scholarly journals EBF Deficient Hematopoietic Progenitor Cells Potentialy Differentiated into Immature B Cell: EBF1 Dispensable for B Cell Linage Commitment from Pro-B to Pre-B Stage

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5127-5127
Author(s):  
Bidisha Chanda ◽  
Tomokatsu Ikawa ◽  
Kazuki Okuyama ◽  
Katsuto Hozumi ◽  
Kiyoshi Ando ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cell ◽  
Progenitor Cells ◽  
Hematopoietic Progenitor Cells ◽  
B Cell Differentiation ◽  
Tgf Beta ◽  
Hematopoietic Progenitor ◽  
Vdj Recombination ◽  
Igh Locus ◽  
Non Coding Rna

Abstract Introduction: Canonical notion demonstrates that Cell fate is determined by transcriptional factor. Accordingly, the lineage specific transcriptional factors have been investigated for various kinds of cells. Especially, in the hematopoietic system, the extensive research for lineage specific transcriptional factors had elucidated the transcriptional factors which regulated lineage commitment. B cell commitment and development requires the activities of multiple transcription factors, including the early B cell factor (EBF), PAX5, and E2A. These transcription factors regulate B cell development in a stage specific manner. The hematopoietic progenitor cells which are deficient for any of them, cannot commit B cells. Among them EBF1 is presumed to be more potent. Rescue early pro B cell to induce the expression of several key proteins including RAG that enable gene rearrangement to occur by opening of IgH locus. We found that the B cell developmental arrest caused by EBF1 deficiency can be rescued by a single non coding RNA. These B cells which are deficient EBF1 but showed the expression of CD19, B cell lineage specific surface marker and VDJ recombination, molecular markers of B cell commitment in vitro B cell differentiation system cocultured with Tst4 cells, stromal cell lines. We further investigated the quality and differentiation potential of these B lineage commitment cells in the in vivo mouse model and elucidated the mechanism of this phenomenon. Material and methods: We collected EBF1−/− fetal liver hematopoietic progenitor (Lin−) cells and cultured them on TSt-4 stromal cells after infecting with non coding RNA and control vector in IMDM medium containing cytokines and then injected it into NOG mice. Collect bone marrow (BM), thymus and spleen from those mice. Then comprehensive Gene-Expression analysis, real time PCR for VDJ recombination analysis was performed and checked surface marker by flowcytometry. Result: We analyzed BM and spleen of non coding RNA infected EBF1 KO cells injected mice and found the expression of CD19 in BM as well as in spleen and upregulated of B220 also, comparing with control vector expressed cells. Furthermore, surface IgM expression of CD19 positive cells in the spleen is upregulated compared with the cells in the BM (Figure 1). Several target genes of the non-coding RNAs were identified by use of cDNA array analysis and luciferase reportor assay. Among them, several genes were involved in TGF beta pathway. As TGF beta family and the pathway, has been reported a critical factor which is negatively regulating B lymphopoiesis　(Figure 2). We hypothesized that TGF beta family genes such as Tgfβr3, Acvr2a, are responsible for B cell differentiation for which EBF1 is dispensable .We cultured EBF KO cells for 14 days with and without TGF beta 1,2,3 antibody and Activin A antibody on TST4 cells. We found that increase mean intensity (MFI) of B220 into antibodies positive cocultured cells (Figure 3) to suggest, the suppression of TGF beta pathway is partially responsible for B cell differentiation under EBF1 deficiency. Conclusion: Canonical notion of cell fate determination of B cells defines that EBF1 is an indispensible factor for B lymphopoiesis. However, from our previous and present study it is proved that without EBF1 B cell development can progress to pro B to pre B cell and Immature B cell stage and “VDJ recombination” occur in the absence of EBF. Furthermore, in vivo mouse model, EBF1 deficient hematopoietic progenitor cells differentiated into IgM positive cells. Therefore we can conclude that EBF is dispensable of VDJ recombination, opening of IgH locus, binding of RAG protein and B cell differentiation to the mature stage. One of the mechanisms is possibly due to the stimuli from microenvironment, such as TGF beta family and pathway. Furthermore, the detail mechanism of IgH locus opening, epigenetic changes and chromatin remodeling around the IgH locus in the absence of EBF is under investigation. Disclosures Chanda: Japan Society for the Promotion of Science(JSPS): Research Funding.

