Similar Datasets
Project description:Exhausted CD8 T cells result from chronic antigen stimulation and have reduced ability to clear disease. The epigenetic regulation of the dysfunctional phenotype of exhausted CD8 T cells is a promising avenue for therapies aimed at reversing or preventing CD8 T cell exhaustion. Here, utilizing an in vitro model, we show global increase of the repressive histone modification H3K27me3 in CD8 T cell exhaustion as well as increased gene expression of the subunits of PRC2, the complex responsible for H3K27me3 deposition. H3K27me3 correlated with decreased gene expression and localized to naïve/memory T cell genes in CD8 T cell exhaustion. PRC2 inhibition increased expression of many of these naïve/memory genes while reducing expression of key exhaustion genes. Further, we identified potential enhancers and transcription factors predicted to promote expression of the PRC2 subunits. Our study highlights the importance of the repressive epigenetic landscape of exhausted CD8 T cells as well as a novel role for PRC2 in T cell biology.
2024-10-31 | GSE263937 | GEO
Project description:Exhausted CD8 T cells result from chronic antigen stimulation and have reduced ability to clear disease. The epigenetic regulation of the dysfunctional phenotype of exhausted CD8 T cells is a promising avenue for therapies aimed at reversing or preventing CD8 T cell exhaustion. Here, utilizing an in vitro model, we show global increase of the repressive histone modification H3K27me3 in CD8 T cell exhaustion as well as increased gene expression of the subunits of PRC2, the complex responsible for H3K27me3 deposition. H3K27me3 correlated with decreased gene expression and localized to naïve/memory T cell genes in CD8 T cell exhaustion. PRC2 inhibition increased expression of many of these naïve/memory genes while reducing expression of key exhaustion genes. Further, we identified potential enhancers and transcription factors predicted to promote expression of the PRC2 subunits. Our study highlights the importance of the repressive epigenetic landscape of exhausted CD8 T cells as well as a novel role for PRC2 in T cell biology.
2024-10-31 | GSE263885 | GEO
Project description:Chromatin repression by PRC2 results in reduced gene expression driving key features of CD8 T cell exhaustion
| PRJNA1100417 | ENA
Project description:Chromatin repression by PRC2 results in reduced gene expression driving key features of CD8 T cell exhaustion [Cut & Run]
| PRJNA1100421 | ENA
Project description:Chromatin repression by PRC2 results in reduced gene expression driving key features of CD8 T cell exhaustion [RNA-seq]
| PRJNA1099680 | ENA
Project description:Polycomb Group (PcG) proteins are part of an epigenetic cell memory system that plays essential roles in multicellular development, stem cell biology, X chromosome inactivation, and cancer. In animals, plants, and many fungi, Polycomb Repressive Complex 2 (PRC2) catalyzes trimethylation of histone H3 lysine 27 (H3K27me3) to assemble transcriptionally repressed facultative heterochromatin. PRC2 is structurally and functionally conserved in the model fungus Neurospora crassa, and recent work in this organism has generated insights into PRC2 control and function. To identify components of the facultative heterochromatin pathway, we performed a targeted screen of Neurospora deletion strains lacking individual ATP-dependent chromatin remodeling enzymes. We found the Neurospora homolog of IMITATION SWITCH (ISW) is critical for normal transcriptional repression, nucleosome organization, and establishment of typical histone methylation patterns in facultative heterochromatin domains. We also found that stable interaction between PRC2 and chromatin depends on ISW. A functional ISW ATPase domain is required for gene repression and normal H3K27 methylation. ISW homologs interact with accessory proteins to form multiple complexes with distinct functions. Using proteomics and molecular approaches, we identified three distinct Neurospora ISW-containing complexes. A triple mutant lacking three ISW accessory factors and disrupting multiple ISW complexes led to widespread up-regulation of PRC2 target genes and altered H3K27 methylation patterns, similar to an ISW-deficient strain. Taken together, our data show that ISW is a key component of the facultative heterochromatin pathway in Neurospora, and that distinct ISW complexes perform an apparently overlapping role to regulate chromatin structure and gene repression at PRC2 target domains.
