ABSTRACT: Transcriptome analysis of Blimp1-sufficient (Ctrl) and Blimp1-deficient (CKO) CD4+ Foxp3+ regulatory (Treg) and Foxp3- effector (Teff) T cells
Project description:Although several markers have been associated with the characterization of regulatory T cells (Treg) and their function, no studies have investigated the dynamics of their phenotype during infection. Since the necessity of Treg to control immunopathology has been demonstrated, we used the chronic helminth infection model S. mansoni to address the impact on the Treg gene repertoire. Before gene expression profiling we first chose to study the localization and antigen-specific suppressive nature of classically defined Treg during infection. Presence of Foxp3+ cells were found especially in the periphery of granulomas and isolated CD4+CD25hiFoxp3+ Treg from infected mice blocked IFN-gamma and IL-10 cytokine secretion from infected CD4+CD25- effector T cells (Teff). Furthermore the gene expression patterns of Treg and Teff showed that in total 474 genes were significantly regulated during chronic schistosomiasis. Upon k-means clustering we identified genes exclusively regulated in all four populations including Foxp3, CD103, GITR, OX40 and CTLA-4: classical Treg markers. During infection however, several non-classical genes were up-regulated solely within the Treg population such as Slpi, Gzmb, Mt1, Fabp5, Nfil3, Socs2, Gpr177 and Klrg1. Using RT-PCR we confirmed aspects of the microarray data and in addition showed that the expression profile of Treg from S. mansoni-infected mice is simultaneously unique and comparative with Treg derived from other infections Regulatory T cells (Treg) or effector T cells (Teff) were FACS-sorted as CD4+CD25+ or CD4+CD25- from mesenteric lymph nodes (MLN) of naive mice or from mice infected with Schistosoma mansoni. Affymetrix MOE430A 2.0 genechips were used to identify genes differentially expressed in Treg or Teff under resting or infected conditions.
Project description:Effector (Teff) and regulatory (Treg) CD4 T cells undergo metabolic reprogramming to support proliferation and immune function. While Phosphatidylinositide 3-kinase (PI3K)/Akt/mTORC1 signaling induces the glucose transporter Glut1 and aerobic glycolysis for Teff proliferation and inflammatory function, mechanisms that regulate Treg metabolism and function remain unclear. We show that TLR signals that promote Treg proliferation increase Glut1, PI3K/Akt/mTORC1 signaling, and glycolysis. However, TLR-induced mTORC1 signaling also impaired Treg suppressive capacity. Conversely, FoxP3 opposed PI3K/Akt/mTOR signaling to reduce glycolysis and anabolic metabolism while increasing oxidative and catabolic metabolism. Importantly, Glut1 expression was sufficient to increase Treg numbers but reduced suppressive capacity and FoxP3 expression. Thus, inflammatory signals and FoxP3 balance mTORC1 signaling and glucose metabolism to control Treg proliferation and suppressive function.
