Genome-wide binding map of the HIV Tat protein to the human genome
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Siavash Kurdistani
PROVIDER: E-GEOD-30739 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:The HIV-1 Trans-Activator of Transcription (Tat) protein binds to multiple host cellular factors and greatly enhances the level of transcription of the HIV genome. Here, we report the genome-wide binding map of Tat to the human genome in Jurkat T cells (Jurkat-Tat cells) using chromatin immunoprecipitation combined with next-generation sequencing. cDNA microarray was used to monitor gene expression changes between Jurkat and Jurkat-Tat cells. Additionally, we compared distribution of H3K9ac near gene promoters between Jurkat and Jurkat-Tat cells using ChIP-chip method and hybridized onto Agilent promoter array. Our data reveal that Tat’s interaction with the host genome is more extensive than previously thought, with potentially important implications for the viral life cycle. Agilent gene expression microarray was used to compare gene expression changes between Jurkat T cells and Jurkat T cells expressing HIV-Tat protein (Jurkat-Tat T cells) Expression profiles on Jurkat-Tat cells versus Jurkat cells. ChIP on chip for H3K9ac in Jurkat-Tat versus Jurkat cells. ChIP-seq for HIV-1 Tat protein in Jurkat-Tat cells.
2011-11-06 | E-GEOD-30734 | biostudies-arrayexpress
Project description:The HIV-1 Trans-Activator of Transcription (Tat) protein binds to multiple host cellular factors and greatly enhances the level of transcription of the HIV genome. Here, we report the genome-wide binding map of Tat to the human genome in Jurkat T cells (Jurkat-Tat cells) using chromatin immunoprecipitation combined with next-generation sequencing. cDNA microarray was used to monitor gene expression changes between Jurkat and Jurkat-Tat cells. Additionally, we compared distribution of H3K9ac near gene promoters between Jurkat and Jurkat-Tat cells using ChIP-chip method and hybridized onto Agilent promoter array. Our data reveal that Tat’s interaction with the host genome is more extensive than previously thought, with potentially important implications for the viral life cycle. Expression profiles on Jurkat-Tat cells versus Jurkat cells. ChIP on chip for H3K9ac in Jurkat-Tat versus Jurkat cells. ChIP-seq for HIV-1 Tat protein in Jurkat-Tat cells.
2011-11-06 | E-GEOD-30736 | biostudies-arrayexpress
Project description:The HIV-1 Trans-Activator of Transcription (Tat) protein binds to multiple host cellular factors and greatly enhances the level of transcription of the HIV genome. Here, we report the genome-wide binding map of Tat to the human genome in Jurkat T cells (Jurkat-Tat cells) using chromatin immunoprecipitation combined with next-generation sequencing. cDNA microarray was used to monitor gene expression changes between Jurkat and Jurkat-Tat cells. Additionally, we compared distribution of H3K9ac near gene promoters between Jurkat and Jurkat-Tat cells using ChIP-chip method and hybridized onto Agilent promoter array. Our data reveal that TatM-CM-"M-BM-^@M-BM-^Ys interaction with the host genome is more extensive than previously thought, with potentially important implications for the viral life cycle. Expression profiles on Jurkat-Tat cells versus Jurkat cells. ChIP on chip for H3K9ac in Jurkat-Tat versus Jurkat cells. ChIP-seq for HIV-1 Tat protein in Jurkat-Tat cells.
