Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A dichotomy of gene regulatory associations during the activated B-cell to plasmablast transition [Microarray]

ABSTRACT: The activated B-cell (ABC) to plasmablast transition is the cusp of antibody secreting cell (ASC) differentiation but is incompletely defined. We apply expression time-courses, parsimonious gene correlation network analysis, and ChIP-seq to explore this in human cells. The transition initiates with input signal loss leading within hours from cell growth dominant programs to enhanced proliferation, accompanied from 24h by ER-stress response, secretory optimization and upregulation of ASC features. Clustering of genomic occupancy for ASC transcription factors (TFs) IRF4, BLIMP1 and XBP1 with CTCF and histone marks defines distinct patterns for each factor in plasmablasts. Integrating TF-associated clusters and modular gene expression identifies a dichotomy: XBP1 and IRF4 significantly link to gene modules induced in plasmablasts, but not to modules of repressed genes, while BLIMP1 links to modules of ABC genes repressed in plasmablasts but is not significantly associated with modules induced in plasmablasts. Pharmacological inhibition of the G9A (EHMT2) histone-methytransferase, a BLIMP1 co-factor that catalyzes repressive H3K9me2 marks, leaves functional ASC differentiation intact but de-represses ABC-state genes. Thus, in human plasmablasts IRF4 and XBP1 emerge as the dominant association with ASC gene expression, while BLIMP1 links to repressed modules with particular focus in repression of the B-cell activation state.

ORGANISM(S): Homo sapiens

PROVIDER: GSE142492 | GEO | 2020/08/24

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

A dichotomy of gene regulatory associations during the activated B-cell to plasmablast transition [ChIP-seq]

Project description:The activated B-cell (ABC) to plasmablast transition is the cusp of antibody secreting cell (ASC) differentiation but is incompletely defined. We apply expression time-courses, parsimonious gene correlation network analysis, and ChIP-seq to explore this in human cells. The transition initiates with input signal loss leading within hours from cell growth dominant programs to enhanced proliferation, accompanied from 24h by ER-stress response, secretory optimization and upregulation of ASC features. Clustering of genomic occupancy for ASC transcription factors (TFs) IRF4, BLIMP1 and XBP1 with CTCF and histone marks defines distinct patterns for each factor in plasmablasts. Integrating TF-associated clusters and modular gene expression identifies a dichotomy: XBP1 and IRF4 significantly link to gene modules induced in plasmablasts, but not to modules of repressed genes, while BLIMP1 links to modules of ABC genes repressed in plasmablasts but is not significantly associated with modules induced in plasmablasts. Pharmacological inhibition of the G9A (EHMT2) histone-methytransferase, a BLIMP1 co-factor that catalyzes repressive H3K9me2 marks, leaves functional ASC differentiation intact but de-represses ABC-state genes. Thus, in human plasmablasts IRF4 and XBP1 emerge as the dominant association with ASC gene expression, while BLIMP1 links to repressed modules with particular focus in repression of the B-cell activation state.

2020-08-24 | GSE142493 | GEO

Blimp1 controls plasma cell physiology and function

Project description:Antibody-secreting plasma cells are the terminal stage of the B-cell lineage. Plasma cell differentiation requires a major resetting of gene expression to silence the B cell transcriptional program, whilst establishing secretory function and long-term survival. The transcription factors Blimp1 and Irf4 are essential for the initial differentiation of activated B cells to antibody-secreting cells, however their function in mature plasma cells remains elusive. We have found that while Irf4 was essential for plasma cell survival, Blimp1 was dispensable. Blimp1-deficient cells retained the unique plasma cell transcriptional signature, but lost the ability to secrete antibody or to maintain the characteristic size and ultrastructure of plasma cells. Blimp1 was required for full expression of many components of the unfolded protein response (UPR), including Xbp1 and Atf6, as well as for the appropriate processing of Igh mRNA. The overlap of Blimp1 and Xbp1 function was restricted to the UPR genes, with Blimp1 uniquely regulating activity of the mTOR pathway, plasma cell size and morphology. These studies establish Blimp1 as a major regulator of the UPR pathway that is also required for the unique metabolic requirements of plasma cells enabling the secretion of protective antibody. RNA-seq was performed on wild type, Blimp1-/- and Xbp1-/- mouse plasma cells. Between two to four biological replicates were generated and sequenced for each sample.

