Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA319639 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:B cells diversify and affinity-mature their antigen receptor repertoire in germinal centers (GC). GC B cells receive help signals during transient interaction with T cells, yet it remains unknown how these transient T-B interactions sustain the subsequent proliferative program of selected B cells. Here we show that the transcription factor AP4 is required for sustained GC B cell proliferation and subsequent establishment of a diverse and protective antibody repertoire. AP4 is induced by c-MYC during the T-B interactions and maintained by T cell-derived IL-21. B cell-specific deletion of AP4 resulted in reduced GC sizes and somatic hypermutation and a failure to control chronic viral infection. These results indicate that AP4 integrates T cell-mediated selection and sustained expansion of GC B cells for humoral immunity. Splenic B cells activated with anti-IgM and CD40L in vitro and germinal center B cells sorted from C57BL/6 mice eight days after immunization with sheep red blood cells (SRBCs) were obtained and genome-wide occupancy of c-MYC, AP4 and active histone marks was profiled by chromatin immunoprecipitation and high-throughput sequencing. Gene expression in MYCâAP4â LZ, MYC+AP4+ LZ, AP4+ DZ, and APâ DZ GC B cells from SRBC-immunized AP4-mCherry / c-MYC-GFP dual reporter mice was profiled by RNA-seq.
2016-08-23 | E-GEOD-80669 | biostudies-arrayexpress
Project description:Defining AP4-regulated gene expression programs in pro/pre-B cells overexpressing c-MYC
| PRJNA551667 | ENA
Project description:A hallmark feature of adaptive immune cells is their capacity for rapid cell proliferation required for producing and expanding cells with a diverse repertoire of antigen receptor and amplification of antigen-specific receptors. While proliferation is beneficial for host protection from infection and cancers, it inevitably elevates the risk of oncogenic transformation. Developing lymphocytes, as well as B cells in the germinal center (GC), are considered tumor-prone due to additional genomic insults from physiological antigen receptor gene rearrangement and editing. However, oncogenic transformation of lymphocytes is relatively rare, perhaps owing to an intrinsic, tumor-suppressive program. Here, we show that c-MYC not only facilitates rapid cell proliferation but, unexpectedly, also engages a counteracting tumor suppressive program through its downstream transcription factor, AP4. Haploinsufficiency for AP4 dramatically accelerates MYC-driven tumorigenesis in a B cell-intrinsic manner. At a mechanistic level, AP4 suppresses Erg, which is required for B cell development but also oncogenic, in MYC+ developing B cells, and thus AP4 restricts simultaneous expression of multiple oncogenic factors during B cell development. Thus, c-MYC has dual action that permit proliferative expansion of B cell precursors, while concurrently safeguarding against their transformation via engagement of an AP4-dependent, tumor-suppressive program.
2021-06-19 | GSE133514 | GEO
Project description:Germinal centers (GC) arise within B cell follicles upon antigenic challenge. In the dark zones (DZ) of GCs, B cells proliferate and hypermutate their immunoglobulin genes, and mutants with increased affinity are positively selected in the light zone (LZ) to either differentiate into plasma and memory cells, or re-enter the DZ for further refinement. However, the molecular circuits governing GC positive selection are not known. Here, we show that the GC reaction requires the biphasic regulation of c-MYC expression, involving its transient induction during early GC commitment, its repression by BCL6 in DZ B cells, and its re-induction in a subpopulation of positively selected LZ B cells destined to DZ re-entry. Accordingly, acute disruption of MYC function in vivo leads to GC collapse, indicating an essential role in GC physiology. These results have implications for our understanding of GC selection and the role of MYC deregulation in B cell lymphomas. We used microarrays to determine the global gene expression programs that distinguish MYC+ GC B cells from their MYC- negative counterparts.
2012-09-24 | GSE38304 | GEO
Project description:Germinal centers (GC) arise within B cell follicles upon antigenic challenge. In the dark zones (DZ) of GCs, B cells proliferate and hypermutate their immunoglobulin genes, and mutants with increased affinity are positively selected in the light zone (LZ) to either differentiate into plasma and memory cells, or re-enter the DZ for further refinement. However, the molecular circuits governing GC positive selection are not known. Here, we show that the GC reaction requires the biphasic regulation of c-MYC expression, involving its transient induction during early GC commitment, its repression by BCL6 in DZ B cells, and its re-induction in a subpopulation of positively selected LZ B cells destined to DZ re-entry. Accordingly, acute disruption of MYC function in vivo leads to GC collapse, indicating an essential role in GC physiology. These results have implications for our understanding of GC selection and the role of MYC deregulation in B cell lymphomas. We used microarrays to determine the global gene expression programs that distinguish MYC+ GC B cells from their MYC- negative counterparts. GFPMYC+ and GFPMYC- GC B cell subpopulations were collected by Fluorescence Activated Cell Sorting (FACS) from B cell enriched fractions of splenic mononuclear cell pools of GFPMYC knock-in mice (12 days after SRBC immunization). 5-20ng of total RNA (RIN>9) for each sample was used as a template for linear cDNA amplification (Ovation RNA amplification Kit, NuGen). cDNA was labeled using the Encore Biotin Labeling Kit (NuGen) and hybridized to Affymetrix Mouse 430.2 gene expression arrays.
