CD109 is expressed on a subpopulation of CD34+ cells enriched in hematopoietic stem and progenitor cells

Obtaining sufficient numbers of functional natural killer (NK) cells is crucial for the success of NK-cell-based adoptive immunotherapies. While expansion from peripheral blood (PB) is the current method of choice, ex vivo generation of NK cells from hematopoietic stem and progenitor cells (HSCs) may constitute an attractive alternative. Thereby, HSCs mobilized into peripheral blood (PB-CD34+) represent a valuable starting material, but the rather poor and donor-dependent differentiation of isolated PB-CD34+ cells into NK cells observed in earlier studies still represents a major hurdle. Here, we report a refined approach based on ex vivo culture of PB-CD34+ cells with optimized cytokine cocktails that reliably generates functionally mature NK cells, as assessed by analyzing NK-cell-associated surface markers and cytotoxicity. To further enhance NK cell expansion, we generated K562 feeder cells co-expressing 4-1BB ligand and membrane-anchored IL-15 and IL-21. Co-culture of PB-derived NK cells and NK cells that were ex-vivo-differentiated from HSCs with these feeder cells dramatically improved NK cell expansion, and fully compensated for donor-to-donor variability observed during only cytokine-based propagation. Our findings suggest mobilized PB-CD34+ cells expanded and differentiated according to this two-step protocol as a promising source for the generation of allogeneic NK cells for adoptive cancer immunotherapy.

Download Full-text

Enforced Expression of GATA-2 Confers Quiescence on Human Hematopoietic Stem and Progenitor Cells In Vitro and In Vivo.

Blood ◽

10.1182/blood.v108.11.83.83 ◽

2006 ◽

Vol 108 (11) ◽

pp. 83-83

Author(s):

Alex J. Tipping ◽

Cristina Pina ◽

Anders Castor ◽

Ann Atzberger ◽

Dengli Hong ◽

...

Keyword(s):

Cell Cycle ◽

Progenitor Cells ◽

Zinc Finger ◽

Human Cord Blood ◽

Hematopoietic Stem ◽

Cd34 Cells ◽

Stem And Progenitor Cells ◽

Colony Number

Abstract Hematopoietic stem cells (HSCs) in adults are largely quiescent, periodically entering and exiting cell cycle to replenish the progenitor pool or to self-renew, without exhausting their number. Expression profiling of quiescent HSCs in our and other laboratories suggests that high expression of the zinc finger transcription factor GATA-2 correlates with quiescence. We show here that TGFβ1-induced quiescence of wild-type human cord blood CD34+ cells in vitro correlated with induction of endogenous GATA-2 expression. To directly test if GATA-2 has a causative role in HSC quiescence we constitutively expressed GATA-2 in human cord blood stem and progenitor cells using lentiviral vectors, and assessed the functional output from these cells. In both CD34+ and CD34+ CD38− populations, enforced GATA-2 expression conferred increased quiescence as assessed by Hoechst/Pyronin Y staining. CD34+ cells with enforced GATA-2 expression showed reductions in both colony number and size when assessed in multipotential CFC assays. In CFC assays conducted with more primitive CD34+ CD38− cells, colony number and size were also reduced, with myeloid and mixed colony number more reduced than erythroid colonies. Reduced CFC activity was not due to increased apoptosis, as judged by Annexin V staining of GATA-2-transduced CD34+ or CD34+ CD38− cells. To the contrary, in vitro cultures from GATA-2-transduced CD34+ CD38− cells showed increased protection from apoptosis. In vitro, proliferation of CD34+ CD38− cells was severely impaired by constitutive expression of GATA-2. Real-time PCR analysis showed no upregulation of classic cell cycle inhibitors such as p21, p57 or p16INK4A. However GATA-2 expression did cause repression of cyclin D3, EGR2, E2F4, ANGPT1 and C/EBPα. In stem cell assays, CD34+ CD38− cells constitutively expressing GATA-2 showed little or no LTC-IC activity. In xenografted NOD/SCID mice, transduced CD34+ CD38−cells expressing high levels of GATA-2 did not contribute to hematopoiesis, although cells expressing lower levels of GATA-2 did. This threshold effect is presumably due to DNA binding by GATA-2, as a zinc-finger deletion variant of GATA-2 shows contribution to hematopoiesis from cells irrespective of expression level. These NOD/SCID data suggest that levels of GATA-2 may play a part in the in vivo control of stem and progenitor cell proliferation. Taken together, our data demonstrate that GATA-2 enforces a transcriptional program on stem and progenitor cells which suppresses their responses to proliferative stimuli with the result that they remain quiescent in vitro and in vivo.

