Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Huwe1 supports B-cell development, B-cell-dependent immunity, somatic hypermutation and class switch recombination by regulating proliferation

ABSTRACT: The development and differentiation of B cells is intimately linked to cell proliferation and the generation of diverse immunoglobulin gene (Ig) repertoires. The ubiquitin E3 ligase HUWE1 controls proliferation, DNA damage responses, and DNA repair, including the base excision repair (BER) pathway. These processes are of crucial importance for B-cell development in the bone marrow, and the germinal center (GC) response, which results in the clonal expansion and differentiation of B cells expressing high affinity immunoglobulins. Here, we re-examined the role of HUWE1 in B-cell proliferation and Ig gene diversification, focusing on its involvement in somatic hypermutation (SHM) and class switch recombination (CSR). B-cell-specific deletion of Huwe1 resulted in impaired development, differentiation and maturation of B cells in the bone marrow and peripheral lymphoid organs. HUWE1 deficiency diminished SHM and CSR by impairing B-cell proliferation and AID expression upon activation in vitro and in vivo, and was unrelated to the HUWE1-dependent regulation of the BER pathway. Interestingly, we found that HUWE1-deficient B cells showed increased mRNA expression of Myc target genes upon in vitro activation despite diminished proliferation. Our results confirm that the E3 ligase HUWE1 is an important contributor in coordinating the rapid transition of antigen naïve, resting B cells into antigen-activated B cells and regulates mutagenic processes in B cells by controlling AID expression and the post-transcriptional output of Myc target genes.

ORGANISM(S): Mus musculus

PROVIDER: GSE221351 | GEO | 2022/12/23

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Gene expression analysis of B cell lymphomas from representative IÂµHABcl6, IÂµHABcl6 Ung-/- Msh2-/-, and IÂµHABcl6 Msh2-/- mouse models.

Project description:Somatic hypermutation (SHM) and class switch recombination (CSR) of immunoglobulin (Ig) genes are genomic modification events that occur in germinal center (GC) B cells and are initiated through deamination of cytidine to uracil by activation induced cytidine deaminase (AID). Resulting uracil-guanine (U-G) mismatches are subsequently processed by low-fidelity base-excision (BER) and mismatch repair (MMR) pathways to yield mutations and DNA strand lesions. Although off-target AID activity also contributes to oncogenic point mutations and chromosome translocations associated with B cell lymphomas, the role of downstream AID-associated DNA repair pathways in the pathogenesis of these lymphomas is unknown. Here, we show that simultaneous BER and MMR deficiency causes genomic instability and a shorter latency to the development of a BCL6-driven GC B cell lymphoma. In contrast, loss of BER alone is highly protective against B cell transformation while loss of MMR fosters the development of a variety of malignancies. These findings lend insight into a complex interplay between AID-associated BER and MMR pathways that produces a net protective effect against GC B cell lymphomagenesis. Representative B cell lymphomas from 3 IÂµHABcl6, 6 IÂµHABcl6 Ung-/- Msh2-/-, and 5 IÂµHABcl6 Msh2-/- mice were analyzed in this study. Total RNA was extracted from frozen tumor cells and processed according to Illumina standard protocols.

2015-12-08 | E-GEOD-48304 | biostudies-arrayexpress

Gene expression analysis of B cell lymphomas from representative IµHABcl6, IµHABcl6 Ung-/- Msh2-/-, and IµHABcl6 Msh2-/- mouse models.

2015-12-08 | GSE48304 | GEO

A broad atlas of somatic hypermutation allows prediction of activation-induced deaminase targets.

Project description:Activation Induced Deaminase (AID) initiates somatic hypermutation (SHM) and class switch recombination (CSR) in germinal center (GC) B cells through the deamination of deoxycytidine residues (dC) into deoxyuridines (dU) in immunoglobulin (Ig) genes. Although AID has a strong preference for Ig genes, it can also target other genomic regions, giving rise to mutations or chromosomal translocations. Thus, understanding the specificity of AID has major implications for oncogenic transformation. However, approaching AID specificity has proved extremely challenging because AID deamination events occur at low frequencies. Here we have sequenced at very high depth >1500 genomic regions from GC B cells and identified 275 genes targeted by AID, including 30 of the previously known 35 AID targets. This has enabled for the first time to define the molecular features predictive of AID target specificity genome-wide. Furthermore, we identify the most highly mutated hotspot for AID activity described to date. We also find that Base Excision Repair (BER) and Mismatch Repair (MMR) systems, which are responsible for the resolution of AID deaminations, back-up each other to faithfully repair AID-induced lesions. Finally, our data establishes a novel link between AID mutagenic activity and malignant transformation.

