Project description:Foxo1 and Ebf1 deficiency leads to a similar disruption of normal B-cell development at the level of the common lymphoid progenitor (CLP). Both mouse strains display the existance of LY6D+ CLPs but a marked/complete lack of proB cells. To investigate similarities of the developmental defects observed we generated gene expression profiles from both genotypes (with corresponding WT controls). This illustrated a shared gene expression signature in Ebf1/Foxo1 deficient CLPs. Gene expression profiling was done using highly purified (FACS sorted) progenitor cells. Cells were purified from bone marrow of wild-type, Foxo1 deficient and Ebf1 deficient mice. Ebf1 deficient bone marrow was aquired by transplantation of Ebf1 deficient progenitors into irradiated hosts. Populations analysed were CLP LY6D-, CLP LY6D+ and proB cells.
Project description:Haematopoietic stem cells (HSC) and multipotent progenitor cells (MPP) generate all cells of the blood system, although cellular heterogeneity and bias in lineage potential have been observed. Here, we examined whether lineage-specific transcription factors, such as the B-lineage determinant EBF1, establish lineage bias in early progenitors. We detect low level EBF1 expression in myeloid-biased MPP3 and lymphoid-biased MPP4 cells, and show that Ebf1-deficient animals display reduced HSC quiescence and repopulation capacity, enhanced myelopoiesis and enhanced myeloid differentiation potential of MPP3 and MPP4 cells. Bulk and single-cell RNA-seq analysis revealed a CEBPa-driven myeloid transcriptome in Ebf1-deficient progenitors, and we find that EBF1 binds and potentially antagonizes the haematopoietic Cebpa enhancer. In MPP3 cells, EBF1 additionally primes enhancers associated with B-lymphoid genes that gain expression in common lymphoid progenitors. Thus, our study identifies EBF1 as an important determinant in regulating the balance of myeloid versus lymphoid potential in the earliest hematopoietic progenitors.
Project description:Haematopoietic stem cells (HSC) and multipotent progenitor cells (MPP) generate all cells of the blood system, although cellular heterogeneity and bias in lineage potential have been observed. Here, we examined whether lineage-specific transcription factors, such as the B-lineage determinant EBF1, establish lineage bias in early progenitors. We detect low level EBF1 expression in myeloid-biased MPP3 and lymphoid-biased MPP4 cells, and show that Ebf1-deficient animals display reduced HSC quiescence and repopulation capacity, enhanced myelopoiesis and enhanced myeloid differentiation potential of MPP3 and MPP4 cells. Bulk and single-cell RNA-seq analysis revealed a CEBPa-driven myeloid transcriptome in Ebf1-deficient progenitors, and we find that EBF1 binds and potentially antagonizes the haematopoietic Cebpa enhancer. In MPP3 cells, EBF1 additionally primes enhancers associated with B-lymphoid genes that gain expression in common lymphoid progenitors. Thus, our study identifies EBF1 as an important determinant in regulating the balance of myeloid versus lymphoid potential in the earliest hematopoietic progenitors.
Project description:Haematopoietic stem cells (HSC) and multipotent progenitor cells (MPP) generate all cells of the blood system, although cellular heterogeneity and bias in lineage potential have been observed. Here, we examined whether lineage-specific transcription factors, such as the B-lineage determinant EBF1, establish lineage bias in early progenitors. We detect low level EBF1 expression in myeloid-biased MPP3 and lymphoid-biased MPP4 cells, and show that Ebf1-deficient animals display reduced HSC quiescence and repopulation capacity, enhanced myelopoiesis and enhanced myeloid differentiation potential of MPP3 and MPP4 cells. Bulk and single-cell RNA-seq analysis revealed a CEBPa-driven myeloid transcriptome in Ebf1-deficient progenitors, and we find that EBF1 binds and potentially antagonizes the haematopoietic Cebpa enhancer. In MPP3 cells, EBF1 additionally primes enhancers associated with B-lymphoid genes that gain expression in common lymphoid progenitors. Thus, our study identifies EBF1 as an important determinant in regulating the balance of myeloid versus lymphoid potential in the earliest hematopoietic progenitors.
Project description:Foxo1 and Ebf1 deficiency leads to a similar disruption of normal B-cell development at the level of the common lymphoid progenitor (CLP). Both mouse strains display the existance of LY6D+ CLPs but a marked/complete lack of proB cells. To investigate similarities of the developmental defects observed we generated gene expression profiles from both genotypes (with corresponding WT controls). This illustrated a shared gene expression signature in Ebf1/Foxo1 deficient CLPs.
Project description:Early B cell development is orchestrated by the combined activities of the transcriptional regulators E2A, EBF1, Foxo1 and Ikaros. However, how the genome-wide binding patterns of these regulators are modulated during B-lineage development remains to be determined. Here, we found that in lymphoid progenitors the chromatin remodeler Brg1 specified the B cell fate. In committed pro-B cells Brg1 regulated Igh locus contraction and controlled c-Myc expression to modulate the expression of genes that regulate ribosome biogenesis. In committed pro-B cells Brg1 also suppressed a pre-B lineage-specific pattern of gene expression. Finally, we found that Brg1 acted mechanistically to establish B cell fate and modulate cell growth by facilitating access of lineage-specific transcription factors to poised enhancer repertoires.
Project description:Mature lymphoid cells express the transcriptional repressor Bach2, which imposes regulation on humoral and cellular immunity. Here we found critical roles for Bach2 in the development of cells of the B lineage, commencing from the common lymphoid progenitor (CLP) stage, with Bach1 as an auxiliary. Overexpression of Bach2 in pre-pro-B cells deficient in the transcription factor EBF1 and single-cell analysis of CLPs revealed that Bach2 and Bach1 repressed the expression of genes important for myeloid cells (M-bM-^@M-^Xmyeloid genesM-bM-^@M-^Y). Bach2 and Bach1 bound to presumptive regulatory regions of the myeloid genes. Bach2hi CLPs showed resistance to myeloid differentiation even when cultured under myeloid conditions. Our results suggest that Bach2 functions with Bach1 and EBF1 to promote B cell development by repressing myeloid genes in CLPs. WT and Bach1 and Bach2 double deficient (DD) CLPs. Multipotent progenitors (MPPs) infected with control-GFP and Bach2-GFP and cultured several condition. Follicular B cells (Fo B) stimulated with IgM. Three expreriments was performed in this paper.