RNAseq of pro-B cells and CD19+B220- cells in the bone marrow of WT and PAX5 Y351*/351* mice
Ontology highlight
ABSTRACT: Gene expression profiling of pro-B cells in the bone marrow of WT and PAX5 mice and also of CD19+B220- cells found only in the BM of PAX5 mice. We used a modified single-cell protocol (4 wells of 50 cells each per sample) and then combined all data from the same sample for the analysis.
Project description:STAT5 is critical for differentiation, proliferation and survival of progenitor B cells suggesting a possible role in Acute Lymphoblastic Leukemia (ALL). Herein, we show increased expression of activated STAT5 in ALL patients, which correlates with treatment outcome. Mutations in Ebf1 and Pax5, genes critical for B cell development have also been identified in human ALL. To determine whether mutations in Ebf1 or Pax5 synergize with STAT5 activation to induce ALL we crossed mice expressing a constitutively active form of STAT5 (Stat5b-CA) with mice heterozygous for Ebf1 or Pax5. Haploinsufficiency of either Pax5 or Ebf1 synergized with Stat5b-CA to rapidly induce ALL in 100% of the mice. The leukemic cells displayed reduced expression of both Pax5 and Ebf1 but this had little affect on most EBF1 or PAX5 target genes. However, a subset of these genes was deregulated and included a large percentage of potential tumor suppressor genes and oncogenes. Further, most of these genes appear to be jointly regulated by both EBF1 and PAX5. Our findings suggest a model whereby small perturbations in a self-reinforcing network of transcription factors critical for B cell development, specifically PAX5 and EBF1, cooperate with STAT5 activation to initiate ALL. Gene expression profiling was performed on cells isolated from lymph nodes of Stat5b-CA x Ebf1+/- and Stat5b-CA x Rag2-/- leukemic mice and pre B cells sorted from bone marrow of C57BL/6 mice and Stat5b-CA transgenic mice. 17 Samples.
Project description:The CCR4-NOT complex, bearing poly(A) deadenylation activity, is a highly conserved regulator that is involved in biological control; however its action mechanisms and physiological targets remain unclear. Using genetic deletion of the CNOT3 subunit of this complex in early B cell progenitors, we show that CNOT3 plays a critical role in pro- to pre-B cell transition. CNOT3 participated in controlling germline transcription, compaction of the immunoglobulin heavy chain (Igh) locus, and Igh rearrangement, and in destabilizing tumor suppressor p53 mRNA. Moreover, by genetic ablation of p53 or introduction of pre-rearranged Igh transgene, the B cell developmental defect in the Cnot3 knockout background could be partly rescued, suggesting that CCR4-NOT complex exerts critical control in B cell differentiation processes by co-utilizing transcriptional and post-transcriptional mechanisms. Pro-B cells mRNA profiles of Mb1(cre/+) and Cnot3(fl/fl)Mb1(cre/+) mice were generated by deep sequencing using Illumina HiSeq 1500
Project description:We used a novel probe-level microarray analysis, revealing connections between mRNA processing and lymphoid neoplasia, in a mouse leukemia model. Characteristic differences in mRNA processing, primarily in the 3’-untranslated region, distinguished histologically similar tumor subtypes with different survival characteristics. Gene sets with specific processing in each tumor subtype defined signatures useful for tumor subclassification, as demonstrated by internal cross-validation with up to 80% discrimination accuracy. A combination of mRNA expression and sequence analysis suggested that differences in isoform abundance likely arose from both alternative polyadenylation and differential degradation. Experiment Overall Design: 5 types of samples were analyzed with multiple biological replicates. Progenitor B-cells, mature B-cells were the control. LPC, APC, APN were the tumor cells. LPC (Lig4/P53 deficient cells developed pro-B lymphoma with c-myc amplification), APC (Artemis/P53 deficient cells developed pro-B lymphoma with c-myc amplification), APN (Artemis/P53 deficient cells developed pro-B lymphoma with N-myc amplification)
