scholarly journals Efficient IL-2R signaling differentially affects the stability, function, and composition of the regulatory T-cell pool

2021 ◽  
Author(s):  
Marc Permanyer ◽  
Berislav Bošnjak ◽  
Silke Glage ◽  
Michaela Friedrichsen ◽  
Stefan Floess ◽  
...  
Keyword(s):  
T Cell ◽  
Treg Cell ◽  
Cell Function ◽  
Interleukin 2 ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Receptor Expression ◽  
Spontaneous Mutant ◽  
Cell Pool ◽  
And Function

AbstractSignaling via interleukin-2 receptor (IL-2R) is a requisite for regulatory T (Treg) cell identity and function. However, it is not completely understood to what degree IL-2R signaling is required for Treg cell homeostasis, lineage stability and function in both resting and inflammatory conditions. Here, we characterized a spontaneous mutant mouse strain endowed with a hypomorphic Tyr129His variant of CD25, the α-chain of IL-2R, which resulted in diminished receptor expression and reduced IL-2R signaling. Under noninflammatory conditions, Cd25Y129H mice harbored substantially lower numbers of peripheral Treg cells with stable Foxp3 expression that prevented the development of spontaneous autoimmune disease. In contrast, Cd25Y129H Treg cells failed to efficiently induce immune suppression and lost lineage commitment in a T-cell transfer colitis model, indicating that unimpaired IL-2R signaling is critical for Treg cell function in inflammatory environments. Moreover, single-cell RNA sequencing of Treg cells revealed that impaired IL-2R signaling profoundly affected the balance of central and effector Treg cell subsets. Thus, partial loss of IL-2R signaling differentially interferes with the maintenance, heterogeneity, and suppressive function of the Treg cell pool.

scholarly journals Inhibition of CD4+CD25+ regulatory T-cell function by calcineurin-dependent interleukin-2 production

Blood ◽  
2006 ◽  
Vol 108 (1) ◽  
pp. 390-399 ◽  
Author(s):  
Robert Zeiser ◽  
Vu H. Nguyen ◽  
Andreas Beilhack ◽  
Martin Buess ◽  
Stephan Schulz ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
Cell Function ◽  
Interleukin 2 ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Treg Function ◽  
Functional Defect ◽  
In Vivo Bioluminescence Imaging

CD4+CD25+ regulatory T (Treg) cells control immunologic tolerance and antitumor immune responses. Therefore, in vivo modification of Treg function by immunosuppressant drugs has broad implications for transplantation biology, autoimmunity, and vaccination strategies. In vivo bioluminescence imaging demonstrated reduced early proliferation of donor-derived luciferase-labeled conventional T cells in animals treated with Treg cells after major histocompatibility complex mismatch bone marrow transplantation. Combining Treg cells with cyclosporine A (CSA), but not rapamycin (RAPA) or mycophenolate mofetil (MMF), suppressed Treg function assessed by increased T-cell proliferation, graft-versus-host disease (GVHD) severity, and reduced survival. Expansion of Treg and FoxP3 expression within this population was lowest in conjunction with CSA, suggesting that calcineurin-dependent interleukin 2 (IL-2) production is critically required for Treg cells in vivo. The functional defect of Treg cells after CSA exposure could be reversed by exogenous IL-2. Further, the Treg plus RAPA combination preserved graft-versus-tumor (GVT) effector function against leukemia cells. Our data indicate that RAPA and MMF rather than CSA preserve function of Treg cells in pathologic immune responses such as GVHD without weakening the GVT effect. (Blood. 2006;108:390-399)

scholarly journals DNAM-1 regulates Foxp3 expression in regulatory T cells by interfering with TIGIT under inflammatory conditions

2021 ◽  
Vol 118 (21) ◽  
pp. e2021309118
Author(s):  
Kazuki Sato ◽  
Yumi Yamashita-Kanemaru ◽  
Fumie Abe ◽  
Rikito Murata ◽  
Yuho Nakamura-Shinya ◽  
...  
Keyword(s):  
Treg Cell ◽  
Intracellular Signaling ◽  
Cell Function ◽  
Inflammatory Diseases ◽  
Mammalian Target Of Rapamycin ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Cell Dysfunction ◽  
Inflammatory Conditions ◽  
Treg Cell Function

