scholarly journals Developmental Stage Specific B-Progenitor Expansion in Normal Fetal Bone Marrow Is Absent in Down Syndrome: Implications for Infant ALL

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4331-4331
Author(s):  
Anindita Roy ◽  
Georg Bohn ◽  
Katerina Goudevenou ◽  
Gillian Cowan ◽  
Neha Bhatnagar ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Fetal Life ◽  
Second Trimester ◽  
Leukemic Transformation ◽  
Developmentally Regulated ◽  
Cd34 Cells

Abstract Although distinct fetal and adult B-cell lineage development has been demonstrated in murine studies, human fetal B-lymphopoiesis remains poorly understood. Previous work from our lab identified a population of PreProB progenitors (CD34+CD19+CD10-) in fetal liver (FL), co-existing with adult-type CD34+CD19+CD10+ ProB progenitors (Roy, A., Cowan G et al. PNAS: 109, 17579-17584; 2012). This supports other work demonstrating a PreProB progenitor population in normal cord blood (Sanz, E., et al. PNAS: 107, 5925-5930; 2010) and suggests that fetal pathways of B-cell development are also likely to be markedly different from adult bone marrow (AdBM) in humans. FL PreProB progenitors give rise solely to B-cells in vitro and display a gene expression pattern of successive activation of B-cell transcription factors as determined by Fluidigm RQ-PCR. In addition, increasing evidence indicates that infant ALL and many cases of childhood ALL arise in fetal life, suggesting that ontogeny-related changes in B-cell development may provide the cellular and microenvironmental context for in utero leukemia initiation. We therefore investigated B-cell development in normal human fetal BM from the onset of BM hematopoiesis in late first trimester. The composition and function of the early lymphoid and committed B-progenitor compartments of fetal BM(12-22 weeks; n=20) were compared with FL (n=25) at the same gestation, paediatric (Paed) BM (n=6) and AdBM (n=7), by multiparameter flow cytometry, differentiation in stromal co-culture assays and clonogenic assays. All stages of B-cell development were demonstrable in human fetal BM. However, there was a significantly higher frequency of B-progenitors in fetal BM (45.8±2.7% of CD34+ cells) compared to FL (10.3±0.97%; p<0.0001), PaedBM (28.2±4.2%; p=0.001) and AdBM (25.8±2.8%; p<0.0001). As in FL, both CD34+CD19+CD10- (PreProB) and CD34+CD19+10+ (ProB) progenitors were identified in fetal BM. PreProB progenitors were significantly higher in fetal BM (21.9±2.3% of CD34+ cells) compared to FL (3.8±0.4%), PaedBM (4.2±0.9%) and AdBM (3.4±0.9%) (p<0.0001 for all). Fetal BM PreProB progenitors gave rise solely to B-cells when co-cultured on MS5 stromal cells with FLT3L, SCF and IL7 in contrast to multilineage output of fetal BM HSC and LMPP cultured under identical conditions. Furthermore, fetal BM Lin-CD10-CD34+ cells cultured in vitro acquire CD19 expression before CD10 expression (n=6) consistent with a unique, fetal-specific B-cell differentiation pathway. The progressive decline in the proportion of PreProB progenitors from 47.8% to 36.8%, 14.8% and 13% of total B-progenitors in fetal BM, FL, PaedBM and AdBM respectively points towards a developmental stage-specific emergence of these progenitors. Finally, the fetal BM B-progenitor: B-cell ratio falls rapidly from ~4:1 at 12 weeks gestation to 1:1 at 18 weeks gestation as mature B-cell production in fetal BM gradually increases. This is consistent with a developmentally-regulated drive to B-progenitor proliferation, at the expense of differentiation, early in the second trimester which might represent a target population vulnerable to leukemic transformation in fetal life. Since children with Down syndrome (DS) do not develop infant ALL, we examined DS fetal BM as they may lack susceptible target cells for leukemic transformation. Consistent with this, PreProB progenitors in DS fetal BM (n=7) were >6-fold lower than normal fetal BM (3.3±0.8% vs. 21.9±2.3% of CD34+ cells; p<0.0001). Furthermore, CD19+ cells with an infant ALL-associated immunophenotype (CD19+CD10-CD20-) are detectable in normal fetal BM mononuclear cells, but are rarely found in DS fetal BM. Conclusion: There is a marked expansion of PreProB progenitors in normal second trimester human fetal BM which is virtually absent in DS fetal BM, in normal PaedBM and in normal AdBM. We suggest that developmentally-regulated, functional and molecular characteristics of these fetal-specific B-progenitors may provide the 'oncogenic' cellular context necessary to co-operate with genetic events, such as MLL rearrangements, to induce ALL in infants without DS. Disclosures No relevant conflicts of interest to declare.

