Project description:Regulatory T cells (Treg) contribute to the crucial immunological processes of self-tolerance and immune homeostasis. However, the mechanisms underlying Treg function and cell fate decisions to differentiate between Treg and conventional T cells (Tconv) remain to be fully elucidated, especially at the histone modification level. Covalent modifications of histones establish and maintain chromatin structure, and regulate gene transcription events by facilitating access to cis-elements by trans-acting factors during mammalian development and cellular differentiation. We aimed to investigate the role of the methylation form of histone modification as related to Treg function and phenotype. High-resolution maps of the genome-wide distribution of monomethylated histone H3 lysine 4, H3K4me1, and the trimethylated form H3K4me3 were generated for human activated conventional CD4+CD25+FOXP3- T cells (aTconv) and CD4+CD25+FOXP3+ regulatory T cells (Treg) by sequencing using the Solexa 1G Genetic Analyzer. We found 2115 H3K4me3 regions corresponding to proximal promoter regions; the genes associated with these regions in Treg cells included the crucial transcription factor forkhead box P3 (FOXP3) and the chemokine receptor CCR7. We also identified 41024 Treg cell type-specific H3K4me1 regions. The majority of the H3K4me1 regions differing between the Treg and aTconv cells were located at promoter-distal sites, some of which were selected and consolidated to further examine enhancer activity in in vitro reporter gene assays. The findings from our study provide a comprehensive genome-wide dataset of lineage-specific H3K4me1 and H3K4me3 patterns in Treg and aTconv cells, which may control the differentiation decision, lineage commitment and cell type-specific gene regulation. This basic principle is likely not confined to the two closely-related T cell populations, but may apply generally to somatic cell lineages in adult organisms. Genome-wide distribution of monomethylated histone H3 lysine 4, H3K4me1, and the trimethylated form H3K4me3 in human activated conventional CD4+CD25+FOXP3- T cells (aTconv) and CD4+CD25+FOXP3+ regulatory T cells (Treg) (5 samples in total)
Project description:Regulatory T cells (Treg) contribute to the crucial immunological processes of self-tolerance and immune homeostasis. However, the mechanisms underlying Treg function and cell fate decisions to differentiate between Treg and conventional T cells (Tconv) remain to be fully elucidated, especially at the histone modification level. Covalent modifications of histones establish and maintain chromatin structure, and regulate gene transcription events by facilitating access to cis-elements by trans-acting factors during mammalian development and cellular differentiation. We aimed to investigate the role of the methylation form of histone modification as related to Treg function and phenotype. High-resolution maps of the genome-wide distribution of monomethylated histone H3 lysine 4, H3K4me1, and the trimethylated form H3K4me3 were generated for human activated conventional CD4+CD25+FOXP3- T cells (aTconv) and CD4+CD25+FOXP3+ regulatory T cells (Treg) by sequencing using the Solexa 1G Genetic Analyzer. We found 2115 H3K4me3 regions corresponding to proximal promoter regions; the genes associated with these regions in Treg cells included the crucial transcription factor forkhead box P3 (FOXP3) and the chemokine receptor CCR7. We also identified 41024 Treg cell type-specific H3K4me1 regions. The majority of the H3K4me1 regions differing between the Treg and aTconv cells were located at promoter-distal sites, some of which were selected and consolidated to further examine enhancer activity in in vitro reporter gene assays. The findings from our study provide a comprehensive genome-wide dataset of lineage-specific H3K4me1 and H3K4me3 patterns in Treg and aTconv cells, which may control the differentiation decision, lineage commitment and cell type-specific gene regulation. This basic principle is likely not confined to the two closely-related T cell populations, but may apply generally to somatic cell lineages in adult organisms.
