scholarly journals TRAF3 regulates the effector function of regulatory T cells and humoral immune responses

2013 ◽  
Vol 211 (1) ◽  
pp. 137-151 ◽  
Author(s):  
Jae-Hoon Chang ◽  
Hongbo Hu ◽  
Jin Jin ◽  
Nahum Puebla-Osorio ◽  
Yichuan Xiao ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Immune Responses ◽  
Treg Cell ◽  
Cell Function ◽  
Treg Cells ◽  
Antibody Responses ◽  
Effector Memory ◽  
Humoral Immune ◽  
Treg Cell Function

Regulatory T cells (Treg cells) control different aspects of immune responses, but how the effector functions of Treg cells are regulated is incompletely understood. Here we identified TNF receptor–associated factor 3 (TRAF3) as a regulator of Treg cell function. Treg cell–specific ablation of TRAF3 impaired CD4 T cell homeostasis, characterized by an increase in the Th1 type of effector/memory T cells. Moreover, the ablation of TRAF3 in Treg cells resulted in increased antigen-stimulated activation of follicular T helper cells (TFH cells), coupled with heightened formation of germinal centers and production of high-affinity IgG antibodies. Although the loss of TRAF3 did not reduce the overall frequency of Treg cells, it attenuated the antigen-stimulated production of follicular Treg cells (TFR cells). TRAF3 signaling in Treg cells was required to maintain high level expression of inducible co-stimulator (ICOS), which in turn was required for TFR cell generation and inhibition of antibody responses. These findings establish TRAF3 as a mediator of Treg cell function in the regulation of antibody responses and suggest a role for TRAF3 in mediating ICOS expression in Treg cells.

scholarly journals The Therapeutic Strategies of Regulatory T Cells in Malignancies and Stem Cell Transplantations

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Rana G. Zaini ◽  
Amani A. Al-Rehaili
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
Immune System ◽  
Regulatory T Cells ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Treg Cell ◽  
Cell Function ◽  
Treg Cells ◽  
Treg Cell Function

Regulatory T cells (Treg cells) are considered one of the main dynamic cell types within the immune system. Because Treg cells suppress immune responses, they have potential roles in immunological self-tolerance and may help to maintain immune homeostasis. Promoting Treg cell function and increasing their numbers might be useful in treating autoimmune disorders, as well as preventing allograft rejection. However, studies of mice and humans demonstrate that Treg cells promote cancer progression and suppress antitumor immunity. Therefore, suppressing Treg cell function or reducing their numbers could support the immune system’s response to pathogenic microorganisms and tumors. As a result, there is great interest in investigating the Treg cells role in the treatment of hematological and nonhematological malignancies. Consequently, Treg cells could be a fundamentally important target for pathologies of the immune system. Targeting effector Treg cells could help to distinguish and selectively decrease these cells while preserving other Treg cells needed to suppress autoimmunity. Currently, a promising way to treat malignancies and other autoimmune disorders is stem cell transplantation. Stem cell transplants (SCT) can help to manage the production of Treg cells and also may produce more efficient Treg cells, thereby suppressing clinical disease progression. Specifically, mature T cells within the engrafted stem cells mediate this SCT beneficial effect. During SCT, the recipient’s immune system is replaced with a donor, which allows for improved immune system function. In addition, SCT can protect from disease relapse, as graft-versus-host disease (GvHD) in transplant patients can be protective against cancer recurrence. The current review will define the role of regulatory T cells in treatment of malignancy. Additionally, it will summarize current promising research regarding the utility of regulatory T cells in stem cell transplantation.