Download Full-text

Analysis of Mesenchymal Stromal Cells (MSC) and Their Interactions with CD34 Stem and Progenitor Cells in Patients with Myelodysplastic Syndromes (MDS)

Blood ◽

10.1182/blood.v118.21.2393.2393 ◽

2011 ◽

Vol 118 (21) ◽

pp. 2393-2393

Author(s):

Stefanie Geyh ◽

Ron Patrick Cadeddu ◽

Julia Fröbel ◽

Ingmar Bruns ◽

Fabian Zohren ◽

...

Keyword(s):

Progenitor Cells ◽

Myelodysplastic Syndromes ◽

Stromal Cells ◽

Median Number ◽

Lower Number ◽

Differentiation Potential ◽

Receptor Ligand ◽

Hematopoietic Stem ◽

Cd34 Cells ◽

Stem And Progenitor Cells

Abstract Abstract 2393 Background: Myelodysplastic syndromes (MDS) represent a heterogeneous group of hematopoietic stem cell disorders and research in this field has mainly focused on hematopoietic stem and progenitor cells (HSPC). Still, recent data from mouse models indicate that the bone marrow (BM) microenvironment might be involved in the pathogenesis MDS (Raaijmakers et al., 2010). The role of mesenchymal stromal cells (MSC) in particular as a key component of the BM microenvironment remains elusive in human MDS and data so far are controversial. Design/Methods: We therefore investigated MSC and immunomagnetically enriched CD34+ HSPC from BM of 42 untreated patients (pts) with MDS (12 RCMD, 12 RAEB, 12 sAML, 3 del5q, 1 CMML-1, 1 MDS hypocellular, 1 MDS unclassifiable according to WHO) and age-matched healthy controls (HC, n=13). MSC were examined with regard to growth kinetics, morphology and differential potential after isolation and expansion according standard procedures in line with the international consensus criteria (Dominici et al., 2006). Furthermore corresponding receptor-ligand pairs on MSC and CD34+ cells (Kitlg/c-kit; CXCL12/CXCR4; Jagged1/Notch1; Angpt1-1/Tie-2; ICAM1/LFA-1) were investigated by RT-PCR. Results: In MDS, the colony forming activity (CFU-F) of MSC was significantly reduced in comparison to HC (median number of colonies per 1×107MNC in MDS: 8, range 2–74 vs. HC: 175, 10–646, p=0.003) and this was also true when looking at the different subtypes (RCMD median: 16, p=0.04; RAEB median: 8, p=0.31; sAML median: 26, p=0.02). According to this, MSC from pts with RCMD and del5q could only be maintained in culture for a lower number of passages (median number of passages: MDS 3 passages, range 1–15; HD 14 passages, range 8–15, p=0.01), had a lower number of cumulative population doublings (CPD) and needed a longer timer to reach equivalent CPD (MDS median: 18,16 CPD, HD median: 33,68 CPD, p=0,0059). All types of MDS-MSC showed an abnormal morphology, while an impaired osteogenic differentiation potential was exclusively observed in pts with RCMD. These findings of an altered morphology together with a diminished growth and differentiation potential prompted us to test, whether the interaction between MSC and CD34+ HSPC in BM of pts with MDS was also disturbed. On the MDS-MSC, we found a significant lower expression of Angpt1 in pts with RAEB (3.5-fold, p=0.01) and del5q (4.9-fold, p=0.009) compared to HD. The expression of CXCL12 (2.5-fold, p=0.057) and jagged1 was reduced in trend in MSC from pts with MDS, while no differences were observed with regard to the expression of kitlg and ICAM1. When looking on CD34+ cells, we found a significantly reduced expression of CXCR4 (RCMD 2.5-fold, p=0.02; RAEB 2.46-fold, p=0.02), notch1 (RCMD 6-fold, p=0.04) and Tie-2 (RAEB 5.91-fold, p=0.02) in pts with MDS, while LFA-1 was overexpressed in pts with RAEB (2.6-fold, p=0.036). Conclusion: Taken together, our data indicate that MSC from pts with MDS are structurally altered and that the crosstalk between CD34+ HSPC and MSC in the BM microenvironment of pts with MDS might be deregulated as a result of an abnormal expression of relevant receptor-ligand pairs. Ongoing research is required to corroborate these findings and to definitely address their functional relevance for the pathogenesis of MDS. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Loss of ASXL1 Triggers an Apoptotic Response in Human Hematopoietic Stem and Progenitor Cells