Mechanisms of MEF2C-Dependent Transcription in Lymphoid Differentiation

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 4341-4341
Author(s):  
Nikki R. Kong ◽  
Li Chai ◽  
Astar Winoto ◽  
Robert Tjian
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Cell Differentiation ◽  
B Cell ◽  
Progenitor Cells ◽  
Luciferase Reporter ◽  
B Cell Differentiation ◽  
Reporter Assays ◽  
B Lineage ◽  
Transcription Program

Abstract Hematopoiesis is a multi-step developmental process that requires an intricate coordination of signal relays and transcriptional regulation to give rise to all blood lineages in the organism. Hematopoietic stem/progenitor cells (HSPCs) can be driven to differentiate along three main lineages: myeloid, erythroid, and lymphoid. One of the earliest lineage decisions for HSPCs is whether to adopt the lymphoid or myeloid fate. Despite the discovery of several transcription factors required for different lineages of hematopoietic differentiation, the understanding of how gene expression allows HSPCs to adopt the lymphoid fate still remains incomplete. A study using an inducible hematopoietic-specific (Mx1-Cre) KO mouse line found that Myocyte Enhancer Factor 2C (MEF2C) is required for multi-potent HSPCs to differentiate into the lymphoid lineage (Stehling-Sun et al, 2009). However, the mechanisms of how MEF2C is activated and in turn, drives lymphoid fate specification are not known. Through a candidates approach with co-expression and co-immunoprecipitation, we have identified Early B Cell Factor 1 (EBF1) to be a specific interacting partner of MEF2C, and not other B cell specific transcription factors such as E12, E47, or PAX5. Genome-wide survey of MEF2C and EBF1 binding sites via chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) in a proB cell line revealed that these two sequence-specific transcription factors co-occupy the promoters and intragenic regions of many B cell specific genes such as Il7ra, Myb, Foxo1, Ets1, Ebf1 itself, and Pou2af1. Regulatory regions of Il7ra and Foxo1 derived from the ChIP-seq data, as well as an artificial enhancer containing trimerized MEF2C and EBF1 binding sites, were examined in luciferase reporter assays and found to be sufficient to drive transcription from a minimal reporter in 293T cells. Further, this activation was co-dependent on MEF2C and EBF1 expression. The functional relevance of MEF2C binding was further supported by gene expression analyses of MEF2C-regulated B lineage genes in Mx1-Cre Mef2c KO mice compared to WT mice. Consistent with ChIP-seq and luciferase reporter assays, Myb, Ebf1, Il7ra, and Foxo1 all had significantly decreased expression levels in MEF2C-null HSPCs as well as B lineage progenitor cells, compared to sex-matched littermate control mice. Interestingly, myeloid gene expression in Mef2c-KO mice was increased compared to WT control. MEF2C ChIP-seq in a murine HSPC line revealed that it binds myeloid lineage gene targets that are not regulated by MEF2C in proB cells. These results suggest that MEF2C can repress myeloid gene expression in HSPCs. To elucidate the mechanism of this functional switch, we tested the requirement for MAPK pathways to phosphorylate and activate MEF2C at three previously identified residues in order to drive B cell differentiation. Inhibition of p38 MAPK (p38i), but not ERK1/2/5, decreased the potential of HSPCs to differentiate into B220+CD19+ B cells cultured with cytokines that drive this particular lineage fate. Instead, p38i-treated progenitor cells gave rise to more myeloid cells. 65% of this phenotype was rescued by over-expressing a phosphomimetic mutant of MEF2C that can bypass p38 inhibition. Furthermore, MEF2C is known to bind class II HDAC proteins to repress gene expression, providing a possible mechanism for its repression of myeloid transcription program. Supporting this mechanism, phosphomimetic and HDAC-binding double mutant of MEF2C can rescue p38 inhibition phenotype almost 100%. Taken together, this study elucidated the molecular mechanisms of a key lymphoid-specific lineage fate determinant, MEF2C. We discovered that p38 MAPK converts MEF2C from a transcriptional repressor to an activator by phosphorylation in B cell specification, which can be applied to understanding other cell differentiation processes regulated by this important stress-induced signaling pathway. Furthermore, we identified MEF2C’s binding and co-activating partner EBF1, several novel B cell specific targets that it activates in proB cells, and a novel myeloid transcription program that it represses in hematopoietic progenitors. Therefore, these results expanded our understanding of the intricate transcription network that regulates B cell differentiation. Disclosures No relevant conflicts of interest to declare.

scholarly journals Inhibition of purified CD34+ hematopoietic progenitor cells by human immunodeficiency virus 1 or gp120 mediated by endogenous transforming growth factor beta 1.

