scholarly journals Prostaglandin E2 Reverses the Effects of DNA Methyltransferase Inhibitor and TGFB1 on the Conversion of Naive T Cells to iTregs

2019 ◽  
Vol 47 (3) ◽  
pp. 244-253
Author(s):  
Mehmet Sahin ◽  
Emel Sahin
Keyword(s):  
T Cells ◽  
Prostaglandin E2 ◽  
Dna Methyltransferase ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Dna Methyltransferase Inhibitor

Naturally occurring regulatory T cells (nTregs) are produced under thymic (tTregs) or peripherally induced (pTregs) conditions in vivo. On the other hand, Tregs generated from naive T cells in vitro under some circumstances, such as treatment with transforming growth factor-β (TGFB), are called induced Tregs (iTregs). Tregs are especially characterized by FOXP3 expression, which is mainly controlled by DNA methylation. nTregs play important roles in the suppression of immune response and self-tolerance. The prostaglandin E2 (PGE2) pathway was reported to contribute to regulatory functions of tumor-infiltrating nTregs. In this study, we examined whether PGE2 contributes to the formation of iTregs treated with TGFB1 and 5-aza-2′-deoxycytidine (5-aza-dC), which is a DNA methyltransferase inhibitor. We found that the protein and gene expression levels of FOXP3 and IL-10 were increased in 5-aza-dC and TGFB1-treated T cells in vitro. However, the addition of PGE2 to these cells reversed these increments significantly. In CFSE-based cell suppression assays, we demonstrated that PGE2 decreased the suppressive functions of 5-aza-dC and TGFB1-treated T cells.

scholarly journals TRAF6 inhibits Th17 differentiation and TGF-β–mediated suppression of IL-2

Blood ◽  
2010 ◽  
Vol 115 (23) ◽  
pp. 4750-4757 ◽  
Author(s):  
Pedro J. Cejas ◽  
Matthew C. Walsh ◽  
Erika L. Pearce ◽  
Daehee Han ◽  
Gretchen M. Harms ◽  
...  
Keyword(s):  
T Cells ◽  
Transforming Growth Factor ◽  
Interleukin 2 ◽  
Transforming Growth Factor Β ◽  
Main Function ◽  
Normal Numbers ◽  
T Helper 17 ◽  
Th17 Differentiation

Abstract Transforming growth factor-β (TGF-β) has an essential role in the generation of inducible regulatory T (iTreg) and T helper 17 (Th17) cells. However, little is known about the TGF-β–triggered pathways that drive the early differentiation of these cell populations. Here, we report that CD4+ T cells lacking the molecular adaptor tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) exhibit a specific increase in Th17 differentiation in vivo and in vitro. We show that TRAF6 deficiency renders T cells more sensitive to TGF-β–induced Smad2/3 activation and proliferation arrest. Consistent with this, in TRAF6-deficient T cells, TGF-β more effectively down-regulates interleukin-2 (IL-2), a known inhibitor of Th17 differentiation. Remarkably, TRAF6-deficient cells generate normal numbers of Foxp3-expressing cells in iTreg differentiation conditions where exogenous IL-2 is supplied. These findings show an unexpected role for the adaptor molecule TRAF6 in Smad-mediated TGF-β signaling and Th17 differentiation. Importantly, the data also suggest that a main function of TGF-β in early Th17 differentiation may be the inhibition of autocrine and paracrine IL-2–mediated suppression of Th17 cell generation.

scholarly journals Transcription factors RUNX1 and RUNX3 in the induction and suppressive function of Foxp3+ inducible regulatory T cells

2009 ◽  
Vol 206 (12) ◽  
pp. 2701-2715 ◽  
Author(s):  
Sven Klunker ◽  
Mark M.W. Chong ◽  
Pierre-Yves Mantel ◽  
Oscar Palomares ◽  
Claudio Bassin ◽  
...  
Keyword(s):  
T Cells ◽  
Transcription Factors ◽  
Cd4 T Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Foxp3 Expression ◽  
Human Tonsil ◽  
Suppressive Function