Blood ◽

10.1182/blood.v126.23.4107.4107 ◽

2015 ◽

Vol 126 (23) ◽

pp. 4107-4107

Author(s):

Susan Hilgendorf ◽

Hendrik Folkerts ◽

Jan Jacob Schuringa ◽

Edo Vellenga

Keyword(s):

Progenitor Cells ◽

Colony Formation ◽

Erythroid Differentiation ◽

Lentiviral Vectors ◽

Apoptotic Response ◽

Double Positive ◽

Hematopoietic Stem ◽

Cd34 Cells ◽

Stem And Progenitor Cells

Abstract In recent clinical studies, it has been shown that ASXL1 is frequently mutated in myelodysplastic syndrome (MDS), in particular in high-risk MDS patients who have a significant chance to progress to acute myeloid leukemia (AML). The majority of ASXL1 mutations leads to truncation of the protein and thereby to loss of its chromatin interacting and modifying domain, possibly facilitating malignant transformation. However, the functions of ASXL1 in human hematopoietic stem and progenitor cells are not well understood. In this study, we addressed whether manipulation of ASXL1-expression in the hematopoietic system in vitro mimics the changes observed in MDS-patients. We downregulated ASXL1 in CD34+ cord blood (CB) cells using lentiviral vectors containing several independent shRNAs and obtained a 40-50% reduction of ASXL1 expression. Colony Forming Cell (CFC) assays revealed that erythroid colony formation was significantly impaired (p<0.01) and, to some extent, granulocytic and macrophage colony formation as well (p<0.09, p<0.05 respectively). In myeloid suspension culture assays, we observed a modest reduction in expansion (two-fold at week 1) upon ASXL1 knockdown under myeloid conditions. In erythroid conditions, shASXL1 CB CD34+ cells showed a strong four-fold growth disadvantage, with a more than two-fold delay in erythroid differentiation. The reduced expansion was partly due to a significant increase in apoptosis (5.9% in controls vs. 14.0% shASXL1, p<0.02). The increase in cell death was restricted to differentiating cells, defined as CD71 bright- and CD71/GPA-double positive. In addition, we tested whether HSCs were affected by ASXL1 loss. Long-term culture-initiating cell (LTC-IC) assays revealed a two-fold decrease in stem cell frequency. To test dependency of shASXL1 CB 34+ cells on the microenvironment, transduced cells were cultured on MS5 bone marrow stromal cells with or without additional cytokines. shASXL1 CB CD34+ cells cultured on MS5 showed a modest two-fold reduction in cell growth at week 4. In the presence of EPO and SCF, we detected a growth disadvantage (three-fold at week 2) and a delay in erythroid differentiation, similar to what was observed in liquid culture. ASXL1 has been proposed to be an epigenetic modifier by recruiting/stabilizing the polycomb repressive complex 2 (PRC2). Active PRC2 can lead to trimethylation of H3K27 and silencing of certain loci. It has been proposed that perturbed ASXL1 activity may disturb PRC2 function, leading to reduced H3K27me3 and increased gene expression. Using an erythroid leukemic cell line, we downregulated ASXL1 and as a positive control EZH2, one of the core subunits of PRC2. We then performed ChIP and did PCR for several loci. Upon knockdown of ASXL1, we did not observe changes in H3K27me3 on any of he investigated loci. However, upon knockdown of EZH2 we observed more than 50% loss of the H3k27m3 mark for many of the loci. This implies that our observed phenotypes may not be conveyed via the PRC2 complex but maybe via an alternative pathway. Preliminary data revealed an increase in H2AK119ub, suggesting that the BAP1-ASXL1 complex may be involved. In patients, mutations in ASXL1 are frequently accompanied by a mutation of TP53. Possibly, this additional mutation is necessary to allow ASXL1-mutant induced transformation thereby bypassing the apoptotic response. Therefore, we modeled simultaneous loss of ASXL1 and TP53 using shRNA lentiviral vectors. Our data showed that while in primary CFC cultures shASXL1/shTP53 did not give rise to more colonies, an increase in colony-forming activity was observed upon replating of the cells. Furthermore, shASXL1/shTP53 transduced cells grown in erythroid liquid conditions revealed a decrease in apoptosis compared to the ASXL1 single mutation and an outgrowth of these double positive cells. Nevertheless, no transformation occurred in vitro. We therefore injected shASXL/TP53 transduced CB CD34+ in a humanized scaffold model in mice to determine whether transformation can occur in vivo. In conclusion, our data indicate that mutations in ASXL1 trigger an apoptotic response in CB CD34+ cells with a delay in differentiation, which leads to reduced stem and progenitor output in vitro without affecting H3K27me3. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Functional Stability (at +4°C) of Hematopoietic Stem and Progenitor Cells Amplified Ex Vivo from Cord Blood CD34+Cells