Regulatory T Cell-Based Immunotherapy

2013 ◽  
pp. 112-136 ◽  
Author(s):  
Sonja Schallenberg ◽  
Cathleen Petzold ◽  
Julia Riewaldt ◽  
Karsten Kretschmer
Keyword(s):  
Immune Responses ◽  
Treg Cell ◽  
Cell Function ◽  
Treg Cells ◽  
Clinical Settings ◽  
Host Immune Responses ◽  
Forkhead Box ◽  
Cell Induction ◽  
Organ Specific ◽  
Treg Cell Function

CD4+CD25+ regulatory T (Treg) cells expressing the forkhead box transcription factor Foxp3 have a vital function in the maintenance of immune homeostasis and the prevention of fatal multi-organ autoimmunity throughout life. In the last decade, Foxp3+ Treg cells have raised the hope for novel cell-based therapies to achieve tolerance in clinical settings of unwanted immune responses such as autoimmunity and graft rejection. Conceptually, the antigen-specific enhancement of Treg cell function is of particular importance because such strategies will minimize the requirements for pharmaceutical immunosuppression, sparing desired protective host immune responses to infectious and malignant insults. This chapter discusses current concepts of Treg cell-based immunotherapy with particular emphasis on antigen-specific Treg cell induction from conventional CD4+ T cells to deal with organ-specific autoimmunity.

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.

scholarly journals Function of regulatory T-cells improved by dexamethasone in Graves' disease

2012 ◽  
Vol 166 (4) ◽  
pp. 641-646 ◽  
Author(s):  
Yun Hu ◽  
Wei Tian ◽  
Ling-Ling Zhang ◽  
Hao Liu ◽  
Guo-Ping Yin ◽  
...  
Keyword(s):  
T Cells ◽  
Mrna Expression ◽  
Treg Cell ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Cell Function ◽  
Treg Cells ◽  
Th2 Cells ◽  
Graves Disease ◽  
Treg Cell Function

ObjectiveIntrathyroid injection of dexamethasone (DEX) has been used to treat Graves' disease (GD); however, the mechanism of this treatment remains poorly understood. The objective of this study was to investigate the effects of DEX on the function of regulatory T (Treg) cells (CD4+CD25+T cells) in patients with GD.MethodsPeripheral blood was obtained from 20 patients with GD, and peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll–Hypaque density gradient separation. CD4+CD25–/CD4+CD25+T cells were isolated by immunomagnetic selection and DEX was co-cultured with PBMCs or isolated T-cells for 72 h. Treg cell function was analyzed using the proliferation rate of CD4+CD25–T cells.ResultsThe proportion of Treg cells and the transcription factor forkhead box P3 (FOXP3) mRNA expression in PBMCs decreased in GD patients compared with healthy subjects, and Treg cell function was impaired in patients with GD. Although the proportion of Treg cells and FOXP3 mRNA expression in PBMCs did not increase, the function of Treg cells improved after the treatment with DEX. Moreover, the proportion of T-helper 2 (Th2) cells was decreased by the DEX treatment.ConclusionsDEX could effectively improve the function of Treg cells and set up a new balance of Th1/Th2 in GD patients. This study might help to further understand the immune mechanism of the intrathyroid injection of DEX in the treatment of GD and facilitate the potential use of this therapy.

Dysfunctional T Regulatory Cells in Myeloma: Molecular Mechanisms of Dysregulation.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3462-3462
Author(s):  
Rao H. Prabhala ◽  
Paola Neri ◽  
Pierfrancesco Tassone ◽  
Jooeun E. Bae ◽  
Masood A. Shammas ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Treg Cell ◽  
Cell Function ◽  
Cell Activity ◽  
T Cell Responses ◽  
Treg Cells ◽  
Cell Responses ◽  
Treg Cell Function

