CTLA-4 is thought to inhibit effector T cells both intrinsically, by competing with CD28 for B7 ligands, and extrinsically, through the action of regulatory T cells. We studied in vivo responses of normal and CTLA-4-deficient antigen-specific murine effector CD4+ T cells. In order to do these studies in a physiological model of immunity to foreign antigen, we transferred small numbers of congenically marked RAG2-deficient 5C.C7 T cells with either a normal or knockout allele of CTLA-4 into normal syngeneic B10.A recipient mice. The T cells were then activated by immunization with MCC peptide and LPS. To look for transcriptional signatures of negative regulation of T cell responses by CTLA-4, we used microarray analysis to compare transcripts in wild type and CTLA-4 KO 5C.C7 T cells four days after immunization. This is the first instance in which differences are observed in extent of accumulation of wild type and CTLA-4 KO 5C.C7 T cells.
Cutting edge: CTLA-4 on effector T cells inhibits in trans.
Specimen part
View SamplesA LHX4 transgenic reporter line with high specificity for developing mouse cone photoreceptors was identified and used to purify early stage cone photoreceptors for profiling by single cell RNA sequencing. Overall design: Collection of FACS-sorted LHX4::GFP+ E14.5 early cones and LHX4::GFP- retinal cells for further analysis.
Identification of Genes With Enriched Expression in Early Developing Mouse Cone Photoreceptors.
Specimen part, Cell line, Subject
View SamplesAnalysis of knockdown of SDHD with or without knockdown of CDKN1C or SLC22A18 at gene expression level.
Parent-of-origin tumourigenesis is mediated by an essential imprinted modifier in SDHD-linked paragangliomas: SLC22A18 and CDKN1C are candidate tumour modifiers.
Specimen part, Cell line
View SamplesCure rates for patients with acute myeloid leukemia (AML) remain low despite ever-increasing dose intensity of cytotoxic therapy. In an effort to identify novel approaches to AML therapy, we recently reported a new method of chemical screening based on the modulation of a gene expression signature of interest. We applied this approach to the discovery of AML-differentiation-promoting compounds. Among the compounds inducing neutrophilic differentiation was DAPH1 (4,5-dianilinophthalimide), previously reported to inhibit epidermal growth factor receptor (EGFR) kinase activity. Here we report that the Food and Drug Administration (FDA)-approved EGFR inhibitor gefitinib similarly promotes the differentiation of AML cell lines and primary patient-derived AML blasts in vitro. Gefitinib induced differentiation based on morphologic assessment, nitro-blue tetrazolium reduction, cell-surface markers, genome-wide patterns of gene expression, and inhibition of proliferation at clinically achievable doses. Importantly, EGFR expression was not detected in AML cells, indicating that gefitinib functions through a previously unrecognized EGFR-independent mechanism. These studies indicate that clinical trials testing the efficacy of gefitinib in patients with AML are warranted.
Gefitinib induces myeloid differentiation of acute myeloid leukemia.
Disease, Disease stage, Cell line
View SamplesInfluenza virus infection-induced gene expression changes of regional B cells are mediated at least in part through type I Interferon:
Influenza virus infection causes global respiratory tract B cell response modulation via innate immune signals.
Sex, Specimen part
View SamplesRett syndrome is caused by mutations in the gene encoding methyl-CpG binding protein 2 (MECP2), an epigenetic regulator of mRNA transcription. Here we report a test of the hypothesis of shared pathophysiology of Rett syndrome and fragile X, another monogenic cause of autism and intellectual disability. In fragile X, the loss of the mRNA translational repressor FMRP leads to exaggerated protein synthesis downstream of metabotropic glutamate receptor 5 (mGluR5). We found that mGluR5- and protein synthesis-dependent synaptic plasticity is similarly altered in area CA1 of Mecp2 KO mice. CA1 pyramidal cell-type-specific, genome-wide profiling of ribosome-bound mRNAs was performed in wild-type and Mecp2 KO hippocampal CA1 neurons to reveal the MeCP2-regulated 'translatome'. We found significant overlap between ribosome-bound transcripts overexpressed in the Mecp2 KO and FMRP mRNA targets. These tended to encode long genes that are functionally related to either cytoskeleton organization or the development of neuronal connectivity. In the Fmr1 KO mouse, chronic treatment with mGluR5 negative allosteric modulators (NAMs) has been shown to ameliorate many mutant phenotypes by correcting excessive protein synthesis. In the Mecp2 KO mice we found that mGluR5 NAM treatment significantly reduces the level of overexpressed ribosome-associated transcripts, particularly those that are also FMRP targets. Some Rett phenotypes were also ameliorated by treatment, most notably hippocampal cell size and life span. Together, these results suggest a potential mechanistic link between MeCP2-mediated transcription regulation and mGluR5/FMRP-mediated protein translation regulation through co-regulation of a subset of genes relevant to synaptic functions. Overall design: TRAP-seq analysis of the effect of negative modulator of mGluR5 on the CA1 neurons (marked by Cck-EGFP-L10a) of a mouse model of Rett syndrome
Negative Allosteric Modulation of mGluR5 Partially Corrects Pathophysiology in a Mouse Model of Rett Syndrome.
