Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA240890 | ENA |
REPOSITORIES: ENA
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Project description:The protozoan parasite Toxoplasma gondii is a highly successful intracellular pathogen, owing in part to its ability to subvert the host immune system. In particular, parasite infection suppresses STAT1 signaling in a variety of cell types, including IFN-γ activated macrophages, via a block within the nucleus. A high-throughput screen to identify genes able to overcome parasite-mediated suppression of STAT1 activity identified 9 transcription factors as enhancers of STAT1 signaling in T. gondii infected cells, including the orphan nuclear hormone receptor TLX. Expression profiling revealed that TLX is a transcriptional regulator that drives the steady-state expression of STAT1-independent genes involved brain function and development, while enhancing the output of a subset of IFN-γ-dependent target genes. Infection of TLX deficient mice with Toxoplasma results in impaired production of interleukin-12 by dendritic cells and increased parasite burden in the brain during chronic infection. These results demonstrate a previously unrecognized function for this orphan nuclear hormone receptor in regulating STAT1 signaling and host defense, and reveal that STAT1 activity can be modulated in a context-specific manner by such ‘modifiers’.
2015-05-29 | GSE55750 | GEO
Project description:The protozoan parasite Toxoplasma gondii is a highly successful intracellular pathogen, owing in part to its ability to subvert the host immune system. In particular, parasite infection suppresses STAT1 signaling in a variety of cell types, including IFN-γ activated macrophages, via a block within the nucleus. A high-throughput screen to identify genes able to overcome parasite-mediated suppression of STAT1 activity identified 9 transcription factors as enhancers of STAT1 signaling in T. gondii infected cells, including the orphan nuclear hormone receptor TLX. Expression profiling revealed that TLX is a transcriptional regulator that drives the steady-state expression of STAT1-independent genes involved brain function and development, while enhancing the output of a subset of IFN-γ-dependent target genes. Infection of TLX deficient mice with Toxoplasma results in impaired production of interleukin-12 by dendritic cells and increased parasite burden in the brain during chronic infection. These results demonstrate a previously unrecognized function for this orphan nuclear hormone receptor in regulating STAT1 signaling and host defense, and reveal that STAT1 activity can be modulated in a context-specific manner by such ‘modifiers’.
2015-05-29 | GSE55749 | GEO
Project description:A Gain-of-Function Genomic Screen Identifies the Orphan Nuclear Receptor TLX as an Enhancer of STAT1-mediated Transcription and Immunity to Toxoplasma gondii: TLX siRNA
| PRJNA240891 | ENA
Project description:We previously showed that the orphan nuclear hormone receptor, TLX (also known as NR2E1), selectively modifies the output of IFN-gamma-driven, STAT1-dependent gene expression. Since IFN-gamma and STAT1 are also known to regulate myeloid cell development and function, we tested whether ectopic expression of TLX or COUPTF2 (a closely related orphan nuclear receptor) might influence hematopoietic differentiation. Indeed, TLX promotes lineage commitment toward myeloid development and suppresses erythropoiesis, phenocopying IFN-gamma treatment. Moreover, TLX expression in our assay is sufficient to activate a proinflammatory transcriptional program with two hallmarks: differential regulation of STAT1-dependent genes, and suppression of an anti-inflammatory program in favor of a fatty acid signature – a process known to be essential for cellular remodeling during macrophage maturation and phagocytosis. These results demonstrate an important role for a new nuclear hormone receptor in STAT1 signaling, and link TLX to myeloid lineage commitment and function.
2016-09-21 | GSE87126 | GEO
Project description:Intracellular pathogens including the apicomplexan and opportunistic parasite Toxoplasma gondii profoundly modify their host cells in order to establish infection. We have shown previously that intracellular T. gondii inhibit up-regulation of regulatory and effector functions in murine macrophages (MΦ) stimulated with interferon (IFN)-γ, which is the cytokine crucial for controlling the parasites’ replication. Using genome-wide transcriptome analysis we show herein that infection with T. gondii leads to global unresponsiveness of murine macrophages to IFN-γ. More than 61% and 89% of the transcripts, which were induced or repressed by IFN-γ in non-infected MΦ, respectively, were not altered after stimulation of T. gondii-infected cells with IFN-γ. These genes are involved in a variety of biological processes, which are mostly but not exclusively related to immune responses. Analyses of the underlying mechanisms revealed that IFN-γ-triggered nuclear translocation of STAT1 still occurred in Toxoplasma-infected MΦ. However, STAT1 bound aberrantly to oligonucleotides containing the IFN-γ-responsive gamma-activated site (GAS) consensus sequence. Conversely, IFN-γ did not induce formation of active GAS-STAT1 complexes in nuclear extracts from infected MΦ. Mass spectrometry of protein complexes bound to GAS oligonucleotides showed that T. gondii-infected MΦ are unable to recruit non-muscle actin to IFN-γ-responsive DNA sequences, which appeared to be independent of stimulation with IFN-γ and of STAT1 binding. IFN-γ-induced recruitment of BRG-1 and acetylation of core histones at the IFN-γ-regulated CIITA promoter IV, but not β-actin was diminished by >90% in Toxoplasma-infected MΦ as compared to non-infected control cells. Remarkably, treatment with histone deacetylase inhibitors restored the ability of infected macrophages to express the IFN-γ regulated genes H2-A/E and CIITA. Taken together, these results indicate that Toxoplasma-infected MΦ are unable to respond to IFN-γ due to disturbed chromatin remodelling, but can be rescued using histone deacetylase inhibitors. Comparison of 4 different RNA pools with a 2-Color-Loop Design including 10 microarrays: [1] T. gondii infected and IFN-gamma treated, [2] T. gondii infected and untreated, [3] Non-infected and IFN-gamma treated, and [4] Non-infected and untreated.
