2011.01090.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Although the diverse functions served by the nuclear factor-κB (NF-κB) pathway in virtually all cell types are typically employed to deal with stress responses, NF-κB transcription factors also play key roles in the development of hemopoietic cells. This review focuses on how NF-κB transcription factors control various aspects of thymic T-cell and myeloid cell differentiation that include its roles in hemopoietic precursors, conventional αβ T cells, CD4(+) regulatory T cells, natural killer T cells, γδ T cells, macrophages, and dendritic cells.
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220
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Cuss SM, Green EA. Abrogation of CD40-CD154 signaling impedes the homeostasis of thymic resident regulatory T cells by altering the levels of IL-2, but does not affect regulatory T cell development. THE JOURNAL OF IMMUNOLOGY 2012; 189:1717-25. [PMID: 22802415 DOI: 10.4049/jimmunol.1200588] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Identification of costimulatory signals required for murine regulatory T (Treg) cell development relies on measuring the frequency of total thymic Treg cells. However, the thymus contains both resident and newly developed Treg cells; whether such signals target both populations is unknown. In this study, we show that CD40-CD154 blockade specifically targeted thymic resident Treg cells, but not, as was previously believed, newly developed Treg cells. Unlike CD28-CD80/CD86 signals, CD40-CD154 signals were not required for Treg cell precursor development. Instead we demonstrate that homeostatic proliferation of thymic resident Treg cells was dependent on CD40-CD154 signals maintaining IL-2 levels. Furthermore, in newborn mice, where all Treg cells are newly developed, blockade of CD40-CD154 signals had no effect on thymic Treg numbers or their proliferation. Our studies highlight the complexity in the study of thymic Treg cell development due to the heterogeneity of thymic Treg cells.
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Affiliation(s)
- Steven M Cuss
- Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge CB2 0XY, United Kingdom
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221
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Baba T, Badr MES, Tomaru U, Ishizu A, Mukaida N. Novel process of intrathymic tumor-immune tolerance through CCR2-mediated recruitment of Sirpα+ dendritic cells: a murine model. PLoS One 2012; 7:e41154. [PMID: 22815949 PMCID: PMC3397991 DOI: 10.1371/journal.pone.0041154] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 06/18/2012] [Indexed: 11/18/2022] Open
Abstract
Immune surveillance system can detect more efficiently secretory tumor-specific antigens, which are superior as a target for cancer immunotherapy. On the contrary, immune tolerance can be induced in the thymus when a tumor antigen is massively secreted into circulation. Thus, the secretion of tumor-specific antigen may have contradictory roles in tumor immunity in a context-dependent manner. However, it remains elusive on the precise cellular mechanism of intrathymic immune tolerance against tumor antigens. We previously demonstrated that a minor thymic conventional dendritic cell (cDC) subset, CD8α−Sirpα+ cDCs, but not the major subset, CD8α+Sirpα− cDCs can selectively capture blood-borne antigens and crucially contribute to the self-tolerance. In the present study, we further demonstrated that Sirpα+ cDCs can capture a blood-borne antigen leaking inside the interlobular vascular-rich regions (IVRs). Blood-borne antigen selectively captured by Sirpα+ cDCs can induce antigen-specific Treg generation or negative selection, depending on the immunogenicity of the presented antigen. Furthermore, CCR2 expression by thymic Sirpα+ cDCs and abundant expression of its ligands, particularly, CCL2 by tumor-bearing mice prompted us to examine the function of thymic Sirpα+ cDCs in tumor-bearing mice. Interestingly, tumor-bearing mice deposited CCL2 inside IVRs in the thymus. Moreover, tumor formation induced the accumulation of Sirpα+ cDCs in IVRs under the control of CCR2-CCL2 axis and enhanced their capacity to take up antigens, resulting in the shift from Treg differentiation to negative selection. Finally, intrathymic negative selection similarly ensued in CCR2-competent mice once the tumor-specific antigen was secreted into bloodstream. Thus, we demonstrated that thymic Sirpα+ cDCs crucially contribute to this novel process of intrathymic tumor immune tolerance.
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Affiliation(s)
- Tomohisa Baba
- Division of Molecular Bioregulation, Cancer Research Institute, Kanazawa University, Kanazawa, Ishikawa, Japan.
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222
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Cheng G, Yuan X, Tsai MS, Podack ER, Yu A, Malek TR. IL-2 receptor signaling is essential for the development of Klrg1+ terminally differentiated T regulatory cells. THE JOURNAL OF IMMUNOLOGY 2012; 189:1780-91. [PMID: 22786769 DOI: 10.4049/jimmunol.1103768] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Thymic-derived natural T regulatory cells (Tregs) are characterized by functional and phenotypic heterogeneity. Recently, a small fraction of peripheral Tregs has been shown to express Klrg1, but it remains unclear as to what extent Klrg1 defines a unique Treg subset. In this study, we show that Klrg1(+) Tregs represent a terminally differentiated Treg subset derived from Klrg1(-) Tregs. This subset is a recent Ag-responsive and highly activated short-lived Treg population that expresses enhanced levels of Treg suppressive molecules and that preferentially resides within mucosal tissues. The development of Klrg1(+) Tregs also requires extensive IL-2R signaling. This activity represents a distinct function for IL-2, independent from its contribution to Treg homeostasis and competitive fitness. These and other properties are analogous to terminally differentiated short-lived CD8(+) T effector cells. Our findings suggest that an important pathway driving Ag-activated conventional T lymphocytes also operates for Tregs.