Regulatory T (Treg) cells that express forkhead box P3 (Foxp3) are pivotal for immune tolerance. Although inflammatory mediators cause Foxp3 instability and Treg cell dysfunction, their regulatory mechanisms remain incompletely understood. Here, we show that the transfer of Treg cells deficient in the activating immunoreceptor DNAM-1 ameliorated the development of graft-versus-host disease better than did wild-type Treg cells. We found that DNAM-1 competes with T cell immunoreceptor with Ig and ITIM domains (TIGIT) in binding to their common ligand CD155 and therefore regulates TIGIT signaling to down-regulate Treg cell function without DNAM-1–mediated intracellular signaling. DNAM-1 deficiency augments TIGIT signaling; this subsequently inhibits activation of the protein kinase B–mammalian target of rapamycin complex 1 pathway, resulting in the maintenance of Foxp3 expression and Treg cell function under inflammatory conditions. These findings demonstrate that DNAM-1 regulates Treg cell function via TIGIT signaling and thus, it is a potential molecular target for augmenting Treg function in inflammatory diseases.

scholarly journals Androgen receptor modulates Foxp3 expression in CD4+CD25+Foxp3+ regulatory T-cells

2015 ◽  
Vol 26 (15) ◽  
pp. 2845-2857 ◽  
Author(s):  
Magdalena Walecki ◽  
Florian Eisel ◽  
Jörg Klug ◽  
Nelli Baal ◽  
Agnieszka Paradowska-Dogan ◽  
...  
Keyword(s):  
T Cells ◽  
Androgen Receptor ◽  
Treg Cell ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Strong Increase ◽  
Histone H4 ◽  
And Function

CD4+CD25+Foxp3+ regulatory T (Treg) cells are able to inhibit proliferation and cytokine production in effector T-cells and play a major role in immune responses and prevention of autoimmune disease. A master regulator of Treg cell development and function is the transcription factor Foxp3. Several cytokines, such as TGF-β and IL-2, are known to regulate Foxp3 expression as well as methylation of the Foxp3 locus. We demonstrated previously that testosterone treatment induces a strong increase in the Treg cell population both in vivo and in vitro. Therefore we sought to investigate the direct effect of androgens on expression and regulation of Foxp3. We show a significant androgen-dependent increase of Foxp3 expression in human T-cells from women in the ovulatory phase of the menstrual cycle but not from men and identify a functional androgen response element within the Foxp3 locus. Binding of androgen receptor leads to changes in the acetylation status of histone H4, whereas methylation of defined CpG regions in the Foxp3 gene is unaffected. Our results provide novel evidence for a modulatory role of androgens in the differentiation of Treg cells.

Inhibiting IL-2 Signaling and the Regulatory T-Cell Pathway Using Computationally Designed Novel Peptides

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3875-3875
Author(s):  
Tammy Price-Troska ◽  
David Diller ◽  
Alexander Bayden ◽  
Mark Jarosinski ◽  
Joseph Audies ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Function ◽  
Treg Cell ◽  
Immune Cell ◽  
Conflicts Of Interest ◽  
Interleukin 2 ◽  
Computational Design ◽  
Treg Cells ◽  
Cell Numbers

Abstract Regulatory T-cells (TREG) are the gateway to immune function and typically regulate immune cell activation. Cytokines, including interleukin-2 (IL-2), induce T-cell differentiation and promote a regulatory phenotype. Once activated via the IL-2 receptor (IL-2R), a cascade of events in T-cells initiate signal transducer and activator of transcription 5 (STAT5) and Forkhead box P3 (FOXP3) activation which appear to function as important regulators of this immunologic pathway and promote the development and function of TREG cells. In non-Hodgkin lymphoma (NHL), we have found that intratumoral TREG cells are increased in number and suppress immune function. In previous work, we have found that TREG cells inhibit T-cell proliferation, suppress cytokine production and limit effector cell cytotoxicity. We have also shown that increased serum levels of soluble sIL-2Rα is a prognostic factor in NHL and that sIL-2Rα can bind to IL-2 and promote its signaling thereby increasing TREG cell numbers. In this study, we developed a strategy to inhibit the binding of IL-2 to sIL-2Rα with the goal of suppressing the induction of FOXP3 and decreasing TREG cell numbers. To do this, we developed peptides designed to disrupt the interaction between IL2 and sILRα. In collaboration with CMDBioscienceSM, we developed and analyzed 22 peptide compounds derived by structure-based computational design. Initially, we screened each peptide at increasing concentrations using an ELISA assay to test the inhibition of IL-2/IL-2Rα binding by the solubilized peptide. Candidate peptides were then further tested using upregulation of pSTAT5 and FOXP3 in T-cells measured by flow cytometry as a measure of inhibition of IL-2 signaling. The peptides were developed according to different design hypotheses and grouped into different families; the screening ELISA results indicated 4 promising peptides that inhibited IL2/IL2Rα binding (up to 100% inhibition; max peptide concentration of 100uM). These peptides were then used to determine their effect on STAT5 and FOXP3 expression. A lead candidate peptide consistently reduced the expression of FOXP3 and STAT5 expression compared to cells not exposed to peptide. Use of the peptide to disrupt IL-2 signaling inhibited the development of cells with a TREG phenotype. We conclude that structure-based peptide design can be used to identify novel peptide inhibitors that block IL-2/IL-2Rα signaling and inhibit STAT5 and FOXP3 upregulation. These peptides could be used as new therapeutic agents to limit immune suppression by TREG cells and promote a more effective anti-tumor immune response in NHL. Disclosures No relevant conflicts of interest to declare.

