Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

35 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Lineage-specific functions of Bcl6 Â in immunity and inflammation are mediated through distinct biochemical mechanisms

ABSTRACT: The transcription factor Bcl6 orchestrates the germinal center reaction through its actions in B and T cells, and regulates inflammatory signaling in macrophages. We report that genetic replacement by mutant Bcl6, which cannot bind corepressors to its BTB domain, disrupted Â germinal center formation and immunoglobulin affinity maturation, due to a defect in B cell Â proliferation and survival. In contrast, BTB loss of function had no effect on T follicular helper cell differentiation and function, nor other T helper subsets. Bcl6 null mice displayed a lethal inflammatory phenotype, whereas BTB mutant mice experienced normal healthy lives with no inflammation. Bcl6 repression of inflammatory responses in macrophages was accordingly independent of the BTB domain repressor function. Bcl6 thus mediates its actions through lineage-specific biochemical functions. ChIP-seq for Bcl6, SMRT and BCOR in germinal center B cells

ORGANISM(S): Homo sapiens

SUBMITTER: Katerina Hatzi

PROVIDER: E-GEOD-43350 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

A biochemical basis for toggling enhancers from the active to poised state in B cells

Project description:BCL6 is crucial for B-cell activation and lymphomagenesis. We used integrative genomics to explore BCL6 mechanism in normal and malignant B-cells. Surprisingly, BCL6 assembled distinct complexes at enhancers vs. promoters. At enhancers BCL6 preferentially recruited SMRT, which mediated H3K27 deacetylation through HDAC3, antagonized p300 activity and repressed transcription, but without decommissioning enhancers. This provides a biochemical basis for toggling enhancers from the active to poised state. Virtually all SMRT was bound with BCL6 suggesting that in B-cells BCL6 uniquely sequesters SMRT from other factors. In promoters BCL6 preferentially recruited BCOR, but most potently repressed promoters where it formed a distinctive ternary complex with SMRT and BCOR. Promoter repression was associated with decreased H3K36me3, H3K79me2 and Pol II elongation, linking BCL6 to transcriptional pausing. We identified the binding patterns of BCL6, SMRT, NCOR and BCOR corepressors in normal germinal center B cells and a DLBCL cell line (OCI-Ly1) using ChIP-seq. Additionally we treated lymphoma cells with siRNA against BCL6 and a non-targeted siRNA (NT control) and performed RNA-seq to identify the genes bound and repressed by BCL6. RNA-seq experiments were performed at 24h and 48h after siRNA treatments. Additional biological triplicate RNA-seq experiments were performed at 48h after BCL6 knockdown. Furthermore, a series of histone mark ChIP-seq and RNA polymerase ChIP-seq (total, Ser5-P and Ser2-P) were preformed to capture the chromatin states associated with the formation of BCL6 corepressor complexes.

2013-08-05 | E-GEOD-29282 | biostudies-arrayexpress

Lineage-specific functions of Bcl6 in immunity and inflammation are mediated through distinct biochemical mechanisms

Project description:The transcription factor Bcl6 orchestrates the germinal center reaction through its actions in B and T cells, and regulates inflammatory signaling in macrophages. We report that genetic replacement by mutant Bcl6, which cannot bind corepressors to its BTB domain, disrupted germinal center formation and immunoglobulin affinity maturation, due to a defect in B cell proliferation and survival. In contrast, BTB loss of function had no effect on T follicular helper cell differentiation and function, nor other T helper subsets. Bcl6 null mice displayed a lethal inflammatory phenotype, whereas BTB mutant mice experienced normal healthy lives with no inflammation. Bcl6 repression of inflammatory responses in macrophages was accordingly independent of the BTB domain repressor function. Bcl6 thus mediates its actions through lineage-specific biochemical functions.

2013-03-03 | GSE43350 | GEO

Transcription profiling of chicken Bcl6 deficient DT40 B cell line to investigate the targets of Bcl6 which is required for germinal center formation

Project description:The transcription factor Bcl6 is required for germinal center formation and deregulated expression of Bcl6 has been observed in lymphomas. To gain insight to the function of Bcl6 in terminal differentiation of B cells to plasma cells and to investigate the targets of Bcl6, we established a Bcl6 deficient DT40 B cell line.