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Affiliation(s)
- Guoyan Cheng
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33101, USA
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223
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Abstract
Somatic recombination of TCR genes in immature thymocytes results in some cells with useful TCR specificities, but also many with useless or potentially self-reactive specificities. Thus thymic selection mechanisms operate to shape the T-cell repertoire. Thymocytes that have a TCR with low affinity for self-peptide-MHC complexes are positively selected to further differentiate and function in adaptive immunity, whereas useless ones die by neglect. Clonal deletion and clonal diversion (Treg differentiation) are the major processes in the thymus that eliminate or control self-reactive T cells. Although these processes are thought to be efficient, they fail to control self-reactivity in all circumstances. Thus, peripheral tolerance processes exist wherein self-reactive T cells become functionally unresponsive (anergy) or are deleted after encountering self-antigens outside of the thymus. Recent advances in mechanistic studies of central and peripheral T-cell tolerance are promoting the development of therapeutic strategies to treat autoimmune disease and cancer and improve transplantation outcome.
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Affiliation(s)
- Yan Xing
- Center for Immunology, Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, 55455, USA
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224
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Delpoux A, Poitrasson-Rivière M, Le Campion A, Pommier A, Yakonowsky P, Jacques S, Letourneur F, Randriamampita C, Lucas B, Auffray C. Foxp3-independent loss of regulatory CD4+T-cell suppressive capacities induced by self-deprivation. Eur J Immunol 2012; 42:1237-49. [DOI: 10.1002/eji.201142148] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Arnaud Delpoux
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Maud Poitrasson-Rivière
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Armelle Le Campion
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Arnaud Pommier
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Philippe Yakonowsky
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Sébastien Jacques
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Franck Letourneur
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Clotilde Randriamampita
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Bruno Lucas
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
| | - Cédric Auffray
- CNRS UMR8104; Cochin Hospital; Paris France
- INSERM U567; Cochin Hospital; Paris France
- Paris Descartes University; Cochin Hospital; Paris France
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225
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Maine CJ, Hamilton-Williams EE, Cheung J, Stanford SM, Bottini N, Wicker LS, Sherman LA. PTPN22 alters the development of regulatory T cells in the thymus. THE JOURNAL OF IMMUNOLOGY 2012; 188:5267-75. [PMID: 22539785 DOI: 10.4049/jimmunol.1200150] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PTPN22 encodes a tyrosine phosphatase that inhibits Src-family kinases responsible for Ag receptor signaling in lymphocytes and is strongly linked with susceptibility to a number of autoimmune diseases. As strength of TCR signal is critical to the thymic selection of regulatory T cells (Tregs), we examined the effect of murine PTPN22 deficiency on Treg development and function. In the thymus, numbers of pre-Tregs and Tregs increased inversely with the level of PTPN22. This increase in Tregs persisted in the periphery and could play a key part in the reduced severity observed in the PTPN22-deficient mice of experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. This could explain the lack of association of certain autoimmune conditions with PTPN22 risk alleles.
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Affiliation(s)
- Christian J Maine
- Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, CA 92037, USA
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226
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Heltemes-Harris LM, Farrar MA. The role of STAT5 in lymphocyte development and transformation. Curr Opin Immunol 2012; 24:146-52. [PMID: 22342169 DOI: 10.1016/j.coi.2012.01.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 01/23/2012] [Accepted: 01/25/2012] [Indexed: 01/19/2023]
Abstract
STAT5 plays a crucial role in B and T lymphocyte development. However, whether STAT5 primarily plays a role as a permissive factor, involved in lymphocyte survival, or an instructive factor, involved in lymphocyte differentiation, has been unclear. In addition, while STAT5 has been suggested to act as a transcriptional repressor, the mechanism by which it represses transcription was undefined. Recent reports have begun to shed new light on these roles for STAT5 in lymphocyte development, transcriptional repression, and leukemic transformation.
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Affiliation(s)
- Lynn M Heltemes-Harris
- University of Minnesota, Center for Immunology, Masonic Cancer Center, Department of Laboratory Medicine and Pathology, Minneapolis, MN 55455, USA
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227
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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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228
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Abstract
The generation of regulatory T (T(Reg)) cells in the thymus is crucial for immune homeostasis and self-tolerance. Recent discoveries have revealed the cellular and molecular mechanisms that govern the differentiation of a subset of developing thymocytes into natural T(Reg) cells. Several models, centred on the self-reactivity of the T cell receptor (TCR), have been proposed to explain the generation of a T(Reg) cell population that is cognizant of self. Several molecular pathways link TCR and cytokine signalling with the expression of the T(Reg) cell-associated transcription factor forkhead box P3 (FOXP3). Moreover, interplay between thymocytes and thymic antigen-presenting cells is also involved in T(Reg) cell generation.