scholarly journals Targeting of Cdc42 GTPase in regulatory T cells unleashes anti-tumor T cell immunity

2021 ◽  
Author(s):  
Khalid W Kalim ◽  
Jun-Qi Yang ◽  
Mark Wunderlich ◽  
Vishnu Modur ◽  
Phuong Nguyen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Treg Cell ◽  
Cell Function ◽  
Treg Cells ◽  
T Cell Response ◽  
T Cell Immunity ◽  
Cell Plasticity ◽  
Effector T Cell ◽  
Cell Immunity

Regulatory T (Treg) cells play an important role in maintaining immune tolerance through inhibiting effector T cell function. In the tumor microenvironment, Treg cells are utilized by tumor cells to counteract effector T cell-mediated tumor killing. Targeting Treg cells may thus unleash the anti-tumor activity of effector T cells. While systemic depletion of Treg cells can cause excessive effector T cell responses and subsequent autoimmune diseases, controlled targeting of Treg cells may benefit cancer patients. Here we show that Treg cell-specific heterozygous deletion or pharmacological targeting of Cdc42 GTPase does not affect Treg cell numbers but induces Treg cell plasticity, leading to anti-tumor T cell immunity without detectable autoimmune reactions. Cdc42 targeting potentiates an immune checkpoint blocker anti-PD-1 antibody-mediated T cell response against mouse and human tumors. Mechanistically, Cdc42 targeting induces Treg cell plasticity and unleashes anti-tumor T cell immunity through carbonic anhydrase I-mediated pH changes. Thus, rational targeting of Cdc42 in Treg cells holds therapeutic promises in cancer immunotherapy.

FOXP3 Expression in B and T Cell Lymphomas.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4503-4503
Author(s):  
Giovanna Roncador ◽  
Juan Fernando Garcia ◽  
Jose Francisco Garcia ◽  
Lorena Maestre ◽  
Elena Lucas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory Gene ◽  
Immune Surveillance ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Cell Leukaemia ◽  
Tissue Sections ◽  
T Cell Lymphomas ◽  
And Function

Abstract Foxp3, which encodes a forkhead/winged helix transcription factor designated Scurfin, is a key regulatory gene required for the development and function of regulatory CD4+CD25+ T cells (Treg), a subpopulation of T-cells specialized in maintaining the balance between immunity and tolerance. Humans with defects in the FOXP3 gene, develop strong activation of the immune system, leading to multiorgan autoimmune disease, allergies, inflammatory bowel disease and severe infections, collectively known as the IPEX syndrome (immune deregulation, polyendocrinopathy, enteropathy, X-linked inheritance syndrome) Because of the importance of FOXP3 in the development and function of Treg cells, and its potential use as a specific Treg marker, we have developed several monoclonal antibodies against FOXP3, for use on paraffin-embedded tissue sections and evaluated its expression in a large series (150 cases) of B- and T-cell lymphomas. In reactive lymphoid tissue, strong nuclear FOXP3 expression was observed in approximately 5% of interfollicular T-cells. FOXP3 expression in tumour cells was confined to most of Adult T-cell Leukaemia/Lymphoma (ATLL) cases (68%), with some variability in protein expression. In other lymphoma types, FOXP3 expression was only detected in the reactive T-cell background, and the number of FOXP3-positive reactive T-cells was variable, ranging from almost a complete absence (Burkitt’s lymphoma) to abundant infiltrate (common in follicular lymphoma). In conclusion, the availability of a FOXP3 monoclonal antibody, not only provides an important tool for the study of the development and function of Treg cells, but also represents a useful marker for the identification of ATLL cases in formalin-fixed paraffin-embedded tissue sections. The presence or absence of Treg cells in the tumour environment could also play a role in the immune surveillance of tumours, thus implying a potential additional value for the detection of this cell population in tumour samples.