Cell Transplantation ◽

10.3727/096368912x657611 ◽

2013 ◽

Vol 22 (8) ◽

pp. 1501-1506 ◽

Cited By ~ 5

Author(s):

Pascale Duchez ◽

Jean Chevaleyre ◽

Philippe Brunet De La Grange ◽

Marija Vlaski ◽

Jean-Michel Boiron ◽

...

Keyword(s):

Cord Blood ◽

Progenitor Cells ◽

Ex Vivo ◽

Functional Stability ◽

Hematopoietic Stem ◽

Cd34 Cells ◽

Stem And Progenitor Cells ◽

Cord Blood Cd34

Download Full-text

Mesenchymal Stem Cell-Derived Microvesicles Support Ex Vivo Expansion of Cord Blood-Derived CD34+Cells

Stem Cells International ◽

10.1155/2016/6493241 ◽

2016 ◽

Vol 2016 ◽

pp. 1-13 ◽

Cited By ~ 19

Author(s):

Hui Xie ◽

Li Sun ◽

Liming Zhang ◽

Teng Liu ◽

Li Chen ◽

...

Keyword(s):

Cord Blood ◽

Progenitor Cells ◽

Mononuclear Cells ◽

Ex Vivo ◽

Ex Vivo Expansion ◽

Hematopoietic Stem ◽

Promising Therapeutic Approach ◽

Cd34 Cells ◽

Stem And Progenitor Cells

Mesenchymal stem cells (MSCs) are known to support the characteristic properties of hematopoietic stem and progenitor cells (HSPCs) in the bone marrow hematopoietic microenvironment. MSCs are used in coculture systems as a feeder layer for the ex vivo expansion of umbilical cord blood (CB) to increase the relatively low number of HSPCs in CB. Findings increasingly suggest that MSC-derived microvesicles (MSC-MVs) play an important role in the biological functions of their parent cells. We speculate that MSC-MVs may recapitulate the hematopoiesis-supporting effects of their parent cells. In the current study, we found MSC-MVs containing microRNAs that are involved in the regulation of hematopoiesis. We also demonstrated that MSC-MVs could improve the expansion of CB-derived mononuclear cells and CD34+cells and generate a greater number of primitive progenitor cells in vitro. Additionally, when MSC-MVs were added to the CB-MSC coculture system, they could improve the hematopoiesis-supporting effects of MSCs. These findings highlight the role of MSC-MVs in the ex vivo expansion of CB, which may offer a promising therapeutic approach in CB transplantation.

