scholarly journals Aryl Hydrocarbon Receptor Antagonism Promotes Hematoendothelial Development from Human Pluripotent Stem Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3585-3585
Author(s):  
Mathew G. Angelos ◽  
Anna Kim ◽  
Dan S. Kaufman

Abstract The aryl hydrocarbon receptor (AHR) is an evolutionarily conserved transcription factor originally characterized for its role in mediating biological responses to carcinogenic environmental agents. Recent studies have elucidated the importance of AHR-dependent signaling for normal physiological function in the absence of environmental ligands, most notably the development of Th17 cells, regulatory T-cells, and natural killer (NK) cells from human peripheral blood and umbilical cord blood. Additionally, AHR is highly expressed in hematopoietic stem/progenitor cells (HSPCs), and antagonism of AHR using small molecules results in a marked expansion of umbilical cord blood-derived HSPCs suitable for clinical transplantation. It remains unclear what role, if any, AHR plays during early human hematoendothelial development. We hypothesized inhibition of AHR-mediated cell signaling could promote early human hematopoietic cell development. To model human hematopoiesis, we employed a xenogeneic-free and chemically defined in vitro method to differentiate human embryonic stem cells (hESCs) into endothelial and hematopoietic cells. qRT-PCR analysis demonstrated a significant increase in AHR (13.36±5.52 fold change, p<0.05, n=3) by Day 11 of differentiation relative to undifferentiated hESCs. CYP1A1 and CYP1B1, two downstream targets of AHR-mediated signaling, were similarly upregulated on Day 11 (27.90±6.17 fold change, p<0.05, n=3; 134.28±10.06 fold change, n=3, respectively). Increase in AHR expression mirrored the onset of early hematopoietic progenitor cell differentiation; CD34+ CD43+ and CD34+ CD41a+ cells were markedly increased by Day 12 of hematopoietic differentiation as assessed by flow cytometry (18.9%±3.22, p<0.01, n=7; 8.23±2.00, p<0.05, n=7, respectively). We next modified the relative activity of AHR signaling by differentiating hESCs in the presence of 2,3,7,8-tetrachlorodibenzo-p- dioxin (TCDD), a prototypical AHR agonist, or StemReginin-1 (SR-1), an AHR antagonist, and assessed its effects on hematopoietic progenitor cell production. Interestingly, we observed a significant increase in the appearance of both CD34+ CD31+ hematoendothelial cells in SR-1 treated hESCs relative to DMSO treated controls (17.63%±1.25, p<0.05, n=3 vs. 11.21±0.63, p<0.05, n=3) at Day 9. Later by Day 12, we also found approximately a two-fold expansion of CD34+ CD45+ hematopoietic progenitor cells in SR-1 treated hESCs relative to DMSO treated controls (16.35%±4.05, p<0.05, n=3 vs. 7.53±0.19, p<0.05, n=3). Treatment with TCDD reciprocally attenuated the development of CD34+ CD45+ progenitor cells at Day 15 relative to DMSO treated controls (3.99%±0.80 vs. 11.79%±1.41, p<0.05, n=3) and resulted in an expansion of terminally differentiated hematopoietic cells (CD34- CD43+: 84.5%±2.78 vs. 70.9±1.58, p<0.05, n=3; CD34- CD45+: 81.75%±1.75 vs. 71.95±2.35, p<0.05, n=3). We confirmed the functionality of the hematopoietic progenitor cells in each group by harvesting non-adherent cells at Day 12 and performing standard colony-forming assays. SR-1 treated cells yielded a 4-fold increase in the total number of colonies generated relative to DMSO treated control cells along with an increased proportion of CFU-M and CFU-GM. We also evaluated whether AHR antagonism could be used to promote NK cell differentiation from hESCs. Using previously optimized and defined NK cell differentiation conditions, we found SR-1 treatment caused an increase in CD56+ CD45+ NK cells relative to DMSO treated controls (26.4% vs. 19.7%, n=2) whereas TCDD treatment caused a decrease (6.7%, n=2). Work assessing how hematopoiesis from hESCs is affected using AHR gene knockouts developed from CRISPR/Cas9-mediated gene deletion is ongoing. Collectively, our results demonstrate AHR antagonism promotes early human hematoendothelial development and may be used as a potential molecular target to enhance hematopoietic cell production from human pluripotent stem cells for clinical applications. Disclosures No relevant conflicts of interest to declare.

