scholarly journals E47 is required for V(D)J recombinase activity in common lymphoid progenitors

2005 ◽  
Vol 202 (12) ◽  
pp. 1669-1677 ◽  
Author(s):  
Lisa Borghesi ◽  
Jennifer Aites ◽  
Shakira Nelson ◽  
Preslav Lefterov ◽  
Pamela James ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
B Cell ◽  
Cell Stage ◽  
Cis Acting ◽  
Lymphoid Progenitors ◽  
B Lineage

Common lymphoid progenitors (CLPs) are the first bone marrow precursors in which V(D)J recombinase activity is up-regulated. Here, we show that loss of the transcription factor E47 produces a reduced CLP population that lacks V(D)J recombinase activity and D-JH rearrangements in vivo. Apart from a profound arrest before the pro–B cell stage, other downstream lymphoid progeny of CLPs are still intact in these mice albeit at reduced numbers. In contrast to the inhibition of recombinase activity in early B lineage precursors in E47-deficient animals, loss of either E47 or its cis-acting target Erag (enhancer of rag transcription) has little effect on recombinase activity in thymic T lineage precursors. Taken together, this work defines a role for E47 in regulating lineage progression at the CLP stage in vivo and describes the first transcription factor required for lineage-specific recombinase activity.

scholarly journals B lymphocytes express and lose syndecan at specific stages of differentiation.

1989 ◽  
Vol 1 (1) ◽  
pp. 27-35 ◽  
Author(s):  
R D Sanderson ◽  
P Lalor ◽  
M Bernfield
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
B Lymphocyte ◽  
Plasma Cells ◽  
Receptor Expression ◽  
Cell Stage ◽  
Precursor B Cells

Lymphopoietic cells require interactions with bone marrow stroma for normal maturation and show changes in adhesion to matrix during their differentiation. Syndecan, a heparan sulfate-rich integral membrane proteoglycan, functions as a matrix receptor by binding cells to interstitial collagens, fibronectin, and thrombospondin. Therefore, we asked whether syndecan was present on the surface of lymphopoietic cells. In bone marrow, we find syndecan only on precursor B cells. Expression changes with pre-B cell maturation in the marrow and with B-lymphocyte differentiation to plasma cells in interstitial matrices. Syndecan on B cell precursors is more heterogeneous and slightly larger than on plasma cells. Syndecan 1) is lost immediately before maturation and release of B lymphocytes into the circulation, 2) is absent on circulating and peripheral B lymphocytes, and 3) is reexpressed upon their differentiation into immobilized plasma cells. Thus, syndecan is expressed only when and where B lymphocytes associate with extracellular matrix. These results indicate that B cells differentiating in vivo alter their matrix receptor expression and suggest a role for syndecan in B cell stage-specific adhesion.

scholarly journals High frequency of normal DJH joints in B cell progenitors in severe combined immunodeficiency mice.

1993 ◽  
Vol 178 (3) ◽  
pp. 1007-1016 ◽  
Author(s):  
J L Pennycook ◽  
Y Chang ◽  
J Celler ◽  
R A Phillips ◽  
G E Wu
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Fetal Liver ◽  
Severe Combined Immunodeficiency ◽  
Cell Activity ◽  
Scid Mice ◽  
Combined Immunodeficiency ◽  
Cell Stage ◽  
Reading Frame ◽  
B Lineage

The severe combined immunodeficiency (scid) mouse has a defective V(D)J recombinase activity that results in arrested lymphoid development at the pro-B cell stage in the B lineage. The defect is not absolute and scid mice do attempt gene rearrangement. Indeed, approximately 15% of all scid mice develop detectable levels of oligoclonal serum immunoglobulin and T cell activity. To gain more insight into the scid defect and its effect on V(D)J rearrangement, we analyzed DJH recombination in scid bone marrow. We determined that DJH structures are present in scid bone marrow and occur at a frequency only 10-100 times less than C.B-17+/+. The scid DJH repertoire is limited and resembles fetal liver DJH junctions, with few N insertions and predominant usage of reading frame 1. Moreover, 70% of the DJH structures were potentially productive, indicating that normal V(D)J recombinants should be arising continually.

scholarly journals Single cell characterization of B-lymphoid differentiation and leukemic cell states during chemotherapy in ETV6-RUNX1-positive pediatric leukemia identifies drug-targetable transcription factor activities

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Juha Mehtonen ◽  
Susanna Teppo ◽  
Mari Lahnalampi ◽  
Aleksi Kokko ◽  
Riina Kaukonen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Regulatory Network ◽  
Leukemic Cell ◽  
Immune Microenvironment ◽  
Ets Transcription Factors ◽  
Lineage Differentiation ◽  
B Lineage

