Project description:The transcription factor Helios is expressed in a large subset of Foxp3+ Tregs of both mouse and man. We previously demonstrated that Treg induced in peripheral sites (pTreg) from Foxp3- T conventional (Tconv) cells were Helios- and proposed that Helios is a marker of thymic derived Treg (tTreg). To compare the two Treg subpopulations, we generated Helios-GFP reporter mice and crossed them to Foxp3-RFP reporter mice. The Helios+ Treg population expressed a more activated phenotype and had a higher suppressive capacity in vitro. Both populations expressed a highly demethylated TSDR and both subsets were equivalent in their ability to suppress inflammatory bowel disease in vivo. However, Helios+ Treg more effectively inhibited the proliferation of activated, autoreactive splenocytes from scurfy mice. When Helios+ and Helios- Treg were transferred to lymphoreplete mice, both populations maintained comparable Foxp3 expression, but Foxp3 expression was less stable in Helios- Treg when transferred to lymphopenic mice. Gene expression profiling of the two populations demonstrated a large number of differentially expressed genes and that Helios- Treg subpopulation expressed certain genes normally expressed in CD4+Foxp3- T cells. TCR repertoire analysis indicated very little overlap between Helios+ and Helios- Treg. Thus, Helios+ and Helios- Treg subpopulations are phenotypically and functionally distinct, consistent with thymic and peripheral sites of origin, respectively. Because of their superior suppressive activity and enhanced stability Foxp3+Helios+ Treg represent the optimal Treg population for cellular immunotherapy.
Project description:We report RNA sequencing data for three human engineered regulatory T cell lines expressing FOXP3, FOXP+Helios-FL, FOXP3+Helios-Δ3b. From total RNA from 3 biological replicates from each cell line, we generated RNA Sequencing data that compared gene expression between CD4+ and CD8+ cells for each cell line. RNA Sequencing demonstrated that the addition of full-length Helios changed gene expression in cellular pathways and the Treg signature compared to FOXP3 alone or the other major Helios isoform.
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability. To study the impact of deficiency of candidate FoxP3 cofactors (Xbp1, Eos, Gata1) on the expression of the Treg transcriptional signature, gene expression profiles were generated from purified splenic CD4+CD25hi Tregs of these mutant or knockout mice and their wildtype littermates.
Project description:The maintenance of immune homeostasis requires regulatory T cells (Tregs). Given their intrinsic self-reactivity, Tregs must stably maintain a suppressive phenotype to avoid autoimmunity. We report that impaired expression of the transcription factor (TF) Helios by FoxP3+ CD4 and Qa-1-restricted CD8 Tregs results in defective regulatory activity and autoimmunity in mice. Helios-deficient Treg develop an unstable phenotype during inflammatory responses characterized by reduced FoxP3 expression and increased effector cytokine expression secondary to diminished activation of the STAT5 pathway. CD8 Treg also require Helios-dependent STAT5 activation for survival and to prevent terminal T cell differentiation. Definition of Helios as a key transcription factor that stabilizes regulatory T-cells in the face of inflammatory responses provides a genetic explanation for a core property of regulatory T-cells. We used microarrays to detail the global programs of gene expression by CD8 Treg (CD44+CD122+Ly49+) and conventional memory type of CD8 cells (CD44+CD122+Ly49-).
Project description:Regulatory T cells (Treg) have been shown to adopt a catabolic metabolic programme with increased capacity for fatty acid oxidation fuelled oxidative phosphorylation (OXPHOS). The role of Foxp3 in this metabolic shift is poorly understood. Here we show that Foxp3 was sufficient to induce a significant increase in the spare respiratory capacity of the cell, the extra OXPHOS capacity available to a cell to meet increased demands on energy in response to work. Foxp3-expressing cells were enhanced in their ability to utilise palmitate for respiration and, in addition, the activity of electron transport complexes I, II and IV were enhanced following Foxp3 expression. Foxp3 also imparts a selective advantage in ATP generation capacity, one that might be exploited as a source of adenosine for functional immunomodulation. In order to explore possible mechanisms for these differences in metabolism we conducted a quantitative proteomics study to compare the contribution of TGFβ and the transcription factor Foxp3 to the Treg proteome. We used quantitative mass spectrometry to examine differences between proteomes of nuclear and cytoplasmic Foxp3-containing CD4+ T cells from various sources with Foxp3- activated CD4 T cells, as well as Treg from human peripheral blood. Gene set enrichment analysis of our proteomic datasets demonstrated that Foxp3 expression is associated with a significant up regulation of several members of the mitochondrial electron transport chain. Not only does Foxp3 influence genes directly concerned with immune function, but also with the energy generating functions of Treg.
