The response of drosophila to bacterial and fungal infections involves two signaling pathways, Toll and Imd, which both activate NF-kB family members. We have studied the global transcriptional response of flies to infection with drosophila C virus. Viral infection induced a set of genes distinct from those regulated by the Toll or Imd pathways, and triggered activation of a STAT binding activity. Genetic experiments showed that the JAK kinase Hopscotch was involved in the control of the viral load in infected flies, and was required, though not sufficient, for the induction of some virus-regulated genes. Our results indicate that in addition to Toll and Imd, a third evolutionary conserved innate immunity pathway operates in drosophila and counters viral infection.
The Jak-STAT signaling pathway is required but not sufficient for the antiviral response of drosophila.
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View SamplesThe fruit fly Drosophila melanogaster is a good model to unravel the molecular mechanisms of innate immunity, and has led to some important discoveries on the sensing and signalling of microbial infections. The response of drosophila to virus infections remains poorly characterized, and appears to involve two facets. On one hand RNA interference (RNAi) involves the recognition and processing of dsRNA into small interfering (si) RNAs by the host ribonuclease Dicer-2 (Dcr-2), whereas on the other hand an inducible response controlled by the evolutionarily conserved JAK/STAT pathway contributes to the antiviral host defence. In order to clarify the contribution of the siRNA and JAK/STAT pathways to the control of viral infections, we have compared the resistance of flies wild-type or mutant for Dcr-2 or the JAK kinase Hopscotch (Hop) to infections by seven RNA or DNA viruses belonging to different families. Our results reveal a unique susceptibility of hop mutant flies to infection by DCV and CrPV, two members of the Dicistroviridae family. Genome-wide microarray analysis confirmed that different sets of genes were induced following infection by DCV (GSE2828) or two unrelated RNA viruses, FHV and SINV. Overall, our data reveal that RNAi is an efficient antiviral mechanism, operating against a large range of viruses, including a DNA virus. By contrast, the antiviral contribution of the JAK/STAT pathway appears to be virus-specific.
Broad RNA interference-mediated antiviral immunity and virus-specific inducible responses in Drosophila.
Time
View SamplesThis dataset contains microarray data from normal controls (aged 20-99 yrs) and Alzheimer's disease cases, from 4 brain regions: hippocampus, entorhinal cortex, superior frontal cortex, post-central gyrus. Changes in expression of synaptic and immune related genes were analyzed, investigating age-related changes and AD-related changes, and region-specific patterns of change.
Gene expression changes in the course of normal brain aging are sexually dimorphic.
Sex, Subject
View SamplesThis dataset of cognitively normal controls is a subset of the GSE48350 dataset, which additionally contains microarray data from AD brains.
Gene expression changes in the course of normal brain aging are sexually dimorphic.
Sex, Subject
View SamplesPBMC from house dust mite (HDM) sensitized atopics with or without asthma (or nonallergic controls) were cultured in the presence or absence of HDM extract for 24 hours.
Differential gene network analysis for the identification of asthma-associated therapeutic targets in allergen-specific T-helper memory responses.
Specimen part, Disease stage, Subject
View SamplesDNA methylation is essential for mammalian development and plays crucial roles in a variety of biological processes. The DNA methyltransferase Dnmt1 serves to maintain parental cell methylation patterns on daughter DNA strands in mitotic cells, however, the precise role of Dnmt1 in regulation of quiescent adult stem cells is not known.
DNA methyltransferase 1 is essential for and uniquely regulates hematopoietic stem and progenitor cells.
Specimen part
View SamplesIn order to find a relationship between gene expression of blood and brain in Rett Syndrome (RTT), we performed RNA sequencing on from cerebella and blood of 7 week-old male Mecp2-null mice (a model of RTT) and WT controls. Overall design: Transcriptional profiles were generated from cerebellum and blood of 3 Mecp2-null and 3 WT 7 week-old male mice, by RNAseq performed on an Illumina HiSeq 2000 System, generating approximately 60 million 2x75bp paired-end reads/sample. Blood and cerebellum samples originate from the same animal
Transcriptomic Analysis of <i>Mecp2</i> Mutant Mice Reveals Differentially Expressed Genes and Altered Mechanisms in Both Blood and Brain.
Age, Specimen part, Cell line, Subject
View SamplesWe sequenced mRNA extracted from heads of a D. melanogaster population that was sedated with a stream of ethanol saturated vapor, 30 minutes before RNA extraction; and from an age-matched untreated control group. Differential gene expression between the two groups was calculated and reported. Overall design: Examination of mRNA levels in heads of D. melanogaster adult females after ethanol exposure was performed using next generation sequencing (NGS) technology.
Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway.
Cell line, Treatment, Subject
View SamplesVery little is known about how animals discriminate pathogens from innocuous microbes. To address this question, we examined infection-response gene induction in the nematode Caenorhabditis elegans. We focused on genes that are induced in C. elegans by infection with the bacterial pathogen Pseudomonas aeruginosa, but are not induced by an isogenic attenuated gacA mutant. Most of these genes are induced independently of known immunity pathways. We generated a GFP reporter for one of these genes, infection response gene 1 (irg-1), which is induced strongly by wild-type P. aeruginosa strain PA14, but not by other C. elegans pathogens or by other wild-type P. aeruginosa strains that are weakly pathogenic to C. elegans. To identify components of the pathway that induces irg-1 in response to infection, we performed an RNA interference screen of C. elegans transcription factors. This screen identified zip-2, a bZIP transcription factor that is required for inducing irg-1, as well as several other genes, and is important for defense against infection by P. aeruginosa. These data indicate that zip-2 is part of a specialized pathogen response pathway that is induced by virulent strains of P. aeruginosa and provides defense against this pathogen.
bZIP transcription factor zip-2 mediates an early response to Pseudomonas aeruginosa infection in Caenorhabditis elegans.
Time
View SamplesLeukemia stem cells (LSCs) are an attractive target in treatment of many types of blood cancers. There remains an incomplete understanding of the epigenetic mechanisms driving LSC formation and maintenance, and how this compares to the epigenetic regulation of normal hematopoietic stem cells (HSCs).
Haploinsufficiency of Dnmt1 impairs leukemia stem cell function through derepression of bivalent chromatin domains.
Specimen part
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