scholarly journals WASP regulates suppressor activity of human and murine CD4+CD25+FOXP3+ natural regulatory T cells

2007 ◽  
Vol 204 (2) ◽  
pp. 369-380 ◽  
Author(s):  
Francesco Marangoni ◽  
Sara Trifari ◽  
Samantha Scaramuzza ◽  
Cristina Panaroni ◽  
Silvana Martino ◽  
...  
Keyword(s):  
T Cells ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Cell Receptor ◽  
Effector T Cells ◽  
Peripheral Tolerance ◽  
Wild Type ◽  
Suppressor Activity ◽  
Suppressor Function

A large proportion of Wiskott-Aldrich syndrome (WAS) patients develop autoimmunity and allergy. CD4+CD25+FOXP3+ natural regulatory T (nTreg) cells play a key role in peripheral tolerance to prevent immune responses to self-antigens and allergens. Therefore, we investigated the effect of WAS protein (WASP) deficiency on the distribution and suppressor function of nTreg cells. In WAS−/− mice, the steady-state distribution and phenotype of nTreg cells in the thymus and spleen were normal. However, WAS−/− nTreg cells engrafted poorly in immunized mice, indicating perturbed homeostasis. Moreover, WAS−/− nTreg cells failed to proliferate and to produce transforming growth factor β upon T cell receptor (TCR)/CD28 triggering. WASP-dependent F-actin polarization to the site of TCR triggering might not be involved in WAS−/− nTreg cell defects because this process was also inefficient in wild-type (WT) nTreg cells. Compared with WT nTreg cells, WAS−/− nTreg cells showed reduced in vitro suppressor activity on both WT and WAS−/− effector T cells. Similarly, peripheral nTreg cells were present at normal levels in WAS patients but failed to suppress proliferation of autologous and allogeneic CD4+ effector T cells in vitro. Thus, WASP appears to play an important role in the activation and suppressor function of nTreg cells, and a dysfunction or incorrect localization of nTreg cells may contribute to the development of autoimmunity in WAS patients.

scholarly journals TCR-based lineage tracing: no evidence for conversion of conventional into regulatory T cells in response to a natural self-antigen in pancreatic islets

2007 ◽  
Vol 204 (9) ◽  
pp. 2039-2045 ◽  
Author(s):  
Jamie Wong ◽  
Diane Mathis ◽  
Christophe Benoist
Keyword(s):  
T Cells ◽  
Transforming Growth Factor ◽  
Nod Mice ◽  
Transforming Growth Factor Β ◽  
Cell Receptor ◽  
Lineage Tracing ◽  
Peripheral Tolerance ◽  
Cell Conversion ◽  
Endogenous Loci ◽  
Self Antigen

Foxp3-expressing regulatory T (T reg) cells derive primarily from selection in the thymus. Yet conversion of mature conventional CD4+ T (T conv) cell lymphocytes can be achieved in several conditions, such as transforming growth factor β treatment, homeostatic expansion, or chronic exposure to low-dose antigen. Such conversion might provide a means to generate peripheral tolerance by “converting” potentially damaging T cells that react to self-antigens. We tested this hypothesis in mice transgenic for the BDC2.5 T cell receptor (TCR), which is representative of a diabetogenic specificity that is naturally present in NOD mice and reactive against a pancreatic self-antigen. In the thymus, before any exposure to antigen, clonotype-positive T reg and T conv cells express a second TCRα chain derived from endogenous loci. High-throughput single-cell sequencing of secondary TCRs of the Vα2 family showed their joining CDR3α regions to be very different in T reg and T conv cell thymocytes. These specific CDR3α motifs, thus, provided a “tag” with which to test the actual impact of T conv to T reg cell conversion in response to peripheral self-antigen; should the autoreactive clonotypic TCR induce T conv to T reg cell conversion upon encounter of cognate antigen in the pancreas or draining lymph node, one would expect to detect tag CDR3α motifs from T conv cells in the T reg cell populations. Sequencing large numbers of peripheral BDC+Vα2+ cells showed that little to no conversion occurs in response to this pancreatic autoantigen.