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 ◽  
...  

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.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3833-3833
Author(s):  
Mieke WH Roeven ◽  
Jeanette Cany ◽  
Frans Maas ◽  
Arwa Kohela ◽  
Jansen Joop ◽  
...  

Abstract Introduction Allogeneic stem cell transplantation (SCT) can be a curative treatment for hematological malignancies. The therapeutic effectiveness is attributed to the graft-versus-tumor (GVT) effect, mediated by alloreactive T cells and natural killer (NK) cells. Although T cells can induce a potent GVT effect, they can also induce graft-versus-host disease (GVHD), causing high morbidity and mortality. Interestingly, after non-myeloablative allogeneic SCT, early NK cell repopulation has been associated with decreased relapse rates, without increasing GVHD incidence, illustrating a possible role for donor NK cell adoptive transfer after allogeneic SCT. However, isolation of sufficient numbers of activated NK cells from donor origin is challenging. Recently, it has been described that antagonizing the aryl hydrocarbon receptor (AhR) using the antagonist StemReginin1 (SR1) promotes expansion of human hematopoietic stem cells. Furthermore, AhR turned out to regulate differentiation of multiple immune cells like dendritic cells, regulatory T cells, γδ T cells, and also NK cells. Therefore, we investigated if SR1 could enhance NK cell generation in a cytokine-based culture system. Methods CD34+ hematopoietic progenitor cells (HPCs) were isolated using immunomagnetic beads from G-CSF mobilized aphaeresis material. These HPCs were expanded during 14 days in medium containing SCF, Flt3L, TPO, IL-7 and IL-15 and subsequently differentiated into NK cells using IL-15 and IL-2. HPC-NK cell expansions were performed with or without SR1. RNA was collected from the cultures weekly and expression of NK cell related genes was analyzed using qPCR. After 35 days, HPC-NK cells were assessed for their cytolytic functions against acute myeloid leukemia (AML) and multiple myeloma (MM) cell lines and primary AML blasts. In addition, expression levels of typical NK-activating receptors and differentiation markers were analyzed by flow cytometry. Results Interestingly, SR1 induced expression of TOX, ID2, EOMES, GATA3 and SH2D1B, which are important factors involved in early and late NK cell differentiation. In addition, SR1 improved the expansion, differentiation, and functionality of the NK cells generated. In the presence of SR1, we were able to expand PB-derived HPCs up to 1000-fold in 5 weeks. The SR1-generated HPC-NK cell products contained 80 – 92% NK cells, which expressed high levels of activating NKG2D and natural cytotoxicity receptors. Furthermore, functional analysis showed marked degranulation and cytokine release upon co-culture with AML and MM cell lines and efficient lysis of primary AML blasts at low NK-target ratios. Conclusion Addition of the AHR antagonist SR1 in our culture system induces expression of transcription factors involved in NK cell differentiation and thereby facilitates the generation of high numbers of functional NK cells from G-CSF mobilized CD34+ progenitor cells. These NK cells hold great promise for future donor NK cell-mediated therapy after allogeneic SCT. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
1996 ◽  
Vol 87 (7) ◽  
pp. 2632-2640 ◽  
Author(s):  
E Mrozek ◽  
P Anderson ◽  
MA Caligiuri