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229
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Haftmann C, Stittrich AB, Sgouroudis E, Matz M, Chang HD, Radbruch A, Mashreghi MF. Lymphocyte signaling: regulation of FoxO transcription factors by microRNAs. Ann N Y Acad Sci 2012; 1247:46-55. [DOI: 10.1111/j.1749-6632.2011.06264.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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230
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Abstract
The immune system has evolved to mount an effective defense against pathogens and to minimize deleterious immune-mediated inflammation caused by commensal microorganisms, immune responses against self and environmental antigens, and metabolic inflammatory disorders. Regulatory T (Treg) cell-mediated suppression serves as a vital mechanism of negative regulation of immune-mediated inflammation and features prominently in autoimmune and autoinflammatory disorders, allergy, acute and chronic infections, cancer, and metabolic inflammation. The discovery that Foxp3 is the transcription factor that specifies the Treg cell lineage facilitated recent progress in understanding the biology of regulatory T cells. In this review, we discuss cellular and molecular mechanisms in the differentiation and function of these cells.
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Affiliation(s)
- Steven Z Josefowicz
- Howard Hughes Medical Institute and Immunology Program, Sloan Kettering Institute, New York, NY 10021, USA
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231
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Moore C, Fuentes C, Sauma D, Morales J, Bono MR, Rosemblatt M, Fierro JA. Retinoic acid generates regulatory T cells in experimental transplantation. Transplant Proc 2012; 43:2334-7. [PMID: 21839265 DOI: 10.1016/j.transproceed.2011.06.057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Regulatory T cells play a key role to inhibit effector lymphocytes, avoid, autoimmunity, and restrain allogeneic immunity. Retinoic acid is an important cofactor that stimulates the generation and expansion of regulatory T cells. Naive T cells, coincubated with allogeneic antigen-presenting cells and retinoic acid, in conjunction with transforming growth factor (TGF) β and interleukin (IL) 2, generated allogeneic regulatory T cells de novo. These cells were able to inhibit skin rejection in adoptive transfer experiments. The generation of regulatory T cells ex vivo with retinoic acid, TGF-β, and IL-2 represents a new step toward specific regulation of allogeneic immune responses.
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Affiliation(s)
- C Moore
- Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile
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232
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Jin B, Sun T, Yu XH, Yang YX, Yeo AET. The effects of TLR activation on T-cell development and differentiation. Clin Dev Immunol 2012; 2012:836485. [PMID: 22737174 PMCID: PMC3376488 DOI: 10.1155/2012/836485] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 01/26/2012] [Indexed: 02/07/2023]
Abstract
Invading pathogens have unique molecular signatures that are recognized by Toll-like receptors (TLRs) resulting in either activation of antigen-presenting cells (APCs) and/or costimulation of T cells inducing both innate and adaptive immunity. TLRs are also involved in T-cell development and can reprogram Treg cells to become helper cells. T cells consist of various subsets, that is, Th1, Th2, Th17, T follicular helper (Tfh), cytotoxic T lymphocytes (CTLs), regulatory T cells (Treg) and these originate from thymic progenitor thymocytes. T-cell receptor (TCR) activation in distinct T-cell subsets with different TLRs results in differing outcomes, for example, activation of TLR4 expressed in T cells promotes suppressive function of regulatory T cells (Treg), while activation of TLR6 expressed in T cells abrogates Treg function. The current state of knowledge of regarding TLR-mediated T-cell development and differentiation is reviewed.
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Affiliation(s)
- Bo Jin
- 1Department of Gastroenterology, The 309th Hospital of The People's Liberation Army, Beijing 100091, China
- 2Department of Infectious Diseases, Naval General Hospital, Beijing 100048, China
- *Bo Jin: and
| | - Tao Sun
- 2Department of Infectious Diseases, Naval General Hospital, Beijing 100048, China
- *Tao Sun:
| | - Xiao-Hong Yu
- 2Department of Infectious Diseases, Naval General Hospital, Beijing 100048, China
| | - Ying-Xiang Yang
- 2Department of Infectious Diseases, Naval General Hospital, Beijing 100048, China
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233
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Mizoguchi A. Animal models of inflammatory bowel disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 105:263-320. [PMID: 22137435 DOI: 10.1016/b978-0-12-394596-9.00009-3] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is medicated by genetic, immune, and environmental factors. At least 66 different kinds of animal models have been established to study IBD, which are classified primarily into chemically induced, cell-transfer, congenial mutant, and genetically engineered models. These IBD models have provided significant contributions to not only dissect the mechanism but also develop novel therapeutic strategies for IBD. In addition, recent advances on genetically engineered techniques such as cell-specific and inducible knockout as well as knockin mouse systems have brought novel concepts on IBD pathogenesis to the fore. Further, mouse models, which lack some IBD susceptibility genes, have suggested more complicated mechanism of IBD than previously predicted. This chapter summarizes the distinct feature of each murine IBD model and discusses the previous and current lessons from the IBD models.