Forkhead box P3 (FOXP3)+CD4+CD25+ inducible regulatory T (iT reg) cells play an important role in immune tolerance and homeostasis. In this study, we show that the transforming growth factor-β (TGF-β) induces the expression of the Runt-related transcription factors RUNX1 and RUNX3 in CD4+ T cells. This induction seems to be a prerequisite for the binding of RUNX1 and RUNX3 to three putative RUNX binding sites in the FOXP3 promoter. Inactivation of the gene encoding RUNX cofactor core-binding factor-β (CBFβ) in mice and small interfering RNA (siRNA)-mediated suppression of RUNX1 and RUNX3 in human T cells resulted in reduced expression of Foxp3. The in vivo conversion of naive CD4+ T cells into Foxp3+ iT reg cells was significantly decreased in adoptively transferred CbfbF/F CD4-cre naive T cells into Rag2−/− mice. Both RUNX1 and RUNX3 siRNA silenced human T reg cells and CbfbF/F CD4-cre mouse T reg cells showed diminished suppressive function in vitro. Circulating human CD4+ CD25high CD127− T reg cells significantly expressed higher levels of RUNX3, FOXP3, and TGF-β mRNA compared with CD4+CD25− cells. Furthermore, FOXP3 and RUNX3 were colocalized in human tonsil T reg cells. These data demonstrate Runx transcription factors as a molecular link in TGF-β–induced Foxp3 expression in iT reg cell differentiation and function.

scholarly journals Transforming Growth Factor β and Immunosuppression in Experimental Visceral Leishmaniasis

1998 ◽  
Vol 66 (3) ◽  
pp. 1233-1236 ◽  
Author(s):  
Virmondes Rodrigues ◽  
João Santana da Silva ◽  
Antonio Campos-Neto
Keyword(s):  
T Cells ◽  
Growth Factor ◽  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Spleen Cells ◽  
Immunohistochemical Studies

ABSTRACT Hamsters infected with Leishmania donovani develop a disease similar to human kala-azar. They present hypergammaglobulinemia, and their T cells do not respond to parasite antigens. This unresponsiveness has been primarily ascribed to defects in antigen-presenting cells (APCs), because these cells are unable to stimulate proliferation of parasite-specific T cells from immunized animals. In this study, we show that APCs (adherent spleen cells) fromL. donovani-infected hamsters produce high levels of the inhibitory cytokine transforming growth factor β (TGF-β). Immunohistochemical studies with an anti-TGF-β monoclonal antibody (MAb) showed that this cytokine is abundantly produced in vivo by the spleen cells of infected animals. In addition, high levels of TGF-β are produced in vitro by infected hamster cells, either spontaneously or after stimulation with parasite antigen or lipopolysaccharide. Furthermore, in vivo-infected adherent cells obtained from spleens ofL. donovani-infected hamsters caused profound inhibition of the in vitro antigen-induced proliferative response of lymph node cells from hamsters immunized with leishmanial antigens. Moreover, this inhibition was totally abrogated by the anti-TGF-β MAb. These results suggest that the immunosuppression observed in visceral leishmaniasis is, at least in part, due to the abundant production of TGF-β during the course of the infection.

Antigen-Pulsed, Interleukin-4-Treated B Cells Activate Primed T Cells In Vitro but not Naive T Cells In Vivo

1995 ◽  
Vol 42 (5) ◽  
pp. 517-523 ◽  
Author(s):  
R. GRAINGER ◽  
D. N. J. HART ◽  
J. D. WATSON ◽  
M. A. BAIRD
Keyword(s):  
T Cells ◽  
B Cells ◽  
Interleukin 4 ◽  
Naive T Cells ◽  
Naïve T Cells

Calcineurin-dependent negative regulation of CD94/NKG2A expression on naive CD8+ T cells

Blood ◽  
2011 ◽  
Vol 118 (1) ◽  
pp. 116-128 ◽  
Author(s):  
Jae-Ho Cho ◽  
Hee-Ok Kim ◽  
Kylie Webster ◽  
Mainthan Palendira ◽  
Bumsuk Hahm ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Chronic Infections ◽  
Nk Receptors ◽  
Variable Expression ◽  
Dependent Inhibition

