Dam identification (DamID) is a powerful technique to generate genome-wide maps of chromatin protein binding. Due to its high sensitivity it is particularly suited to study the genome interactions of chromatin proteins in small tissue samples in model organisms such as Drosophila. Here we report an intein-based approach to tune the expression level of Dam and Dam-fusion proteins in Drosophila by addition of a ligand to fly food. This helps to suppress toxic effects of Dam. In addition we describe a strategy for genetically controlled expression of Dam in a specific cell type in complex tissues. We demonstrate the utility of the latter by generating a glia-specific map of Polycomb in small samples of brain tissue. Overall design: RNA sequencing of 3 samples, each using 2 biological replicates.
Inducible DamID systems for genomic mapping of chromatin proteins in Drosophila.
Sex, Specimen part, Subject
View SamplesT follicular helper (TFH) cells promote affinity maturation of B cells in germinal centers (GCs), whereas T follicular regulatory (TFR) cells limit GC reaction. Store-operated Ca2+ entry (SOCE) through Ca2+ release-activated Ca2+ (CRAC) channels mediated by STIM and ORAI proteins is a fundamental signaling pathway in T lymphocytes. Here we show that SOCE is required for the differentiation and function of both TFH and TFR cells. Conditional deletion of Stim1 and Stim2 genes in T cells or Treg cells results in spontaneous autoantibody production and humoral autoimmunity. Conversely, antibody-mediated immune responses following viral infection critically depend on SOCE in TFH cells. Mechanistically, STIM1 and STIM2 control early TFR and TFH cell differentiation through NFAT-mediated IRF4, BATF and Bcl-6 expression. SOCE plays a dual role in GC response by controlling TFH and TFR cell function, thus enabling protective B cell responses and preventing humoral autoimmunity. Overall design: RNAseq analyses of WT and Stim1Stim2 DKO follicular T cells and non-follicular T cells; 4-6 mice per cohort in duplicates. Mice were infected for 10 days with LCMV.
Store-Operated Ca(2+) Entry in Follicular T Cells Controls Humoral Immune Responses and Autoimmunity.
Specimen part, Subject
View SamplesThe aim of this study was to identify differentially-expressed genes in CCR4hi/CXCR3- and CCR4lo CXCR3+ CCR6+ human Th17 cell subsets
Pro-inflammatory human Th17 cells selectively express P-glycoprotein and are refractory to glucocorticoids.
No sample metadata fields
View SamplesThe aim of this study was to characterize the transcriptional signature of MDR1+ human memory T cells isolated from clinically inflamed gut tissue, and compare it to local MDR1- memory T cells
Pro-inflammatory human Th17 cells selectively express P-glycoprotein and are refractory to glucocorticoids.
Specimen part
View SamplesInfluence of STIM1 on the transcriptome of CD4+ T cell subsets
STIM1 controls T cell-mediated immune regulation and inflammation in chronic infection.
Treatment
View SamplesIRAK-4 is an essential component of the signal transduction complex downstream of the IL-1- and Toll-like receptors. Though regarded as the first kinase in the signaling cascade, the role of IRAK-4 kinase activity versus its scaffold function is still controversial. In order to investigate the role of IRAK-4 kinase function in vivo, knock-in mice were generated by replacing the wild type IRAK-4 gene with a mutant gene encoding kinase deficient IRAK-4 protein (IRAK-4 KD). Analysis of bone marrow macrophages obtained from WT and IRAK-4 KD mice with a number of experimental techniques demonstrated that the IRAK-4 KD cells greatly lack responsiveness to stimulation with the Toll-like receptor 4 (TLR4) agonist LPS. One of the techniques used, microarray analysis, identified IRAK-4 kinase-dependent LPS response genes and revealed that the induction of LPS-responsive mRNAs was largely ablated in IRAK-4 KD cells. In summary, our results suggest that IRAK-4 kinase activity plays a critical role in TLR4-mediated induction of inflammatory responses.
IRAK-4 kinase activity-dependent and -independent regulation of lipopolysaccharide-inducible genes.