Human natural killer (NK) cells are bone marrow (BM)-derived CD2+CD16+CD56+ large granular lymphocytes (LGL) that lack CD3 yet contain the T-cell receptor zeta-chain (zeta-TCR). NK cells provide requisite interferon-gamma (IFN-gamma) during the early stages of infection in several experimental animal models. A number of studies have shown that human CD3-CD56+ NK cells can be obtained from BM- derived CD34+ hematopoietic progenitor cells (HPCs) cultured in the presence of interleukin-2 (IL-2) and an allogeneic feeder cell layer, or IL-2 and other hematopoietic growth factors such as the c-kit ligand (KL). The failure to detect the IL-2 gene product within the BM stroma and the presence of NK cells in IL-2-deficient mice suggested that cytokines other than IL-2 may participate in NK cell differentiation from HPCs in vivo. IL-15 is a cytokine which, while lacking any sequence homology in IL-2, can activate cells via the IL-2 receptor. Here we show that human BM stromal cells express the IL-15 transcript, and supernatants from long-term BM stromal cell cultures contain IL-15 protein. In vitro, CD3-CD56+ NK cells can be obtained from 21-day cultures of CD34+ HPCs supplemented with IL-15 in the absence of IL-2, stromal cells, or other cytokines. The addition of the KL to these cultures had no effect on the differentiation of the CD3-CD56+ cytotoxic effector cells, but greatly enhanced their expansion. The majority of these cells lack CD2 and CD16, but do express zeta-TCR. Similar to NK cells found in peripheral blood, the CD2-CD16-CD56+ NK cells grown in the presence of IL-15 were found to be potent producers of IFN-gamma in response to monocyte-derived cytokines. Thus IL-15, like KL, appears to be produced by BM stromal cells. IL-15 can induce CD34+ HPCs to differentiate into CD3-CD56+ NK cells, and KL can amplify this. Therefore, IL-15 may be a physiologically relevant ligand for NK cell differentiation in vivo.


Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2569-2577 ◽  
Author(s):  
Huei-Mei Huang ◽  
Jian-Chiuan Li ◽  
Yueh-Chun Hsieh ◽  
Hsin-Fang Yang-Yen ◽  
Jeffrey Jong-Young Yen

Abstract In vitro proliferation of hematopoietic stem cells requires costimulation by multiple regulatory factors whereas expansion of lineage-committed progenitor cells generated by stem cells usually requires only a single factor. The distinct requirement of factors for proliferation coincides with the differential temporal expression of the subunits of cytokine receptors during early stem cell differentiation. In this study, we explored the underlying mechanism of the requirement of costimulation in a hematopoietic progenitor cell line TF-1. We found that granulocyte-macrophage colony-stimulating factor (GM-CSF) optimally activated proliferation of TF-1 cells regardless of the presence or absence of stem cell factor (SCF). However, interleukin-5 (IL-5) alone sustained survival of TF-1 cells and required costimulation of SCF for optimal proliferation. The synergistic effect of SCF was partly due to its anti-apoptosis activity. Overexpression of the IL-5 receptor  subunit (IL5R) in TF-1 cells by genetic selection or retroviral infection also resumed optimal proliferation due to correction of the defect in apoptosis suppression. Exogenous expression of an oncogenic anti-apoptosis protein, Bcl-2, conferred on TF-1 cells an IL-5–dependent phenotype. In summary, our data suggested SCF costimulation is only necessary when the expression level of IL5R is low and apoptosis suppression is defective in the signal transduction of IL-5. Expression of Bcl-2 proteins released the growth restriction of the progenitor cells and may be implicated in leukemia formation.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1491-1491 ◽  
Author(s):  
Birgitta Mitchell ◽  
Maritza Gonzalez ◽  
Jared Manning ◽  
Gerald J Spangrude

