ABSTRACT: T helper cells (Th) play an important role guarding, regulating and modulating immune responses. The different Th lineages fulfill different tasks in response to infections. The two best defined subtypes are Th1 (involved in cellular immunity) and Th2 (humoral immunity). The cytokine environment after activation determines the differentiation path of a Th cell. We defined a strategy to investigate the differentiation signature of T helper cells with a proteomics approach. Murine primary naïve CD4+ T-cells from spleen were differentiated and activated in vitro. After 3 days of differentiation proteins were analysed. The proteomic profile of the Th1 and Th2 cells will help understand these phenotypes better, which is important in finding therapeutic targets for disease and for the development of effective vaccines.
Project description:Following antigen encounter by CD4 T cells, polarizing cytokines induce the expression of master regulators that control differentiation. Inactivation of the histone methyltransferase Ezh2 was found to specifically enhance T-helper (Th)1 and Th2 cell differentiation and plasticity. Ezh2 directly bound and facilitated correct expression of Tbx21 and Gata3 in differentiating Th1 and Th2 cells, accompanied by substantial tri-methylation at lysine 27 of histone 3 (H3K27-Me3). In addition, Ezh2 deficiency resulted in spontaneous generation of discrete IFN-γ and Th2 cytokine-producing populations in non-polarizing cultures, and under these conditions IFN-γ expression was largely dependent on enhanced expression of the transcription factor Eomesodermin. In vivo, Loss of Ezh2 caused increased pathology in a model of allergic asthma and resulted in progressive accumulation of memory phenotype Th2 cells. This study establishes a functional link between Ezh2 and transcriptional regulation of lineage-specifying genes in terminally differentiated CD4 T cells. Wild type and Ezh2 knock out unpolarized Th cells, Th1 cells and Th2 cells are profiled for mRNA expression
Project description:Transcriptional analysis of human T cells differentiated in 4 T Helper context ( Th0, Th1, Th2 and Th17) in the presence or not of Interferon alpha We analyzed the transcriptomic profiles of 4 human naives T cells diferentiated in Th0, Th1, Th2 and Th17 in the presence or not of Interferon Alpha. Microarray analyses were performed in 2 time points : 1/ after Day 5 of polarization (= Day5); 2/ after Day 5+ four hours of re-stimulation (=Day 5+ 4H restim) in 3 different donors.
Project description:Following antigen encounter by CD4 T cells, polarizing cytokines induce the expression of master regulators that control differentiation. Inactivation of the histone methyltransferase Ezh2 was found to specifically enhance T-helper (Th)1 and Th2 cell differentiation and plasticity. Ezh2 directly bound and facilitated correct expression of Tbx21 and Gata3 in differentiating Th1 and Th2 cells, accompanied by substantial tri-methylation at lysine 27 of histone 3 (H3K27-Me3). In addition, Ezh2 deficiency resulted in spontaneous generation of discrete IFN-γ and Th2 cytokine-producing populations in non-polarizing cultures, and under these conditions IFN-γ expression was largely dependent on enhanced expression of the transcription factor Eomesodermin. In vivo, Loss of Ezh2 caused increased pathology in a model of allergic asthma and resulted in progressive accumulation of memory phenotype Th2 cells. This study establishes a functional link between Ezh2 and transcriptional regulation of lineage-specifying genes in terminally differentiated CD4 T cells. Examination of Ezh2 binding in Th1 and Th2 cells.
Project description:The differentiation of human CD4+ T cells into different subtypes of T helper cells and regulatory T cells is crucial for an appropriate immunological response. Among all subtypes Th1 cells are the most prominent specific cell type, representing about 50% of all lymphocytes. So far most global proteomic studies have used either only partially purified T helper cell subpopulations and/or have employed artificial protocols for inducing specific T helper cell subtypes and/or applied gel based approaches. These studies have shed light on molecular details of certain aspects of the proteome. Nevertheless a more global analysis of highly pure primary naïve and Th1 cells by LC-MS/MS is needed in order to contribute to the proteome based T cell subtype characterization. We were able to identify 1757 proteins in total, out of which 49 were significantly regulated. The utilization of highly purified Th1 cells for a global proteome assessment and the bioinformatical comparison to naïve cells reveals the relevance of changes in the metabolism and the ubiquitination pathways upon T cell differentiation.
Project description:We did microarray experiments to elucidate the transcriptome changes due to TCF-1 deficiency in Tfh cells. These data clearly demonstrate that Tfh-associated genes were down-regulated in TCF-1-null Tfh cells, whereas Th1-associated signatures were up-regulated, indicating that TCF-1 initiates the Tfh fate by directly strengthening Tfh signatures while suppressing Th1-associated genes. We first sorted WT and TCF-1-null Tfh cells (2 samples per group, each sample was pooled from 4 mice) at day 8 after LCMV Armstrong infection. Then, we extracted RNA, which were subsequently sent to microarray analysis.
