The immune system relies on the plasticity of its components to produce appropriate responses to frequent environmental challenges. Dendritic cells (DCs) are critical initiators of innate immunity and orchestrate the later and more specific adaptive immunity. The generation of diversity in transcriptional programs is central for effective immune responses. Alternative splicing is widely considered a key generator of transcriptional and proteomic complexity, but its role has been rarely addressed systematically in immune cells. Here we used splicing-sensitive arrays to assess genome-wide gene- and exon-level expression profiles in human DCs in response to a bacterial challenge. We find widespread alternative splicing events and splicing factor transcriptional signatures induced by an E. coli challenge to human DCs. Alternative splicing acts in concert with transcriptional modulation, but these two mechanisms of gene regulation affect primarily distinct functional gene groups. Alternative splicing is likely to have an important role in DC immunobiology because it affects genes known to be involved in DC development, endocytosis, antigen presentation and cell cycle arrest
Genome-wide analysis of alternative splicing during dendritic cell response to a bacterial challenge.
Specimen part, Treatment
View SamplesHnRNPLL was identified as a critical regulator of CD45 alternative splicing in a lentiviral shRNA screen. RNAi-mediated depletion of hnRNPLL eliminated the activation-induced induced transition from the CD45RA to the CD45RO isoform. HnRNPLL is induced during the process of T cell activation, raising the possibility that it regulates a broad program of alternative splicing in activated T cells. To test this possibility and to identify additional potential targets of hnRNPLL, we performed exon array analysis on RNA isolated from five cellular conditions: 1) activated peripheral CD4+ T cells, 2) peripheral CD4+ T cells infected with a control shRNA directed against GFP, 3) peripheral CD4+ T infected with an shRNA directed against hnRNPLL, 4) nave cord blood CD4+ T cells, and 5) cord blood CD4+ T cells that had been activated with anti-CD3 and anti-CD28 for 24 hours. The RNA was hybridized to Affymetrix human exon arrays and the hybridization signals were analyzed with XRAYTM software (Biotique). Using stringent filters for non-expressed probesets, we identified 132 genes that showed significant alternative exon usage (p<0.01) in response to hnRNPLL knockdown, but not in response to shGFP infection. Of these 132 genes, 36 also showed significant alternative exon usage in response to activation of cord blood cells, which results in an approximate 5-fold increase in hnRNPLL expression. We thus conclude that induction of hnRNPLL represents a mechanism by which cells can rapidly shift their transcriptomes during the process of T cell activation.
Regulation of CD45 alternative splicing by heterogeneous ribonucleoprotein, hnRNPLL.
No sample metadata fields
View SamplesIn order to identify genes with differential gene expression or alternative splicing between the groups LL-sh4, uninfected, and shGFP we study 6 hybridizations on the Human Exon 1.0 ST array using mixed model analysis of variance. 842 genes with significant gene expression differences between the groups and 1118 genes with significant exon-group interaction (a symptom of alternative splicing) were found, including 192 genes with both gene and possible splicing differences (p<0.01). Contingency table analysis of the set of studied genes and a dataset of known pathways and gene classifications revealed that the set of alternatively spliced and expressed genes were found to be significantly over-represented in groups of the GOMolFn, GOProcess, GOCellLoc, and Pathway classes (p<0.01).
Regulation of CD45 alternative splicing by heterogeneous ribonucleoprotein, hnRNPLL.
No sample metadata fields
View SamplesIn order to identify genes with differential gene expression or alternative splicing between the groups naive and activated we study 4 hybridizations on the Human Exon 1.0 ST array using mixed model analysis of variance. 1904 genes with significant gene expression differences between the groups and 1603 genes with significant exon-group interaction (a symptom of alternative splicing) were found, including 427 genes with both gene and possible splicing differences (p<0.01). Contingency table analysis of the set of studied genes and a dataset of known pathways and gene classifications revealed that the set of alternatively spliced and expressed genes were found to be significantly over-represented in groups of the GOMolFn, GOProcess, GOCellLoc, and Pathway classes (p<0.01).
Regulation of CD45 alternative splicing by heterogeneous ribonucleoprotein, hnRNPLL.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Genome-wide screen reveals APC-associated RNAs enriched in cell protrusions.
No sample metadata fields
View SamplesThe goal of the study was to identify on a genome-wide scale RNAs that are enriched at the leading edge of migrating cells. For this, we employed a fractionation method in which cells are plated on a microporous filter whose bottom side only is coated with fibronectin. The cells thus polarize and extend pseudopodial protrusions towards the bottom surface. These protruding pseudopodia can then be physically isolated from the bottom surface of the filter and their contents compared with the remaining cell bodies, which are isolated from the upper surface of the filter.
Genome-wide screen reveals APC-associated RNAs enriched in cell protrusions.
No sample metadata fields
View SamplesThe goal of the study was to identify on a genome-wide scale RNAs that are enriched at the leading edge of migrating cells. For this, we employed a fractionation method in which serum-starved cells are first plated and allowed to spread on a microporous filter. Addition of LPA at the bottom side of the filter induces the cells to polarize and extend pseudopodial protrusions. These protruding pseudopodia can then be physically isolated from the bottom surface of the filter and their contents compared with the remaining cell bodies, which are isolated from the upper surface of the filter.
Genome-wide screen reveals APC-associated RNAs enriched in cell protrusions.
No sample metadata fields
View SamplesPURPOSE To identify retinal pigment epithelial (RPE)/choroid genes and their relevant expression pathways affected by intravitreal injections of dexamethasone and triamcinolone acetonide in mice at clinically relevant time points for patient care. METHODS Differential gene expression of over 34,000 well-characterized mouse genes, in the RPE/choroid of 6 week old C57BL/6J mice were analyzed after intravitreal steroid injections at 1 week and 1 month post injection, using Affymetrix Mouse Genome 430 2.0 microarrays. The data were analyzed using GeneSpringGX12.5 and Ingenuity Pathway Analysis (IPA) microarray analysis software for biologically relevant changes. RESULTS Both triamcinolone and dexamethasone caused differential activation of genes involved in Circadian Rhythm Signaling pathway at both time points tested. Triamcinolone (TAA) uniquely induced significant changes in gene expression in Calcium Signaling (1 week) and Glutamate Signaling pathways (1month). In contrast, Dexamethasone (Dex) affected the GABA Receptor Signaling (1 week) and Serotonin Receptor Signaling (1month) pathways. CONCLUSIONS Understanding how intraocular steroids affect the gene expression of RPE/choroid is clinically relevant. This in vivo study has elucidated several genes and pathways that are potentially altering the circadian rhythms and several other neurotransmitter pathways in RPE/choroid cells during intravitreal steroid injections, which likely has consequences in the dysregulation of RPE function and neurodegeneration of the retina.
Comparison of In Vivo Gene Expression Profiling of RPE/Choroid following Intravitreal Injection of Dexamethasone and Triamcinolone Acetonide.
Sex, Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Global gene expression analysis of amniotic fluid cell-free RNA from recipient twins with twin-twin transfusion syndrome.
Sex
View SamplesTo understand the biological pathways involved in twin-twin transfusion syndrome (TTTS) by performing global gene expression analysis of amniotic fluid (AF) cell-free RNA
Global gene expression analysis of amniotic fluid cell-free RNA from recipient twins with twin-twin transfusion syndrome.
Sex
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