This SuperSeries is composed of the SubSeries listed below.
Spatial Interplay between Polycomb and Trithorax Complexes Controls Transcriptional Activity in T Lymphocytes.
Specimen part, Treatment
View SamplesVariable strengths of T cell receptor (TCR) signaling can produce divergent outcomes for T cell development and function. The mechanisms leading to different outcomes are incompletely understood, but may include distinct activation thresholds for different transcription factors as well as distinct sensitivities among target genes to transcription factors. IRF4 is one transcription factor implicated in responses to variable TCR signal strength. IRF4 expression increases uniformly with increasing TCR signal strength (i.e., analog), but it is unclear how IRF4 induced distinct genes at different levels, rather than different amounts of the same genes. Here, we analyzed global gene expression in TH2 cells and used ChIP-seq to define the relationship between TCR signal strength, enhancer occupancy and transcriptional activity for BATF/IRF4-dependent genes. We show that enhancers exhibit a spectrum of affinity for the BATF/IRF4 ternary complex mediate graded responsiveness of individual genes to increasing TCR signal strength. Differential gene induction by BATF and IRF4 occurs through interaction with enhancer elements of different affinity for BATF/IRF4 complexes. The increased resolution of factor binding site identified using ChIP-exo allowed the identification of a novel AICE2 motif binding BATF/IRF4 with higher affinity and that this may explain the protective role of a single nucleotide polymorphism in the CTLA-4 locus known to decrease the incidence of autoimmune diseases.
Quality of TCR signaling determined by differential affinities of enhancers for the composite BATF-IRF4 transcription factor complex.
Specimen part
View SamplesDifferentiation of naive CD4 T cells into type 2 helper (Th2) cells is accompanied by chromatin remodeling and increased expression of a set of Th2-specific genes including those encoding Th2 cytokines. IL-4-mediated STAT6 activation induces high levels of transcription of GATA3, a master regulator of Th2 cell differentiation, and enforced expression of GATA3 induces Th2 cytokine expression. However, it remains unclear whether the expression of other Th2-specific genes is induced directly by GATA3. A genome-wide unbiased ChIP-seq analysis revealed that GATA3 bound to 1,279 genes selectively in Th2 cells, and 101 genes in both Th1 and Th2 cells. Simultaneously, we identified 26 highly Th2-specific STAT6-dependent inducible genes by a DNA microarray analysis-based three-step selection processes, and among them 17 genes showed GATA3 binding. We assessed dependency on GATA3 for the transcription of these 26 Th2-specific genes, and 10 genes showed increased transcription in a GATA3-dependent manner while 16 genes showed no significant responses. The transcription of the 16 GATA3-nonresponding genes was clearly increased by the introduction of an active form of STAT6, STAT6VT. Therefore, although GATA3 has been recognized as a master regulator of Th2 cell differentiation, many Th2-specific genes are not regulated by GATA3 itself but in collaboration with STAT6.
Genome-wide analysis reveals unique regulation of transcription of Th2-specific genes by GATA3.
Specimen part
View SamplesAS2 encodes a protein containing AS2 domain and epigenetically regulate transcription. RH10 encodes an ortholog of human DEAD-box RNA helicase DDX47. These genes are involved in the formation of axes of leaves of Arabidopsis thaliana. To know the gene regulation in the leaf development, expression profile among wild-type, as2, rh10 and as2 rh10 double mutant plants were compared.
A genetic link between epigenetic repressor AS1-AS2 and a putative small subunit processome in leaf polarity establishment of Arabidopsis.
Specimen part
View SamplesFunctionally polarized CD4+ T helper (Th) cells such as Th1, Th2 and Th17 cells are central to the regulation of acquired immunity. However, the molecular mechanisms governing the maintenance of the polarized functions of Th cells remain unclear. GATA3, a master regulator of Th2 cell differentiation, initiates the expressions of Th2 cytokine genes and other Th2-specific genes. GATA3 also plays important roles in maintaining Th2 cell function and in continuous chromatin remodeling of Th2 cytokine gene loci. However, it is unclear whether continuous expression of GATA3 is required to maintain the expression of various other Th2-specific genes. In this report, genome-wide DNA gene expression profiling revealed that GATA3 expression is critical for the expression of a certain set of Th2-specific genes. We demonstrated that GATA3 dependency is reduced for some Th2-specific genes in fully developed Th2 cells compared to that observed in effector Th2 cells, whereas it is unchanged for other genes. Moreover, effects of a loss of GATA3 expression in Th2 cells on the expression of cytokine and cytokine receptor genes were examined in detail. A critical role of GATA3 in the regulation of Th2-specific gene expression is confirmed in in vivo generated antigen-specific memory Th2 cells. Therefore, GATA3 is required for the continuous expression of the majority of Th2-specific genes involved in maintaining the Th2 cell identity.