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability.
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability. To study the impact of FoxP3 and its candidate cofactors (Eos, Gata1, Helios, Irf4, Lef1, Satb1, Xbp1) on the expression of the Treg transcriptional signature, CD4+ conventional T cells (Tconv) activated with anti-CD3+CD28 beads were retrovirally transduced with cDNAs encoding FOXP3, candidate TFs, or a combination of FOXP3 and candidate TFs. After 3 days in culture, the transduced cells were sorted into Trizol, and RNA was purified, labeled and hybridized to Affymetrix arrays.
Project description:Natural CD4+FOXP3+ regulatory T (Treg) cells constitute a unique T-cell lineage that plays a pivotal role in maintaining immune homeostasis and immune tolerance. Recent studies provide evidence for the heterogeneity and plasticity of the Treg cell lineage. However, the fate of human Treg cells after loss of FOXP3 expression and the underlying epigenetic mechanisms remain to be fully elucidated. Here, we compared gene expression profiles and histone methylation status on two histone H3 lysine residues (H3K4me3 and H3K27me3) of expanded FOXP3+ and corresponding FOXP3-losing Treg cells. DGE assay showed that human Treg cells down-regulated Treg signature genes, whereas up-regulated a set of Th lineages-associated genes, especially for Th2, such as GATA3, GFI1 and IL13, after in vitro expansion. Furthermore, we found that reprogramming of Treg cells was associated with histone modifications, as shown by decreased abundance of permissive H3K4me3 within down-regulated Treg signature genes, such as FOXP3, CTLA4 and LRRC32 loci, although with no significant changes in H3K27me3 modification. Thus, our results indicate that human Treg cells could convert into a Th-like cells upon in vitro expansion, displaying a gene expression signature dominated by Th2 lineage associated genes, and the histone methylation might contribute to such conversion. mRNA profiles of in-vitro-expanded FOXP3+ Treg and FOXP3-losing Treg cells generated by deep sequencing.
Project description:The maintenance of immune homeostasis requires regulatory T cells (Tregs). Given their intrinsic self-reactivity, Tregs must stably maintain a suppressive phenotype to avoid autoimmunity. We report that impaired expression of the transcription factor (TF) Helios by FoxP3+ CD4 and Qa-1-restricted CD8 Tregs results in defective regulatory activity and autoimmunity in mice. Helios-deficient Treg develop an unstable phenotype during inflammatory responses characterized by reduced FoxP3 expression and increased effector cytokine expression secondary to diminished activation of the STAT5 pathway. CD8 Treg also require Helios-dependent STAT5 activation for survival and to prevent terminal T cell differentiation. Definition of Helios as a key transcription factor that stabilizes regulatory T-cells in the face of inflammatory responses provides a genetic explanation for a core property of regulatory T-cells.
Project description:The maintenance of immune homeostasis requires regulatory T cells (Tregs). Given their intrinsic self-reactivity, Tregs must stably maintain a suppressive phenotype to avoid autoimmunity. We report that impaired expression of the transcription factor (TF) Helios by FoxP3+ CD4 and Qa-1-restricted CD8 Tregs results in defective regulatory activity and autoimmunity in mice. Helios-deficient Treg develop an unstable phenotype during inflammatory responses characterized by reduced FoxP3 expression and increased effector cytokine expression secondary to diminished activation of the STAT5 pathway. CD8 Treg also require Helios-dependent STAT5 activation for survival and to prevent terminal T cell differentiation. Definition of Helios as a key transcription factor that stabilizes regulatory T-cells in the face of inflammatory responses provides a genetic explanation for a core property of regulatory T-cells.