Project description:Regulatory T (Treg) cells play an important role in the induction and maintenance of peripheral tolerance. Treg cells also suppress a variety of other immune responses, including anti-tumor and alloimmune responses. We have previously reported that tumor-activated Treg cells express granzyme B and that granzyme B is important for Treg cell-mediated suppression of anti-tumor immune responses (GSE13409). Here, we report that allogeneic mismatch also induces the expression of granzyme B. Granzyme B-deficient mice challenged with fully mismatched allogeneic P815 mastocytoma cells have markedly improved survival compared to WT and other granzyme- or perforin-deficient mice, suggesting an immunoregulatory role for granzyme B in this setting. Treg cells harvested from the tumor environment of P815-challenged mice express granzyme B. Treg cells also express granzyme B in vitro during mixed lymphocyte reactions and in vivo in a mouse model of graft-versus-host disease (GVHD). However, in contrast to findings from our previously published tumor model, granzyme B is not required for the suppression of effector T cell (Teff) proliferation in in vitro Treg suppression assays stimulated by either Concanavalin A or allogeneic antigen presenting cells. Additionally, in an ex vivo assay, sort-purified in vivo-activated CD4+Foxp3+ Treg cells from mice with active GVHD -- under conditions known to induce granzyme B expression in Treg cells -- suppressed Teff cell proliferation in a granzyme B-independent manner. Adoptive transfer of naive granzyme B-deficient CD4+CD25+ Treg cells into a mouse model of GVHD rescued hosts from lethatlity equivalently to naive wild-type Treg cells. Serum analysis of GVHD-associated cytokine production in these recipients also demonstrated that Treg cells suppressed production of IL-2, IL-4, IL-5, GM-CSF, and IFN-gamma in a granzyme B-independent manner. In order to determine whether the context in which Treg cells are activated alters the intrinsic properties of Treg cells, we used Foxp3 reporter mice to obtain gene expression profiles of CD4+Foxp3+ Treg cells purifed from naive resting spleens, spleens from mice with acute GVHD, and from ascites fluid of mice challenged intraperitoneally with allogeneic P815 tumor cells. Unsupervised analyses revealed distinct activation signatures of Treg cells among the 3 experimental groups. Taken together, these findings demonstrate that granzyme B is not required for Treg cell-mediated suppression of GVHD, which is in contrast to what we have previously reported for Treg cell function in the setting of tumor challenge. Cell intrinsic differences could partially account for these differential phenotypes. These data also suggest the therapeutic potential of targeting specific Treg cell suppressive functions in order to segregate GVHD and graft-versus-tumor effector functions. Experiment Overall Design: Six replicates of Naive CD4+Foxp3+ Treg cells were purified from resting spleens, five replicates of allogeneic tumor-activated Treg cells and three samples of GVHD-activated Treg cells. Experiment Overall Design: Naive reps 1-3 are controls for the GVHD-activated samples. Experiment Overall Design: Naive reps 4-6 are controls for the Allogeneic tumor-activated samples.
Project description:CD4+ cells from Foxp3.eGFP mice containing Foxp3- Teff and Foxp3+ Treg cells were treated with anti-CD3/CD28 monoclonal antibodies or soluble OX40L and JAG1 for 3 days to induce TCR-dependent vs TCR-independent Treg proliferation. Untreated fresh CD4+ T-cells used as control. Post treatment T-cell proliferation was confirmed by Cell Trace violet dilution and Foxp3+ (Treg) and Foxp3-(Teff) were sorted. Differential gene expression profiling between Tregs and Teff cells among control, anti-CD3/CD28 and OX40L-JAG1 treated cultured was performed using affymetrix mouse gene 2.0 ST micro array. We used microarrays to detail the global programme of gene expression underlying Treg proliferation and identified distinct classes of up-regulated genes during this process under different methods of expansion.
Project description:Foxp3+Tregcells are essential modulators of immune responses but under specific conditions can acquire inflammatory properties and potentially contribute to disease pathogenesis. Here we show that the transcription factor Blimp1 is a critical regulator of Foxp3+Treg functional plasticity. The intrinsic expression of Blimp1 was required to prevent Treg from producing Th17-associated cytokines and acquiring an inflammatory phenotype while preserving Foxp3 expression. Mechanistically, Blimp1 acts as a direct repressor of the Il17a/Il17f genes in Foxp3+Treg and binding of Blimp1 at this locus is associated with altered chromatin status, reduced binding the co-activator p300, unaltered binding of the Th17-asssociated transcription factor RORt and more abundant binding of IRF4, which was required for the production of IL17A in Blimp1-deficient Foxp3+Tregcells, as shown by IRF4 siRNA-mediated knockdown. Consistent with their capacity to produce inflammatory cytokines, Blimp1-deficient Foxp3+Treg exacerbate Th17-mediated inflammation in vivo indicating that Blimp1 is required to prevent Treg cells from acquiring pathogenic properties
Project description:To understand the differentiation of effector Tregs in more detail, we have performed transcriptional profiling of central Tregs and effector Tregs, based on Blimp1 expression. We performed RNA-sequencing of Foxp3+ regulatory T cells, comparing Blimp1/GFP+ and Blimp1/GFP- cells Three biologically independent samples for each condition were sequenced (condition 1: CD4+ CD25high Blimp1/GFP+; condition 2: CD4+ CD25high Blimp1/GFP-); cells were sorted from pooled spleens and lymphnodes of Blimp1/GFP reporter mice
Project description:In this study, we determined the signature of CD4+Foxp3- effector T cells and CD4+Foxp3+ Treg cells in naive animals and following LCMV WE infection. In addition, transcriptional signatures were determined in CXCR3+ CD4+Foxp3+ Treg cells arising in Th1 settings following LCMV infection.