Project description:Spleens from the B6 mice were isolated and single cell suspension was made. CD4 T cells were purified from the splenocytes using magnetic bead separation. Briefly, Splenocytes were incubated with biotinylated antibody cocktail consisting of antibodies (Biolegend) to CD19, B220, CD11b, CD11c, NK1.1, Gr1, CD25 CD8. After a wash step, cells were incubated with streptavidin conjugated magnetic particles (BD Biosciences). After washing, CD4 T cells were isolated by applying a magnetic field and removing the untouched cells. Purified CD4 T cells were then activated with plate-bound anti-CD3 plus anti-CD28 in presence of either Th1 or Th17 or Th1/17 polarizing condition for 3 days. Total RNA from the 3 days differentiated Th1, Th17 and Th1/17 cells was isolated using mirVana miRNA isolation Kit (Invitrogen).
Project description:T cell function is regulated by epigenetic mechanisms. 5-methylcytosine (5mC) conversion to 5-hydroxymethylcytosine (5hmC) by ten-eleven translocation (Tet) proteins was identified to mediate DNA demethylation. Here, we characterize the genome-wide distribution of 5hmC in T cells using DNA immunoprecipitation coupled with high-throughput DNA sequencing. 5hmC marks signature genes associated with effector cell differentiation in the putative regulatory elements. Moreover, Tet2 protein is recruited to 5hmC-containing regions, dependent on lineage-specific transcription factors. Deletion of the Tet2 gene in T cells decreased their cytokine expression, associated with reduced p300 recruitment. In vivo, Tet2 plays a critical role in the expression of cytokine genes. Collectively, our findings for the first time demonstrate a key role of Tet-mediated active DNA demethylation in T cells. A total of 8 samples were analyzed. The expression patterns in Tet2 wild-type and deficient Th1 and Th17 cells were analyzed.
Project description:Epigenetic factors have been implicated in the regulation of CD4(+) T-cell differentiation. Jmjd3 plays a role in many biological processes, but its in vivo function in T-cell differentiation remains unknown. Here we report that Jmjd3 ablation promotes CD4(+) T-cell differentiation into Th2 and Th17 cells in the small intestine and colon, and inhibits T-cell differentiation into Th1 cells under different cytokine-polarizing conditions and in a Th1-dependent colitis model. Jmjd3 deficiency also restrains the plasticity of the conversion of Th2, Th17 or Treg cells to Th1 cells. The skewing of T-cell differentiation is concomitant with changes in the expression of key transcription factors and cytokines. H3K27me3 and H3K4me3 levels in Jmjd3-deficient cells are correlated with altered gene expression through interactions with specific transcription factors. Our results identify Jmjd3 as an epigenetic factor in T-cell differentiation via changes in histone methylation and target gene expression. ChIP-seq of histone modification marks H3K4me3 and H3K27me3 in WT and JMJD3 cKO mouse CD4+ T-cells
Project description:IL-27 is a potent antagonist of TH1-mediated inflammation, but the basis for this effect is not fully understood. Recent studies identified a population of T-bet+ CXCR3+ Treg that limit TH1-mediated immune pathology. The studies presented here demonstrate that IL-27-mediated STAT1 activation promotes Treg expression of T-bet and CXCR3. Infection with Toxoplasma gondii induced a similar Treg population that limits T cell responses and this population at mucosal sites is IL-27-dependent. Furthermore, transfer of Treg ameliorated the infection-induced CD4+ T cell-mediated pathology observed in IL-27p28-/- mice. Although IFN-γ promoted a similar population of cells in the periphery, it did not compensate for the absence of IL-27 at mucosal sites and microarray analysis revealed that Treg exposed to either cytokine have distinct transcriptional profiles. These findings suggest that IFN-γ and IL-27 have different roles in Treg biology but define IL-27 as a key cytokine that promotes the development of Treg specialized to control TH1 immunity. Three conditions were analyzed across two timepoints. Inducible regulatory T cells (iTreg) were generated in vitro in the presence of IL-27, IFNg or under 'Neutral' conditions as a control. Samples were collected at 10 hours and 2 days during the culture period. Three biological replicates were used for each condition.
Project description:Naïve CD4+ T cells were isolated from spleen of AND TcR transgenic/green fluorescence protein (GFP) transgenic mice (Kaye et al., Nature 1989;341:746, Wright et al, Blood 2001;97:2278) that recognize a peptide of pigeon cytochrome C in the context of I-Ek and express CD44lo, CD62Lhi, CD45RBhi, and CD25-. After 4 days in vitro stimulation with antigen presenting cells (APC) under either Th1 or Th2 condition, naïve cells become Th1 or Th2 effector cells expressing CD44hi, CD62L lo, CD45RBhi, and CD25+. Additional 3 days culture in the absence of APC, those effector cells become rested expressing a phenotype similar to memory cells (CD44 hi, CD62L lo, CD45RB lo and CD25-). These rested effector cells were adaptively transferred into thymectomized, lethally irradiated, and T cell depleted bone marrow reconstituted mice and memory cells were isolated after 4-12 weeks by flow sort. Generation and purification of Th1 and Th2 effector and memory CD4+ T cells of 42 samples.