2010-02-17 | E-MEXP-2062 | biostudies-arrayexpress

EZH2 and BCL6 cooperate to assemble CBX8-BCOR Polycomb complex to repress bivalent promoters, mediate germinal center formation and promote lymphomagenesis [RNA-seq]

Project description:EZH2 mediates the humoral immune response and drives lymphomagenesis through de novo formation of bivalent chromatin domains and critical germinal center (GC) B cell promoters. We show that such formation is dependent on the presense of BCL6 and the presence of non-canonical PRC1-BCOR complex. We observe that BCL6 and EZH2 cooperate to accelerate diffuse large B cell lymphoma (DLBCL) development and combinatorial targeting of these repressors results in enhanced anti-lymphoma activity in vitro, in vivo, and in primary human DLBCLs. DLBCL cell lines treated with BCL6 inhibitor 79-6.1085

2016-07-20 | E-GEOD-73109 | biostudies-arrayexpress

ChIP-on-chip of BCL6

Project description:Identification BCL6 target genes in primary germinal center cells and DLBCL cell lines by ChIP-on-chip

2009-03-14 | GSE15179 | GEO

ChIP-on-chip of BCL6

Project description:Identification BCL6 target genes in primary germinal center cells and DLBCL cell lines by ChIP-on-chip Three replicates in each type of cells

2010-06-21 | E-GEOD-15179 | biostudies-arrayexpress

The BCL6 RD2 domain governs commitment of activated B-cells to form germinal centers

Project description:Our data demonstrated that Bcl6 directly binds and represses trafficking receptors S1pr1 and Grp183 by recruiting Hdac2 through the RD2 domain. Deregulation of these genes impairs B-cell migration and may contribute to the Germinal Center failure in Bcl6RD2MUT mice. RNAseq was performed in endogenous BCL6-depleted OCI-LY1 cells rescued with either WT or RD mutant BCL6 (N=3 for each group).

2014-09-14 | E-GEOD-58365 | biostudies-arrayexpress

ChIP-chip from different B cell stages with Abs to H3K4me3, H3K4me1, H3K9,K14-diacetyl, H3K27me3 and RNA polymerase II

Project description:B cell differentiation stage specific histone modifications detected within and upstream of genes that play critical roles in B cell differentation. Germinal center B cell stage specific activating histone marks in regions far upstream of the BCL6 promoter regulate BCL6 expression.

2010-07-06 | GSE19910 | GEO

Cooperative transcriptional repression by BCL6 and BACH2 in germinal center B-cell differentiation

Project description:The transcriptional repressors BCL6 and BACH2 are crucial regulators of germinal center (GC) B-cell fate, and are known to interact and repress transcription of PRDM1, a key driver of plasma cell differentiation. How these factors cooperate is not fully understood. Herein we show that while GC formation is only minimally impaired in Bcl6+/- or Bach2+/- mice, double heterozygous Bcl6+/-Bach2+/- mice exhibit profound reduction in GC formation. Splenic B-cells from Bcl6+/- Bach2+/- mice display accelerated plasmacytic differentiation and high expression of key plasma cell genes such as Prdm1, Xbp1 and CD138. ChIP-seq revealed that in B-cells BACH2 is mostly bound to genes together with its heterodimer partner MAFK. The BACH2-MAFK complex binds to sets of genes known to be involved in the GC response, 60% of which are also targets of BCL6. Approximately 30% of BACH2 peaks overlap with BCL6 including cis-regulatory sequences of the PRDM1 gene. BCL6 also modulates BACH2 protein stability and their protein levels are positively correlated in GC B-cells. Therefore, BCL6 and BACH2 cooperate to orchestrate gene expression patterning in GC B cells through both transcriptional and biochemical mechanisms, which collectively determine the proper initiation and timing of terminal differentiation. ChIP-seq using P18 antibodies in OCI-Ly7 cells

2013-11-17 | E-GEOD-47784 | biostudies-arrayexpress

Small molecule-induced polymerization triggers degradation of BCL6

Project description:Most small-molecule protein degraders act as interface stabilizers ‘molecular glues’ between E3 ubiquitin ligases and target proteins to induce ternary complex formation and ubiquitin-dependent target protein degradation. Here we report polymerization as a novel mechanism for small molecule-induced degradation. Using functional screens in combination with molecular and biochemical assays, we found that BI-3802, which binds to the BTB domain of the oncogenic transcription factor BCL6, induces polymerization of BCL6 into regular helical structures in vitro and foci in vivo. Polymerization precedes degradation by the SIAH1 E3 ubiquitin ligase. Hereby, a VxP amino acid motif on BCL6, distal from the drug-binding BTB domain, is required for SIAH1 binding, ubiquitination and BI-3802-induced degradation. Our findings propose that small molecule-induced polymerization is not only a new modality for targeted protein degradation, but also provides synthetic biology with a tool for tunable protein polymerization and opens new avenues for future drug design.

2020-11-20 | PXD016185 | Pride

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data