1996 ◽  
Vol 183 (1) ◽  
pp. 99-108 ◽  
Author(s):  
G Zauli ◽  
M Vitale ◽  
D Gibellini ◽  
S Capitani
Keyword(s):  
Human Immunodeficiency Virus ◽  
Growth Factor ◽  
Progenitor Cells ◽  
Transforming Growth Factor ◽  
Hematopoietic Progenitor Cells ◽  
Tgf Beta ◽  
Hematopoietic Progenitor ◽  
Cd34 Cells ◽  
Immunodeficiency Virus ◽  
Hiv 1

Human CD34+ hematopoietic progenitor cells, stringently purified from the peripheral blood of 20 normal donors, showed an impaired survival and clonogenic capacity after exposure to either heat-inactivated human immunodeficiency virus (HIV) 1 (strain IIIB) or cross-linked envelope gp120. Cell cycle analysis, performed at different times in serum-free liquid culture, showed an accumulation in G0/G1 in HIV-1- or gp120-treated cells and a progressive increase of cells with subdiploid DNA content, characteristic of apoptosis. In blocking experiments with anti-transforming growth factor (TGF) beta 1 neutralizing serum or TGF-beta 1 oligonucleotides, we demonstrated that the HIV-1- or gp120-mediated suppression of CD34+ cell growth was almost entirely due to an upregulation of endogenous TGF-beta 1 produced by purified hematopoietic progenitors. Moreover, by using a sensitive assay on the CCL64 cell line, increased levels of bioactive TGF-beta 1 were recovered in the culture supernatant of HIV-1/gp120-treated CD34+ cells. Anti-TGF-beta 1 neutralizing serum or TGF-beta 1 oligonucleotides were also effective in inducing a significant increase of the plating efficiency of CD34+ cells, purified from the peripheral blood of three HIV-1-seropositive individuals, suggesting that a similar mechanism may be also operative in vivo. The relevance of these findings to a better understanding of the pathogenesis of HIV-1-related cytopenias is discussed.

C-Kit Signaling Blocks B Cell Differentiation of Common Lymphoid Progenitor Cells by Negatively Regulating Stat5-Dependent Activation of Ebf Expressionc-Kit Signaling Blocks B Cell Differentiation of Common Lymphoid Progenitor Cells by Negatively Regulating Stat5-Dependent Activation of Ebf1 Expression

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1209-1209
Author(s):  
Oleg Kolupaev ◽  
Melissa Thal ◽  
Christopher Klug
Keyword(s):  
Bone Marrow ◽  
Cell Differentiation ◽  
B Cell ◽  
Progenitor Cells ◽  
Signaling Pathway ◽  
B Cell Development ◽  
B Cell Differentiation ◽  
Flt3 Ligand ◽  
Cell Commitment