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Affiliation(s)
- Atsushi Mizoguchi
- Department of Pathology, Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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234
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Song KD, Hwang S, Yun CH. T cell receptor signaling that regulates the development of intrathymic natural regulatory T cells. Immune Netw 2011; 11:336-41. [PMID: 22346772 PMCID: PMC3275701 DOI: 10.4110/in.2011.11.6.336] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Revised: 11/25/2011] [Accepted: 12/06/2011] [Indexed: 01/01/2023] Open
Abstract
T cell receptor (TCR) signaling plays a critical role in T cell development, survival and differentiation. In the thymus, quantitative and/or qualitative differences in TCR signaling determine the fate of developing thymocytes and lead to positive and negative selection. Recently, it has been suggested that self-reactive T cells, escape from negative selection, should be suppressed in the periphery by regulatory T cells (Tregs) expressing Foxp3 transcription factor. Foxp3 is a master factor that is critical for not only development and survival but also suppressive activity of Treg. However, signals that determine Treg fate are not completely understood. The availability of mutant mice which harbor mutations in TCR signaling mediators will certainly allow to delineate signaling events that control intrathymic (natural) Treg (nTreg) development. Thus, we summarize the recent progress on the role of TCR signaling cascade components in nTreg development from the studies with murine model.
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Affiliation(s)
- Ki-Duk Song
- Center for Agricultural Biomaterials, Seoul National University, Seoul 151-921, Korea
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235
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Influenza A virus infection results in a robust, antigen-responsive, and widely disseminated Foxp3+ regulatory T cell response. J Virol 2011; 86:2817-25. [PMID: 22205730 DOI: 10.1128/jvi.05685-11] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Foxp3(+) CD4(+) regulatory T cells (Tregs) represent a highly suppressive T cell subset with well-characterized immunosuppressive effects during immune homeostasis and chronic infections, although the role of these cells in acute viral infections is poorly understood. The present study sought to examine the induction of Foxp3(+) CD4(+) Tregs in a nonlethal murine model of pulmonary viral infection by the use of the prototypical respiratory virus influenza A. We establish that influenza A virus infection results in a robust Foxp3(+) CD4(+) T cell response and that regulatory T cell induction at the site of inflammation precedes the effector T cell response. Induced Foxp3(+) CD4(+) T cells are highly suppressive ex vivo, demonstrating that influenza virus-induced Foxp3(+) CD4(+) T cells are phenotypically regulatory. Influenza A virus-induced regulatory T cells proliferate vigorously in response to influenza virus antigen, are disseminated throughout the site of infection and primary and secondary lymphoid organs, and retain Foxp3 expression in vitro, suggesting that acute viral infection is capable of inducing a foreign-antigen-specific Treg response. The ability of influenza virus-induced regulatory T cells to suppress antigen-specific CD4(+) and CD8(+) T cell proliferation and cytokine production correlates closely to their ability to respond to influenza virus antigens, suggesting that virus-induced Tregs are capable of attenuating effector responses in an antigen-dependent manner. Collectively, these data demonstrate that primary acute viral infection is capable of inducing a robust, antigen-responsive, and suppressive regulatory T cell response.
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236
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Abstract
Regulatory T cells (Tregs), either thymic derived or peripherally induced, suppress a variety of physiological and pathological immune responses, and the absence of this cell subset has been shown to result in severe systemic autoimmunity. Since their acceptance almost two decades ago, intensive research aiming to characterize the phenotype, to elucidate the suppressive activity, and to decipher the migratory behavior of Tregs has been performed. A substantial number of studies, however, focused on understanding whether defects in Treg numbers and function contribute to the development and progression of inflammatory, autoimmune, and malignant disorders, and how Treg numbers/function might be modulated to treat patients with autoimmune diseases or cancer. In the skin, an organ that is constantly exposed to the environment, Tregs are known to be critically involved not only in the maintenance of skin homeostasis but also in the regulation of cutaneous immune responses. In this review, we present an overview on recent data concerning Treg development and expansion, the molecular mechanisms underlying their immunosuppressive activity, and the modulation of Treg function. Furthermore, we discuss the role of Tregs in cutaneous inflammatory and autoimmune disorders.
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Affiliation(s)
- Karin Loser
- Department of Dermatology, Interdisciplinary Center of Clinical Research, University of Münster, Münster, Germany.
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237
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Stritesky GL, Jameson SC, Hogquist KA. Selection of self-reactive T cells in the thymus. Annu Rev Immunol 2011; 30:95-114. [PMID: 22149933 DOI: 10.1146/annurev-immunol-020711-075035] [Citation(s) in RCA: 237] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
On the whole, the healthy adaptive immune system is responsive to foreign antigens and tolerant to self. However, many individual lymphocytes have, and even require, substantial self-reactivity for their particular functions in immunity. In this review, we discuss several populations of lymphocytes that are thought to experience agonist stimulation through the T cell receptor during selection: nTreg cells, iNKT cells, nIELs, and nTh17s. We discuss the nature of this self-reactivity, how it compares with conventional T cells, and why it is important for overall immune health. We also outline molecular pathways unique to each lineage and consider possible commonalities to their development and survival.