Abstract Immune responses lead to expression of immunoregulatory molecules on T cells, including natural killer (NK) receptors, such as CD94/NKG2A on CD8+ T cells; these receptors restrain CD8+ responses, thereby preventing T-cell exhaustion in chronic infections and limiting immunopathology. Here, we examined the requirements for inducing CD94/NKG2A on T cells responding to antigen. In vitro, moderate induction of CD94/NKG2A expression occurred after exposure of naive CD8+ (but not CD4+) cells to CD3 ligation or specific peptide. Surprisingly, expression was inhibited by CD28/B7 costimulation. Such inhibition applied only to CD94/NKG2A and not other NK receptors (NKG2D) and was mediated by IL-2. Inhibition by IL-2 occurred via a NFAT cell-independent component of the calcineurin pathway, and CD94/NKG2A induction was markedly enhanced in the presence of calcineurin blockers, such as FK506 or using calcineurin-deficient T cells, both in vitro and in vivo. In addition to CD28-dependent inhibition by IL-2, CD94/NKG2A expression was impaired by several other cytokines (IL-4, IL-23, and transforming growth factor-β) but enhanced by others (IL-6, IL-10, and IL-21). The complex interplay between these various stimuli may account for the variable expression of CD94/NKG2A during responses to different pathogens in vivo.

scholarly journals Smad3 binding to the foxp3 enhancer is dispensable for the development of regulatory T cells with the exception of the gut

2012 ◽  
Vol 209 (9) ◽  
pp. 1529-1535 ◽  
Author(s):  
Susan M. Schlenner ◽  
Benno Weigmann ◽  
Qingguo Ruan ◽  
Youhai Chen ◽  
Harald von Boehmer
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Transcription Initiation ◽  
Foxp3 Expression ◽  
Cell Development ◽  
Naive T Cells ◽  
Naïve T Cells ◽  
Smad3 Binding

Regulatory T cells (T reg cells) are essential for the prevention of autoimmunity throughout life. T reg cell development occurs intrathymically but a subset of T reg cells can also differentiate from naive T cells in the periphery. In vitro, Smad signaling facilitates conversion of naive T cells into T reg cells but results in unstable Foxp3 expression. The TGF-β–Smad response element in the foxp3 locus is located in the CNS1 region in close proximity to binding sites for transcription factors implicated in TCR and retinoic acid signaling. From in vitro experiments it was previously postulated that foxp3 transcription represents a hierarchical process of transcription factor binding in which Smad3 would play a central role in transcription initiation. However, in vitro conditions generate T reg cells that differ from T reg cells encountered in vivo. To address the relevance of Smad3 binding to the CNS1 enhancer in vivo, we generated mice that exclusively lack the Smad binding site (foxp3CNS1mut). We show that binding of Smad3 to the foxp3 enhancer is dispensable for T reg cell development in newborn and adult mice with the exception of the gut.

Mesenchymal stromal cells cross-present soluble exogenous antigens as part of their antigen-presenting cell properties

Blood ◽  
2009 ◽  
Vol 114 (13) ◽  
pp. 2632-2638 ◽  
Author(s):  
Moïra François ◽  
Raphaëlle Romieu-Mourez ◽  
Sophie Stock-Martineau ◽  
Marie-Noëlle Boivin ◽  
Jonathan L. Bramson ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Stromal Cells ◽  
Antigen Processing ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cross Presentation ◽  
Ifn Γ