Abstract Abstract 1209 B-lymphocyte commitment from common lymphoid progenitor cells (CLP) is orchestrated by a number of transcription factors and external cues such as IL-7, stem cell factor (SCF) and Flt3 ligand. IL-7 signaling plays a critical role in promoting B-cell differentiation by inducing the expression of transcription factor Ebf1 via the Jak-Stat5 signaling pathway (Kikuchi et al., 2007; Tsapogas et al., 2011). Previously, it has been shown that Flt3 ligand acts synergistically with IL-7 during the earliest stages of B-cell commitment (CLP and pre-pro-B fraction)(Åhsberg et al., 2010), but is downregulated by the pre-B stage to ensure normal development of B lymphocytes (Holmes et al., 2006). The role of SCF signaling in this early cell fate decision, however, remains unclear. Here, we demonstrate that SCF dominantly inhibits IL-7-induced B-cell differentiation from CLP by negatively regulating the Jak-Stat5 signaling pathway. Co-culture of bone marrow Lin-Kit+Sca-1+(LSK) cells with OP9 feeder cells in the presence of IL-7 (10 ng/ml) and SCF (10 ng/ml) resulted in 1.5–2-fold reduction in the frequency and absolute numbers of B220+CD19+ cells compared to cultures stimulated with IL-7 alone. To test whether c-Kit signaling inhibits B cell commitment in vivo, BM progenitor cells overexpressing a constitutively active form of KIT (MSCV-Kit-V814D-IRES-VEX) were transplanted into lethally irradiated mice. VEX+ cells in reconstituted mice had a very limited potential for B-lymphoid lineage differentiation, as judged by severe reduction in the frequency of B220+ cells in BM at 7 weeks post-transplant [B220+CD19-IgM-: 1.5%±0.3 (control) vs 0.6%±0.2 (V814D), p<0.05, n=6); B220+CD19+: 19.4%± 2.7 vs 2.1%±0.6, p<0.001; CD19+IgM+: 6.7%±1.3 vs 0.9%±0.3, p<0.01)]. Analysis of CLP cells isolated from IL-7−/− mice revealed that co-culture with IL-7 and SCF inhibited IL-7-induced upregulation of Ebf1 as well as other Stat5 target genes (Socs3, Cish, Osm). Furthermore, short-term treatment of BM cells isolated from IL-7−/− mice with a combination of SCF and IL-7 resulted in a significant reduction of phospho-Stat5 in CLP cells compared to cells treated with IL-7 alone. Class III receptor tyrosine kinases such as Flt3 and c-Kit are able to activate multiple signaling pathways via a juxtamembrane SH2-docking site. Mutation of the SH2 domain in the context of the Kit-V814D mutation (Kit-V814D-Y567/569F) did not rescue B-cell development when this mutant protein was expressed in primary murine bone marrow cells in vivo. In contrast, expression of a mutant form of Kit-V814D that inhibited binding of the SH2B adapter protein 2 (APS) (Kit-V814D-I570A/L937A) rescued B-lymphopoiesis, indicating that a signaling pathway coupled to APS dominantly suppresses B cell commitment when CLP are co-stimulated with SCF and IL-7. Based on the observations that APS is a known adapter for the E2-ubiquitin ligase, c-Cbl, which has been shown to negatively regulate Stat5 in other systems, we speculate that c-Kit signaling inhibits IL-7-induced Stat5 activation via an APS-Cbl pathway during early B-cell development. Further characterization of this inhibitory developmental pathway will be discussed. Disclosures: No relevant conflicts of interest to declare.

scholarly journals A new case of autosomal recessive agammaglobulinaemia with impaired pre-B cell differentiation due to a large deletion of the IGH locus

2002 ◽  
Vol 161 (9) ◽  
pp. 479-484 ◽  
Author(s):  
Michèle Milili ◽  
Henedina Antunes ◽  
Carla Blanco-Betancourt ◽  
Ana Nogueiras ◽  
Eugénia Santos ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
B Cell ◽  
Autosomal Recessive ◽  
Large Deletion ◽  
B Cell Differentiation ◽  
Igh Locus

γc Gene Transfer in the Presence of Stem Cell Factor, FLT-3L, Interleukin-7 (IL-7), IL-1, and IL-15 Cytokines Restores T-Cell Differentiation From γc(−) X-Linked Severe Combined Immunodeficiency Hematopoietic Progenitor Cells in Murine Fetal Thymic Organ Cultures

Blood ◽  
1998 ◽  
Vol 92 (11) ◽  
pp. 4090-4097 ◽  
Author(s):  
S. Hacein-Bey ◽  
G. De Saint Basile ◽  
J. Lemerle ◽  
A. Fischer ◽  
M. Cavazzana-Calvo
Keyword(s):  
Stem Cell ◽  
Cell Differentiation ◽  
Gene Transfer ◽  
Progenitor Cells ◽  
Stem Cell Factor ◽  
Severe Combined Immunodeficiency ◽  
T Cell Differentiation ◽  
Hematopoietic Progenitor Cells ◽  
Combined Immunodeficiency ◽  
Hematopoietic Progenitor