Project description:Regulatory T (Treg) maintain the tumor microenvironment in an immunosuppressive state preventing effective anti-tumor immune response. A possible strategy to overcome Treg cell suppression focuses on OX40, a costimulatory molecule expressed constitutively by Treg cells while induced in activated effector T (Teff) cells. OX40 stimulation by the agonist mAb OX86 inhibits Treg cell suppression and boosts Teff cell activation. Here we uncover the mechanisms underlying the therapeutic activity of OX86 treatment dissecting its distinct effects on Treg and on effector memory T (Tem) cells, which are the most abundant CD4+ populations strongly expressing OX40 at the tumor site. In response to OX86, tumor-infiltrating Treg cells produced significantly less interleukin 10 (IL-10), possibly in relation to a decrease in the transcription factor IRF1. Tem cells responded to OX86 by upregulating surface CD40L expression, providing a licensing signal to dendritic cells (DCs). The CD40L/CD40 axis was required for Tem cell-mediated in vitro DC maturation and in vivo DC migration. Accordingly, OX86 treatment was no longer therapeutic in CD40 KO mice. In conclusion, following OX40 stimulation, blockade of Treg cell suppression and enhancement of the Tem cell adjuvant effect both concurred to free DCs from immunosuppression and to activate the immune response against the tumor. Total RNA obtained from sorted mouse FoxP3-GFP+ Treg activated in vitro with anti-CD3 in the presence of an OX40-agonist mAb (OX86) or isotype control.
Project description:The interplay between effector and regulatory T (Treg) cells is crucial for adaptive immunity, but how Treg control effector cell flexibility is elusive. We found that the phosphatase PTEN links Treg stability to the repression of TH1 and TFH (follicular helper) responses. Depletion of PTEN in Treg resulted in excessive TFH and germinal center responses and spontaneous inflammatory disease. These defects are considerably blocked by deletion of Interferon-γ, indicating coordinated control of TH1 and TFH responses. Mechanistically, PTEN maintains Treg stability and proper metabolic balance between glycolysis and mitochondrial fitness. Moreover, PTEN deficiency markedly upregulates mTORC2-Akt activity, and loss of this activity restores PTEN-deficient Treg function. Our studies establish a PTEN-mTORC2 axis that actively maintains Treg stability and coordinates Treg-mediated control of effector cell flexibility. We used microarrays to explore the gene expression profiles differentially expressed in CD4+CD25+Foxp3-YFP+ Treg cells from wild-type (WT; C57BL/6 crossed with Foxp3-Cre) and Ptenfl/flFoxp3-Cre (Ptenfl/fl mice crossed with Foxp3-Cre) mice
Project description:To gain in depth transcriptional information about the Noc4L deficient and Noc4L sufficient Tregs, we performed RNA-seq analysis to compare the transcriptomes of Noc4L deficient (CD4+GFP+CD62Lhigh, cKO) and Noc4L sufficient (CD4+GFP+CD62Lhigh, Het) Tregs activated in vitro with Dynabeads for 48 hours or 72 hours. We found ~25 unique genes with differential expression between the Noc4L deficient and Noc4L sufficient Treg cells when activated for 48 hours in vitro. And ~100 unique genes with differential expression between the Noc4L deficient and Noc4L sufficient Treg cells when activated for 72 hours in vitro in two times experiment.