Project description:CD4+CD25+FOXP3+ human regulatory T cells (Treg) are essential for self-tolerance and immune homeostasis. Here, we generated genome-wide maps of poised and active enhancer elements marked by histone H3 lysine 4 monomethylation and histone H3 lysine 27 acetylation for CD4+CD25highCD45RA+ naive and CD4+CD25highCD45RA- memory Treg and their CD25- conventional T cell (Tconv) counterparts after in vitro expansion . In addition we generated genome-wide maps of the transcription factors STAT5, FOXP3, RUNX1 and ETS1 in expanded CD4+CD25highCD45RA+ Treg- and CD4+CD25- Tconv to elucidate their role in cell type-specific gene regulation. ChIP-seq of 2 histone marks and transcription factors ETS1, STAT5, FOXP3 and RUNX1 in expanded T cell subpopulations
Project description:We analyzed the individual transcriptomes of thymic Treg cells (CD4+Foxp3+), their immediate precursors (CD25+CD4+Foxp3-) and mature CD4 single positive thymocytes (CD4+Foxp3-CD25-CD62L+CD24-).
Project description:Regulatory T (Treg) cells are involved in self tolerance, immune homeostasis, prevention of autoimmunity, and suppression of immunity to pathogens or tumours. The forkhead transcription factor FOXP3 is essential for Treg cell development and function as mutations in FOXP3 cause severe autoimmunity in mice and humans. However, the FOXP3-dependent molecular mechanisms leading to this severe phenotype are not well understood. Here we introduce the chromatin remodelling enzyme SATB1 (special AT-rich sequence-binding protein-1) as an important target gene of FOXP3. So far, SATB1 has been associated with normal thymic T-cell development, peripheral T-cell homeostasis, TH1/TH2 polarization, and reprogramming of gene expression. In natural and induced murine and human FOXP3+ Treg cells SATB1 expression is significantly reduced. While there is no differential epigenetic regulation of the SATB1 locus between Treg and Teffector cells, FOXP3 reduces SATB1 expression directly as a transcriptional repressor at the SATB1 locus and indirectly via miR-155 induction, which specifically binds to the 3’UTR of the SATB1 mRNA. Reduced SATB1 expression in FOXP3+ cells achieved either by overexpression or induction of FOXP3 is linked to significant reduction in TH1 and TH2 cytokines, while loss of FOXP3 function either by knock down or genetic mutation leads to significant upregulation of SATB1 and subsequent cytokine production. Alltogether, these findings demonstrate that reduced SATB1 expression in Treg cells is necessary for maintenance of a Treg-cell phenotype in vitro and in vivo and places SATB1-mediated T cell-specific modulation of global chromatin remodelling central during the decision process between effector and regulatory T-cell function. Gene expression profiling of freshly isolated CD4+ T cells, separated into CD25 negative and positive subpopulations, from three different donors. FOXP3 is stably and constitutively expressed at a high level in CD4+CD25+ regulatory T cells and at a low level in CD4+CD25- cells.
Project description:CD4+CD25+FOXP3+ human regulatory T cells (Treg) are essential for self-tolerance and immune homeostasis. Here, we generated genome-wide maps of poised and active enhancer elements marked by histone H3 lysine 4 monomethylation and histone H3 lysine 27 acetylation for CD4+CD25highCD45RA+ naive and CD4+CD25highCD45RA- memory Treg and their CD25- conventional T cell (Tconv) counterparts after in vitro expansion . In addition we generated genome-wide maps of the transcription factors STAT5, FOXP3, RUNX1 and ETS1 in expanded CD4+CD25highCD45RA+ Treg- and CD4+CD25- Tconv to elucidate their role in cell type-specific gene regulation.
Project description:Here, we report on experiments in double-transgenic mice, in which RFP is expressed in all Foxp3+ Treg cells, whereas Foxp3-dependent GFP expression is exclusively confined to intrathymically induced Foxp3+ Treg cells. This novel molecular genetic tool enabled us to faithfully track and characterize naturally induced Treg cells of intrathymic (RFP+GFP+) and extrathymic (RFP+GFPM-bM-^HM-^R) origin in otherwise unmanipulated mice. These experiments directly demonstrate that extrathymically induced Treg cells substantially contribute to the overall pool of mature Foxp3+ Treg cells residing in peripheral lymphoid tissues of steady-state mice. Furthermore, we provide evidence that intra- and extrathymically induced Foxp3+ Treg cells represent distinct phenotypic and functional sublineages. CD4+CD25+ RFP+GFP- and CD4+CD25+ RFP+GFP+ T cells from pooled lymph nodes and pooled spleens of 20 mice were FACS sorted for RNA extraction and hybridization on Affymetrix microarrays in duplicates.