2016-01-18 | E-GEOD-70981 | biostudies-arrayexpress

Multifunctional role of the transcription factor Blimp1 in coordinating plasma cell differentiation

Project description:Blimp1 is an essential regulator of plasma cells. Here we studied its functions in early plasmablast differentiation by identifying regulated Blimp1 target genes. Blimp1 promoted plasmablast migration and adhesion by controlling many genes involved in these processes. It repressed several transcription factor genes and Aicda, thus silencing B-cell-specific gene expression, antigen presentation and class switch recombination in plasmablasts. It also directly activated genes, leading to increased expression of the plasma cell regulator IRF4 and proteins involved in immunoglobulin secretion. Blimp1 strongly induced immunoglobulin gene transcription by controlling the activity of Igh and Igk 3’ enhancers and regulated the posttranscriptional switch of expression from the membrane-bound to secreted immunoglobulin heavy-chain by activating Ell2. Notably, Blimp1 recruited chromatin-remodeling and histone-modifying complexes to regulate its target gene. Hence, many essential functions of plasma cells are under Blimp1 control.

2015-12-01 | GSE71698 | GEO

Blimp1 controls plasma cell physiology and function

2016-01-18 | GSE70981 | GEO

A CRISPR/Cas9-mediated screen identifies regulators of early plasma cell differentiation

Project description:The differentiation of B cells into antibody-secreting cells depends on cell division-coupled, epigenetic and other cellular processes that are incompletely understood. We have developed a CRISPR/Cas9-based screen that models an early stage of T cell-dependent plasma cell differentiation and measures B cell survival or proliferation versus the formation of CD138+ plasmablasts. Here, we refined and extended this screen to more than 500 candidate genes that are highly expressed in plasma cells. Among known genes whose deletion preferentially affected plasmablast formation were the transcriptional regulators Prdm1, Irf4 and Pou2af1, and the Ern1 gene encoding the ER stress sensor IRE1a. Moreover, we newly identified several genes involved in NF-kB or p38 signaling (Pim2, Nfkbia, Mapk14), vesicle trafficking (Arf4, Preb) and epigenetic regulators that form part of the NuRD complexes (Hdac1, Mta2, Mbd2). Defective plasmablast formation caused by Ern1 deletion could not be rescued by spliced XBP1 (XBP1s), a transcription factor dependent on and downstream of IRE1a, suggesting that in early plasma cell differentiation IRE1a acts independently of XBP1s. The deletion of ARF4, a small GTPase required for ER-to-Golgi transport, impaired plasmablast formation by blocking antibody secretion. Plasmablast formation after Hdac1 deletion was consistently reduced by about 50%, while deletion of the closely related Hdac2 gene had no effect. Hdac1 knock-out led to strongly perturbed protein expression of antagonistic transcription factors that specify plasma cell versus B cell identity (by decreasing IRF4 and BLIMP1 and increasing BACH2 and PAX5). Taken together, our results highlight specific and non-redundant roles for Ern1, Arf4 and Hdac1 in the early steps of plasma cell differentiation.

2022-12-22 | PXD038201 | Pride

Chromatin accessibility profiling of terminal B cell differentiation [ATAC-Seq]

Project description:The terminal differentiation of B cells into antibody-secreting cells (ASCs) is a critical component of adaptive immune responses. Using our in vitro differentiation system, we combined RNA sequencing with ATAC-seq to characterize genomic events driving the ASC differentiation of human primary naive B cells. After an initial response to IL-4, cells that committed to an ASC fate downregulated the CD23 marker and IL-4 signaling, whereas cells that maintained IL-4 signaling did not differentiate. As demonstrated in the mouse, downregulation of the human ubiquitin ligase CBLB was required to free IRF4 from proteasomal degradation and produce levels needed for ASC differentiation. Our results evidenced two previously undocumented mechanisms driving human terminal B cell differentiation. Lastly, we showed that CD23-negative cells (i) carried the imprint of their previous activated B-cell status, (ii) were precursors of plasmablasts, and (iii) had a similar phenotype to in vivo pre-plasmablasts.

