Identification of host responses at the gene transcription level provides a molecular profile of the events that occur following infection. Brucella abortus is a facultative intracellular pathogen of macrophages that induces chronic infection in humans and domestic animals. Using microarray technology, the response of macrophages 4 hours following B. abortus infection was analyzed to identify early intracellular infection events that occur in macrophages. Of the more than 6,000 genes, we identified over 140 genes that were reproducibly differentially transcribed. First, an increase in the transcription of a number of pro-inflammatory cytokines and chemokines, such as TNF-, IL-1, IL-1, and members of the SCY family of proteins, was evident that may constitute a general host recruitment of antibacterial defenses. Alternatively, Brucella may subvert newly arriving macrophages for additional intracellular infection. Second, transcription of receptors and cytokines associated with antigen presentation, e.g., MHC class II and IL-12p40, were not evident at this 4 hour period of infection. Third, Brucella inhibited transcription of various host genes involved in apoptosis, cell cycling, and intracellular vesicular trafficking. Identification of macrophage genes whose transcription was inhibited suggests that Brucella utilizes specific mechanisms to target certain cell pathways. In conclusion, these data suggest that B. abortus can alter macrophage pathways to recruit additional macrophages for future infection while simultaneously inhibiting apoptosis and innate immune mechanisms within the macrophage permitting intracellular survival of the bacterium. These results provide insights into the pathogenic strategies used by Brucella to survive long-term within a hostile environment.
Microarray analysis of mRNA levels from RAW264.7 macrophages infected with Brucella abortus.
Specimen part
View SamplesSheep scrapie (Sc) is the classical transmissible spongiform encephalopathy (prion disease). The conversion of normal cellular prion protein (PrPC) to disease-associated prion protein (PrPSc) is a fundamental component of prion disease pathogenesis. The molecular mechanisms contributing to prion diseases and the impact of PrPSc accumulation on cellular biology are not fully understood. To define the molecular changes associated with PrPSc accumulation, primary sheep microglia were inoculated with PrPSc and then the transcriptional profile of these PrPSc-accumulating microglial cells was compared to the profile of PrPSc-lacking microglial cells using the Affymetrix Bovine Genome Array. The experimental design included three biological replicates, each with three technical replicates, and samples that were collected at the point of maximal PrPSc accumulation levels as measured by ELISA. The array analysis revealed 19 upregulated genes and 30 downregulated genes in PrPSc-accumulating microglia. Three transcripts (CCL2, SGK1, and AASDHPPT) were differentially regulated in a direction similar to previous reports from mouse or human models, whereas the response of three other transcripts (MT1E, NR4A1, PKP2) conflicted with previous reports. Overall, the results demonstrated a limited transcriptional response to PrPSc accumulation, when compared to microglia and macrophage cultures infected with other agents such as viruses and bacteria. This is the first microarray-based analysis of prion accumulation in primary cells derived from a natural TSE-host.
Limited transcriptional response of ovine microglia to prion accumulation.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Brucella melitensis, B. neotomae and B. ovis elicit common and distinctive macrophage defense transcriptional responses.
Specimen part
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 SamplesBrucella dynamically engage macrophages while trafficking to an intracellular replicative niche as macrophages, the first line of innate host defense, attempt to eliminate organisms. Brucella melitensis, B. neotomae, and B. ovis are highly homologous, yet exhibit a range of host pathogenicity and specificity. RAW 264.7 macrophages infected with B. melitensis, and B. ovis exhibit divergent patterns of bacterial persistence and clearance; conversely, B. melitensis and B. neotomae exhibit similar patterns of infection. Evaluating early macrophage interaction with Brucella spp. allows discovery of host entry and intracellular translocation mechanisms, rather than bacterial replication. Microarray analysis of macrophage transcript levels following a 4 hr Brucella spp. infection revealed 130 probe sets altered compared to uninfected macrophages; specifically, 72 probe sets were increased and 58 probe sets were decreased with any Brucella spp. Interestingly, much of the inflammatory response was not regulated by the number of Brucella gaining intracellular entry, as macrophage transcript levels were often equivalent among B. melitensis, B. ovis, and B. neotomae infections. An additional 33 probe sets were identified with altered macrophage transcript levels among Brucella spp. infections that may correlate with species specific host defenses and intracellular survival. Gene ontological categorization unveiled genes altered among species are involved in cell growth and maintenance, response to external stimuli, transcription regulation, transporter activity, endopeptidase inhibitor activity and G-protein mediated signaling. Host transcript profiles provide a foundation to understand variations in Brucella spp. infections, while structure of the macrophage response and intracellular niche of Brucella spp. will be revealed through piecewise consideration of host signaling pathways.
Brucella melitensis, B. neotomae and B. ovis elicit common and distinctive macrophage defense transcriptional responses.
Specimen part
View SamplesComparison of gene expression between T regulatory and T effector cells isolated from the pancreatic lesion of 3-4 wk old BDC2.5 tg NOD mice
Where CD4+CD25+ T reg cells impinge on autoimmune diabetes.
Age, Specimen part
View SamplesTo understand the nature of glucocorticoids targeting non-immune cell function, we generate RNA sequencing data from 3 human podocyte cell lines derived from 3 kidney transplant donors and identify the genes that are significantly regulated in dexamethasone-treated podocytes compared to vehicle-treated cells.Our results represent a significant step forward in the genome-wide characterization of the molecular effects of glucocorticoids on human podocytes. The resource generated in this study is important for understanding the targeting of non-immune cell function by glucocorticoids and also for designing more specific podocyte-targeted agents for MCN therapy. Overall design: Transcriptome profiles of human podocytes treated with vehicle and dexamethasone were generated by RNA-sequencing using Illumina HiSeq 2500
RNA sequencing analysis of human podocytes reveals glucocorticoid regulated gene networks targeting non-immune pathways.
Specimen part, Subject
View SamplesWe report the effect of TGFß vs PDGF 2h treatment in hepatic stellate cells. We also report the effect of TGFß treatment for 48h in human hepatic stellate cells. Overall design: RNA sequencing was performed after treating human hepatic stellate cells with TGFß and PDGF for 2h and also with TGFß for 48h
Enhancer of Zeste Homologue 2 Inhibition Attenuates TGF-β Dependent Hepatic Stellate Cell Activation and Liver Fibrosis.
Specimen part, Treatment, Subject
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 embryonic fibroblasts and macrophages obtained from IRAK-4 KD mice with a number of experimental techniques demonstrated that they greatly lack responsiveness to stimulation with IL-1b or a Toll-like receptor 7 (TLR7) agonist. One of the techniques used, microarray analysis, identified IRAK-4 kinase-dependent IL-1b response genes in mouse embryonic fibroblasts and revealed that the induction of IL-1b-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 IL-1R/TLR7-mediated induction of inflammatory responses.
IRAK-4 kinase activity is required for interleukin-1 (IL-1) receptor- and toll-like receptor 7-mediated signaling and gene expression.
No sample metadata fields
View SamplesCo-stimulatory molecules of the CD28 family on T lymphocytes integrate cues from innate immune system sensors, and modulate activation responses in conventional CD4+ T cells (Tconv) and their FoxP3+ regulatory counterparts (Treg). To better understand how costimulatory and co-inhibitory signals might be integrated, we profiled the changes in gene expression elicited in the hours and days after engagement of Treg and Tconv by anti-CD3 and either anti-CD28, -CTLA4, -ICOS, -PD1, -BTLA or -CD80.
Convergent and divergent effects of costimulatory molecules in conventional and regulatory CD4+ T cells.
Sex, Age, Specimen part
View Samples