Abstract Multiple myeloma (MM) is characterized by production of monoclonal immunoglobulin, associated with suppressed uninvolved immunoglobulins and dysfunctional T cell responses. The biological basis of this dysfunction remains ill defined. Since T regulatory (Treg) cells play an important role in suppressing normal immune responses, we have here evaluated the potential role of Treg cells in immune dysfunction in MM. We observed a significant increase in CD4+CD25+ T cells in individuals with monoclonal gammopathy of undetermined significance (MGUS) and patients with MM compared to normal donors (25% and 26% versus 14%, respectively); however, Treg cells as measured by Foxp3 expression are significantly decreased in both MGUS (1.6±0.5%, p<0.01) and MM (1.6±0.5%, p<0.01) compared to normal donors (6.0±0.8%). Additionally, these Treg cells also do not function normally. Treg cells from patients with MM and MGUS even when added in higher proportions are unable to suppress anti-CD3-mediated T cell proliferation. This decreased number and function of Treg cells in MGUS and in MM may account, at least in part, for the non-specific increase in CD4+CD25+ T cells, thereby contributing to dysfunctional T cell responses. We have further analyzed the molecular basis for the Treg cell dysfunction in myeloma. Based on the preliminary results suggesting a role of IL-6 in Treg cell function and since both serum IL-6 and soluble IL-6 receptor levels are significantly elevated in MGUS and MM, we evaluated the role of IL-6 and its soluble receptor on Treg cell function. We observed that the addition of IL-6 and/or sIL-6 receptor to the culture leads to loss of Treg cell activity in normal donor cells similar to one observed in myeloma patients; and conversely, when Treg cells from MM patients are treated with the anti-IL-6 antibody or IL-6 receptor super antagonist, sant 7, the suppressive activity of Treg cells is restored. Additionally, we have preliminary evidence of expansion of Foxp3+ cell numbers in PBMC from MM patients following in vitro treatment with anti-IL-6 antibody. This data suggests a role of IL-6 and bone marrow microenvironment in dysfunctional Treg cells in MM and that inhibition of IL-6 signaling results in beneficial effects on T cell activity by increasing Treg cell activity. A blockade of IL-6 signaling thus emerges as a potential approach to establish immune homeostasis to improve immune function in MM.

scholarly journals Secretome screening reveals immunomodulating functions of IFNα-7, PAP and GDF-7 on regulatory T-cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mei Ding ◽  
Rajneesh Malhotra ◽  
Tomas Ottosson ◽  
Magnus Lundqvist ◽  
Aman Mebrahtu ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Foxp3 Expression ◽  
Treg Cells ◽  
Secreted Proteins ◽  
External Stimulation ◽  
Marker Proteins ◽  
Positive Regulators ◽  
Conformational Model

AbstractRegulatory T cells (Tregs) are the key cells regulating peripheral autoreactive T lymphocytes. Tregs exert their function by suppressing effector T cells. Tregs have been shown to play essential roles in the control of a variety of physiological and pathological immune responses. However, Tregs are unstable and can lose the expression of FOXP3 and suppressive functions as a consequence of outer stimuli. Available literature suggests that secreted proteins regulate Treg functional states, such as differentiation, proliferation and suppressive function. Identification of secreted proteins that affect Treg cell function are highly interesting for both therapeutic and diagnostic purposes in either hyperactive or immunosuppressed populations. Here, we report a phenotypic screening of a human secretome library in human Treg cells utilising a high throughput flow cytometry technology. Screening a library of 575 secreted proteins allowed us to identify proteins stabilising or destabilising the Treg phenotype as suggested by changes in expression of Treg marker proteins FOXP3 and/or CTLA4. Four proteins including GDF-7, IL-10, PAP and IFNα-7 were identified as positive regulators that increased FOXP3 and/or CTLA4 expression. PAP is a phosphatase. A catalytic-dead version of the protein did not induce an increase in FOXP3 expression. Ten interferon proteins were identified as negative regulators that reduced the expression of both CTLA4 and FOXP3, without affecting cell viability. A transcriptomics analysis supported the differential effect on Tregs of IFNα-7 versus other IFNα proteins, indicating differences in JAK/STAT signaling. A conformational model experiment confirmed a tenfold reduction in IFNAR-mediated ISG transcription for IFNα-7 compared to IFNα-10. This further strengthened the theory of a shift in downstream messaging upon external stimulation. As a summary, we have identified four positive regulators of FOXP3 and/or CTLA4 expression. Further exploration of these Treg modulators and their method of action has the potential to aid the discovery of novel therapies for both autoimmune and infectious diseases as well as for cancer.

scholarly journals TGF-β3-expressing CD4+CD25−LAG3+ regulatory T cells control humoral immune responses

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Tomohisa Okamura ◽  
Shuji Sumitomo ◽  
Kaoru Morita ◽  
Yukiko Iwasaki ◽  
Mariko Inoue ◽  
...  
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Immune Responses ◽  
Humoral Immune ◽  
Humoral Immune Responses

517 Regulatory T cell functional identity is sustained by a glucose:lactate axis that is exploited in the tumor microenvironment