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 Dendritic cells induce antigen-specific regulatory T cells that prevent graft versus host disease and persist in mice

2011 ◽  
Vol 208 (12) ◽  
pp. 2489-2496 ◽  
Author(s):  
Uri Sela ◽  
Peter Olds ◽  
Andrew Park ◽  
Sarah J. Schlesinger ◽  
Ralph M. Steinman
Keyword(s):  
T Cells ◽  
Regulatory T Cells ◽  
Graft Versus Host Disease ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Spleen Cells ◽  
Host Disease ◽  
Graft Versus Host ◽  
Naturally Occurring

Foxp3+ regulatory T cells (T reg cells) effectively suppress immunity, but it is not determined if antigen-induced T reg cells (iT reg cells) are able to persist under conditions of inflammation and to stably express the transcription factor Foxp3. We used spleen cells to stimulate the mixed leukocyte reaction (MLR) in the presence of transforming growth factor β (TGF-β) and retinoic acid. We found that the CD11chigh dendritic cell fraction was the most potent at inducing high numbers of alloreactive Foxp3+ cells. The induced CD4+CD25+Foxp3+ cells appeared after extensive proliferation. When purified from the MLR, iT reg cells suppressed both primary and secondary MLR in vitro in an antigen-specific manner. After transfer into allogeneic mice, iT reg cells persisted for 6 mo and prevented graft versus host disease (GVHD) caused by co-transferred CD45RBhi T cells. Similar findings were made when iT reg cells were transferred after onset of GVHD. The CNS2 intronic sequence of the Foxp3 gene in the persisting iT reg cells was as demethylated as the corresponding sequence of naturally occurring T reg cells. These results indicate that induced Foxp3+ T reg cells, after proliferating and differentiating into antigen-specific suppressive T cells, can persist for long periods while suppressing a powerful inflammatory disease.

Phosphorylation of threonine 276 in Smad4 is involved in transforming growth factor-β-induced nuclear accumulation

2003 ◽  
Vol 285 (4) ◽  
pp. C823-C830 ◽  
Author(s):  
Bernard A. J. Roelen ◽  
Ori S. Cohen ◽  
Malay K. Raychowdhury ◽  
Deborah N. Chadee ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Phosphorylation Site ◽  
Transforming Growth Factor Β ◽  
Nuclear Accumulation ◽  
Mutant Protein ◽  
Wild Type ◽  
Type Protein ◽  
Wild Type Protein

Smad4, the common Smad, is central for transforming growth factor (TGF)-β superfamily ligand signaling. Smad4 has been shown to be constitutively phosphorylated (Nakao A, Imamura T, Souchelnytskyi S, Kawabata M, Ishisaki A, Oeda E, Tamaki K, Hanai J, Heldin C-H, Miyazono K, and ten Dijke P. EMBO J 16: 5353-5362, 1997), but the site(s) of phosphorylation, the kinase(s) that performs this phosphorylation, and the significance of the phosphorylation of Smad4 are currently unknown. This report describes the identification of a consensus ERK phosphorylation site in the linker region of Smad4 at Thr276. Our data show that ERK can phosphorylate Smad4 in vitro but not Smad4 with mutated Thr276. Flag-tagged Smad4-T276A mutant protein accumulates less efficiently in the nucleus after stimulation by TGF-β and is less efficient in generating a transcriptional response than Smad4 wild-type protein. Tryptic phosphopeptide mapping identified a phosphopeptide in Smad4 wild-type protein that was absent in phosphorylated Smad4-T276A mutant protein. Our results suggest that MAP kinase can phosphorylate Thr276 of Smad4 and that phosphorylation can lead to enhanced TGF-β-induced nuclear accumulation and, as a consequence, enhanced transcriptional activity of Smad4.

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.

scholarly journals In Vitro Generation of Allospecific Human CD8+ T Cells of Tc1 and Tc2 Phenotype

Blood ◽  
1997 ◽  
Vol 90 (5) ◽  
pp. 2089-2096 ◽  
Author(s):  
David C. Halverson ◽  
Gretchen N. Schwartz ◽  
Charles Carter ◽  
Ronald E. Gress ◽  
Daniel H. Fowler
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Cell Receptor ◽  
T Cell Subsets ◽  
Interleukin 12 ◽  
Type I

Abstract We have previously shown that allospecific murine CD8+ T cells of the Tc1 and Tc2 phenotype could be generated in vitro, and that such functionally defined T-cell subsets mediated a graft-versus-leukemia (GVL) effect with reduced graft-versus-host disease (GVHD). To evaluate whether analogous Tc1 and Tc2 subsets might be generated in humans, CD8+ T cells were allostimulated in the presence of either interleukin-12 (IL-12) and transforming growth factor-beta (TGF-β) (Tc1 culture) or IL-4 (Tc2 culture). Tc1-type CD8 cells secreted the type I cytokines IL-2 and interferon gamma (IFN-γ), whereas Tc2-type cells primarily secreted the type II cytokines IL-4, IL-5, and IL-10. Both cytokine-secreting populations effectively lysed tumor targets when stimulated with anti–T-cell receptor (TCR) antibody; allospecificity of Tc1- and Tc2-mediated cytolytic function was demonstrated using bone marrow–derived stimulator cells as targets. In addition, both Tc1 and Tc2 subsets were capable of mediating cytolysis through the fas pathway. We therefore conclude that allospecific human CD8+ T cells of Tc1 and Tc2 phenotype can be generated in vitro, and that these T-cell populations may be important for the mediation and regulation of allogeneic transplantation responses.