Abstract X-linked severe combined immunodeficiency (SCID-Xl) is a rare human inherited disorder in which early T and natural killer (NK) lymphocyte development is blocked. The genetic disorder results from mutations in the common γc chain that participates in several cytokine receptors including the interleukin-2 (IL-2), IL-4, IL-7, IL-9, and IL-15 receptors. We have shown in a previous report that γc gene transfer into SCID-Xl bone marrow (BM) cells restores efficient NK cell differentiation. In this study, we have focused on the introduction of the γc gene into SCID-Xl hematopoietic stem cells with the goal of obtaining differentiation into mature T cells. For this purpose, we used the in vitro hybrid fetal thymic organ culture (FTOC) system in which a combination of cytokines consisting of stem cell factor (SCF), Flt-3L, IL-7, IL-1, and IL-15 is added concomitantly. In this culture system, CD34+ marrow cells from two SCID-Xl patients were able to mature into double positive CD4+ CD8+ cells and to a lesser degree into CD4+ TCRβ+ single positive cells after retroviral-mediated γc gene transfer. In addition, examination of the output cell population at the TCR DJβ1 locus exhibited multiple rearrangements. These results indicate that restoration of the γc/JAK/STAT signaling pathway during the early developmental stages of thymocytes can correct the T-cell differentiation block in SCID-Xl hematopoietic progenitor cells and therefore establishes a basis for further clinical γc gene transfer studies.

scholarly journals Role of interleukin-2 (IL-2), IL-7, and IL-15 in natural killer cell differentiation from cord blood hematopoietic progenitor cells and from gamma c transduced severe combined immunodeficiency X1 bone marrow cells

Blood ◽  
1996 ◽  
Vol 88 (10) ◽  
pp. 3901-3909 ◽  
Author(s):  
M Cavazzana-Calvo ◽  
S Hacein-Bey ◽  
G de Saint Basile ◽  
C De Coene ◽  
F Selz ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Cord Blood ◽  
Nk Cells ◽  
Progenitor Cells ◽  
Nk Cell ◽  
Severe Combined Immunodeficiency ◽  
Interleukin 2 ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Nk Cell Differentiation

Natural killer (NK) cells are characterized by their ability to mediate spontaneous cytotoxicity against susceptible tumor cells and infected cells. They differentiate from hematopoietic progenitor cells. Patients with X-linked severe combined immunodeficiency (SCID X1) carry mutations in the gamma c cytokine receptor gene that result in lack of both T and NK cells. To assess the role of interleukin-2 (IL-2), IL-7, and IL-15 cytokines, which share gamma c receptor subunit, in NK cell differentiation, we have studied NK cell differentiation from cord blood CD34 (+) cells in the presence of either stem cell factor (SCF), IL-2, and IL-7 or SCF and IL-15. The former cytokine combination efficiently induced CD34 (+) CD7 (+) cord blood cells to proliferate and mature into NK cells, while the latter was also able to induce NK cell differentiation from more immature CD34 (+) CD7 (-) cord blood cells. NK cells expressed CD56 and efficiently killed K562 target cells. These results show that IL-15 could play an important role in the maturation of NK cell from cord blood progenitors. Following retroviral-mediated gene transfer of gamma c into SCID X1 bone marrow progenitors, it was possible to reproduce a similar pattern of NK cell differentiation in two SCID-X1 patients with SCF + IL-2 + IL-7 and more efficiently in one of them with SCF + IL-15. These results strongly suggest that the gamma c chain transduces major signal(s) involved in NK cell differentiation from hematopoietic progenitor cells and that IL-15 interaction with gamma c is involved in this process at an earlier step than IL-2/IL-7 interactions of gamma c are. It also shows that gene transfer into hematopoietic progenitor cells could potentially restore NK cell differentiation in SCID X1 patients.

Btg1-Deficiency Promotes ETV6-RUNX1-Mediated Leukemic Transformation By Upregulation of BCL6

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5193-5193
Author(s):  
Esther Tijchon ◽  
Liesbeth van Emst ◽  
Dorette van Ingen Schenau ◽  
Laurens T van der Meer ◽  
Simone de Rijk ◽  
...  
Keyword(s):  
B Cell ◽  
Progenitor Cells ◽  
Fetal Liver ◽  
Housekeeping Gene ◽  
Hematopoietic Progenitor Cells ◽  
Proliferative Capacity ◽  
Wild Type ◽  
Hematopoietic Progenitor ◽  
Targeted Deletion ◽  
Effector Pathways