Project description:In order to investigate how transcription factor dose impacts B-lymphocyte development, we generated mice carrying transheterozygous mutations in the Pax5 and Ebf1 genes. While combined reduction of Pax5 and Ebf1 dose had minimal impact on the development of the earliest CD19+ progenitors, these cells displayed an increased T-cell potential in vivo and in vitro. Alteration in lineage fate depended on a Notch1 mediated conversion process while no signs of de-differentiation could be detected. The differences in functional response to Notch signaling in Wt and Pax5+/-Ebf1+/- pro-B cells was reflected in the transcriptional response because even though cells of both genotypes responded by the generation of intracellular Notch1 and activation of a set of target genes, only the Pax5+/-Ebf1+/- pro-B cells down-regulated genes central for the preservation of stable B-cell identity. This report stresses the importance of transcription factor dose in lymphocyte development and suggests that Pax5 and Ebf1 collaborate to modulate the transcriptional response to Notch signaling after the generation of activated intracellular Notch1. This provides an insight to how transcription factors like Ebf1 and Pax5 preserve cellular identity during differentiation. EBF-1 ChIP-seq: Cultivated CD43+IgM- cells (ProB) cells from Wt, EBF-1 +/-, PAX-5 +/- and EBF-1 +/- PAX-5 +/- (TH) were assessed for EBF-1 binding by ChIP-seq. Replicate Ebf1 ChIP-seq runs on each genotype (Wt, TH, Ebf1+/- and Pax5+/-) and corresponding inputs were pooled into one dataset and analyzed as one combined sample per genotype. RNA-seq no treatment: Briefly, ProB-cells from C57BL/6J Ebf1+/-Pax5+/- (n=4), WT (n=4), Ebf1+/- (n=2) and Pax5+/- (n=2) were sorted and RNA extracted with Qiagen RNeasy Micro Kit. RNA was sent to UCLA Microarray Core for library preparation and were subsequently for 50 cycles of HiSeq 2000 SBS sequencing generating 20-30 million reads/sample. Data analysis was performed with Arraystar® (DNASTAR)). RNA-seq 1 day on OP9DL1 and OP9: In short, in vitro expanded ProB-cells from C57BL/6J Ebf1+/-Pax5+/- (n=4) and WT (n=4) were exposed either on OP9 or OP9-DL1 stromal cells for 24 hours and RNA extracted with Qiagen RNeasy Micro Kit. Due to low reads, two Wt and Ebf1+/-Pax5+/- were sequenced twice. Libraries were constructed using Nugen's Ovation Ultralow Library systems and were subsequently for 50 cycles of NextSeq500 sequencing generating 20-30 million reads/sample. Data analysis was performed with Arraystar® (DNASTAR)).
Project description:4C-Seq has proven to be a powerful technique to identify genome-wide interactions with a single locus of interest (or "bait") that can be important for gene regulation. However, analysis of 4C-Seq data is complicated by the many biases inherent to the technique. An important consideration when dealing with 4C-Seq data is the differences in resolution of signal across the genome that result from differences in 3D distance separation from the bait. This leads to the highest signal in the region immediately surrounding the bait and increasingly lower signals in far-cis and trans. Another important aspect of 4C-Seq experiments is the resolution, which is greatly influenced by the choice of restriction enzyme and the frequency at which it can cut the genome. Thus, it is important that a 4C-Seq analysis method is flexible enough to analyze data generated using different enzymes and to identify interactions across the entire genome. Current methods for 4C-Seq analysis only identify interactions in regions near the bait or in regions located in far-cis and trans, but no method comprehensively analyzes 4C signals of different length scales. In addition, some methods also fail in experiments where chromatin fragments are generated using frequent cutter restriction enzymes. Here, we describe 4C-ker, a Hidden-Markov Model based pipeline that identifies regions throughout the genome that interact with the 4C bait locus. In addition, we incorporate methods for the identification of differential interactions in multiple 4C-seq datasets collected from different genotypes or experimental conditions. Adaptive window sizes are used to correct for differences in signal coverage in near-bait regions, far-cis and trans chromosomes. Using several datasets, we demonstrate that 4C-ker outperforms all existing 4C-Seq pipelines in its ability to reproducibly identify interaction domains at all genomic ranges with different resolution enzymes. 4C-Seq experiments from Igh and Cd83 bait in activated B cells and Tcrb (Eb) bait in double negative T cells and immature B cells. RNA-Seq and ATAC-Seq experiments in DN and Immature B cells.