2011-11-06 | E-GEOD-30738 | biostudies-arrayexpress
Project description:Transcription factors mediate precise regulation of gene expression programs to modulate key biological processes. In addition to controlling HIV transcription, Tat appears to modulate cellular transcription to alter the biology of target immune cells and generate a permissive state for HIV infection. However, the molecular mechanisms of transcriptional control have remained elusive. Here, we identified the direct target genes of Tat using genomics and defined mechanisms by which Tat selectively rewires cellular transcriptional programs. Interestingly, Tat functions as both transcriptional activator and repressor of a defined set of genes sharing functional annotations and regulated by master transcriptional regulators such as T-cell identity factors. Tat is recruited to precise genomic domains (promoters and intragenic enhancers) through interaction with master transcriptional regulators to control both the transcription initiation and elongation steps. Tat mediates transcription initiation by modulating Pol II recruitment to promoters and intragenic enhancers and fine-tuning chromatin looping. Tat stimulates or blocks RNA Polymerase (Pol) II recruitment or promoter-proximal pause release thereby promoting gene activation or repression, respectively. Global analysis of chromatin signatures revealed correlation of transcription activity marks with Pol II recruitment or pause release status at gene promoters and enhancers, and transcription elongation at coding units. We propose that Tat has evolved these unique properties to hijack precise genomic domains to control cellular transcription using unexpected regulatory mechanisms, which showed marked differences to the regulation of the HIV genome. Our studies also reveal that Tat can be used as a molecular probe to decode general principles of transcriptional regulation. Tat vs. GFP
2015-06-15 | E-GEOD-65688 | biostudies-arrayexpress
Project description:Transcription factors mediate precise regulation of gene expression programs to modulate key biological processes. In addition to controlling HIV transcription, Tat appears to modulate cellular transcription to alter the biology of target immune cells and generate a permissive state for HIV infection. However, the molecular mechanisms of transcriptional control have remained elusive. Here, we identified the direct target genes of Tat using genomics and defined mechanisms by which Tat selectively rewires cellular transcriptional programs. Interestingly, Tat functions as both transcriptional activator and repressor of a defined set of genes sharing functional annotations and regulated by master transcriptional regulators such as T-cell identity factors. Tat is recruited to precise genomic domains (promoters and intragenic enhancers) through interaction with master transcriptional regulators to control both the transcription initiation and elongation steps. Tat mediates transcription initiation by modulating Pol II recruitment to promoters and intragenic enhancers and fine-tuning chromatin looping. Tat stimulates or blocks RNA Polymerase (Pol) II recruitment or promoter-proximal pause release thereby promoting gene activation or repression, respectively. Global analysis of chromatin signatures revealed correlation of transcription activity marks with Pol II recruitment or pause release status at gene promoters and enhancers, and transcription elongation at coding units. We propose that Tat has evolved these unique properties to hijack precise genomic domains to control cellular transcription using unexpected regulatory mechanisms, which showed marked differences to the regulation of the HIV genome. Our studies also reveal that Tat can be used as a molecular probe to decode general principles of transcriptional regulation. ChIP of various DNA binding proteins
2015-06-15 | E-GEOD-65687 | biostudies-arrayexpress
Project description:Our previous work demonstrated that HIV-1 infection progressively reduces TCR/CD3 expression due to a defect in CD3g gene transcripts. We further found that knocking down expression of the viral tat and/or nef genes was correlated with CD3g transcript and TCR/CD3 surface receptor levels on HIV-1 infected cells. This study was undertaken to investigate the direct effect of HIV-1 Tat expression on the TCR/CD3 machinery. Progressive downregulation from TCR/CD3hi to TCR/CD3lo to TCR/CD3â was observed on Tat expressing cells in a manner that emulated HIV-1 infection, with a lack of CD3g transcripts again responsible for the defect. When Tat cell cultures containing a mixture of TCR/CD3 surface densities were separated into TCR/CD3hi and TCR/CD3lo/â populations, they quickly reverted to a mixed CD3 phenotype. Thus, the progression TCR/CD3hi to TCR/CD3lo to TCR/CD3â is an active, reversible process with receptor levels fluctuating in response to intracellular dynamics. Examination of tat mutants found that the regions involved in Tat-mediated transactivation and TAR binding are required for TCR/CD3 downregulation while the lysine at position 28 and Tat exon 2 are dispensable. Global gene expression, assessed in association with TCR/CD3 downregulation in HIV-1 infected and Tat expressing cells, detected broad suppression of TCR/CD3 signaling, co-stimulation and negative regulatory genes along with target transcription factors, ligands and receptors. A significant subset of the genes altered in HIV-1 infected cells was specifically targeted by Tat in association with TCR/CD3 loss. Our finding that Tat negatively regulates many facets of the TCR/CD3 machinery has important implications for disease pathogenesis. We used microarrays to investigate changes in CD4+ T cell gene expression induced by expression of the HIV-1 Tat protein. Examine changes in gene expression in HIV-1 Tat transduced cells compared with cells transduced with an antisense Tat sequence used as a control.