Abstract Abstract 1491 Poster Board I-514 Introduction: A complete understanding of lymphocyte development, particularly factors driving T and natural killer (NK) cell differentiation from progenitor cells, remains an elusive goal in medicine. T and NK cells are key regulators in the defense against infections and malignancies and play a direct causative role in autoimmune diseases and graft-versus-host disease. The OP9-DL1 stromal line is an important tool in the in vitro study of lymphocyte development. Lymphocyte progenitors (KLS,Thy1.1-) harvested from adult murine bone marrow and seeded on this stromal line can be followed through stages of maturation by immunophenotyping. We observed that addition of stem cell factor (SCF), contaminated with lipopolysaccharide (LPS) through its production in E. coli, was particularly effective at promoting NK cell development in the OP9-DL1 culture system. Toll-like receptors, an important component of anti-microbial defense by the innate immune response, recognize LPS and other microbial products. Toll-like receptor ligands (TLR-L) have been shown to enhance NK cell proliferation, however an effect on NK cell differentiation from progenitor cells has not been established. A separate set of experiments led us to hypothesize that ascorbic acid (vitamin C) promotes T cell differentiation. We therefore designed experiments to evaluate the differential effects of TLR-L and ascorbic acid on NK and T cell development from lymphoid progenitors co-cultured with OP9-DL1 stromal cells. Methods: Lymphocyte progenitor cells (KLS,Thy1.1-) were sorted from adult mouse bone marrow and 1000-2000 progenitor cells were seeded per well in a 24 well plate coated with OP9-DL1 stroma. Cultures were supplemented with IL-7 (5 ng/ml), Flt3 ligand (5 ng/ml), and SCF (100 ng/ml) plus one of 5 different TLR-L (TLR1/2, TLR3, TLR4, TLR5, and a crude LPS preparation that likely contains a number of TLR-L), with or without addition of a stabilized form of ascorbic acid. Cells were passaged, counted and re-seeded with fresh media and supplements twice a week over a 30-day period. Immunophenotype and viability were evaluated by flow cytometry. Markers for T cell development included CD44, CD25, CD3, CD4, CD8, T cell receptor beta chain and T cell receptor gamma-delta chains. NK cells were evaluated for the presence of NKp46, NK1.1, and DX5. Results: We observed robust cell expansion, inhibited somewhat by addition of ascorbic acid. The inhibitory effect of ascorbate on expansion was most pronounced in the culture condition lacking TLR-L. T cell differentiation was markedly advanced by the addition of ascorbic acid in the absence of TLR-L, with the majority of cells co-expressing CD4/CD8 and TCRB/CD3. The addition of different TLR-Ls inhibited T cell differentiation, and this inhibition was partially rescued by addition of ascorbic acid. NK cell differentiation, defined as co-expression of NKp46 and NK1.1, was two to three-fold greater with the addition of TLR1/2, TLR4, TLR5, and crude LPS compared to cultures lacking TLR-L addition. In each of these conditions, NK cell differentiation was markedly inhibited by addition of ascorbic acid. Conclusions: Our data supports the hypothesis that both T and NK cell progenitors require Notch signaling for differentiation. In our in vitro model, differentiation of one lineage at the expense of the other can be manipulated with addition of TLR-L or ascorbic acid. Addition of bacterial TLR-L promotes NK cell differentiation at the expense of T cell differentiation; an effect that is partially overcome with the addition of ascorbic acid. The addition of ascorbic acid promotes robust T cell differentiation, and inhibits significant NK cell differentiation in all conditions. The ability of ascorbic acid to promote T cell differentiation appears to dominate over TLR-L promotion of NK lineage differentiation. Further work will include microarray to evaluate these effects at a genetic level. These findings will contribute to our understanding of the immune response under normal and pathologic conditions, and further a model both for study and ex vivo expansion of immune cells for therapeutic use. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2569-2577 ◽  
Author(s):  
Huei-Mei Huang ◽  
Jian-Chiuan Li ◽  
Yueh-Chun Hsieh ◽  
Hsin-Fang Yang-Yen ◽  
Jeffrey Jong-Young Yen

In vitro proliferation of hematopoietic stem cells requires costimulation by multiple regulatory factors whereas expansion of lineage-committed progenitor cells generated by stem cells usually requires only a single factor. The distinct requirement of factors for proliferation coincides with the differential temporal expression of the subunits of cytokine receptors during early stem cell differentiation. In this study, we explored the underlying mechanism of the requirement of costimulation in a hematopoietic progenitor cell line TF-1. We found that granulocyte-macrophage colony-stimulating factor (GM-CSF) optimally activated proliferation of TF-1 cells regardless of the presence or absence of stem cell factor (SCF). However, interleukin-5 (IL-5) alone sustained survival of TF-1 cells and required costimulation of SCF for optimal proliferation. The synergistic effect of SCF was partly due to its anti-apoptosis activity. Overexpression of the IL-5 receptor  subunit (IL5R) in TF-1 cells by genetic selection or retroviral infection also resumed optimal proliferation due to correction of the defect in apoptosis suppression. Exogenous expression of an oncogenic anti-apoptosis protein, Bcl-2, conferred on TF-1 cells an IL-5–dependent phenotype. In summary, our data suggested SCF costimulation is only necessary when the expression level of IL5R is low and apoptosis suppression is defective in the signal transduction of IL-5. Expression of Bcl-2 proteins released the growth restriction of the progenitor cells and may be implicated in leukemia formation.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3317-3317
Author(s):  
Jeffrey S. Miller ◽  
Karen Brungaard ◽  
Robert A.J. Oostendorp ◽  
Valarie McCullar

