Project description:T-cell activation induces context-specific gene expression programs that promote energy generation and biosynthesis, progression through the cell cycle and ultimately cell differentiation. The aim of this study was to apply the omni ATAC-seq method to characterize the landscape of chromatin changes induced by T-cell activation in mature naïve CD4+ T-cells. Using a well-established ex vivo protocol of canonical T-cell receptor signaling, we generated genome-wide chromatin maps of naïve T-cells from pediatric donors in quiescent or recently activated states. We identified thousands of individual chromatin accessibility peaks that are associated with T-cell activation. The majority of these were localized to intronic and intergenic enhancer regions, marked by active histone modifications whilst quiescence was maintained by repressive histone marks. Regions of activation-associated gains in chromatin accessibility were enriched for well-known pioneer transcription factor motifs, and super-enhancer regions associated with distinct gene regulatory networks. These cis-regulatory elements together brought about distinct transcriptional signatures in activated cells including TNFa-NFkB signaling, hormone-responsive genes, inflammatory response genes and IL2-STAT5 signaling. Our data provides novel insights into the chromatin dynamics and motif usage of T-cell receptor signaling events in early life. The characterized pathways demonstrate the utility of chromatin profiling techniques applied to bio-banked samples for characterizing gene regulatory elements.
Project description:We compared differences in fetal and adult T cells by performing whole genome profiling on sort-purified T cells (naïve CD4+ and Treg cells) from human fetal specimens (18-22 gestational weeks) and adult specimens (age 25-40 years old). Fetal and Adult Naïve CD4+ T cells phenotype: CD3+CD4+CD45RA+CCR7+CD27+, Fetal and Adult CD4+CD25+ Treg phenotype: CD3+CD4+CD25bright Four different groups were analyzed: Fetal Naïve CD4+ T cells, Adult Naïve CD4+ T cells, Fetal Treg cells, Adult Treg cells. For each group three independent donors were analyzed.
Project description:Systemic lupus erythematosus is a relapsing autoimmune disease that affects multiple organ systems. T cells play an important role in the pathogenesis of lupus, however, early T cell events triggering disease flares are incompletely understood. We studied DNA methylation in naïve CD4+ T cells from lupus patients to determine if epigenetic landscape change in CD4+ T cells is an early event in lupus flares.
Project description:The epigenetic determinants driving the rapid responses of memory CD4 T cells to antigen are currently an area of active research. While much has been done to characterize various Th subsets and their associated genome-wide epigenetic patterns, the dynamics of histone modifications during CD4 T cell activation and the differential kinetics of these epigenetic marks between naïve and memory T cells have not been evaluated. In this study we have detailed the dynamics of genome-wide promoter H3K4me2 and H3K4me3 over a time course during activation of human naïve and memory CD4 T cells. Our results demonstrate that changes to H3K4 methylation predominantly occur relatively late after activation (120 hours) and reinforce activation-induced upregulation of gene expression affecting multiple pathways important to T cell activation, differentiation, and function. The dynamics and mapped pathways of H3K4 methylation are distinctly different in memory cells. Memory CD4 have substantially more promoters marked by H3K4me3 alone, and that is influenced by promoter CpG content, reinforcing their more differentiated state. Our study provides the first data examining genome-wide histone modification dynamics during T cell activation, providing insight into the cross-talk between H3K4 methylation and gene expression, and underscoring the impact of these marks upon key pathways integral to CD4 T cell activation and function.
Project description:Histone modifications have been shown critically involved in transcriptional regulation, but the functions of histone modifiers and the impact of histone modifications in early transcription induction post CD4 T cell activation are unclear. We show here that JMJD3 binds to chromatin rapidly after naïve CD4 T cell activation, which is correlated with removal of H3K27me3 at promoter, enhancer and intronic regions.
Project description:Gene expression data from wild-type and Bcl6-/- naive CD4 T cells In order to find genes regulated by Bcl6 in follicular helper T cells Naïve CD4 T cells were sorted from wild-type (WT) and T cell-specific conditional Bcl6-/- (KO) mice-- 8 samples, 4 WT and 4 KO
Project description:Gene expression data from wild-type and Bcl6-/- naive CD4 T cells In order to find genes regulated by Bcl6 in follicular helper T cells Naïve CD4 T cells were sorted from wild-type (WT) and T cell-specific conditional Bcl6-/- (KO) mice-- 8 samples, 4 WT and 4 KO