2018-01-19 | GSE102944 | GEO

Activation-induced cytidine deaminase induces reproducible DNA breaks at many non-Ig loci in activated B cells

Project description:After immunization or infection, activation-induced cytidine deaminase (AID) initiates diversification of immunoglobulin (Ig) genes in B cells, introducing mutations within the antigen binding V regions (somatic hypermutation, SHM) and double-strand DNA breaks (DSBs) into switch (S) regions, leading to antibody class switch recombination (CSR). Using a candidate approach, AID has been shown to initiate mutations at numerous non-Ig genes in B cells in Peyer’s patches. However, it is not known if during B cell activation, AID also induces DNA breaks at genes other than IgH genes, which would lead to genomic instability and malignancy. Using a non-biased genome-wide approach, we have identified hundreds of reproducible AID-dependent DSBs in mouse splenic B cells shortly after induction of CSR in culture. Most interestingly, AID induces DSBs at sites syntenic with sites of translocations, deletions, and amplifications found in human B cell lymphomas, including within the oncogene B cell lymphoma11a (bcl11a)/evi9. The AID-dependent DSBs are not restricted to transcribed regions, and they frequently occur within repeated sequence elements, including CA and non-CA repeats, and SINEs. Comparison of Nbs1 binding sites in wild-type vs. aid-/- splenic B cells induced to undergo CSR; aid-dependent Nbs1 sites correlated with gene transcription (RNA Pol2).

2011-01-21 | E-GEOD-24827 | biostudies-arrayexpress

Activation-induced cytidine deaminase induces reproducible DNA breaks at many non-Ig loci in activated B cells

2011-01-21 | GSE24827 | GEO

Gene expression analysis of B-NHL from λMYC, λMYC/IµHABCL6, λMYC/AIDKO and λMYC/IµHABCL6/AIDKO mouse models

Project description:Most human B cell lymphomas (B-NHL) are derived from germinal centers (GCs), the structure where B-cells undergo class switch recombination (CSR) and somatic hypermutation (SHM) and are selected for high-affinity antibody production. The pathogenesis of B-NHL is associated with distinct genetic lesions, including chromosomal translocations and aberrant somatic hypermutation, which appear to arise from mistakes occurring during CSR and SHM. To ascertain the role of CSR and SHM in lymphomagenesis, we crossed three oncogene-driven (MYC, BCL6, MYC/BCL6) mouse models of B cell lymphoma with mice lacking activation-induced cytidine deaminase (AID), the enzyme required for both processes. We show that AID deficiency prevents BCL6-dependent, GC-derived B-NHL, while it has no impact on the formation of MYC-driven, pre-GC lymphomas. Accordingly, abrogation of AID is associated with the disappearance of both CSR- and SHM-mediated structural alterations, including cMYC-IgH chromosomal translocations and aberrant SHM. These results demonstrate that AID is required for GC-derived lymphomagenesis, providing direct support to the notion that errors in AID-mediated antigen-receptor gene modification events represent major contributors to the pathogenesis of human B-NHL. Keywords: Phenotypic characterization of tumors developing in oncogene-driven mouse models of lymphomas

2007-11-01 | GSE9249 | GEO

RNA-sequencing of Nedd4+/+ and Nedd4-/- mouse splenic B cells

Project description:Programmed mutagenesis of the immunoglobulin locus of B-lymphocytes during class switch recombination and somatic hypermutation requires RNA polymerase II (RNA polII) transcription complex dependent targeting of the DNA mutator, Activation Induced cytidine Deaminase (AID). AID deaminates cytidine residues on substrate sequences in the immunoglobulin (Ig) locus via a transcription-dependent mechanism and this activity is stimulated by the RNA polII stalling co-factor Spt5 and the eleven-subunit cellular non-coding RNA 3’-5’ exonucleolytic processing complex, RNA exosome. The mechanism by which the RNA exosome recognizes immunoglobulin locus RNA substrates to stimulate AID DNA deamination activity on its in vivo substrate sequences is an important question. Here we report that E3-ubiquitin ligase Nedd4 destabilizes AID-associated RNA polII by a ubiquitination event leading to generation of 3’-end free RNA exosome RNA substrates at the Ig locus and other AID target sequences genome-wide. Using highthrough-out RNA sequencing technology, we find that lack of Nedd4 activity in B cells leads to accumulation of RNA exosome substrates at AID target genes. Moreover, we find that Nedd4-deficient B cells are inefficient in undergoing class switch recombination. Taken together, our study links non-coding RNA processing following RNA polymerase II pausing with regulation of the mutator AID protein. Our study also identifies Nedd4 as a regulator of non-coding RNA that are generated by stalled RNA polII genome-wide. Splenic B cells from Nedd4+/+ and Nedd4-/- B cells fetal liver chimeric mice were were stimulated in culture for IgG1 CSR. Total RNA was isolated and evaluated with whole genome RNA-seq