Specimen part, Cell line, Treatment, Subject
View SamplesThe ability to regenerate or recover from injuries varies greatly not only between species but also between tissues and organs or developmental stages of the same species. The mechanisms behind these different regenerative capabilities are ultimately dependent on the control of genome activity, determined by a complex interplay of regulatory elements functioning at the level of chromatin. Resetting of gene expression patterns during injury responses is, thus, shaped by the coordinated action of genomic regions (enhancers, silencers) that integrate the activity of multiple sequence-specific DNA binding proteins (transcription factors and cofactors). Using genome- wide approaches to interrogate chromatin function here we identify the regulatory elements governing tissue recovery in Drosophila wing imaginal discs, which show a high regenerative capacity after genetically induced cell death. Our findings point to a global co-regulation of gene expression and provide evidence for Damage Responding Regulatory Elements (DRRE), some of which are novel whereas others are also used in other tissues or developmental stages. Overall design: We collected data at different time points (0, 15 and 25h) after apoptosis induction. These time periods were selected because they included the most important transcriptional responses to apoptosis, ranging from the earliest gene expression up to complete re-patterning. Discs kept at the same conditions without inducing cell death were used as controls.
Damage-responsive elements in <i>Drosophila</i> regeneration.
Specimen part, Subject
View SamplesVarious mesenchymal cell types have been identified as critical components of the hematopoietic stem/progenitor cell (HSPC) niche. Although several groups have described the generation of mesenchyme from human pluripotent stem cells (hPSC), the capacity of such cells to support hematopoiesis has not been reported. Here we have demonstrated that distinct mesenchymal subpopulations co-emerge from mesoderm during hPSC differentiation. Despite co-expression of common mesenchymal markers (CD73, CD105, CD90, PDGFRß), a subset of cells defined as CD146++CD140alow supported functional HSPC ex vivo while CD146-CD140a+ cells drove differentiation. The CD146++ subset expressed genes associated with the HSPC niche and high levels of the Wnt inhibitors. HSPC support was contact-dependent and was mediated in part through JAG1 expression. Molecular profiling revealed remarkable transcriptional similarity between hPSC-derived CD146++ and primary human CD146++ perivascular cells. The derivation of diverse pools of mesenchymal populations from hPSC opens potential avenues to model their developmental and functional differences and to improve cell-based therapeutics from hPSC. Overall design: Our goal was to analyze and compare transcriptome of human pluripoten stem cell-derived mesenchyme (CD146++ and CD146-) with primary human lipoaspirate tissue-derived pericyte (CD146+) and CD146- mesenchymal populations.
Transcriptionally and Functionally Distinct Mesenchymal Subpopulations Are Generated from Human Pluripotent Stem Cells.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Esrrb extinction triggers dismantling of naïve pluripotency and marks commitment to differentiation.
Specimen part, Cell line
View SamplesA key event in the pathogenic process of prion diseases is the conversion of the cellular prion protein (PrPC) to an abnormal and protease-resistant isoform (PrPSc). Mice lacking PrP are resistant to prion infection, and down-regulation of PrPC during prion infection prevents neuronal loss and the progression to clinical disease. These results are suggestive of the potential beneficial effect of silencing PrPC during prion diseases. However, the silencing of a protein that is widely expressed throughout the CNS could be detrimental to brain homeostasis. The physiological role of PrPC remains still unclear, but several putative functions have been proposed. Among these, several lines of evidence support PrPC function in neuronal development and maintenance.
Developmental influence of the cellular prion protein on the gene expression profile in mouse hippocampus.
Specimen part
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