A number of autoimmunity-associated MHC class II proteins interact only weakly with the invariant chain-derived class II-associated invariant chain peptide (CLIP). CLIP dissociates rapidly from I-Ag7 even in the absence of DM, and this property is related to the type 1 diabetes-associated b57 polymorphism. We generated knock-in Non-obese Diabetic (NOD) mice with a single amino acid change in the CLIP segment of invariant chain in order to moderately slow CLIP dissociation from I-Ag7. These knock-in mice had a significantly reduced incidence of spontaneous type 1 diabetes and diminished islet infiltration by CD4 T cells, in particular T cells specific for fusion peptides generated by covalent linkage of proteolytic fragments within b cell secretory granules. Rapid CLIP dissociation enhanced presentation of such extracellular peptides, thus bypassing the conventional MHC class II antigen processing pathway. Autoimmunity-associated MHC class II polymorphisms therefore not only modify binding of self-peptides, but also alter the biochemistry of peptide acquisition. Overall design: Mouse pancreatic tissue was digested by collagenase, and islets were isolated and dissociated into single cells. Beta-cell-specific CD4 T cells were single-cell sorted by FACS based on tetramer labeling, and individual cells were profiled with a modified full length SMART-Seq2 protocol.
Rapid CLIP dissociation from MHC II promotes an unusual antigen presentation pathway in autoimmunity.
Specimen part, Subject
View SamplesCutaneous squamous cell carcinoma (cSCC) is the second most common malignancy in humans and approximately 5% metastasize, usually to regional lymph nodes. Epigenetic regulation of gene expression may allow tumoral cells to acquire new functions in order to escape from the primary tumor. The aim of this study was to investigate the expression and function of proteins of the Polycomb family of epigenetic regulators in the metastatic process of cSCC. A higher expression of RING1B and EZH2 was detected by immunohistochemistry in a series of primary cSCC tumors that metastasized (MSCC) when compared to non metastasizing cSCC (non MSCC). Stable downregulation of RING1B and EZH2 in cSCC cells results in enhanced expression of inflammatory cytokines and activation of the NFB signaling pathway. Accordingly, non MSCC display higher levels of membranous pS176 IKK and their stroma is enriched in neutrophils and eosinophils when compared to MSCC. In vitro, hematopoietic cells exhibit a substantial migratory response to supernatants from Polycomb depleted cSCC cells. Altogether these data indicate that RING1B and EZH2 repress the innate inflammatory cSCC function and impair tumor immunosurveillance and suggest that patients with high risk cSCC could benefit from clinical therapies addressed to harness the immune response.
The Polycomb proteins RING1B and EZH2 repress the tumoral pro-inflammatory function in metastasizing primary cutaneous squamous cell carcinoma.
Specimen part, Cell line
View SamplesNon-syndromic cleft lip/palate (NSCL/P) is a complex, frequent congenital malformation, determined by the interplay between genetic and environmental factors during embryonic development. Previous findings have appointed an aetiological overlap between NSCL/P and cancer, and alterations in similar biological pathways may underpin both conditions. Here, using a combination of transcriptomic profiling and functional approaches, we report that NSCL/P dental pulp stem cells exhibit dysregulation of a co-expressed gene network mainly associated with DNA double-strand break repair and cell cycle control (p = 2.88x10-2 5.02x10-9). This network included important genes for these cellular processes, such as BRCA1, RAD51, and MSH2, which are predicted to be regulated by transcription factor E2F1. Functional assays support these findings, revealing that NSCL/P cells accumulate DNA double-strand breaks upon exposure to H2O2. Furthermore, we show that E2f1, Brca1 and Rad51 involved in DNA repair are co-expressed in the developing embryonic orofacial primordia, and may act as a molecular hub playing a role in lip and palate morphogenesis. In conclusion, we show that cellular defences against DNA damage may take part in the pathogenesis of NSCL/P, in accordance with the hypothesis of aetiological overlap between this malformation and cancer. These results provide more information regarding the aetiology of NSCL/P and have the potential tocan potentially assist incontribute to the development of future preventive strategies.
Susceptibility to DNA damage as a molecular mechanism for non-syndromic cleft lip and palate.
Sex, Specimen part
View SamplesOne clear hallmark of mammalian promoters is the presence of CpG islands (CGIs) at more than two thirds of genes whereas TATA boxes are only present at a minority of promoters. Using genome-wide approaches, we show that GC content and CGIs are major promoter elements in mammalian cells, able to govern open chromatin conformation and support paused transcription. First, we define three classes of promoters with distinct transcriptional directionality and pausing properties which correlate with their GC content. We further analyze the direct influence of GC content on nucleosome positioning and depletion, and show that CGIs correlate with nucleosome depletion both in vivo and in vitro. We also show that transcription is not essential for nucleosome exclusion but influences both a weak +1 and a well-positioned nucleosome at CGI borders. Altogether our data support the idea that CGIs have become an essential feature of promoter structure defining novel regulatory properties in mammals. Overall design: Nucleosome density and positioning were studied by high-throughput sequencing of DNA previously treated with Mnase. In parallel, chIPseq for PolII and H3K27ac were performed in mouse and human with different conditions to assess a potential effect of transcription on nucleosomes properties. To investigate transcription at promoters, we analyzed together with genome-wide Pol II accumulation by ChIP-Seq, paused bidirectional transcripts associated with transcription start sites (TSS RNAs).
CpG islands and GC content dictate nucleosome depletion in a transcription-independent manner at mammalian promoters.
Specimen part, Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcription-dependent generation of a specialized chromatin structure at the TCRβ locus.