2015-12-31 | E-GEOD-33705 | biostudies-arrayexpress
Project description:HIV-1 Tat induces the expression of interferon (IFN)-inducible genes in immature dendritic cells (iDC) in the absence of IFN production. We evaluated how three alleles of Tat and some Tat mutants differ in cellular gene modulation and whether a similar gene induction pattern could be detected by treating cells with IFNM-bM-^@M-^Ys. The three alleles and mutants, with the exception of mutants TatSF21-47 and TatSF2G48-R57A that do not localize in the nucleous, modulated to different degrees IFN-inducible genes without concomitant induction of IFNM-bM-^@M-^Ys. The first exon TatSF21-72 and the minimal transactivator TatSF21-58, all induced genes to a significantly greater extent than full-length Tat. The 2nd exon appears to diminish the gene modulation that can be observed when the first exon alone is expressed. We investigated the effect of various Tat alleles and mutants on host cell gene expression in immature dendritic cells (iDC). The cells were infected with adenoviruses expressing the Tat constructs. The Tat alleles and mutants are under a tetracycline inducible promoter and are expressed only in cells co-infected with Ad-tTA, which expresses the tetracycline responsive transactivator. 10e6 iDC were infected with 5 plague forming units per cell of the adenoviruses and cells were collected 10 and 20 hours post-infection. RNA was isolated and mRNA expression levels were analyzed by microarrays. As controls we used cells that were left uninfected and cells that were infected with Ad-LacZ, which expresses beta-galactosidase.
2013-06-01 | E-GEOD-42924 | biostudies-arrayexpress
Project description:We have used RNA immunoprecipitation to identify the set of mRNAs that HIV-1 Tat interacts with in T-cells. We have also performed measurements of relative RNA abundance to determine if Tat binding is associated with an increase in RNA abundance in Tat-expressing T-cells and during HIV infection of primary T-cells. We have also used RNA IP and ChIP-Chip to compare the RNAs with which Tat interacts with to the RNAs that RISC interacts with and the genes associated with pTEF-b.
2013-11-05 | E-MEXP-3199 | biostudies-arrayexpress
Project description:Our previous work demonstrated that HIV-1 infection progressively reduces TCR/CD3 expression due to a defect in CD3g gene transcripts. We further found that knocking down expression of the viral tat and/or nef genes was correlated with CD3g transcript and TCR/CD3 surface receptor levels on HIV-1 infected cells. This study was undertaken to investigate the direct effect of HIV-1 Tat expression on the TCR/CD3 machinery. Progressive downregulation from TCR/CD3hi to TCR/CD3lo to TCR/CD3? was observed on Tat expressing cells in a manner that emulated HIV-1 infection, with a lack of CD3g transcripts again responsible for the defect. When Tat cell cultures containing a mixture of TCR/CD3 surface densities were separated into TCR/CD3hi and TCR/CD3lo/? populations, they quickly reverted to a mixed CD3 phenotype. Thus, the progression TCR/CD3hi to TCR/CD3lo to TCR/CD3? is an active, reversible process with receptor levels fluctuating in response to intracellular dynamics. Examination of tat mutants found that the regions involved in Tat-mediated transactivation and TAR binding are required for TCR/CD3 downregulation while the lysine at position 28 and Tat exon 2 are dispensable. Global gene expression, assessed in association with TCR/CD3 downregulation in HIV-1 infected and Tat expressing cells, detected broad suppression of TCR/CD3 signaling, co-stimulation and negative regulatory genes along with target transcription factors, ligands and receptors. A significant subset of the genes altered in HIV-1 infected cells was specifically targeted by Tat in association with TCR/CD3 loss. Our finding that Tat negatively regulates many facets of the TCR/CD3 machinery has important implications for disease pathogenesis. This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2015-12-31 | E-GEOD-32626 | biostudies-arrayexpress
Project description:Anti-retroviral therapy (ART) has transformed human immunodeficiency virus (HIV) infection from a fatal illness to a chronic condition by controlling viral replication and restoring immune function. However, chronic T-cell activation can be observed in 20-35% of individuals on ART, resulting in an immune reconstitution inflammatory syndrome (IRIS) [1-3]. IRIS involving the CNS can result in permanent disability and death [4]. Tat is a viral protein produced in HIV-infected cells and released into the extracellular space [5]. We show that the secreted-Tat protein activated uninfected T-cells in an antigen-independent manner without inducing proliferation. Notably, Tat induced the secretion of IL-17 from T-cells and increased the percentage of T-cells with a Th17 phenotype. T-cell activation was independent of the T-cell receptor but dependent on endocytosis of Tat and activation of vascular endothelial growth factor receptor 2 (VEGFR2). Tat induced global changes in histone acetylation and increased HIV infection in non-replicating T-cells. Furthermore, in an individual with CNS IRIS, Tat expressing infiltrates and secretion of IL-17 was detected in the absence of viral replication in the brain. Thus Tat can induce T-cell activation in a paracrine and autocrine manner resulting in propagation of inflammation and increased virulence. 12 Human samples in 6 pairs: 6 Human T cell HIV tat exposed 0hrs, 6 Human T cell HIV tat exposed 24hrs
2013-08-02 | E-GEOD-44460 | biostudies-arrayexpress