Abstract Background Tight regulatory loops orchestrate commitment to B cell fate within bone marrow. Genetic lesions in this gene regulatory network underlie the emergence of the most common childhood cancer, acute lymphoblastic leukemia (ALL). The initial genetic hits, including the common translocation that fuses ETV6 and RUNX1 genes, lead to arrested cell differentiation. Here, we aimed to characterize transcription factor activities along the B-lineage differentiation trajectory as a reference to characterize the aberrant cell states present in leukemic bone marrow, and to identify those transcription factors that maintain cancer-specific cell states for more precise therapeutic intervention. Methods We compared normal B-lineage differentiation and in vivo leukemic cell states using single cell RNA-sequencing (scRNA-seq) and several complementary genomics profiles. Based on statistical tools for scRNA-seq, we benchmarked a workflow to resolve transcription factor activities and gene expression distribution changes in healthy bone marrow lymphoid cell states. We compared these to ALL bone marrow at diagnosis and in vivo during chemotherapy, focusing on leukemias carrying the ETV6-RUNX1 fusion. Results We show that lymphoid cell transcription factor activities uncovered from bone marrow scRNA-seq have high correspondence with independent ATAC- and ChIP-seq data. Using this comprehensive reference for regulatory factors coordinating B-lineage differentiation, our analysis of ETV6-RUNX1-positive ALL cases revealed elevated activity of multiple ETS-transcription factors in leukemic cells states, including the leukemia genome-wide association study hit ELK3. The accompanying gene expression changes associated with natural killer cell inactivation and depletion in the leukemic immune microenvironment. Moreover, our results suggest that the abundance of G1 cell cycle state at diagnosis and lack of differentiation-associated regulatory network changes during induction chemotherapy represent features of chemoresistance. To target the leukemic regulatory program and thereby overcome treatment resistance, we show that inhibition of ETS-transcription factors reduced cell viability and resolved pathways contributing to this using scRNA-seq. Conclusions Our data provide a detailed picture of the transcription factor activities characterizing both normal B-lineage differentiation and those acquired in leukemic bone marrow and provide a rational basis for new treatment strategies targeting the immune microenvironment and the active regulatory network in leukemia.

scholarly journals The Earliest Step in B Lineage Differentiation from Common Lymphoid Progenitors Is Critically Dependent upon Interleukin 7

2002 ◽  
Vol 196 (5) ◽  
pp. 705-711 ◽  
Author(s):  
Juli P. Miller ◽  
David Izon ◽  
William DeMuth ◽  
Rachel Gerstein ◽  
Avinash Bhandoola ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Gamma Chain ◽  
Lineage Differentiation ◽  
Lymphoid Progenitors ◽  
B Lineage

Little is known about the signals that promote early B lineage differentiation from common lymphoid progenitors (CLPs). Using a stromal-free culture system, we show that interleukin (IL)-7 is sufficient to promote the in vitro differentiation of CLPs into B220+ CD19+ B lineage progenitors. Consistent with current models of early B cell development, surface expression of B220 was initiated before CD19 and was accompanied by the loss of T lineage potential. To address whether IL-7 receptor (R) activity is essential for early B lineage development in vivo, we examined the frequencies of CLPs and downstream pre–pro- and pro-B cells in adult mice lacking either the α chain or the common gamma chain (γc) of the IL-7R. The data indicate that although γc−/− mice have normal frequencies of CLPs, both γc−/− and IL-7Rα−/− mice lack detectable numbers of all downstream early B lineage precursors, including pre–pro-B cells. These findings challenge previous notions regarding the point in B cell development affected by the loss of IL-7R signaling and suggest that IL-7 plays a key and requisite role during the earliest phases of B cell development.

scholarly journals Single cell characterization of B-lymphoid differentiation and leukemic cell states during chemotherapy in ETV6-RUNX1 positive pediatric leukemia identifies drug-targetable transcription factor activities

2020 ◽  
Author(s):  
Juha Mehtonen ◽  
Susanna Teppo ◽  
Mari Lahnalampi ◽  
Aleksi Kokko ◽  
Riina Kaukonen ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Regulatory Network ◽  
Leukemic Cell ◽  
Immune Microenvironment ◽  
Ets Transcription Factors ◽  
Lineage Differentiation ◽  
B Lineage