2020-11-08 | GSE136989 | GEO

Expression profiling of terminal B cell differentiation [RNA-Seq]

2020-11-08 | GSE136988 | GEO

The Xbp1-regulated transcription factor Mist1 restricts antibody secretion by restraining Blimp1 expression in plasma cells

Project description:Antibody secretion by plasma cells provides acute and long-term protection against pathogens. The high secretion potential of plasma cells depends on the unfolded protein response, which is controlled by the transcription factor Xbp1. Here, we analyzed the Xbp1-dependent gene expression program of plasma cells and identified Bhlha15 (Mist1) as the most strongly activated Xbp1 target gene. As Mist1 plays an important role in other secretory cell types, we analyzed in detail the phenotype of Mist1-deficient plasma cells in Cd23-Cre Bhlha15(fl/fl) mice under steady-state condition or upon NP-KLH immunization. Under both conditions, Mist1-deficient plasma cells were 1.4-fold reduced in number and exhibited increased IgM production and antibody secretion compared to control plasma cells. At the molecular level, Mist1 regulated a largely different set of target genes compared to Xbp1. Notably, expression of the Blimp1 protein, which is known to activate immunoglobulin gene expression and to contribute to antibody secretion, was 1.3-fold upregulated in Mist1-deficient plasma cells, which led to a moderate downregulation of most Blimp1-repressed target genes in the absence of Mist1. Importantly, a 2-fold reduction of Blimp1 (Prdm1) expression was sufficient to restore the cell number and antibody expression of plasma cells in Prdm1(Gfp/+) Cd23-Cre Bhlha15(fl/fl) mice to the same level seen in control mice. Together, these data indicate that Mist1 restricts antibody secretion by restraining Blimp1 expression, which likely contributes to the viability of plasma cells.

2022-10-18 | GSE190591 | GEO

BLIMP-1 is insufficient to induce antibody secretion in the absence of IRF4

Project description:Differentiation of B cells into antibody secreting cells (ASCs), plasmablasts and plasma cells, is regulated by a network of transcription factors. Within this network factors including PAX5 and BCL6 prevent ASC differentiation and maintain the B cell phenotype whereas BLIMP-1 and high IRF4 expression promote plasmacytic differentiation. BLIMP-1 is thought to induce immunoglobulin secretion. While IRF4 is needed for the survival of ASCs, its role in the regulation of antibody secretion has been controversial. BCL6-deficient DT40 B cell line has upregulated BLIMP-1 expression and secrete antibodies. In order to study the role of IRF4 in regulation of antibody secretion we have created a double knockout (DKO) DT40 B cell line deficient in both IRF4 and BCL6. This DKO cell line did not upregulate PRDM1 (the gene encoding for BLIMP-1) expression or secrete IgM. Even enforced BLIMP-1 expression in DKO cells or IRF4-deficient cells could not induce IgM secretion while it did in WT cells. However, enforced IRF4 expression in DKO cells induced strong IgM secretion. Our findings support a model where IRF4 expression in addition to BLIMP-1 expression is required to induce antibody secretion.

2018-03-05 | GSE94836 | GEO

Determining IRF4 target genes using RNA interference in ABC-DLBCL and MM

Project description:Interferon regulatory factor 4 (IRF4) is a transcriptional regulator with critical roles in the normal development and malignant transformation of lymphocytes. Recently we have shown that plasma cell cancers (multiple myeloma, MM) are addicted to an aberrant gene expression program ochestrated by wild-type IRF4 for their survival. Here we show that an aggressive malignancy of mature B cells, the activated B cell for of Diffuse Large B Cell lymphoma (ABC-DLBC), also depends on IRF4 for survival. With genome-wide expression profiling and localization (ChIP-Seq) assays, we identified IRF4 target genes in ABC-DLBCL as members of diverse pathways related to B cell biology and malignant behavior, distinct from IRF4 targets in MM. For example, we find the gene encoding the NFkB signal transduction adapter protein CARD11 is a target of IRF4 activation, driving the critical NFkB pathway in ABC-DLBCL. Further, we find enrichment of DNA binding motifs for ETS-IRF factors in regions of IRF4 binding in ABC-DLBCL suggesting cooperative activity between IRF4 and an ETS family transcription factor. Through complementation assays we show that IRF4 and the critical ABC-DLBCL ETS factor SPIB interact with one another and are key to ABC-DLBCL survival. Together our data show that ABC-DLBCL is addicted to the interaction between IRF4 and SPIB, in part through a positive feedback loop invovling CARD11 and the activation of the NFkB pathway. These data suggest theraepeutic potential in targeting the IRF4:SPIB interface in ABC-DLBCL.

2011-07-01 | GSE22901 | GEO

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