scholarly journals Nonpermissive bone marrow environment impairs early B-cell development in common variable immunodeficiency

Blood ◽  
2020 ◽  
Vol 135 (17) ◽  
pp. 1452-1457 ◽  
Author(s):  
Arianna Troilo ◽  
Claudia Wehr ◽  
Iga Janowska ◽  
Nils Venhoff ◽  
Jens Thiel ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Immature B Cells ◽  
Cell Repopulation

Abstract Common variable immunodeficiency (CVID) is a disease characterized by increased susceptibility to infections, hypogammaglobulinemia, and immune dysregulation. Although CVID is thought to be a disorder of the peripheral B-cell compartment, in 25% of patients, early B-cell development in the bone marrow is impaired. Because poor B-cell reconstitution after hematopoietic stem cell transplantation has been observed, we hypothesized that in some patients the bone marrow environment is not permissive to B-cell development. Studying the differentiation dynamics of bone marrow-derived CD34+ cells into immature B cells in vitro allowed us to distinguish patients with B-cell intrinsic defects and patients with a nonpermissive bone marrow environment. In the former, immature B cells did not develop and in the latter CD34+ cells differentiated into immature cells in vitro, but less efficiently in vivo. In a further group of patients, the uncommitted precursors were unable to support the constant development of B cells in vitro, indicating a possible low frequency or exhaustion of the precursor population. Hematopoietic stem cell transplantation would result in normal B-cell repopulation in case of intrinsic B-cell defect, but in defective B-cell repopulation in a nonpermissive environment. Our study points to the importance of the bone marrow niche in the pathogenesis of CVID.

B Cell Development in the Absence of PU.1.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 226-226 ◽  
Author(s):  
Min Ye ◽  
Olga Ermaermakova-Cirilli ◽  
Thomas Graf
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Target Genes ◽  
Fetal Liver ◽  
Cell Formation ◽  
Cell Development ◽  
B Cell Development ◽  
B Lineage

Abstract Mice deficient of the ETS-family transcription factor PU.1 lack B cells as well as macrophages. While most macrophage specific genes are known to be regulated by high levels of PU.1, the reason for the defect in B cell formation is not known. Here we analyzed a mouse strain in which a floxed version of the PU.1 gene, surrounding exon 4 and 5, which encode the DNA, binding and PEST domains (developed by C. Somoza and D. Tenen), was excised by Cre mediated recombination. As expected, this strain lacks both B cells and macrophages and die at birth. Surprisingly, however, we were able to establish lymphoid cell lines from fetal livers of these mice (day 14 to day 18), which proliferated on S17 stromal cells supplemented with IL-7 and stem cell factor. These cells expressed the B lineage cell surface markers CD19, CD43, BP-1 and CD24, but not B220. They also expressed B cell transcription factors, EBF, E47, Pax5, and their target genes, Rag1, IL7R, λ5 and v-preB, as detected by RT-PCR, exhibited DJ and VDJ immunoglobulin heavy chain rearrangements, and expressed IgM after IL-7 withdrawal. We then tested the effect of PU.1 deletion in B cells in adult animals by crossing the floxed PU.1 strain with a CD19 Cre mouse line. The spleen and peripheral blood (but not bone marrow) of these mice contained B cells that were CD19+ IgMlow, IgDhigh but B220 negative and instead expressed CD43. Thus PU.1 is not essential for immunoglobulin production and late B cell development. Although PU.1−/− fetal liver cells can give rise to cells, resembling Pre-B in vitro, the process of B cell formation was delayed by almost 12 days, compared with wt fetal liver, and the efficiency was reduced approximately 25-fold. In addition, PU.1 deficient B cells demonstrated an impaired ability to engraft into the bone marrow, when injected into irradiated SCID mice. We have found that PU.1 deficient B progenitors showed reduced or undetectable levels of the SDF1 receptor CXCR4, a receptor that has been implicated in B cell homing. Taken together, our observations suggest that PU.1 plays two different roles during B cell development: for early B cell formation and for proper migration and engraftment, which might be mediated through regulation of CXCR4 expression.