AbstractTight regulatory loops orchestrate commitment to B-cell fate within bone marrow. Genetic lesions in this gene regulatory network underlie the emergence of the most common childhood cancer, acute lymphoblastic leukemia (ALL). The initial genetic hits, including the common translocation that fuses ETV6 and RUNX1 genes, lead to arrested cell differentiation. Here, we aimed to characterize transcription factor activities along the B-lineage differentiation trajectory as a reference to characterize the aberrant cell states present in leukemic bone marrow, and to identify those transcription factors that maintain cancer-specific cell states for more precise therapeutic intervention.We compared normal B-lineage differentiation and in vivo leukemic cell states using single cell RNA-sequencing (scRNA-seq) and several complementary genomics profiles. Based on statistical tools for scRNA-seq, we benchmarked a workflow to resolve transcription factor activities and gene expression distribution changes in healthy bone marrow lymphoid cell states. We compared these to ALL bone marrow at diagnosis and in vivo during chemotherapy, focusing on leukemias carrying the ETV6-RUNX1 fusion.We show that lymphoid cell transcription factor activities uncovered from bone marrow scRNA-seq have high correspondence with independent ATAC- and ChIP-seq data. Using this comprehensive reference for regulatory factors coordinating B-lineage differentiation, our analysis of ETV6-RUNX1-positive ALL cases revealed elevated activity of multiple ETS-transcription factors in leukemic cells states, including the leukemia genome-wide association study hit ELK3. The accompanying gene expression changes associated with natural killer cell inactivation and depletion in the leukemic immune microenvironment. Moreover, our results suggest that the abundance of G1 cell cycle state at diagnosis and lack of differentiation-associated regulatory network changes during induction chemotherapy represent features of chemoresistance. To target the leukemic regulatory program and thereby overcome treatment-resistance, we show that selective inhibitors of ETS-transcription factors could effectively reduce cell viability.Our data provide a detailed picture of the transcription factor activities that characterize both normal B-lineage differentiation and those acquired in leukemic bone marrow and provide a rational basis for new treatment strategies targeting the immune microenvironment and the active regulatory network in leukemia.

scholarly journals Bone Marrow Microenvironmental Changes Underlie Reduced RAG-mediated Recombination and B Cell Generation in Aged Mice

2004 ◽  
Vol 200 (4) ◽  
pp. 411-423 ◽  
Author(s):  
Joseph E. Labrie ◽  
Alex P. Sah ◽  
David M. Allman ◽  
Michael P. Cancro ◽  
Rachel M. Gerstein
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Molecular Mechanisms ◽  
Extrinsic Factors ◽  
Cell Stage ◽  
Aged Mice ◽  
Microenvironmental Factors ◽  
Bone Marrow Chimeras

During aging, adaptive immunity is severely compromised, due in part to decreased production of B lymphocytes and loss of immunoglobulin (Ig) diversity. However, the molecular mechanisms that underlie age-associated diminished B cell production remain unclear. Using in vivo labeling, we find that this reduction in marrow pre–B cells reflects increased attrition during passage from the pro–B to pre–B cell pool. Analyses of reciprocal bone marrow chimeras reveal that the magnitude and production rates of pre–B cells are controlled primarily by microenvironmental factors, rather than intrinsic events. To understand changes in pro–B cells that could diminish production of pre–B cells, we evaluated rag2 expression and V(D)J recombinase activity in pro–B cells at the single cell level. The percentage of pro–B cells that express rag2 is reduced in aged mice and is correlated with both a loss of V(D)J recombinase activity in pro–B cells and reduced numbers of pre–B cells. Reciprocal bone marrow chimeras revealed that the aged microenvironment also determines rag2 expression and recombinase activity in pro–B cells. Together, these observations suggest that extrinsic factors in the bone marrow that decline with age are largely responsible for less efficient V(D)J recombination in pro–B cells and diminished progression to the pre–B cell stage.

scholarly journals The regulated expression of B lineage associated genes during B cell differentiation in bone marrow and fetal liver.

1993 ◽  
Vol 178 (3) ◽  
pp. 951-960 ◽  
Author(s):  
Y S Li ◽  
K Hayakawa ◽  
R R Hardy
Keyword(s):  
Bone Marrow ◽  
Cell Differentiation ◽  
B Cell ◽  
Fetal Liver ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Multiparameter Flow Cytometry ◽  
B Cell Differentiation ◽  
Cell Stage ◽  
Rag 1 ◽  
B Lineage