Abstract We have shown that a murine fetal liver cell line (AFT024) and human cytokines (IL-15, IL-7, IL-3, Flt3-ligand and c-kit ligand) are needed to induce NK cell differentiation and KIR acquisition. To understand the level of maturation where these factors orchestrate NK cell development, a switch culture was designed to separate early and late events. Cord blood CD34+/Lin−/CD38− stem cells were cultured on AFT024 for 28 days. Use of IL-3 or Flt3-L alone resulted in minimal growth. In contrast, we show that NK cell differentiation can occur, albeit at low frequency, with a combination of IL-3 and Flt3-L, in the absence of IL-15. These early NK cells were negative for both CD94 and KIR. These conditions also allowed accumulation of CD56− NK cell precursors. CD34+CD7−, CD34+CD7+ and CD34−CD7+ cells were detected in cultures lacking IL-15. Each precursor was tested in secondary cultures containing AFT024 with IL-15 alone, IL-15+IL-3, or IL15+IL-3+Flt3-L. After an additional 2–4 weeks, NK cells differentiated from each distinct cell population. A few predominantly KIR negative NK cells resulted from IL-15 alone. Addition of IL-3 or IL-3+Flt3-L significantly increased the absolute number of NK cells as well as the acquisition of CD94 heterodimers and KIR. We next explored other stromal cell lines in attempt to identify novel factors important in early NK cell maturation. A novel cell line derived from murine embryonic liver (EL08-1D2), identified for its ability to support expansion of mouse stem cells, was compared to AFT024. To test the differential capacity of these microenvironments, single cord blood stem cells were plated on the two feeders supplemented with all cytokines. After 4 weeks, EL08-1D2 induced 125,852±1400 NK cells from a single stem cell, significantly more than with AFT024 (23,143±8117). KIR+ NK cells were also significantly more frequent with EL08-1D2 (3689±801 vs. 799±491), always in a polyclonal pattern. NK cell development and KIR acquisition were dependent on direct contact with EL08-1D2. Increased development could be from greater differentiation, proliferation or both. Cord blood stem cells were cultured in direct contact with EL08-1D2 under primary culture conditions with IL-3 and Flt3-L but in the absence of IL-15. All CD56− NK cell precursors developed with greater frequency on EL08-1D2 than AFT024. In conclusion, EL08-1D2, derived from a primitive microenvironment during mouse ontogeny, efficiently recapitulates NK cell development by inducing NK cell differentiation and proliferation. IL-3 and Flt3-L, but not IL-15, facilitate the isolation and study of distinct NK cell precursors. Direct contact with EL08-1D2 induces KIR acquisition, suggesting that unique environmental factors conserved between mouse and man contribute to the extrinsic signals which lead to KIR acquisition.


Blood ◽  
1991 ◽  
Vol 78 (9) ◽  
pp. 2387-2391 ◽  
Author(s):  
G Risdon ◽  
TA Moore ◽  
V Kumar ◽  
M Bennett