The MiR-23a MicroRNA Cluster Inhibits B Cell Development.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1465-1465
Author(s):  
Jason Mullenix ◽  
Kimi Y Kong ◽  
Kristin Severns Owens ◽  
Jason Rogers ◽  
Shannon FitzPatrick ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
B Cell ◽  
Cell Fate ◽  
Conflicts Of Interest ◽  
Myeloid Cells ◽  
Mature Mirnas ◽  
Cell Development ◽  
B Cell Development

Abstract Abstract 1465 Poster Board I-488 The miR-23a microRNA (miRNAs) cluster inhibits both [ITALIC]in vitro[/ITALIC] and [ITALIC]in vivo[/ITALIC] B cell development. When murine hematopoietic progenitor cells expressing the 23a cluster miRNAs were cultured in B cell promoting conditions we observed over a five-fold decrease in the generation of CD19+ B cells compared to control cultures. Conversely, we observed over a five-fold increase in CD11b+ myeloid cells. When irradiated mice were transplanted with bone marrow expressing the miR-23a cluster we observed a two-fold decrease in bone marrow and splenic B cells, 8 weeks post-transplant compared to control mice. The miR-23a cluster codes for a single pri-transcript, which when processed yields three mature miRNAs: miR-23a, miR-27a, and miR-24-2. All three mature miRNAs are more abundant in myeloid cells compared to other hematopoietic cells. In vitro miR-24 alone is necessary and sufficient to inhibit B cell development. The promoter for the cluster contains conserved binding sites for the essential myeloid transcription factors PU.1 and C/EBP alpha. Chromatin immunoprecipitations demonstrated that PU.1 and C/EBP alpha are associated with the promoter in myeloid cells. In addition, C/EBP alpha is bound to several highly conserved regions upstream of the promoter. Both PU.1 and C/EBP alpha promote myeloid development at the expense of lymphopoiesis. Our work suggests that the miR-23a cluster may be a critical downstream target of PU.1 and C/EBP alpha in the specification of myeloid cell fate. Although miRNAs have been identified downstream of PU.1 and C/EBP alpha in mediating the development of monocytes and granulocytes, the 23a cluster is the first downstream miRNA target implicated in the regulating lymphoid cell fate acquisition. We are currently identifying targets of miR-24 that may mediate the inhibitory effect on B lymphopoiesis. Disclosures No relevant conflicts of interest to declare.

scholarly journals Altered Erythrocytes and a Leaky Block in B-Cell Development in CD24/HSA-Deficient Mice

Blood ◽  
1997 ◽  
Vol 89 (3) ◽  
pp. 1058-1067 ◽  
Author(s):  
P.J. Nielsen ◽  
B. Lorenz ◽  
A.M. Müller ◽  
R.H. Wenger ◽  
F. Brombacher ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
B Cell ◽  
Embryonic Stem ◽  
Cell Development ◽  
B Cell Development ◽  
Surface Glycoprotein ◽  
Malarial Parasite ◽  
Heat Stable Antigen ◽  
Deficient Mice

Abstract The heat stable antigen (HSA, or murine CD24) is a glycosyl phosphatidylinositol-linked surface glycoprotein expressed on immature cells of most, if not all, major hematopoietic lineages, as well as in developing neural and epithelial cells. It has been widely used to stage the maturation of B and T lymphocytes because it is strongly induced and then repressed again during their maturation. Terminally differentiated lymphocytes, as well as most myeloid lineages, are negative for HSA. Erythrocytes are an exception in that they maintain high levels of HSA expression. HSA on naive B cells has been shown to mediate cell-cell adhesion, while HSA on antigen-presenting cells has been shown to mediate a costimulatory signal important for activating T lymphocytes during an immune response. Here, we characterize mice that lack a functional HSA gene, constructed by homologous recombination in embryonic stem cells. While T-cell and myeloid development appears normal, these mice show a leaky block in B-cell development with a reduction in late pre-B and immature B-cell populations in the bone marrow. Nevertheless, peripheral B-cell numbers are normal and no impairment of immune function could be detected in these mice in a variety of immunization and infection models. We also observed that erythrocytes are altered in HSA-deficient mice. They show a higher tendency to aggregate and are more susceptible to hypotonic lysis in vitro. In vivo, the mean half-life of HSA-deficient erythrocytes was reduced. When infected with the malarial parasite Plasmodium chabaudi chabaudi, the levels of parasite-bearing erythrocytes in HSA-deficient mice were also significantly elevated, but the mice were able to clear the infection with kinetics similar to wild-type mice and were immune to a second challenge. Thus, apart from alterations in erythrocytes and a mild block in B-cell development, the regulated expression of HSA appears to be dispensable for the maturation and functioning of those cell lineages that normally express it.