Specimen part
View SamplesWe performed ChIP-Seq for hallmark TFs (Ets1, Runx1), histone modification marks (H3K4me1, H3K4me2, H3K4me3, H3K27me3, H3K36me3), total RNA Pol II, short RNA-Seq as well as nucleosome mapping mainly in murine Rag2 -/- thymocytes. We also performed ChIP-Seq for E47 as well as nucleosome mapping, gene expression microarray analysis in CD4+ CD8+ DP thymocytes. Overall, we find a key role for the transcription factor Ets1, contributing towards alpha beta T cell lineage commitment via differential transactivation of stage-specific genes orchestrated by dynamic, co-association -mediated chromatin remodeling, as well as transcription dependent generation of a specialized chromatin structure at the TCR beta locus. Overall design: Genome-wide analysis via ChIP-Seq for Ets1, Runx1, total RNA Pol II binding, H3K4me1, H3K4me2, H3K4me3, H3K27me3, H3K36me3, short RNA-Seq, Mnase-Seq in murine Rag2 -/- thymocytes, ChIP-Seq for E47, Mnase-Seq and gene expression microarray analysis in DP thymocytes This Series represents ShortRNA-Seq data.
Dynamic recruitment of Ets1 to both nucleosome-occupied and -depleted enhancer regions mediates a transcriptional program switch during early T-cell differentiation.
No sample metadata fields
View SamplesWe performed microarray analysis of gene expression in WT and Ets1-/- CD4+ CD8+ DP thymocytes. Overall, we find that Ets1-/- thymocytes display gene expression signatures closer to previous stages of thymocyte development (e.g. DN3-4) than WT DP cells, suggesting that while these cells do become DP thymocytes in the absence of Ets1, that the latter is required for the upregulation of later T-cell genes and that its presence is required for the downregulation of genes corresponding to earlier and alternative stages of development.
Dynamic recruitment of Ets1 to both nucleosome-occupied and -depleted enhancer regions mediates a transcriptional program switch during early T-cell differentiation.
Specimen part
View SamplesWe performed ChIP-Seq for hallmark TFs (Ets1, Runx1), histone modification marks (H3K4me1, H3K4me2, H3K4me3, H3K27me3, H3K36me3), total RNA Pol II, short RNA-Seq as well as nucleosome mapping mainly in murine Rag2 -/- thymocytes. We also performed ChIP-Seq for E47 as well as nucleosome mapping, gene expression microarray analysis in CD4+ CD8+ DP thymocytes. Overall, we find a key role for the transcription factor Ets1, contributing towards alpha beta T cell lineage commitment via differential transactivation of stage-specific genes orchestrated by dynamic, co-association -mediated chromatin remodeling, as well as transcription dependent generation of a specialized chromatin structure at the TCR beta locus.
Dynamic recruitment of Ets1 to both nucleosome-occupied and -depleted enhancer regions mediates a transcriptional program switch during early T-cell differentiation.
Specimen part
View SamplesB-cell chronic lymphocytic leukemia (B-CLL) is characterized by a highly variable clinical course that reflects its heterogeneous genomic pattern. To better define molecular subtypes of the disease, we performed SNP and gene expression profiling microarray analyses in a panel of early stage (Binet A) patients. A clustering analysis of genomic profiles identified four significant groups mainly driven by del(13)(q14) and trisomy 12. Notably, patients with del(13)(q14) were grouped in two separate clusters based on the presence of a biallelic loss and the extension of the deletion. The shorter monoallelic deleted 13q14 region was found to be 635 kb in length, not encompassing the mir-15a/16-1 locus. Interestingly, the mir-15a and mir-16 expression was found to be significantly down-regulated only in patients with biallelic loss. Furthermore, a multiclass supervised analysis identified a different transcriptional signatures in the two genomic subgroups with del(13)(q14). Finally, an integrative approach identified 93 transcripts, mainly mapped to chromosome 12 and 13q12-q14.3, whose expression was significantly correlated with the DNA copy number. Overall, our data further support the notion that transcription deregulation in B-CLL could be mostly due to a gene dosage effect and underscore the presence of two distinct molecular types of 13q14 deleted patients with potential clinical relevance.
Integrative genomics analyses reveal molecularly distinct subgroups of B-cell chronic lymphocytic leukemia patients with 13q14 deletion.
Sex, Specimen part, Disease
View SamplesAlthough the role of macrophage colony stimulating factor (M-CSF/CSF-1) in homeostasis and disease processes has been studied extensively in mice, little is known of the impact of this cytokine on differentiated human macrophages. Here we show that, in contrast to its effects on mouse bone marrow-derived macrophages (BMM), CSF-1 did not induce expression of urokinase plasminogen activator mRNA, repress expression of apolipoprotein E mRNA, or prime LPS-induced TNF secretion in human monocyte-derived macrophages (HMDM) from several independent donors. Using expression profiling, we show that CSF-1 dynamically regulated the expression of several genes that encode chemokines and chemokine receptors (e.g. CXCL10/IP-10, CXCL2, CCL7, SDF2L1, CXCR4) in HMDM. CSF-1 also upregulated the expression of several genes encoding enzymes of the cholesterol biosynthetic pathway (HMGCR, MVD, IDI1, FDPS, SQLE, CYP51A1, EBP, NSDHL, DHCR7 and DHCR24), while expression of ABCG1, encoding a cholesterol efflux transporter, was repressed. Although the CSF-1/CSF-1R system has been proposed as a target for the treatment of inflammatory and metastatic disease based on studies in rodents, this is the first systematic analysis of the effects of CSF-1 on mature human macrophages. Our data demonstrates that CSF-1 represents a further link between inflammation and cardiovascular disease, inflammtion and immunity.
Colony-stimulating factor-1 (CSF-1) delivers a proatherogenic signal to human macrophages.
No sample metadata fields
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