Abstract Dehydroepiandrosterone (DHEA) is a naturally occurring steroid. We have previously shown that dietary DHEA (0.45% wt/wt) inhibits murine lymphopoiesis but not myelopoiesis. To assess the effect of DHEA on stages of natural killer (NK) cell differentiation, lethally irradiated mice fed DHEA or not were infused with 10(6) or 20 x 10(6) syngeneic bone marrow cells (BMC) as a source of transplantable NK cell progenitors. The differentiation of progenitor cells to lytic NK cells was assessed by the ability to clear radiolabeled YAC-1 tumor cells from the lungs. DHEA-fed recipients of 10(6) or 20 x 10(6) BMC failed to generate NK activity. Because NK progenitor cells are believed to differentiate into interleukin-2 (IL-2)-responsive precursor cells before maturation, BMC from recipient mice were cultured with IL-2 and the generation of NK cells was assessed. DHEA feeding prevented the generation of IL-2-responsive precursor cells in recipients of 10(6) BMC, but this inhibition was overcome in recipients of 20 x 10(6) BMC. To evaluate the capacity of stem cells to generate NK progenitor cells in DHEA-fed mice, the ability of marrow cells from primary recipients to generate NK activity in irradiated secondary recipients was determined. The production of NK progenitors was inhibited 20-fold. Thus, DHEA appears to inhibit the generation of NK progenitors from more primitive stem cells, the differentiation of progenitors into IL-2- responsive precursors cells and the maturation of IL-2-responsive precursor cells into mature NK cells.


2020 ◽  
Vol 9 (3) ◽  
pp. 669 ◽  
Author(s):  
Kyeongseok Kim ◽  
Ahmed Abdal Dayem ◽  
Minchan Gil ◽  
Gwang-Mo Yang ◽  
Soo Bin Lee ◽  
...  

Efficient maintenance of the undifferentiated status of human pluripotent stem cells (hiPSCs) is crucial for producing cells with improved proliferation, survival and differentiation, which can be successfully used for stem cell research and therapy. Here, we generated iPSCs from healthy donor peripheral blood mononuclear cells (PBMCs) and analyzed the proliferation and differentiation capacities of the generated iPSCs using single cell NGS-based 24-chromosome aneuploidy screening and RNA sequencing. In addition, we screened various natural compounds for molecules that could enhance the proliferation and differentiation potential of hiPSCs. Among the tested compounds, 3,2′-dihydroxyflavone (3,2′-DHF) significantly increased cell proliferation and expression of naïve stemness markers and decreased the dissociation-induced apoptosis of hiPSCs. Of note, 3,2′-DHF-treated hiPSCs showed upregulation of intracellular glutathione (GSH) and an increase in the percentage of GSH-high cells in an analysis with a FreSHtracer system. Interestingly, culture of the 3,2′-DHF-treated hiPSCs in differentiation media enhanced their mesodermal differentiation and differentiation into CD34+ CD45+ hematopoietic progenitor cells (HPC) and natural killer cells (NK) cells. Taken together, our results demonstrate that the natural compound 3,2′-DHF can improve the proliferation and differentiation capacities of hiPSCs and increase the efficiency of HPC and NK cell production from hiPSCs.


Blood ◽  
1991 ◽  
Vol 78 (9) ◽  
pp. 2387-2391
Author(s):  
G Risdon ◽  
TA Moore ◽  
V Kumar ◽  
M Bennett

Dehydroepiandrosterone (DHEA) is a naturally occurring steroid. We have previously shown that dietary DHEA (0.45% wt/wt) inhibits murine lymphopoiesis but not myelopoiesis. To assess the effect of DHEA on stages of natural killer (NK) cell differentiation, lethally irradiated mice fed DHEA or not were infused with 10(6) or 20 x 10(6) syngeneic bone marrow cells (BMC) as a source of transplantable NK cell progenitors. The differentiation of progenitor cells to lytic NK cells was assessed by the ability to clear radiolabeled YAC-1 tumor cells from the lungs. DHEA-fed recipients of 10(6) or 20 x 10(6) BMC failed to generate NK activity. Because NK progenitor cells are believed to differentiate into interleukin-2 (IL-2)-responsive precursor cells before maturation, BMC from recipient mice were cultured with IL-2 and the generation of NK cells was assessed. DHEA feeding prevented the generation of IL-2-responsive precursor cells in recipients of 10(6) BMC, but this inhibition was overcome in recipients of 20 x 10(6) BMC. To evaluate the capacity of stem cells to generate NK progenitor cells in DHEA-fed mice, the ability of marrow cells from primary recipients to generate NK activity in irradiated secondary recipients was determined. The production of NK progenitors was inhibited 20-fold. Thus, DHEA appears to inhibit the generation of NK progenitors from more primitive stem cells, the differentiation of progenitors into IL-2- responsive precursors cells and the maturation of IL-2-responsive precursor cells into mature NK cells.


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