No sample metadata fields
View SamplesThe retinas of simian primates include a specialized, cone-rich, macula which regards the central visual field and mediates high acuity and colour vision. A prominent feature of the macula is the fovea centralis - a 1 mm-wide, avascular depression in the inner retinal surface that corresponds with a local absence of rods and a peak spatial density of cones in the outer photoreceptor layer. The arrangement of macular photoreceptors, and their specialized midget circuits, are the neural substrate for high resolution vision in primates. Macular-specific photoreceptor loss and abnormal blood vessel growth within the macula are the major causes of untreatable vision loss worldwide. However, the genes that regulate specialization of the macula, and the causes of its vulnerability to degeneration, remain obscure. Microarrays were used to compare gene expression between macula and non-macular regions during a critical phase of human retinal vascular development.
Differential expression of anti-angiogenic factors and guidance genes in the developing macula.
Specimen part
View SamplesThe highly conserved protein eIF5A found in archaea and all eucaryotes uniquely contains the posttranslationally formed amino acid hypusine. Despite being essential the functions of this protein and its modification remain unclear. To gain more insight into these functions temperature sensitive mutants of the human EIF5A1 were characterized in the yeast Saccharomyces cerevisiae.
Temperature-sensitive eIF5A mutant accumulates transcripts targeted to the nonsense-mediated decay pathway.
No sample metadata fields
View SamplesInflammation has a causal role in many cancers. In prostate cancers, epidemiological data suggest a link between prostatitis and subsequent cancer development, but a proof for this concept in a tumor model has been lacking. A constitutively active version of the IkappaB kinase 2 (IKK2), the molecule activated by a plethora of inflammatory stimuli, was expressed specifically in the prostate epithelium. Signaling of the IKK2/NF-kappaB axis was insufficient for transformation of prostate tissue. However, while PTEN+/- epithelia exhibited intraepithelial neoplasias only recognizable by nuclear alterations, additional IKK2 activation led to an increase in tumor size and formation of cribriform structures and to a fiber increase in the fibroblastic stroma. This phenotype was coupled with inflammation in the prostate gland characterized by infiltration of granulocytes and macrophages. Molecular characterization of the tissues showed a specific loss of smooth muscle markers as well as expression of chemokines attracting immune cells. Isolation of epithelial and stromal cells showed differential chemokine expression by these cells. Correlation studies showed the inflammatory phenotype coupled to loss of smooth muscle in infiltrated glands, but maintenance of the phenotype in glands where inflammation had decreased. Despite the loss of the smooth muscle barrier, tumors were not invasive in a stable genetic background. Data mining revealed that smooth muscle markers are downregulated in human prostate cancers and literature data show that loss of these markers in primary tumors is associated with subsequent metastasis. Our data show that loss of smooth muscle and invasiveness of the tumor are not coupled. Thus, inflammation during early steps of tumorigenesis can lead to increased tumor size and a potential change in the subsequent metastatic potential, but the tumor requires an additional transformation to become a carcinoma.
Persistent inflammation leads to proliferative neoplasia and loss of smooth muscle cells in a prostate tumor model.
Age, Specimen part
View SamplesSwiss-Webster female mice (Charles River Laboratories, Wilmington, MA) 5-6 weeks of age were infected intranasally with 5 LD50 of either WT or lpp mutant of Y. pestis CO92. Uninfected mice were used as controls. At either 12 or 48 h post infection (p.i.), 3 mice per group were euthanized and the lungs, livers, and spleens were harvested and homogenized in 1 ml of RNALater (Ambion/Applied Biosystems, Austin, TX) using 50-ml tissue homogenizers (Kendell, Mansfield, MA). RNA was isolated from the tissue homogenates and purified using RNAqueous (Ambion). After an overnight precipitation, the RNA was resuspended in 20 ul of diethylpyrocarbonate (DEPC)-treated water and hybridized to Affymetrix GeneChip Mouse Genome 430 2.0 arrays, performed by the Molecular Genomics Core at UTMB Galveston, Texas, per manufacture protocols. The arrays had 45,000 probe sets representing more than 39,000 transcripts derived from ~34,000 well-substantiated mouse genes. The experiments were performed in triplicate (biological replicates), generating a total of 45 arrays.
Comparative Analyses of Transcriptional Profiles in Mouse Organs Using a Pneumonic Plague Model after Infection with Wild-Type Yersinia pestis CO92 and Its Braun Lipoprotein Mutant.
Sex, Specimen part, Time
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