scholarly journals Cd8− T Cell Transfectants That Express a High Affinity T Cell Receptor Exhibit Enhanced Peptide-Dependent Activation

2001 ◽  
Vol 194 (8) ◽  
pp. 1043-1052 ◽  
Author(s):  
Phillip D. Holler ◽  
Alice R. Lim ◽  
Bryan K. Cho ◽  
Laurie A. Rund ◽  
David M. Kranz
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Receptor ◽  
Cytotoxic T Lymphocyte ◽  
Cell Activity ◽  
Cell Receptor ◽  
Wild Type ◽  
High Affinity ◽  
Antigen Presenting

T cells are activated by binding of the T cell receptor (TCR) to a peptide-major histocompatibility complex (MHC) complex (pMHC) expressed on the surface of antigen presenting cells. Various models have predicted that activation is limited to a narrow window of affinities (or dissociation rates) for the TCR–pMHC interaction and that above or below this window, T cells will fail to undergo activation. However, to date there have not been TCRs with sufficiently high affinities in order to test this hypothesis. In this report we examined the activity of a CD8-negative T cell line transfected with a high affinity mutant TCR (KD = 10 nM) derived from cytotoxic T lymphocyte clone 2C by in vitro engineering. The results show that despite a 300-fold higher affinity and a 45-fold longer off-rate compared with the wild-type TCR, T cells that expressed the mutant TCRs were activated by peptide. In fact, activation could be detected at significantly lower peptide concentrations than with T cells that expressed the wild-type TCR. Furthermore, binding and functional analyses of a panel of peptide variants suggested that pMHC stability could account for apparent discrepancies between TCR affinity and T cell activity observed in several prior studies.

scholarly journals CD4+CD25+ Regulatory T Cells Can Mediate Suppressor Function in the Absence of Transforming Growth Factor β1 Production and Responsiveness

2002 ◽  
Vol 196 (2) ◽  
pp. 237-246 ◽  
Author(s):  
Ciriaco A. Piccirillo ◽  
John J. Letterio ◽  
Angela M. Thornton ◽  
Rebecca S. McHugh ◽  
Mizuko Mamura ◽  
...  
Keyword(s):  
T Cells ◽  
Growth Factor ◽  
Regulatory T Cells ◽  
T Cell Activation ◽  
Transforming Growth Factor ◽  
Cell Contact ◽  
Suppressor Function ◽  
Tgf Β1

CD4+CD25+ regulatory T cells inhibit organ-specific autoimmune diseases induced by CD4+CD25−T cells and are potent suppressors of T cell activation in vitro. Their mechanism of suppression remains unknown, but most in vitro studies suggest that it is cell contact–dependent and cytokine independent. The role of TGF-β1 in CD4+CD25+ suppressor function remains unclear. While most studies have failed to reverse suppression with anti–transforming growth factor (TGF)-β1 in vitro, one recent study has reported that CD4+CD25+ T cells express cell surface TGF-β1 and that suppression can be completely abrogated by high concentrations of anti–TGF-β suggesting that cell-associated TGF-β1 was the primary effector of CD4+CD25+-mediated suppression. Here, we have reevaluated the role of TGF-β1 in CD4+CD25+-mediated suppression. Neutralization of TGF-β1 with either monoclonal antibody (mAb) or soluble TGF-βRII-Fc did not reverse in vitro suppression mediated by resting or activated CD4+CD25+ T cells. Responder T cells from Smad3−/− or dominant-negative TGF-β type RII transgenic (DNRIITg) mice, that are both unresponsive to TGF-β1–induced growth arrest, were as susceptible to CD4+CD25+-mediated suppression as T cells from wild-type mice. Furthermore, CD4+CD25+ T cells from neonatal TGF-β1−/− mice were as suppressive as CD4+CD25+ from TGF-β1+/+ mice. Collectively, these results demonstrate that CD4+CD25+ suppressor function can occur independently of TGF-β1.

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