Abstract Translocation t(12;21) (p13;q22), giving rise to the ETV6-RUNX1 fusion gene, is the most common genetic abnormality in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The ETV6-RUNX1 translocation arises in utero, but its expression is insufficient to induce leukemia and requires other cooperating genetic lesions for BCP-ALL to develop. Deletions affecting the transcriptional coregulator BTG1 are commonly observed in BCP-ALL (9%), but are significantly enriched in ETV6-RUNX1-positive leukemia (25%). The BTG1 protein displays no intrinsic enzymatic activity but may act by recruiting effector molecules like protein arginine methyltransferase 1 (PRMT1) to specific transcription factors. Here, we show that ETV6-RUNX1 interacts both with BTG1 and PRMT1, and this interaction is lost in c-Kit+Ter-119-Btg1-/- fetal liver (FL) derived hematopoietic progenitors (HPCs). Moreover, targeted deletion of Btg1 enhanced the proliferative capacity of ETV6-RUNX1 in FL-HPCs as measured by enhanced colony-forming and serial replating capacity (Figure 1). The combined loss of Btg1 function and ETV6-RUNX1 expression correlated with strong upregulation of the proto-oncogene Bcl6 and downregulation of BCL6 target genes, such as p19Arf and Tp53 (Figure 2). Similarly, ectopic expression of BCL6 promoted both proliferation and replating capacity of FL-derived progenitor cells in the presence of SCF, FLT3L and IL-7. This phenotype correlated with a fivefold suppression of p19Arf and a twofold suppression of Tp53 expression. Inhibition of BCL6 in a variety of human BCP-ALL cell lines by the peptide inhibitor RI-BPI resulted in decreased proliferation and induction of apoptosis as measured by Annexin-V staining. These included the ETV6-RUNX1-positive cell lines UOC-B6, AT-2 and REH, the BCR-ABL1-positive cell line SD1, as well as Nalm6. Together our results point to a novel role for BCL6 in promoting cell proliferation of primitive progenitor B cells and suggest that targeted inhibition of BCL6 may be effective in the treatment of various BCP-ALL subtypes. Figure 1. Btg1-deficiency enhances the proliferative capacity of early FL-HPCs expressing ETV6-RUNX1. FL-derived hematopoietic progenitor cells (FL-HPCs) (cKit+Ter119-) were isolated from wild-type and Btg1-/- embryos at day 13.5dpc and transduced with control and ETV6-RUNX1 virus. Control and ETV6-RUNX1 transduced FL-HPCs (1x104 cells) were added 48 hours after transduction in B cell specific methylcellulose in the presence of FLT-3L, IL-7 and SCF. Serial replating was performed under identical conditions. Mean colony counts (and SEM) were determined (>30 cells/colony) after 6-10 days of culture. Data is a representative of 2 independent experiments. *, P< 0.05, **, P< 0.01. Figure 1. Btg1-deficiency enhances the proliferative capacity of early FL-HPCs expressing ETV6-RUNX1. FL-derived hematopoietic progenitor cells (FL-HPCs) (cKit+Ter119-) were isolated from wild-type and Btg1-/- embryos at day 13.5dpc and transduced with control and ETV6-RUNX1 virus. Control and ETV6-RUNX1 transduced FL-HPCs (1x104 cells) were added 48 hours after transduction in B cell specific methylcellulose in the presence of FLT-3L, IL-7 and SCF. Serial replating was performed under identical conditions. Mean colony counts (and SEM) were determined (>30 cells/colony) after 6-10 days of culture. Data is a representative of 2 independent experiments. *, P< 0.05, **, P< 0.01. Figure 2. Targeted deletion of Btg1 cooperates with ETV6-RUNX1 in regulating critical effector pathways implicated in leukemia. Relative expression levels of Bcl6, Tp53 and p19arf in empty control (Ctrl) and ETV6-RUNX1 transduced wild-type and Btg1-deficient fetal liver-derived hematopoietic progenitor cells by real-time PCR and normalized to the expression of the housekeeping gene TATA box binding protein (TBP). Data represent the mean and SEM of three independent experiments. *, P< 0.05, **, P< 0.01, ***, P< 0.001. Figure 2. Targeted deletion of Btg1 cooperates with ETV6-RUNX1 in regulating critical effector pathways implicated in leukemia. Relative expression levels of Bcl6, Tp53 and p19arf in empty control (Ctrl) and ETV6-RUNX1 transduced wild-type and Btg1-deficient fetal liver-derived hematopoietic progenitor cells by real-time PCR and normalized to the expression of the housekeeping gene TATA box binding protein (TBP). Data represent the mean and SEM of three independent experiments. *, P< 0.05, **, P< 0.01, ***, P< 0.001. Disclosures No relevant conflicts of interest to declare.