Project description:We sequenced mRNA from naive, in vitro activated, and GC B cells obtained from both Aicda-/- and Aicda+/+ mice. Examination of mRNA levels in naive, in vitro activated, and GC B cells.
Project description:We used the NanoString mouse nCounter miRNA expression platform to compare the miRNA expression profiles of pro-B cells sorted from fetal liver and adult bone marrow in order to gain insight into changes in miRNA expression during B cell ontogeny. Fetal liver and adult bone marrow cells were harvested and FACS sorted for pro-B cells (B220+CD43+IgM-veCD19+CD24+). Total RNA was extracted and used for sample preparation and hybridization per manufacturer's instructions.
Project description:Developing B lymphocytes undergo V(D)J recombination to assemble germline V, D, and J gene segments into exons that encode the antigen-binding variable region of immunoglobulin (Ig) heavy (H) and light (L) chains. IgH and IgL chains associate to form the B cell receptor (BCR), which upon antigen binding activates B cells to secrete BCR as an antibody. Each of the huge number of clonally independent B cells expresses a unique set of IgH and IgL variable regions. Ability of V(D)J recombination to generate vast primary B cell repertoires results from combinatorial assortment of large numbers of different V, D, and J segments, coupled with diversification of the junctions between them to generate the complementary determining region 3 (CDR3) for antigen contact. Approaches to evaluate in depth the content of primary antibody repertoires and, ultimately, to study how they are further molded by secondary mutation and affinity maturation processes are of great importance to the B cell development, vaccine, and antibody fields. We now describe an unbiased, sensitive, and readily accessible assay, referred to as HTGTS repertoire sequencing (HTGTS-Rep-seq), to quantify antibody repertoires. HTGTS-Rep-seq quantitatively identifies the vast majority of IgH and IgL V(D)J exons, including their unique CDR3 sequences, from progenitor and mature mouse B lineage cells via the use of specific J primers. HTGTS-Rep-seq also accurately quantifies DJH intermediates and V(D)J exons in either productive or non-productive configurations. HTGTS-Rep-seq should be useful for studies of human samples, including clonal B-cell expansions and also for following antibody affinity maturation processes. We employed high-throughput genome-wide translocation sequencing adapted repertoire sequencing (HTGTS-Rep-seq) to study antibody repertoires. For HTGTS-Rep-seq libraries, we utilize bait coding ends of J segments to identify, in unbiased fashion, mouse IgH DJH repertoires [processed tlx files] along with both productive and non-productive IgH V(D)J repertoires from both pro-B and peripheral B cells [processed xls files of samples 1-18, 21-51]. Similarly, we also identify mouse productive and non-productive Igk repertoires from peripheral B cells [processed xls files of samples 19,20,52-57].
Project description:Interleukin-7 receptor α (encoded by IL7R) is essential for lymphoid development. Whether acute lymphoblastic leukemia (ALL)-related IL7R gain-of-function mutations can trigger leukemogenesis remains unclear. Here, we demonstrate that lymphoid-restricted mutant IL7R, expressed at physiological levels in conditional knock-in mice, establishes a pre-leukemia stage in which B-cell precursors display self-renewal ability, initiating precursor B-ALL that resembles PAX5 P80R or Ph-like human leukemia. Full transformation associates with transcriptional upregulation of oncogenes such as Myc or Bcl2, downregulation of tumor suppressors such as Ikzf1 or Arid2, and major IL-7R signaling upregulation (involving both JAK/STAT5 and PI3K/mTOR), required for leukemia cell viability. Accordingly, maximal signaling drives full penetrance and early leukemia onset in homozygous IL7R mutant animals. Notably, we identify 2 transcriptional subgroups in mouse and human Ph-like ALL, and show that dactolisib and sphingosine-kinase inhibitors are novel treatment avenues for IL-7R-related cases. Our model, a unique resource to explore the pathophysiology and therapeutic vulnerabilities of B-ALL, demonstrates that IL7R can initiate this malignancy.