Abstract Recent studies involving bone marrow mesenchymal stromal cells (MSCs) demonstrated that interferon (IFN)–γ stimulation induces major histocompatibility complex (MHC) class II–mediated antigen presentation in MSCs both in vitro and in vivo. Concordantly, we investigated the ability of MSCs to present extracellular antigen through their MHC class I molecules, a process known as cross-presentation. Using an in vitro antigen presentation assay, we demonstrated that murine MSCs can cross-present soluble ovalbumin (OVA) to naive CD8+ T cells from OT-I mice. Cross-presentation by MSC was proteasome dependent and partly dependent on transporter associated with antigen-processing molecules. Pretreatment of MSC with IFN-γ increased cross-presentation by up-regulating antigen processing and presentation. However, although the transcription of the transporter associated with antigen processing-1 molecules and the immunoproteasome subunit LMP2 induced by IFN-γ was inhibited by transforming growth factor-β, the overall cross-presentation capacity of MSCs remained unchanged after transforming growth factor-β treatment. These observations were validated in vivo by performing an immune reconstitution assay in β2-microglobulin−/− mice and show that OVA cross-presentation by MSCs induces the proliferation of naive OVA-specific CD8+ T cells. In conclusion, we demonstrate that MSCs can cross-present exogenous antigen and induce an effective CD8+ T-cell immune response, a property that could be exploited as a therapeutic cell-based immune biopharmaceutic for the treatment of cancer or infectious diseases.

scholarly journals A tumor-specific mechanism of Treg enrichment mediated by the integrin αvβ8

2021 ◽  
Vol 6 (57) ◽  
pp. eabf0558
Author(s):  
Robert I. Seed ◽  
Kenji Kobayashi ◽  
Saburo Ito ◽  
Naoki Takasaka ◽  
Anthony Cormier ◽  
...  
Keyword(s):  
T Cells ◽  
Tumor Cell ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Specific Mechanism ◽  
Tumor Immune Evasion ◽  
Geometrically Constrained ◽  
And Diffusion

Regulatory T cells (Tregs) that promote tumor immune evasion are enriched in certain tumors and correlate with poor prognosis. However, mechanisms for Treg enrichment remain incompletely understood. We described a mechanism for Treg enrichment in mouse and human tumors mediated by the αvβ8 integrin. Tumor cell αvβ8 bound to latent transforming growth factor–β (L–TGF-β) presented on the surface of T cells, resulting in TGF-β activation and immunosuppressive Treg differentiation in vitro. In vivo, tumor cell αvβ8 expression correlated with Treg enrichment, immunosuppressive Treg gene expression, and increased tumor growth, which was reduced in mice by αvβ8 inhibition or Treg depletion. Structural modeling and cell-based studies suggested a highly geometrically constrained complex forming between αvβ8-expressing tumor cells and L–TGF-β–expressing T cells, facilitating TGF-β activation, independent of release and diffusion, and providing limited access to TGF-β inhibitors. These findings suggest a highly localized tumor-specific mechanism for Treg enrichment.

scholarly journals Platelet-Derived GARP Induces Peripheral Regulatory T Cells—Potential Impact on T Cell Suppression in Patients with Melanoma-Associated Thrombocytosis

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3653
Author(s):  
Niklas Zimmer ◽  
Franziska K. Krebs ◽  
Sophia Zimmer ◽  
Heidrun Mitzel-Rink ◽  
Elena J. Kumm ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cell Interaction ◽  
Platelet Surface ◽  
T Effector Cells

Platelets have been recently described as an important component of the innate and adaptive immunity through their interaction with immune cells. However, information on the platelet–T cell interaction in immune-mediated diseases remains limited. Glycoprotein A repetitions predominant (GARP) expressed on platelets and on activated regulatory T cells (Treg) is involved in the regulation of peripheral immune responses by modulating the bioavailability of transforming growth factor β (TGF-β). Soluble GARP (sGARP) exhibits strong regulatory and anti-inflammatory capacities both in vitro and in vivo, leading to the induction of peripheral Treg. Herein, we investigated the effect of platelet-derived GARP on the differentiation, phenotype, and function of T effector cells. CD4+CD25− T cells cocultured with platelets upregulated FoxP3, the master transcription factor for Treg, were anergic, and were strongly suppressive. These effects were reversed by using a blocking anti-GARP antibody, indicating a dependency on GARP. Importantly, melanoma patients in different stages of disease showed a significant upregulation of GARP on the platelet surface, correlating to a reduced responsiveness to immunotherapy. In conclusion, our data indicate that platelets induce peripheral Treg via GARP. These findings might contribute to diseases such as cancer-associated thrombocytosis, wherein poor prognosis and metastasis are associated with high counts of circulating platelets.

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