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Affiliation(s)
- Gretta L Stritesky
- Center for Immunology and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota 55455, USA
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238
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239
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Li L, Boussiotis VA. Molecular and functional heterogeneity of T regulatory cells. Clin Immunol 2011; 141:244-52. [PMID: 21945485 PMCID: PMC3221919 DOI: 10.1016/j.clim.2011.08.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2011] [Accepted: 08/22/2011] [Indexed: 12/25/2022]
Abstract
Naturally occurring CD4+ T regulatory (Treg) cells are produced during maturation in the thymus and have a mandatory role in maintaining homeostasis and immune quiescence. Development and function of Treg cells depends on the transcription factor forkhead box P3 (Foxp3), which is necessary and sufficient for Treg cell function. Currently emerging evidence indicates Treg cells display molecular and functional heterogeneity and can be categorized into naïve and effector- or memory-like cells, which can produce effector cytokines supporting the idea that Treg cells retain plasticity. The role of Treg cells that acquire these properties remains unclear and is currently under intense investigation. In this review, we summarize recent advances on the differentiation of effector- or memory-like Treg cells, the impact of the cytokine milieu on the molecular and functional heterogeneity of Treg cells, and the clinical implications of the heterogeneity and specialization of Treg cells.
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Affiliation(s)
- Lequn Li
- Department of Medicine, Division of Hematology-Oncology and Cancer Biology, Harvard Medical School, Boston MA 02215, USA
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240
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Grigoriadis G, Vasanthakumar A, Banerjee A, Grumont R, Overall S, Gleeson P, Shannon F, Gerondakis S. c-Rel controls multiple discrete steps in the thymic development of Foxp3+ CD4 regulatory T cells. PLoS One 2011; 6:e26851. [PMID: 22066012 PMCID: PMC3204987 DOI: 10.1371/journal.pone.0026851] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 10/05/2011] [Indexed: 12/21/2022] Open
Abstract
The development of natural Foxp3+ CD4 regulatory T cells (nTregs) proceeds via two steps that involve the initial antigen dependent generation of CD25+GITRhiFoxp3−CD4+ nTreg precursors followed by the cytokine induction of Foxp3. Using mutant mouse models that lack c-Rel, the critical NF-κB transcription factor required for nTreg differentiation, we establish that c-Rel regulates both of these developmental steps. c-Rel controls the generation of nTreg precursors via a haplo-insufficient mechanism, indicating that this step is highly sensitive to c-Rel levels. However, maintenance of c-Rel in an inactive state in nTreg precursors demonstrates that it is not required for a constitutive function in these cells. While the subsequent IL-2 induction of Foxp3 in nTreg precursors requires c-Rel, this developmental transition does not coincide with the nuclear expression of c-Rel. Collectively, our results support a model of nTreg differentiation in which c-Rel generates a permissive state for foxp3 transcription during the development of nTreg precursors that influences the subsequent IL-2 dependent induction of Foxp3 without a need for c-Rel reactivation.
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Affiliation(s)
- George Grigoriadis
- Centre for Immunology, Burnet Institute, Melbourne, Australia
- Australian Centre for Blood Diseases and Department of Clinical Hematology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Australia
| | | | - Ashish Banerjee
- Centre for Immunology, Burnet Institute, Melbourne, Australia
| | - Raelene Grumont
- Centre for Immunology, Burnet Institute, Melbourne, Australia
| | - Sarah Overall
- Bio21, University of Melbourne, Parkville, Australia
| | - Paul Gleeson
- Bio21, University of Melbourne, Parkville, Australia
| | - Frances Shannon
- The John Curtin School of Medical Research, Australian National University, Canberra City, Australia
| | - Steve Gerondakis
- Centre for Immunology, Burnet Institute, Melbourne, Australia
- Australian Centre for Blood Diseases and Department of Clinical Hematology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Australia
- Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Australia
- * E-mail:
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241
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Moon JJ, Dash P, Oguin TH, McClaren JL, Chu HH, Thomas PG, Jenkins MK. Quantitative impact of thymic selection on Foxp3+ and Foxp3- subsets of self-peptide/MHC class II-specific CD4+ T cells. Proc Natl Acad Sci U S A 2011; 108:14602-7. [PMID: 21873213 PMCID: PMC3167500 DOI: 10.1073/pnas.1109806108] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
It is currently thought that T cells with specificity for self-peptide/MHC (pMHC) ligands are deleted during thymic development, thereby preventing autoimmunity. In the case of CD4(+) T cells, what is unclear is the extent to which self-peptide/MHC class II (pMHCII)-specific T cells are deleted or become Foxp3(+) regulatory T cells. We addressed this issue by characterizing a natural polyclonal pMHCII-specific CD4(+) T-cell population in mice that either lacked or expressed the relevant antigen in a ubiquitous pattern. Mice expressing the antigen contained one-third the number of pMHCII-specific T cells as mice lacking the antigen, and the remaining cells exhibited low TCR avidity. In mice lacking the antigen, the pMHCII-specific T-cell population was dominated by phenotypically naive Foxp3(-) cells, but also contained a subset of Foxp3(+) regulatory cells. Both Foxp3(-) and Foxp3(+) pMHCII-specific T-cell numbers were reduced in mice expressing the antigen, but the Foxp3(+) subset was more resistant to changes in number and TCR repertoire. Therefore, thymic selection of self-pMHCII-specific CD4(+) T cells results in incomplete deletion within the normal polyclonal repertoire, especially among regulatory T cells.