| S-EPMC7848606 | biostudies-literature
Project description:BackgroundMechanisms underlying genome 3D organization and domain formation in the mammalian nucleus are not completely understood. Multiple processes such as transcriptional compartmentalization, DNA loop extrusion and interactions with the nuclear lamina dynamically act on chromatin at multiple levels. Here, we explore long-range interaction patterns between topologically associated domains (TADs) in several cell types.ResultsWe find that TAD long-range interactions are connected to many key features of chromatin organization, including open and closed compartments, compaction and loop extrusion processes. Domains that form large TAD cliques tend to be repressive across cell types, when comparing gene expression, LINE/SINE repeat content and chromatin subcompartments. Further, TADs in large cliques are larger in genomic size, less dense and depleted of convergent CTCF motifs, in contrast to smaller and denser TADs formed by a loop extrusion process.ConclusionsOur results shed light on the organizational principles that govern repressive and active domains in the human genome.
| S-EPMC8254932 | biostudies-literature
Project description:It is largely unclear whether genes that are naturally embedded in lamina-associated domains (LADs) are inactive due to their chromatin environment or whether LADs are merely secondary to the lack of transcription. We show that hundreds of human promoters become active when moved from their native LAD position to a neutral context in the same cells, indicating that LADs form a repressive environment. Another set of promoters inside LADs is able to "escape" repression, although their transcription elongation is attenuated. By inserting reporters into thousands of genomic locations, we demonstrate that escaper promoters are intrinsically less sensitive to LAD repression. This is not simply explained by promoter strength but by the interplay between promoter sequence and local chromatin features that vary strongly across LADs. Enhancers also differ in their sensitivity to LAD chromatin. This work provides a general framework for the systematic understanding of gene regulation by repressive chromatin.
| S-EPMC6506275 | biostudies-literature
Project description:Polycomb repressive complex 2 (PRC2) is a key epigenetic multiprotein complex involved in the regulation of gene expression in metazoans. PRC2 is formed by a tetrameric core that endows the complex with histone methyltransferase activity, allowing it to mono-, di- and tri-methylate histone H3 on lysine 27 (H3K27me1/2/3); H3K27me3 is a hallmark of facultative heterochromatin. The core complex of PRC2 is bound by several associated factors that are responsible for modulating its targeting specificity and enzymatic activity. Depletion and/or mutation of the subunits of this complex can result in severe developmental defects, or even lethality. Furthermore, mutations of these proteins in somatic cells can be drivers of tumorigenesis, by altering the transcriptional regulation of key tumour suppressors or oncogenes. In this review, we present the latest results from structural studies that have characterised PRC2 composition and function. We compare this information with data and literature for both gain-of function and loss-of-function missense mutations in cancers to provide an overview of the impact of these mutations on PRC2 activity.
| S-EPMC7000746 | biostudies-literature
Project description:Small cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis. Expression array analysis of 23 SCLC cases and 42 normal tissues revealed that EZH2 and other PRC2 members were highly expressed in SCLC. ChIP-seq for H3K27me3 suggested that genes with H3K27me3(+) in SCLC were extended not only to PRC2-target genes in ES cells but also to other target genes such as cellular adhesion-related genes. These H3K27me3(+) genes in SCLC were repressed significantly, and introduction of the most repressed gene JUB into SCLC cell line lead to growth inhibition. Shorter overall survival of clinical SCLC cases correlated to repression of JUB alone, or a set of four genes including H3K27me3(+) genes. Treatment with EZH2 inhibitors, DZNep and GSK126, resulted in growth repression of SCLC cell lines. High PRC2 expression was suggested to contribute to gene repression in SCLC, and may play a role in genesis of SCLC.
| S-EPMC3665955 | biostudies-literature