2012-09-24 | E-GEOD-38304 | biostudies-arrayexpress
Project description:The trasncription factor cMyc is an essential transcription factor that establishes a metabolically active and proliferative state in T cells after antigen priming. However, its expression is transient. To date, it remains unknown how T cell activation is maintained after cMyc down-regulation. Here, we identify AP4, encoded by the gene Tfap4, as the transcription factor that is induced by cMyc and sustains activation of antigen-specific CD8+ T cells. Despite normal priming, Tfap4–/– CD8+ T cells fail to continue transcription of a broad range of cMyc gene targets necessary for sustained proliferation. Genome-wide analysis suggests that many activation-induced metabolic genes are shared targets of cMyc and AP4. Thus, AP4 maintains Myc-initiated cellular activation programs in CD8+ T cells to control microbial infections. Naive CD8+ T cells from C57BL6 mice were activated with anti-CD3 and anti-CD28 stimulation in vitro for two days and genome-wide occupancy of Myc, AP4 and Ser2 or Ser5 phipsphorylated RNA polymerase II was profiled by chromatin immunoprecipitation and high-throughput sequencing.
2014-07-13 | E-GEOD-58075 | biostudies-arrayexpress
Project description:B cells diversify and affinity-mature their antigen receptor repertoire in germinal centers (GC). GC B cells receive help signals during transient interaction with T cells, yet it remains unknown how these transient T-B interactions sustain the subsequent proliferative program of selected B cells. Here we show that the transcription factor AP4 is required for sustained GC B cell proliferation and subsequent establishment of a diverse and protective antibody repertoire. AP4 is induced by c-MYC during the T-B interactions and maintained by T cell-derived IL-21. B cell-specific deletion of AP4 resulted in reduced GC sizes and somatic hypermutation and a failure to control chronic viral infection. These results indicate that AP4 integrates T cell-mediated selection and sustained expansion of GC B cells for humoral immunity.
2016-08-23 | GSE80669 | GEO
Project description:In this study we investigated to which extend aberrant c Myc activity plays a functional role in other aNHL and whether it is independent from MYC translocations. Based on a combined microarray analysis of human germinal centre (GC) B cells transfected with c Myc and 220 aNHLs cases, we developed a ‘c Myc index’. This data set contains expresssion profiles from Germinal center B-cells transfected with control or Myc expression vectors. The corresponding lymphoma gene expression profiles are included in the series with GEO accession GSE4475. Expression profiling of germinal center B-cells extracted from human tonsils with and without ectopic expression of Myc.
2011-11-01 | E-GEOD-31311 | biostudies-arrayexpress
Project description:Analysis of the gene expression profile between MYC positive and MYC negative germinal center B-cells.
2012-09-11 | GSE39443 | GEO
Project description:PI3K signaling and FOXO transcription factors play opposing roles at several B cell developmental stages. We show here abundant nuclear FOXO1 expression in the proliferative compartment of the germinal center (GC), its dark zone (DZ), and PI3K activity, downregulating FOXO1, in the GC light zone (LZ), where cells are selected for further differentiation. However, here FOXO1 is expressed in c-Myc+ cells destined for DZ reentry. Upon FOXO1 ablation by genetic means or induction of PI3K activity GCs become devoid of their DZ, due at least partly to the downregulation of the chemokine receptor CXCR4. While this is known to prevent proper cyclic selection of cells expressing high-affinity antibodies, the initiation of immunoglobulin switching is essentially dependent on FOXO1 activity. All samples were obtained from mouse germinal center (GC) B cells (Cgamma1-cre; YFP, P110*, FOXO1 f/f or PTEN f/f animals). Cells used for microarray analysis were FACS sorted cells.
2015-11-23 | E-GEOD-68043 | biostudies-arrayexpress