Regulatory T Cells Enhance the Allogeneic Activity of Endothelial-Specific Cytotoxic T Lymphocytes – Protective Effect of Defibrotide

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4693-4693
Author(s):  
Guenther Eissner ◽  
Isabel Hartmann ◽  
Altug Kesikli ◽  
Silvia Haffner ◽  
Tanja Sax ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
T Cell ◽  
T Lymphocytes ◽  
Treg Cell ◽  
Interleukin 2 ◽  
Treg Cells ◽  
Protective Function ◽  
Phenotypic Quality

Abstract Abstract 4693 BACKGROUND: Damage to the vascular endothelium is the primary event of transplant related complications and often precedes loss of organ function. Depending on the amount of co-stimulatory signals, endothelial cells can either act as stimulating or inhibiting antigen presenting cells (APC). On the other hand, numerous data indicate that CD4+CD25+FoxP3+ T cells (Treg cells) can attenuate alloresponses of conventional T lymphocytes against classical APC and thus qualify for clinical use in various transplant settings. However, it is unknown whether Treg cells also influence T cell – endothelial cell interactions. Defibrotide (DF) is a polydisperse mixture of single-stranded deoxyribonucleotides with anti-thrombotic and anti-inflammatory activity, known to modulate the antigenicity of vascular endothelial cells. METHODS: CD8+ T lymphocytes (CTL) were isolated by magnetic microbead separation of peripheral blood mononuclear cells (PBMC) from healthy human blood donors and stimulated with mito-inactivated cells of a human microvascular endothelial cell line (CDC/EU.HMEC-1, further referred to as EC) and other primary and transformed micro- and macrovascular ECs for 7 days in the presence of interleukin 2 (IL-2). Treg cells from the CTL donor were prepared by CD4 (untouched) and a double CD25 microbead separation as well as a CD127bright depletion, followed by anti-CD3/CD28 expansion in the presence of IL-2 and a phenotypic quality control. Treg cells were added to the CTL-EC co-culture (1:1:1) prior to 51Cr release or flow cytometric cytotoxicity assays. Additionally, Treg cells were also tested for their capacity to influence CTL lysis of Epstein-Barr-Virus-transformed B-LCL, which as classical APC were HLA-matched to the HMEC. Furthermore, EC targets were incubated in the presence or absence of DF (25μM) for 24 hrs to assess the drug's protective function on the allogenicity of EC. RESULTS: EC-stimulated CTL showed a specific MHC class I-restricted target lysis. Addition of Treg cells prior to the cytotoxicity assay and during the afferent immune phase surprisingly increased EC lysis by CTL. In contrast, Treg cells alone did not show any lytic activity against EC. As a control, conventional CD4+CD25- T cells did not influence CTL activity either. Treg cell-mediated enhancement was endothelial-specific, since B-LCL lysis was not influenced. Further subpopulation analysis revealed the existence of CD8+/CD28-/CD57+ CTL, requiring cell-to-cell contact with Treg cells for their increased activity towards EC. Importantly, DF could almost fully protect EC against lysis by allogeneic CD28- CTL and the Treg cell-mediated enhancement. Of note, DF exclusively protected EC and did influence T cell function nor viability, suggesting a strong tropism for the endothelial cell type. CONCLUSION: There is no doubt about the potential therapeutic efficacy of Treg cells to ameliorate outcome of allogeneic transplants, but the endothelium might require additional protective interventions to prevent specific alloreactivity, such as DF. Disclosures: Eissner: Gentium, Sp.A.: Consultancy. Iacobelli:Gentium SpA: Employment.

scholarly journals Defective T-Cell Apoptosis and T-Regulatory Cell Dysfunction in Rheumatoid Arthritis