2012-01-25 | E-GEOD-28499 | biostudies-arrayexpress
Project description:TLX (NR2E1), as an orphan nuclear receptor, plays a critical role in growth, self-renewal, and tumorigenesis of glioblastoma stem cells. We used microarrays to investigate the global gene expression regulated by TLX and identified downstream targets of TLX in glioblastoma stem cells. We further investigated the global gene expression regulated by TET3, a downstream target of TLX, to identified downstream targets of TLX-TET3 axis in glioblastoma stem cells.
2016-02-01 | GSE75945 | GEO
Project description:Intracellular pathogens including the apicomplexan and opportunistic parasite Toxoplasma gondii profoundly modify their host cells in order to establish infection. We have shown previously that intracellular T. gondii inhibit up-regulation of regulatory and effector functions in murine macrophages (MΦ) stimulated with interferon (IFN)-γ, which is the cytokine crucial for controlling the parasites’ replication. Using genome-wide transcriptome analysis we show herein that infection with T. gondii leads to global unresponsiveness of murine macrophages to IFN-γ. More than 61% and 89% of the transcripts, which were induced or repressed by IFN-γ in non-infected MΦ, respectively, were not altered after stimulation of T. gondii-infected cells with IFN-γ. These genes are involved in a variety of biological processes, which are mostly but not exclusively related to immune responses. Analyses of the underlying mechanisms revealed that IFN-γ-triggered nuclear translocation of STAT1 still occurred in Toxoplasma-infected MΦ. However, STAT1 bound aberrantly to oligonucleotides containing the IFN-γ-responsive gamma-activated site (GAS) consensus sequence. Conversely, IFN-γ did not induce formation of active GAS-STAT1 complexes in nuclear extracts from infected MΦ. Mass spectrometry of protein complexes bound to GAS oligonucleotides showed that T. gondii-infected MΦ are unable to recruit non-muscle actin to IFN-γ-responsive DNA sequences, which appeared to be independent of stimulation with IFN-γ and of STAT1 binding. IFN-γ-induced recruitment of BRG-1 and acetylation of core histones at the IFN-γ-regulated CIITA promoter IV, but not β-actin was diminished by >90% in Toxoplasma-infected MΦ as compared to non-infected control cells. Remarkably, treatment with histone deacetylase inhibitors restored the ability of infected macrophages to express the IFN-γ regulated genes H2-A/E and CIITA. Taken together, these results indicate that Toxoplasma-infected MΦ are unable to respond to IFN-γ due to disturbed chromatin remodelling, but can be rescued using histone deacetylase inhibitors.
2012-01-25 | GSE28499 | GEO
Project description:Tlx (nr2e1) is an orphan nuclear receptor that is highly expressed in proliferating neural stem cells (NSCs) in the adult mouse forebrain. The goal was to identify Tlx-regulated genes in this specific cell population. Two populations of Tlx-positive neural stem cells were isolated from 2-month-old male mice based on a LacZ marker that was knocked into the Tlx locus. The first population, Tlx(f/Z;CreER), contains a floxed allele of Tlx (f), the LacZ marker (Z), and a CreER fusion transgene. Addition of tamoxifen (4OH-tamoxifen) into this NSC population leads to Cre-mediated deletion of the floxed allele of Tlx. The second NSC population, Tlx(f/Z), does not contain a CreER transgene; thus it does not respond to tamoxifen treatment and was used as a control. Keywords: Nuclear receptor-dependent gene expression
2008-12-01 | GSE9981 | GEO
Project description:Tlx (nr2e1) is an orphan nuclear receptor that is highly expressed in proliferating neural stem cells (NSCs) in the adult mouse forebrain. The goal was to identify Tlx-regulated genes in this specific cell population. Two populations of Tlx-positive neural stem cells were isolated from 2-month-old male mice based on a LacZ marker that was knocked into the Tlx locus. The first population, Tlx(f/Z;CreER), contains a floxed allele of Tlx (f), the LacZ marker (Z), and a CreER fusion transgene. Addition of tamoxifen (4OH-tamoxifen) into this NSC population leads to Cre-mediated deletion of the floxed allele of Tlx. The second NSC population, Tlx(f/Z), does not contain a CreER transgene; thus it does not respond to tamoxifen treatment and was used as a control. Experiment Overall Design: Total RNA samples from two biological replicates were collected at 36 hr or at 60 hr after tamoxifen or vehicle treatment. Total of 16 samples were used to analyze the global gene expression changes using Affymetrix chips.
2009-01-13 | E-GEOD-9981 | biostudies-arrayexpress