In Vitro Analysis of Murine B-Cell Development

1985 ◽  
Vol 3 (1) ◽  
pp. 213-235 ◽  
Author(s):  
C Whitlock ◽  
K Denis ◽  
D Robertson ◽  
O Witte
Keyword(s):  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Vitro Analysis ◽  
In Vitro Analysis

scholarly journals Differential Regulation of Mouse B Cell Development by Transforming Growth Factor β1

2002 ◽  
Vol 9 (2) ◽  
pp. 86-95 ◽  
Author(s):  
Denise A. Kaminski ◽  
John J. Letterio ◽  
Peter D. Burrows
Keyword(s):  
B Cells ◽  
Growth Factor ◽  
B Cell ◽  
Transforming Growth Factor ◽  
Plasma Cells ◽  
Population Analysis ◽  
Cell Development ◽  
B Cell Development

Transforming growth factor β (TGFβ) can inhibit thein vitroproliferation, survival and differentiation of B cell progenitors, mature B lymphocytes and plasma cells. Here we demonstrate unexpected, age-dependent reductions in the bone marrow (BM) B cell progenitors and immature B cells in TGFβ1-/-mice. To evaluate TGFβ responsiveness during normal B lineage development, cells were cultured in interleukin 7 (IL7)±TGFβ. Picomolar doses of TGFβ1 reduced pro-B cell recoveries at every timepoint. By contrast, the pre-B cells were initially reduced in number, but subsequently increased compared to IL7 alone, resulting in a 4-fold increase in the growth rate for the pre-B cell population. Analysis of purified BM sub-populations indicated that pro-B cells and the earliest BP1-pre-B cells were sensitive to the inhibitory effects of TGFβ1. However, the large BP1+pre-B cells, although initially reduced, were increased in number at days 5 and 7 of culture. These results indicate that TGFβ1 is important for normal B cell developmentin vivo, and that B cell progenitors are differentially affected by the cytokine according to their stage of differentiation.

scholarly journals In Vivo Tungsten Exposure Alters B-Cell Development and Increases DNA Damage in Murine Bone Marrow

2012 ◽  
Vol 131 (2) ◽  
pp. 434-446 ◽  
Author(s):  
Alexander D. R. Kelly ◽  
Maryse Lemaire ◽  
Yoon Kow Young ◽  
Jules H. Eustache ◽  
Cynthia Guilbert ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dna Damage ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Murine Bone Marrow

scholarly journals Rictor Is Required for Early B Cell Development in Bone Marrow

PLoS ONE ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. e103970 ◽  
Author(s):  
Yingchi Zhang ◽  
Tianyuan Hu ◽  
Chunlan Hua ◽  
Jie Gu ◽  
Liyan Zhang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development

scholarly journals Osteoclast activity modulates B-cell development in the bone marrow

Cell Research ◽  
2011 ◽  
Vol 21 (7) ◽  
pp. 1102-1115 ◽  
Author(s):  
Anna Mansour ◽  
Adrienne Anginot ◽  
Stéphane J C Mancini ◽  
Claudine Schiff ◽  
Georges F Carle ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Cell Development ◽  
B Cell Development ◽  
Osteoclast Activity

scholarly journals Mutations of the Igβ gene cause agammaglobulinemia in man

2007 ◽  
Vol 204 (9) ◽  
pp. 2047-2051 ◽  
Author(s):  
Simona Ferrari ◽  
Vassilios Lougaris ◽  
Stefano Caraffi ◽  
Roberta Zuntini ◽  
Jianying Yang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cell ◽  
Transmembrane Protein ◽  
Serum Levels ◽  
Cell Development ◽  
B Cell Development ◽  
Surrogate Light Chain ◽  
Human B Cell ◽  
Homozygous Nonsense Mutation

Agammaglobulinemia is a rare primary immunodeficiency characterized by an early block of B cell development in the bone marrow, resulting in the absence of peripheral B cells and low/absent immunoglobulin serum levels. So far, mutations in Btk, μ heavy chain, surrogate light chain, Igα, and B cell linker have been found in 85–90% of patients with agammaglobulinemia. We report on the first patient with agammaglobulinemia caused by a homozygous nonsense mutation in Igβ, which is a transmembrane protein that associates with Igα as part of the preBCR complex. Transfection experiments using Drosophila melanogaster S2 Schneider cells showed that the mutant Igβ is no longer able to associate with Igα, and that assembly of the BCR complex on the cell surface is abrogated. The essential role of Igβ for human B cell development was further demonstrated by immunofluorescence analysis of the patient's bone marrow, which showed a complete block of B cell development at the pro-B to preB transition. These results indicate that mutations in Igβ can cause agammaglobulinemia in man.

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