Download Full-text

A thrombopoietin receptor antagonist is capable of depleting myelofibrosis hematopoietic stem and progenitor cells

Blood ◽

10.1182/blood-2015-10-674465 ◽

2016 ◽

Vol 127 (26) ◽

pp. 3398-3409 ◽

Cited By ~ 11

Author(s):

Xiaoli Wang ◽

David Haylock ◽

Cing Siang Hu ◽

Wioleta Kowalczyk ◽

Tianbo Jiang ◽

...

Keyword(s):

Receptor Antagonist ◽

Progenitor Cells ◽

Hematopoietic Stem ◽

New Approaches ◽

Thrombopoietin Receptor ◽

Cd34 Cells ◽

Key Points ◽

Stem And Progenitor Cells

Key Points Treatment of MF CD34+ cells with a TPO receptor antagonist selectively depletes MF HSCs and HPCs. Agents that target the TPO receptor represent potentially new approaches for the treatment of MF patients.

Download Full-text

STAT5 is required for long-term maintenance of normal and leukemic human stem/progenitor cells

Blood ◽

10.1182/blood-2006-08-039073 ◽

2007 ◽

Vol 110 (8) ◽

pp. 2880-2888 ◽

Cited By ~ 68

Author(s):

Hein Schepers ◽

Djoke van Gosliga ◽

Albertus T. J. Wierenga ◽

Bart J. L. Eggen ◽

Jan Jacob Schuringa ◽

...

Keyword(s):

Progenitor Cells ◽

Myeloid Leukemia ◽

Cell Number ◽

Hematopoietic Stem ◽

Fold Reduction ◽

Cd34 Cells ◽

Stem And Progenitor Cells ◽

Precise Role ◽

Term Maintenance

Abstract The transcription factor STAT5 fulfills a distinct role in the hematopoietic system, but its precise role in primitive human hematopoietic cells remains to be elucidated. Therefore, we performed STAT5 RNAi in sorted cord blood (CB) and acute myeloid leukemia (AML) CD34+ cells by lentiviral transduction and investigated effects of STAT5 downmodulation on the normal stem/progenitor cell compartment and the leukemic counterpart. STAT5 RNAi cells displayed growth impairment, without affecting their differentiation in CB and AML cultures on MS5 stroma. In CB, limiting-dilution assays demonstrated a 3.9-fold reduction in progenitor numbers. Stem cells were enumerated in long-term culture-initiating cell (LTC-IC) assays, and the average LTC-IC frequency was 3.25-fold reduced from 0.13% to 0.04% by STAT5 down-regulation. Single-cell sorting experiments of CB CD34+/CD38− cells demonstrated a 2-fold reduced cytokine-driven expansion, with a subsequent 2.3-fold reduction of progenitors. In sorted CD34+ AML cells with constitutive STAT5 phosphorylation (5/8), STAT5 RNAi demonstrated a reduction in cell number (72% ± 17%) and a decreased expansion (17 ± 15 vs 80 ± 58 in control cultures) at week 6 on MS5 stroma. Together, our data indicate that STAT5 expression is required for the maintenance and expansion of primitive hematopoietic stem and progenitor cells, both in normal as well as leukemic hematopoiesis.

Download Full-text

Long-Term Hydroxyurea Use Is Associated with Lower Levels of Hematopoietic Stem and Progenitor Cells in Patients with Sickle Cell Disease

Blood ◽

10.1182/blood-2019-131648 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 985-985

Author(s):

Seda S. Tolu ◽

Kai Wang ◽

Zi Yan ◽

Andrew Crouch ◽

Gracy Sebastian ◽

...

Keyword(s):