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 223 ◽  
Author(s):  
Charles Malemud
Keyword(s):  
Rheumatoid Arthritis ◽  
T Cell ◽  
Treg Cell ◽  
Cell Function ◽  
Clinical Symptoms ◽  
Treg Cells ◽  
T Cell Subsets ◽  
Systemic Autoimmune Disease ◽  
Apoptosis Resistance ◽  
Cell Dysfunction

Rheumatoid arthritis (RA) is a chronic, progressive, systemic autoimmune disease that mostly affects small and large synovial joints. At the molecular level, RA is characterized by a profoundly defective innate and adaptive immune response that results in a chronic state of inflammation. Two of the most significant alterations in T-lymphocyte (T-cell) dysfunction in RA is the perpetual activation of T-cells that result in an abnormal proliferation state which also stimulate the proliferation of fibroblasts within the joint synovial tissue. This event results in what we have termed “apoptosis resistance”, which we believe is the leading cause of aberrant cell survival in RA. Finding therapies that will induce apoptosis under these conditions is one of the current goals of drug discovery. Over the past several years, a number of T-cell subsets have been identified. One of these T-cell subsets are the T-regulatory (Treg) cells. Under normal conditions Treg cells dictate the state of immune tolerance. However, in RA, the function of Treg cells become compromised resulting in Treg cell dysfunction. It has now been shown that several of the drugs employed in the medical therapy of RA can partially restore Treg cell function, which has also been associated with amelioration of the clinical symptoms of RA.

scholarly journals Inflammation negatively regulates FOXP3 and regulatory T-cell function via DBC1

2015 ◽  
Vol 112 (25) ◽  
pp. E3246-E3254 ◽  
Author(s):  
Yayi Gao ◽  
Jiayou Tang ◽  
Weiqian Chen ◽  
Qiang Li ◽  
Jia Nie ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cell Function ◽  
Inflammatory Diseases ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Autoimmune Encephalomyelitis ◽  
Inflammatory Conditions ◽  
Forkhead Box ◽  
Binding Partners ◽  
And Function

Forkhead box P3 (FOXP3)-positive Treg cells are crucial for maintaining immune homeostasis. FOXP3 cooperates with its binding partners to elicit Treg cells’ signature and function, but the molecular mechanisms underlying the modulation of the FOXP3 complex remain unclear. Here we report that Deleted in breast cancer 1 (DBC1) is a key subunit of the FOXP3 complex. We found that DBC1 interacts physically with FOXP3, and depletion of DBC1 attenuates FOXP3 degradation in inflammatory conditions. Treg cells from Dbc1-deficient mice were more resistant to inflammation-mediated abrogation of Foxp3 expression and function and delayed the onset and severity of experimental autoimmune encephalomyelitis and colitis in mice. These findings establish a previously unidentified mechanism regulating FOXP3 stability during inflammation and reveal a pathway for potential therapeutic modulation and intervention in inflammatory diseases.

Role of regulatory T-cells in autoimmunity

2009 ◽  
Vol 116 (8) ◽  
pp. 639-649 ◽  
Author(s):  
Richard J. Mellanby ◽  
David C. Thomas ◽  
Jonathan Lamb
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Treg Cell ◽  
Cell Function ◽  
Cell Subset ◽  
Treg Cells ◽  
Self Tolerance

There has been considerable historical interest in the concept of a specialist T-cell subset which suppresses over-zealous or inappropriate T-cell responses. However, it was not until the discovery that CD4+CD25+ T-cells had suppressive capabilities both in vitro and in vivo that this concept regained credibility and developed into one of the most active research areas in immunology today. The notion that in healthy individuals there is a subset of Treg-cells (regulatory T-cells) involved in ‘policing’ the immune system has led to the intensive exploration of the role of this subset in disease resulting in a number of studies concluding that a quantitative or qualitative decline in Treg-cells is an important part of the breakdown in self-tolerance leading to the development of autoimmune diseases. Although Treg-cells have subsequently been widely postulated to represent a potential immunotherapy option for patients with autoimmune disease, several studies of autoimmune disorders have demonstrated high numbers of Treg-cells in inflamed tissue. The present review highlights the need to consider a range of other factors which may be impairing Treg-cell function when considering the mechanisms involved in the breakdown of self-tolerance rather than focussing on intrinsic Treg-cell factors.

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