The expression of B lineage associated genes during early B cell differentiation stages is not firmly established. Using cell surface markers and multiparameter flow cytometry, bone marrow (BM) cells can be resolved into six fractions, representing sequential stages of development; i.e., pre-Pro-B, early Pro-B, late Pro-B/large Pre-B, small Pre-B, immature B, and mature B cells. Here we quantitate the levels of several B lineage associated genes in each of these fractions by RT-PCR, demonstrating different patterns of expression. We find that expression of terminal deoxynucleotidyl transferase (TdT), lambda 5, and VpreB is predominantly restricted to the Pro-B stages. Rag-1 and Rag-2 expression is also tightly regulated, and is found largely in the Pro-B through small Pre-B stages. Mb-1 is present from Pro-B throughout the pathway at high levels. Finally, Bcl-2 is expressed at high levels only at the pre-Pro-B and mature B stages, whereas it is low during all the intermediate stages. We also correlate this expression data with an analysis of the onset of Ig gene rearrangement as assessed by amplifying D-JH, VH-DJH, and VK-JK. Finally, we report differences in gene expression during B lymphopoiesis at two distinct ontogenic timings, in fetal liver and adult BM: both TdT and the precursor lymphocyte regulated myosin-like light chain are expressed at high levels in the Pro-B cell stage in bone marrow, but are absent from the corresponding fraction in fetal liver. In contrast, lambda 5, VpreB, Rag-1, and Rag-2 are expressed at comparable levels.

scholarly journals A Selective Culture System for Generating Terminal Deoxynucleotidyl Transferase-Positive Lymphoid CellsIn Vitro. V. Detection of Stage-Specific Pro-B-Cell Stimulating Activity in Medium Conditioned by Mouse Bone Marrow Stromal Cells

1993 ◽  
Vol 3 (3) ◽  
pp. 181-195 ◽  
Author(s):  
Sean D. Mckenna ◽  
Irving Goldschneider
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Stromal Cells ◽  
Culture System ◽  
Lymphoid Cells ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Cell Phenotype ◽  
B Lineage

The selectivein vitrogeneration of rat, mouse, and human terminal deoxynucleotidyl transferase-positive (TdT+lymphoid cells in our long-term xenogeneic bone marrow (BM) culture system is characterized by physical interaction between the developing lymphocytes and mouse BM-adherent stromal cells and macrophages. In the present study, experiments in which micropor)us membrane culture inserts were inoculated with rat BM cells demonstrated that although the generation of primitive B-lineage lymphoid cells requires the presence of a mouse BM feeder layer, cognitive recognition events are not necessary. Similarly, cell-free (and serum-free) medium conditioned with mouse BM (but not thymus or spleen) adherent cells and stromal-cell lines therefrom supported the proliferation of early rat lymphoid cells in a dose-dependent manner. Double immunofluorescence for incorporated bromo-deoxyuridine (BrdU) and early B-lineage markers of rat BM lymphoid cells maintained in culture inserts or conditioned medium (CM), and studies of their in vitro andin vivodevelopmental potentials, indicated that the lymphoproliferative response resulted from the selective stimulation of lymphoid stem and/or progenitor cells. The most primitive of these target cells had a HIS24+HIS50-TdT-cμ-sIg-, pre-pro-B-cell phenotype. Whereas this subset normally constitutes less than 2% of B-lineage BM cellsin vivo, it comprises more than 25% of total lymphoid cellsin vitro. In addition, the number of TdT+cells, predominantly of the early pro-B-cell phenotype (HIS24+HIS50-TdT-cμ-sIg-), was increased approximately tenfold above input levels. Based on these and previous findings, a schematic model is proposed for the developmental pathway of early B-lineage cells in rat BM from the level of the committed (possibly common) lymphoid stem cell to that of the pre-B-cell.

Transformation of murine bone marrow cells with combined v-raf-v-myc oncogenes yields clonally related mature B cells and macrophages

1990 ◽  
Vol 10 (7) ◽  
pp. 3562-3568
Author(s):  
M Principato ◽  
J L Cleveland ◽  
U R Rapp ◽  
K L Holmes ◽  
J H Pierce ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Bone Marrow Cells ◽  
Hematopoietic Differentiation ◽  
Developmental Relationships ◽  
Murine Bone Marrow ◽  
B Lineage ◽  
Marrow Cells

Murine bone marrow cells infected with replication-defective retroviruses containing v-raf alone or v-myc alone yielded transformed pre-B cell lines, while a retroviral construct containing both v-raf and v-myc oncogenes produced clonally related populations of mature B cells and mature macrophages. The genealogy of these transformants demonstrates that mature myeloid cells were derived from cells with apparent B-lineage commitment and functional immunoglobulin rearrangements. This system should facilitate studies of developmental relationships in hematopoietic differentiation and analysis of lineage determination.

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