Gene Therapy ◽

Progenitor Cells ◽

Research Funding ◽

Cell Disease ◽

Transfusion Therapy ◽

Hematopoietic Stem ◽

Hematopoietic System ◽

Cd34 Cells ◽

Stem And Progenitor Cells

Background Sickle cell disease (SCD) is curable by transplantation and potentially by gene therapy, and is generally treated by a combination of blood transfusion and Hydroxyurea (HU). Characterizing the hematopoietic system in SCD patients is important because the long-term effect of HU treatment are not known, and because of lower than expected efficacy of transduction and transplantation in Hematopoietic Stem and Progenitor Cells (HSPCs) in recent gene therapy trials. Previous studies have shown that the number of bone marrow (BM) CD34+ cells is elevated in SCD patients and that HU treatment is associated with decreased level of CD34+ cells in the peripheral blood (PB) and BM relative to steady state patients. However, hematopoiesis in SCD patients naive or treated with HU or transfusion remains poorly understood. Here, we report on the characterization of the HSPC compartment in patients with SCD by prospective isolation of 49f+ long-term Hematopoietic Stem Cells (49f+LT-HSCs), Multipotent Progenitors (MPPs), Common Myeloid Progenitors (CMPs), Megakaryocyte-Erythroid Progenitors (MEPs), and Granulocyte-Monocyte Progenitors (GMPs). Methods After obtaining consent, PB and/or BM were collected from 69 patients with HBSS/SB0, aged 12 to 45years, and 25 healthy adult African American controls. Patients were divided into chronic transfusion therapy (n=19), HU (n=31) and naïve (n=19) groups. Frozen mono-nuclear cells were analyzed by flow cytometry on a BD LSRII using CD 49f, 90 45Ra, 123, 235a, 38, 34, 33 and lineage antibodies. Results FACS analysis revealed that the number PB CD34+ cells was 2.5 CD34+/uL of blood in the HU group as compared to 19 CD34+/uL in the exchange and naive groups, and 7.3 CD34+/uL in the control group (q-value <0.05 in all cases). Analysis with additional markers revealed that the decrease in circulating HSPCs in the HU group affected the entire hematopoietic system since the number of 49f+LT-HSCs, MPPs, CMPs, MEPs were all significantly lower in the HU group. The decrease in cell number in the HU group, however, was not homogeneous. The proportion of LT-HSCs was higher in the HU and transfusion groups when compared to the naive and control groups. The HU group also had the lowest proportion of MPPs and GMPs, as well as the highest proportion of MEPs. We then investigated hematopoiesis as a function of the length of HU treatment to elucidate the long-term treatment effect of this cytotoxic agent. Patients > 18 years of age that had been treated on HU for at least three years exhibited a strong statistically significant negative correlation between years on HU and CD34+/uL (R2 = 0.41), LT-HSC/uL (R2 = 0.35), MPP/uL (R2 =0.43), CMP/uL (R2 = 0.37), MEP/uL (R2 = 0.25) and GMP/uL (R2 0.39, p<0.01 in all cases). Importantly there was no correlation between WBC counts, age, HU dose, or serum erythropoietin level versus the numbers of any HSPC/uL. Lastly, we compared the number of HSPCs in paired PB and BM samples 10 controls and 4 SCD patients. This revealed that the numbers of CD34+, HSCs, MPPs, CMPs, GMPs and MEPs in the PB and BM were well correlated (r2 in 0.6-0.8 range) suggesting that in first approximation, results obtained in the PB reflect changes in the BM rather than changes in egress of HSPCs from the BM. Discussion We have observed lower numbers of circulating CD34+,49f+LT- HSCs, MPPs, CMP, GMP and MEPs in individuals with HBSS on HU therapy when compared to naive, chronic transfusion and, to a lesser extent, controls. Furthermore we observed subtle differences in the proportion of various circulating stem and progenitor cells (HSPCs) suggesting that the various treatments affects hematopoiesis in complex ways. The strong negative correlations between the length of HU treatment and the numbers of HSPCs can be explained either by decreased cell mobilization to the periphery, or by a depletion of the HSPC numbers in the BM overtime. Most patients undergoing gene therapy trials are currently taken off HU and placed on transfusion therapy for several months to increase CD34+ cell collection and LT-HSC transduction efficiency. We observed a greater number of circulating 49f+LT-HSC/uL of blood in the transfusion group than in the HU group, but the proportion of 49f+LT-HSC relative to the number of CD34+ were similar in both groups. Functional studies may help determine whether 49f+LT-HSCs from the transfusion group are qualitatively different from of the HU group and more amenable to gene therapy. Figure Disclosures Manwani: Novartis: Consultancy; Pfizer: Consultancy; GBT: Consultancy, Research Funding. Minniti:Doris Duke Foundation: Research Funding.

Download Full-text