2013-08-07 | E-GEOD-49027 | biostudies-arrayexpress

Genome-wide AID target loci in BL2 cells

Project description:Activation-induced cytidine deaminase (AID) is required for both somatic hypermutation (SHM) and class-switch recombination (CSR) in activated B cells. AID is also known to target non-immunoglobulin genes and introduce mutations or chromosomal translocations, eventually causing tumors. To identify as-yet-unknown AID targets, we screened early AID-induced DNA breaks using two independent genome-wide approaches. Along with known AID targets, this screen identified a set of novel genes (SNHG3, MALAT1, BCL7A, and CUX1), and confirmed that these new loci accumulated mutations as high as Ig locus after AID activation. Moreover, these genes share three important characteristics with the immunoglobulin gene: translocations in tumors, repetitive sequences and the epigenetic modification of chromatin by H3K4 trimethylation in the vicinity of cleavage sites.

2012-02-01 | GSE32027 | GEO

DNA double-strand breaks induced by AID in activated splenic B cells

Project description:Activation-induced cytidine deaminase (AID) is required for initiation of Ig class switch recombination (CSR) and somatic hypermutation (SHM) of antibody genes during immune responses. AID has also been shown to induce chromosomal translocations, mutations, and DNA double-strand breaks (DSBs) involving non-Ig genes in activated B cells. To determine what makes a DNA site a target for AID-induced DSBs, we identify off-target DSBs induced by AID by performing chromatin immunoprecipitation (ChIP) for Nbs1, a protein that binds DSBs, followed by deep sequencing (ChIP-Seq). We detect and characterize hundreds of off-target AID-dependent DSBs. Two types of tandem repeats are highly enriched within the Nbs1-binding sites: long CA repeats, which can form Z-DNA, and tandem pentamers containing the AID target hotspot WGCW. These tandem repeats are not nearly as enriched at AID-independent DSBs, which we also identified. Msh2, a component of the mismatch repair pathway and important for genome stability, increases off-target DSBs, similar to its effect on Ig switch region DSBs, which are required intermediates during CSR. Most of the off-target DSBs are two-ended, consistent with generation during G1 phase, similar to DSBs in Ig switch regions. However, a minority are one-ended, presumably due to conversion of single-strand breaks to DSBs during replication. One-ended DSBs are repaired by processes involving homologous recombination, including break-induced replication repair, which can lead to genome instability. Off-target DSBs, especially those present during S phase, can lead to chromosomal translocations, deletions and gene amplifications, resulting in the high frequency of B cell lymphomas derived from cells that express or have expressed AID.

2015-07-16 | GSE66424 | GEO

Convergent Sense/Antisense Transcription At Intragenic Super-Enhancers Targets AID-initiated Genomic Instability

Project description:Activation-induced cytidine deaminase (AID) initiates both somatic hypermutation (SHM) for antibody affinity maturation and DNA breakage for antibody class switch recombination (CSR) via transcription-dependent cytidine deamination of single stranded DNA targets. While largely specific for immunglobulin genes, AID also acts on a limited set of off-targets, generating oncogenic translocations and mutations that contribute to B cell lymphoma. How AID is recruited to off-targets has been a long-standing mystery. Based on deep GRO-Seq studies of mouse and human B lineage cells activated for CSR or SHM, we report that most robust AID off-target translocations occur within highly focal regions of target genes in which sense and antisense transcription converge. Moreover, we found that such AID-targeting "convergent" transcription arises from antisense transcription that emanates from Super-Enhancers within sense transcribed gene bodies. Our findings provide a mechanistic explanation for AID off-targeting to a small subset of mostly lineage-specific genes in activated B cells. We performed GRO-Seq and H3K27Ac ChIP-Seq with different B lineage cell types and MEF cells to find the signatures associated with AID targeting.

2014-12-04 | E-GEOD-62296 | biostudies-arrayexpress

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