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A553-A553
Author(s):  
McLane Watson ◽  
Paolo Vignali ◽  
Steven Mullet ◽  
Abigail Overacre-Delgoffe ◽  
Ronal Peralta ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Microenvironment ◽  
Treg Cell ◽  
High Glucose ◽  
Cell Function ◽  
Treg Cells ◽  
Effector T Cells ◽  
Flux Analysis ◽  
Major Barrier ◽  
Suppressive Function

BackgroundRegulatory T (Treg) cells are vital for preventing autoimmunity but are a major barrier to robust cancer immunity as the tumor microenvironment (TME) recruits and promotes their function. The deregulated cellular metabolism of tumor cells leads to a metabolite-depleted, hypoxic, and acidic TME. While the TME impairs the effector function of highly glycolytic tumor infiltrating CD8 T cells, Treg cell suppressive function is maintained. Further, studies of in vitro induced and ex vivo Treg cells reveal a distinct metabolic profile compared to effector T cells. Thus, it may be that the altered metabolic landscape of the TME and the increased activity of intratumoral Treg cells are linked.MethodsFlow cytometry, isotopic flux analysis, Foxp3 driven Cre-lox, glucose tracers, Seahorse extracellular flux analysis, RNA sequencing.ResultsHere we show Treg cells display heterogeneity in terms of their glucose metabolism and can engage an alternative metabolic pathway to maintain their high suppressive function and proliferation within the TME and other tissues. Tissue derived Treg cells (both at the steady state and under inflammatory conditions) show broad heterogeneity in their ability to take up glucose. However, glucose uptake correlates with poorer suppressive function and long-term functional stability, and culture of Treg cells in high glucose conditions decreased suppressive function. Treg cells under low glucose conditions upregulate genes associated with the uptake and metabolism of the glycolytic end-product lactic acid. Treg cells withstand high lactate conditions, and lactate treatment prevents the destabilizing effects of high glucose culture. Treg cells utilize lactate within the TCA cycle and generate phosphoenolpyruvate (PEP), a critical intermediate that can fuel intratumoral Treg cell proliferation in vivo. Using mice with a Treg cell-restricted deletion of lactate transporter Slc16a1 (MCT1) we show MCT1 is dispensable for peripheral Treg cell function but required intratumorally, resulting in slowed tumor growth and prolonged survival.ConclusionsThese data support a model in which Treg cells are metabolically flexible such that they can utilize ‘alternative’ metabolites present in the TME to maintain their suppressive identity. Further, our studies support the notion that tumors avoid immune destruction not only by depriving effector T cells of essential nutrients, but also by metabolically supporting regulatory T cells.

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 The Complex Role of Regulatory T Cells in Immunity and Aging

2021 ◽  
Vol 11 ◽  
Author(s):  
Lourdes Rocamora-Reverte ◽  
Franz Leonard Melzer ◽  
Reinhard Würzner ◽  
Birgit Weinberger
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Immune Responses ◽  
Immune Cells ◽  
Treg Cells ◽  
T Cell Subsets ◽  
Γδt Cells ◽  
Cell Functions ◽  
Age Related ◽  
Self Antigens

The immune system is a tightly regulated network which allows the development of defense mechanisms against foreign antigens and tolerance toward self-antigens. Regulatory T cells (Treg) contribute to immune homeostasis by maintaining unresponsiveness to self-antigens and suppressing exaggerated immune responses. Dysregulation of any of these processes can lead to serious consequences. Classically, Treg cell functions have been described in CD4+ T cells, but other immune cells also harbour the capacity to modulate immune responses. Regulatory functions have been described for different CD8+ T cell subsets, as well as other T cells such as γδT cells or NKT cells. In this review we describe the diverse populations of Treg cells and their role in different scenarios. Special attention is paid to the aging process, which is characterized by an altered composition of immune cells. Treg cells can contribute to the development of various age-related diseases but they are poorly characterized in aged individuals. The huge diversity of cells that display immune modulatory functions and the lack of universal markers to identify Treg make the expanding field of Treg research complex and challenging. There are still many open questions that need to be answered to solve the enigma of regulatory T cells.

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