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Affiliation(s)
- James J Moon
- Department of Microbiology and Center for Immunology, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
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242
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Abstract
Regulatory T (Treg) cells play central role in regulation of immune responses to self-antigens, allergens, and commensal microbiota as well as immune responses to infectious agents and tumors. Transcriptional factor Foxp3 serves as a lineage specification factor of Treg cells. Paucity of Treg cells due to loss-of-function mutations of the Foxp3 gene is responsible for highly aggressive, fatal, systemic immune-mediated inflammatory lesions in mice and humans. Recent studies of Foxp3 expression and function provided critical novel insights into biology of Treg cells and into cellular mechanisms of the immune homeostasis.
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Affiliation(s)
- Alexander Y Rudensky
- Howard Hughes Medical Institute and Immunology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
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243
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Redjimi N, Duperrier-Amouriaux K, Raimbaud I, Luescher I, Dojcinovic D, Classe JM, Berton-Rigaud D, Frenel JS, Bourbouloux E, Valmori D, Ayyoub M. NY-ESO-1-specific circulating CD4+ T cells in ovarian cancer patients are prevalently T(H)1 type cells undetectable in the CD25+ FOXP3+ Treg compartment. PLoS One 2011; 6:e22845. [PMID: 21829534 PMCID: PMC3146491 DOI: 10.1371/journal.pone.0022845] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 06/30/2011] [Indexed: 11/18/2022] Open
Abstract
Spontaneous CD4(+) T-cell responses to the tumor-specific antigen NY-ESO-1 (ESO) are frequently found in patients with epithelial ovarian cancer (EOC). If these responses are of effector or/and Treg type, however, has remained unclear. Here, we have used functional approaches together with recently developed MHC class II/ESO tetramers to assess the frequency, phenotype and function of ESO-specific cells in circulating lymphocytes from EOC patients. We found that circulating ESO-specific CD4(+) T cells in EOC patients with spontaneous immune responses to the antigen are prevalently T(H)1 type cells secreting IFN-γ but no IL-17 or IL-10 and are not suppressive. We detected tetramer(+) cells ex vivo, at an average frequency of 1:25,000 memory cells, that is, significantly lower than in patients immunized with an ESO vaccine. ESO tetramer(+) cells were mostly effector memory cells at advanced stages of differentiation and were not detected in circulating CD25(+)FOXP3(+)Treg. Thus, spontaneous CD4(+) T-cell responses to ESO in cancer patients are prevalently of T(H)1 type and not Treg. Their relatively low frequency and advanced differentiation stage, however, may limit their efficacy, that may be boosted by immunogenic ESO vaccines.
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MESH Headings
- Adenocarcinoma, Clear Cell/immunology
- Adenocarcinoma, Clear Cell/metabolism
- Adenocarcinoma, Mucinous/immunology
- Adenocarcinoma, Mucinous/metabolism
- Adult
- Aged
- Antigens, Neoplasm/immunology
- Antigens, Neoplasm/metabolism
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- Cystadenocarcinoma, Serous/immunology
- Cystadenocarcinoma, Serous/metabolism
- Female
- Forkhead Transcription Factors/metabolism
- Humans
- Interleukin-10/metabolism
- Interleukin-17/metabolism
- Interleukin-2 Receptor alpha Subunit/metabolism
- Lymphocyte Count
- Major Histocompatibility Complex
- Membrane Proteins/immunology
- Membrane Proteins/metabolism
- Middle Aged
- Ovarian Neoplasms/immunology
- Ovarian Neoplasms/metabolism
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- Th1 Cells/immunology
- Th1 Cells/metabolism
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Affiliation(s)
- Nassima Redjimi
- Institut National de la Santé et de la Recherche Médicale, Unité 892, CLCC René Gauducheau, Saint Herblain, France
| | - Karine Duperrier-Amouriaux
- Institut National de la Santé et de la Recherche Médicale, Unité 892, CLCC René Gauducheau, Saint Herblain, France
| | - Isabelle Raimbaud
- Institut National de la Santé et de la Recherche Médicale, Unité 892, CLCC René Gauducheau, Saint Herblain, France
| | - Immanuel Luescher
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland
| | - Danijel Dojcinovic
- Ludwig Institute for Cancer Research, Lausanne Branch, University of Lausanne, Epalinges, Switzerland
| | - Jean-Marc Classe
- Department of Surgery, CLCC René Gauducheau, Saint Herblain, France
| | | | | | | | - Danila Valmori
- Institut National de la Santé et de la Recherche Médicale, Unité 892, CLCC René Gauducheau, Saint Herblain, France
- Faculty of Medicine, University of Nantes, Nantes, France
- * E-mail: (MA); (DV)
| | - Maha Ayyoub
- Institut National de la Santé et de la Recherche Médicale, Unité 892, CLCC René Gauducheau, Saint Herblain, France
- * E-mail: (MA); (DV)
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244
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Hinterberger M, Wirnsberger G, Klein L. B7/CD28 in central tolerance: costimulation promotes maturation of regulatory T cell precursors and prevents their clonal deletion. Front Immunol 2011; 2:30. [PMID: 22566820 PMCID: PMC3341949 DOI: 10.3389/fimmu.2011.00030] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 07/14/2011] [Indexed: 12/16/2022] Open
Abstract