Project description:Analysis of the transcriptional correlates of FOXP3 expression in suppressive and non-suppressive primary human Treg cell clones. Individual CD4+CD25High or Cd4+CD25- T cells were isolated from human PBMCs and expanded in vitro. After 3 weeks of expansion, individual clones were analysed for FOXP3 expression and in vitro suppressive activity against freshly sorted allogeneic effector T cells. This study analyses the total RNA isolated from FOXP3+ clones with suppressive potency to their non-suppressive counterparts. The resutls of this study should provide insights into the molecular pathways linking FOXP3 expression to distinct aspects of Treg phenotype and function. Total RNA obtained from individual clones of primary human regulatory and effector CD4+T cells.
Project description:A common method used both in vitro and in vivo, to identify Tregs in CD4+ T cells is through the characterization of surface marker CD25. Although CD25 expression is well correlated with regulatory activity in vitro, CD4+CD25+ T cells are not the only regulatory CD4+ T cells in vivo. Studies suggest that in many situations, CD4+CD25M-bM-^@M-^S T cells are as effective as CD4+CD25+ T cells in controlling T cell mediated disease. Therefore, CD25 is not a uniquely specific cell surface marker for the identification of Tregs. CD49f is an M-NM-16-integrin subunit which dimerizes with either the M-NM-2 1 or M-NM-2 4 subunit to form receptors for various laminin isoforms. We found that CD4+ T cells from NOD mice express CD49f, and old non-diabetic NOD mice had an increase of CD4+CD49f+ T cells in the spleen and peripheral lymph node when compared to both young and diabetic mice. This study was conducted to further characterize CD4+CD49f+ Treg cell subpopulation in NOD mice. It was found that CD4+CD49f+T cells possess suppressive ability and only one third of CD4+CD49f+ T cells expressing CD25. Based on the expression of CD49f and CD25, CD4+ T cells was divided into four populations , CD25+CD49f+ ,CD25+CD49f- ,CD25-CD49f+ but CD25-CD49f- are of suppressive ability, and we further found that Foxp3 expression was highly correlated with the suppressive ability of these three Treg populations. In conclusion our data indicate that CD49f marks a CD4+ CD25+ Treg subset with more potent suppression activity and identifies a CD25-CD4+ T cell population with suppression function in a Foxp3+ expression dependent manner. We divided CD4+ T cells into four populations: CD25+CD49f+, CD25+CD49f-, CD25-CD49f+, CD25-CD49f-; Microarray technology was used to determine gene expression differences among these four groups.
Project description:Changes in Treg function are difficult to quantify due to the lack of Treg-exclusive markers in humans and the complexity of functional experiments. We sorted naive and memory human Tregs and conventional T cells, and identified genes that identify human Tregs regardless of their state of activation. We developed this Treg signature using Affymetrix human genome U133A 2.0 microarrays. To generate Tregs and Tconvs in multiple states of activation, naïve (CD4+CD25hiCD45RA+) and memory (CD4+CD25hiCD45RA-) Tregs, and naïve (CD4+CD25-CD45RA+) and memory (CD4+CD25-CD45RA-) Tconvs were sorted from blood of 7 healthy adults and RNA was isolated ex vivo or after stimulation for 40h, promoting activation-induced FOXP3 in Tconvs. The gene-expression profile of the eight cell subsets was analyzed. 7 adult healthy control samples were sorted into 4 subsets: naïve (CD4+CD25hiCD45RA+) and memory (CD4+CD25hiCD45RA-) Tregs, and naïve (CD4+CD25-CD45RA+) and memory (CD4+CD25-CD45RA-) Tconvs. These were used for RNA ex vivo and after 40h stimulation with anti-CD3/CD28 beads to induce an activation phenotype.