Increased TSLP availability restores T- and B-cell compartments in adult IL-7–deficient mice

Blood ◽  
2007 ◽  
Vol 110 (12) ◽  
pp. 3862-3870 ◽  
Author(s):  
Stephane Chappaz ◽  
Lukas Flueck ◽  
Andrew G. Farr ◽  
Antonius G. Rolink ◽  
Daniela Finke
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
B Cell ◽  
Progenitor Cells ◽  
Hematopoietic Progenitor Cells ◽  
Fetal Life ◽  
Hematopoietic Progenitor ◽  
Interleukin 7 ◽  
Deficient Mice

AbstractInterleukin 7 (IL-7) plays a crucial role in adult lymphopoiesis, while in fetal life its effect can be partially compensated by TSLP. Whether adult hematopoietic progenitor cells are unresponsive to TSLP or whether TSLP is less available in adult microenvironments is still a matter of debate. Here, we show that increased TSLP availability through transgene (Tg) expression fully restored lymphopoiesis in IL-7–deficient mice: it rescued B-cell development, increased thymic and splenic cellularities, and restored double-negative (DN) thymocytes, αβ and γδ T-cell generation, and all peripheral lymphoid compartments. Analysis of bone marrow chimeras demonstrated that hematopoietic progenitor cells from adult wild-type mice efficiently differentiated toward B- and T-cell lineages in lethally irradiated IL-7 deficient mice provided TSLP Tg was expressed in these mice. In vitro, TSLP promoted the differentiation of uncommitted adult bone marrow progenitors toward B and T lineages and the further differentiation of DN1 and DN2 thymocytes. Altogether, our results show that adult hematopoietic cells are TSLP responsive and that TSLP can sustain long-term adult lymphopoiesis.

scholarly journals Effects of B cell stimulatory factor-1/interleukin 4 on hematopoietic progenitor cells

Blood ◽  
1987 ◽  
Vol 70 (1) ◽  
pp. 254-263 ◽  
Author(s):  
C Peschel ◽  
WE Paul ◽  
J Ohara ◽  
I Green
Keyword(s):  
T Cell ◽  
B Cell ◽  
Progenitor Cells ◽  
Colony Formation ◽  
Interleukin 1 ◽  
Interleukin 4 ◽  
Hematopoietic Progenitor Cells ◽  
Recombinant Erythropoietin ◽  
Hematopoietic Progenitor ◽  
Stimulatory Factor

Abstract B cell stimulatory factor-1 (BSF-1)/Interleukin 4 (IL 4) is a T cell product originally characterized on the basis of its actions on B lymphocytes. Recently it has been reported that BSF-1 activates T cell and mast cell lines. We now provide evidence that BSF-1, purified to homogeneity, also has a broad spectrum of activity on hematopoietic progenitor cells (HPC). However, like its action on B cells, prolierative effects were only observed when BSF-1 was combined with an additional factor. Thus BSF-1, in costimulation with recombinant G-CSF, enhances the proliferation of granulocyte-macrophage progenitor cells (CFU-GM). BSF-1 increases the proliferation of CFU-e in the presence of recombinant erythropoietin (rEPO). Furthermore, BSF-1 induces, together with rEPO, colony formation by primitive erythroid (BFU-e) and multipotent (CFU-mix) progenitor cells comparable to that observed with rEPO and interleukin 3 (IL 3). BSF-1 is also active as a megakaryocyte colony-stimulating factor; in combination with recombinant interleukin 1, rEPO or the supernatant of the T cell hybridoma FS7–20.6.18, BSF-1 induces megakaryocyte colony formation (CFU-Mk). The same factors that synergize with BSF-1 also enhance CFU-Mk proliferation induced by IL 3. Although the precise mechanisms of action of BSF-1 on HPC is not yet known, we propose that BSF-1 represents an activation factor for HPC and prepares the progenitor cells to respond to specific growth or differentiation factors.

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