Genome-Wide Gene Expression Profiling Revealed a Critical Role for GATA3 in the Maintenance of the Th2 Cell Identity.
Specimen part, Treatment
View SamplesFollowing 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- and Th2 cytokine-producing populations in non-polarizing cultures, and under these conditions IFN- 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.
The polycomb protein Ezh2 regulates differentiation and plasticity of CD4(+) T helper type 1 and type 2 cells.
Specimen part
View SamplesAS1 and AS2 encode MYB related protein and AS2-domain containing protein, respectively and may regulate transcription. These genes are involved in the determination of axes of leaves of Arabidopsis thaliana. To know the gene regulation in the leaf development, expression profile among wild-type, as1 and as2 mutants and AS2 overexpression plants were compaired.
Meta-analyses of microarrays of Arabidopsis asymmetric leaves1 (as1), as2 and their modifying mutants reveal a critical role for the ETT pathway in stabilization of adaxial-abaxial patterning and cell division during leaf development.
Specimen part
View SamplesMemory helper T (Th) cells are crucial for secondary immune responses against infectious microorganisms but also drive the pathogenesis of chronic inflammatory diseases. Therefore, it is of fundamental importance to understand how memory T cells are generated. However, the molecular mechanisms governing memory Th cell generation remain incompletely understood. Here, we identified CD30 as a molecule heterogeneously expressed on effector Th1 and Th17 cells, and CD30hi effector Th1 and Th17 cells preferentially generated memory Th1 and Th17 cells. We found that CD30 mediated signal induced Transglutaminase-2 (TG2) expression, and that the TG2 expression in effector Th cells is essential for memory Th cell generation. In fact, Cd30-deficiency resulted in the impaired generation of memory Th1 and Th17 cells, which can be rescued by overexpression of TG2. Furthermore, transglutaminase-2 (Tgm2)-deficient CD4 T cells failed to become memory Th cells. As a result, T cells from Tgm2-deficient mice displayed impaired antigen-specific antibody production and attenuated Th17-mediated allergic responses. Our data indicate that CD30-induced TG2 expression in effector Th cells is essential for the generation of memory Th1 and Th17 cells, and that CD30 can be a marker for precursors of memory Th1 and Th17 cells.
Essential Role for CD30-Transglutaminase 2 Axis in Memory Th1 and Th17 Cell Generation.
Specimen part
View SamplesWe used microarray analysis to identify specific molecular mechanisms controlling Th17 cell differentiation in HFD mice
Obesity Drives Th17 Cell Differentiation by Inducing the Lipid Metabolic Kinase, ACC1.
Specimen part
View SamplesTrithorax group (TrxG) and Polycomb group (PcG) proteins are two mutually antagonistic chromatin modifying complexes, however, how they together mediate transcriptional counterregulation remains unknown. Genome-wide analysis revealed that binding of Ezh2 and Menin, central members of the PcG and TrxG complexes, respectively, were reciprocally correlated. Moreover, we identified a developmental change in the positioning of Ezh2 and Menin in differentiated T lymphocytes compared to embryonic stem cells. Ezh2-binding upstream and Menin-binding downstream of the transcription start site (TSS) was frequently found at genes with higher transcriptional levels, and Ezh2-binding downstream and Menin-binding upstream was found at genes with lower expression in T lymphocytes. Interestingly, of the Ezh2 and Menin co-occupied genes, those exhibiting occupancy at the same position displayed greatly enhanced sensitivity to loss of Ezh2. Finally, we also found that different combinations of Ezh2 and Menin occupancy were associated with expression of specific functional gene groups important for T cell development. Therefore, spatial cooperative gene regulation by the PcG and TrxG complexes may represent a novel mechanism regulating the transcriptional identity of differentiated cells.
Spatial Interplay between Polycomb and Trithorax Complexes Controls Transcriptional Activity in T Lymphocytes.
Specimen part
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