According to the “two-step model,” the intrathymic generation of CD4+ regulatory T (Treg) cells segregates into a first, T cell receptor (TCR)-driven phase and a second, cytokine-dependent phase. The initial TCR stimulus gives rise to a CD25+Foxp3− developmental intermediate. These precursors subsequently require cytokine signaling to establish the mature CD25+Foxp3+ Treg cell phenotype. In addition, costimulation via CD28/B7 (CD80/86) axis is important for the generation of a Treg cell repertoire of normal size. Recent data suggest that CD28 or B7 deficient mice lack CD25+Foxp3− Treg cell progenitors. However, these data leave open whether costimulation is also required at subsequent stages of Treg differentiation. Also, the fate of “presumptive” Treg cells carrying a permissive TCR specificity in the absence of costimulation remains to be established. Here, we have used a previously described TCR transgenic model of agonist-driven Treg differentiation in order to address these issues. Intrathymic adoptive transfer of Treg precursors indicated that costimulation is dispensable once the intermediate CD25+Foxp3− stage has been reached. Furthermore, lack of costimulation led to the physical loss of presumptive Treg cells rather than their escape from central tolerance and differentiation into the conventional CD4+ T cell lineage. Our findings suggest that CD28 signaling does not primarily operate through enhancing the TCR signal strength in order to pass the threshold intensity required to initiate Treg cell specification. Instead, costimulation seems to deliver unique and qualitatively distinct signals that coordinately foster the developmental progression of Treg precursors and prevent their negative selection.
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245
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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: 780] [Impact Index Per Article: 60.0] [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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246
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Cell-intrinsic NF-κB activation is critical for the development of natural regulatory T cells in mice. PLoS One 2011; 6:e20003. [PMID: 21625598 PMCID: PMC3097234 DOI: 10.1371/journal.pone.0020003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 04/08/2011] [Indexed: 12/21/2022] Open
Abstract
Background Naturally occurring CD4+CD25+Foxp3+ regulatory T (Treg) cells develop in the thymus and represent a mature T cell subpopulation critically involved in maintaining peripheral tolerance. The differentiation of Treg cells in the thymus requires T cell receptor (TCR)/CD28 stimulation along with cytokine-promoted Foxp3 induction. TCR-mediated nuclear factor kappa B (NF-κB) activation seems to be involved in differentiation of Treg cells because deletion of components of the NF-κB signaling pathway, as well as of NF-κB transcription factors, leads to markedly decreased Treg cell numbers in thymus and periphery. Methodology/Principal Findings To investigate if Treg cell-intrinsic NF-κB activation is required for thymic development and peripheral homeostasis of Treg cells we used transgenic (Tg) mice with thymocyte-specific expression of a stable IκBα mutant to inhibit NF-κB activation solely within the T cell lineage. Here we show that Treg cell-intrinsic NF-κB activation is important for the generation of cytokine-responsive Foxp3− thymic Treg precursors and their further differentiation into mature Treg cells. Treg cell development could neither be completely rescued by the addition of exogenous Interleukin 2 (IL-2) nor by the presence of wild-type derived cells in adoptive transfer experiments. However, peripheral NF-κB activation appears to be required for IL-2 production by conventional T cells, thereby participating in Treg cell homeostasis. Moreover, pharmacological NF-κB inhibition via the IκB kinase β (IKKβ) inhibitor AS602868 led to markedly diminished thymic and peripheral Treg cell frequencies. Conclusion/Significance Our results indicate that Treg cell-intrinsic NF-κB activation is essential for thymic Treg cell differentiation, and further suggest pharmacological NF-κB inhibition as a potential therapeutic approach for manipulating this process.
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247
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Zhu J, Paul WE. Peripheral CD4+ T-cell differentiation regulated by networks of cytokines and transcription factors. Immunol Rev 2011; 238:247-62. [PMID: 20969597 DOI: 10.1111/j.1600-065x.2010.00951.x] [Citation(s) in RCA: 418] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
CD4(+) T cells, also known as T-helper (Th) cells, play an important role in orchestrating adaptive immune responses to various infectious agents. They are also involved in the induction of autoimmune and allergic diseases. Upon T-cell receptor (TCR)-mediated cell activation, naive CD4(+) T cells can differentiate into at least four major lineages, Th1, Th2, Th17, and iTreg cells, that participate in different types of immune responses. Networks of cytokines and transcription factors are critical for determining CD4(+) T-cell fates and effector cytokine production. Here, we review collaboration and cross-regulation between various essential cytokines in the activation/induction of key transcription factors during the process of Th cell differentiation towards these distinct lineages. We also discuss the interactions of key transcription factors at both genetic and protein levels and the function of the resulting network(s) in regulating the expression of effector cytokines.
