The transcriptional repressor BLIMP1 is a master regulator of B and T cell differentiation. To examine the role of BLIMP1 in innate immunity we used a conditional knockout (CKO) of Blimp1 in myeloid cells and found that Blimp1 CKO mice were protected from lethal infection induced by Listeria monocytogenes. Transcriptome analysis of Blimp1 CKO macrophages identified the murine chemokine (C-C motif) ligand 8, CCL8 as a direct target of Blimp1-mediated transcriptional repression in these cells. BLIMP1-deficient macrophages expressed elevated levels of Ccl8 and consequently Blimp1 CKO mice had higher levels of circulating CCL8 resulting in increased neutrophils in the peripheral blood, promoting a more aggressive anti-bacterial response. Mice lacking the Ccl8 gene were more susceptible to L. monocytogenes infection than wild type mice. While CCL8 failed to recruit neutrophils directly, it was chemotactic for / T cells and CCL8-responsive / T cells were enriched for IL-17F. Finally, CCL8-mediated enhanced clearance of L. monocytogenes was dependent on / T cells. Collectively, these data reveal an important role for BLIMP1 in modulating host-defenses by suppressing expression of the chemokine CCL8.
The transcriptional repressor BLIMP1 curbs host defenses by suppressing expression of the chemokine CCL8.
Specimen part
View SamplesAnalysis of H292 cells infected with Mycoplasma hyorhinis. Mycoplasma infection reduces the cytotoxic effect of Nutlin3 on H292 cells. The results provide insight into molecular mechanisms underlying the response of H292 cells to Nutlin3.
Mycoplasma hyorhinis reduces sensitivity of human lung carcinoma cells to Nutlin-3 and promotes their malignant phenotype.
Specimen part, Cell line
View SamplesPolycomb Repressive Complex 2 (PRC2) catalyzes histone H3 lysine 27 tri-methylation, an epigenetic modification associated with gene repression. H3K27me3 is enriched at the promoters of a large cohort of developmental genes in embryonic stem cells (ESCs). Loss of H3K27me3 leads to a failure of ESCs to properly differentiate, which presents a major roadblock for dissecting the precise roles of PRC2 activity during lineage commitment. While recent studies suggest that loss of H3K27me3 leads to changes in DNA methylation in ESCs, how these two pathways coordinate to regulate gene expression programs during lineage commitment is poorly understood. Here, we analyzed gene expression and DNA methylation levels in several PRC2 mutant ESC lines that maintain varying levels of H3K27me3. We found that maintenance of intermediate levels of H3K27me3 allowed for proper temporal activation of lineage genes during directed differentiation of ESCs to spinal motor neurons (SMNs). However, genes that function to specify other lineages failed to be repressed, suggesting that PRC2 activity is necessary for lineage fidelity. We also found that H3K27me3 is antagonistic to DNA methylation in cis. Furthermore, loss of H3K27me3 leads to a gain in promoter DNA methylation in developmental genes in ESCs and in lineage genes during differentiation. Thus, our data suggest a role for PRC2 in coordinating dynamic gene repression while protecting against inappropriate promoter DNA methylation during differentiation. Overall design: Embryonic Stem Cell (ESC) lines mutant for PRC2 core components Suz12 (Suz12GT and Suz12delta) and Eed (Eednull) were subjected to in vitro directed differentiation down the spinal motor neuron lineage. ESCs and day 5 differentiated cells from the three mutant lines and wild-type were used for RNA-seq.
Polycomb Repressive Complex 2 regulates lineage fidelity during embryonic stem cell differentiation.
No sample metadata fields
View SamplesHost cells harbor various intrinsic mechanisms to restrict viral infections as a first line of antiviral defense. Viruses have evolved various countermeasures against these antiviral mechanisms. Here we show that N-Myc Downstream-Reguated Gene 1 (NDRG1) limits productive HCV infection by inhibiting viral assembly. Interestingly, HCV infection down-regulates NDRG1 protein and mRNA expression. Loss of NDRG1 increases the size and number of lipid droplets, which are the sites of HCV assembly. HCV suppresses NDRG1 expression by up-regulating MYC, which directly inhibits the transcription of NDRG1.
N-Myc Downstream-Regulated Gene 1 Restricts Hepatitis C Virus Propagation by Regulating Lipid Droplet Biogenesis and Viral Assembly.
Cell line, Treatment
View SamplesIdentification of genes regulated by GATA-1 independent of the cofactor FOG-1.
Friend of GATA-1-independent transcriptional repression: a novel mode of GATA-1 function.
No sample metadata fields
View SamplesPURPOSE
Gene expression profiling reveals novel biomarkers in nonsmall cell lung cancer.
Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Developmentally regulated higher-order chromatin interactions orchestrate B cell fate commitment.
Specimen part
View SamplesESCs and NPCs are two setm cell types which rely on expression of the transcription factor Sox2. We profilled gene expression in ESCs and NPCs to correlate genome-wide Sox2 ChIP-Seq data in these cells with expression of putative targets
SOX2 co-occupies distal enhancer elements with distinct POU factors in ESCs and NPCs to specify cell state.
No sample metadata fields
View SamplesSON is a large Ser/Arg (SR)-related protein localized in nuclear speckles. SON siRNA causes defects in mitotic progression and genome instability. We used microarrays to detail the pattern of gene expression after SON knockdown.
SON controls cell-cycle progression by coordinated regulation of RNA splicing.
Specimen part
View SamplesOrganization of the genome in 3D nuclear-space is known to play a crucial role in regulation of gene expression. However, the chromatin architecture that impinges on the B cell-fate choice of multi-potent progenitors remains unclear. By employing in situ Hi-C, we have identified distinct sets of genomic loci that undergo a developmental switch between permissive and repressive compartments during B-cell fate commitment. Intriguingly, we show that topologically associating domains (TADs) represent co-regulated subunits of chromatin and display considerable structural alterations as a result of changes in the cis-regulatory interaction landscape. The extensive rewiring of cis-regulatory interactions is closely associated with differential gene expression programs. Further, we demonstrate the regulatory role of Ebf1 and its downstream factor, Pax5, in chromatin reorganization and transcription regulation. Together, our studies reveal that alterations in promoter and cis-regulatory interactions underlie changes in higher-order chromatin architecture, which in turn determines cell-identity and cell-type specific gene expression patterns.
Developmentally regulated higher-order chromatin interactions orchestrate B cell fate commitment.
Specimen part
View Samples