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Affiliation(s)
- Jinfang Zhu
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892-1892, USA.
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248
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Abstract
Signaling through the interleukin-2 receptor (IL-2R) contributes to T-cell tolerance by controlling three important aspects of regulatory T-cell (Treg) biology. IL-2 is essential for thymic Treg development and regulates Treg homeostasis and suppressive function. Analogous to activated conventional T lymphocytes, IL-2R signaling also plays an important part in Treg cell growth, survival, and effector differentiation. However, Treg cells somewhat distinctively assimilate IL-2R signaling. In particular, Treg cells require essentially only IL-2-dependent receptor proximal signal transducer and activator of transcription 5 (Stat5) activation, as they contain inhibitory pathways to minimize IL-2R-dependent activation of the phosphatidyinositol 3-kinase/Akt pathway. Moreover, many IL-2R-dependent activities, including full induction of Foxp3 expression, in Treg cells require minimal and transient Stat5 activation. Thus, Treg cells are equipped to sense and then develop and function within biological niches containing minimal IL-2. These distinguishing features of IL-2R signaling provide a mechanistic underpinning for using IL-2 as an agent to selectively target Treg cells in immunotherapy to induce tolerance in autoimmune diseases and in allogeneic transplant recipients.
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Affiliation(s)
- Guoyan Cheng
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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249
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Continuous activation of the CD122/STAT-5 signaling pathway during selection of antigen-specific regulatory T cells in the murine thymus. PLoS One 2011; 6:e19038. [PMID: 21541329 PMCID: PMC3082544 DOI: 10.1371/journal.pone.0019038] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 03/25/2011] [Indexed: 01/27/2023] Open
Abstract
Signaling events affecting thymic selection of un-manipulated polyclonal natural CD25(+)foxp3(+) regulatory T cells (nTreg) have not been established ex vivo. Here, we report a higher frequency of phosphorylated STAT-5 (pSTAT-5) in nTreg cells in the adult murine thymus and to a lesser extent in the periphery, compared to other CD4(+)CD8(-) subsets. In the neonatal thymus, the numbers of pSTAT-5(+) cells in CD25(+)foxp3(-) and nTreg cells increased in parallel, suggesting that pSTAT-5(+)CD25(+)foxp3(-) cells might represent the precursors of foxp3(+) regulatory T cells. This "specific" pSTAT-5 expression detected in nTreg cells ex vivo was likely due to a very recent signal given by IL-2/IL-15 cytokines in vivo since (i) it disappeared rapidly if cells were left unstimulated in vitro and (ii) was also observed if total thymocytes were stimulated in vitro with saturating amounts of IL-2 and/or IL-15 but not IL-7. Interestingly, STAT-5 activation upon IL-2 stimulation correlated better with foxp3 and CD122 than with CD25 expression. Finally, we show that expression of an endogenous superantigen strongly affected the early Treg cell repertoire but not the proportion of pSTAT-5(+) cells within this repertoire. Our results reveal that continuous activation of the CD122/STAT-5 signaling pathway characterize regulatory lineage differentiation in the murine thymus.
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250
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Shimo Y, Yanai H, Ohshima D, Qin J, Motegi H, Maruyama Y, Hori S, Inoue JI, Akiyama T. TRAF6 directs commitment to regulatory T cells in thymocytes. Genes Cells 2011; 16:437-47. [PMID: 21401811 DOI: 10.1111/j.1365-2443.2011.01500.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Regulatory T cells (Tregs), a subset of CD4(+) helper T cells, are crucial for immunological self-tolerance. Defect in development or function of Tregs results in autoimmune disease in human and mice. Whereas it is known that Tregs mainly develop in the thymus, the molecular mechanism underlying development of Treg is not fully understood. TRAF6-deficient mice showed a severe defect in the Treg development in thymus. In vitro fetal thymic organ culture experiments indicated that the defect is ascribed to the absence of TRAF6 in thymic cells. Moreover, mixed fetal liver transfer experiments revealed that the development of Foxp3(+) cells differentiated from Traf6(-/-) hematopoietic cells was specifically impaired in the thymus, indicating cell-intrinsic requirement for TRAF6 in the Treg development. On the other hand, TRAF6 is not required for the development of conventional CD4(+) T cell. In addition, TGFβ-dependent induction of Foxp3 in CD4(+) T cells in vitro was not impaired by the absence of TRAF6. Overall, our data indicate that TRAF6 plays an essential role on the commitment of immature thymocytes to thymic Tregs in cell-intrinsic fashion.
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Affiliation(s)
- Yusuke Shimo
- Division of Cellular and Molecular Biology, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo Japan
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