scholarly journals Amplification of Sca-1+ Lin-WGA+ cells in serum-free cultures containing steel factor, interleukin-6, and erythropoietin with maintenance of cells with long-term in vivo reconstituting potential

Blood ◽  
1994 ◽  
Vol 83 (1) ◽  
pp. 128-136 ◽  
Author(s):  
VI Rebel ◽  
W Dragowska ◽  
CJ Eaves ◽  
RK Humphries ◽  
PM Lansdorp

Normal murine bone marrow (BM) cells were sorted on the basis of low forward and orthogonal light scatter properties, Sca-1 expression (Sca-1+), lack of staining with a cocktail of mature hematopoietic lineage markers (Lin-), and binding of wheat germ agglutinin (WGA+). This approach allowed the reproducible isolation of a very small subpopulation (0.037% +/-0.023% of all nucleated BM cells) that was approximately 400-fold enriched in cells capable of reconstituting both lymphoid and myeloid lineages in lethally irradiated recipients. Transplantation of 30 or 10 of these Sca-1+Lin-WGA+ cells resulted in > or = to 20% donor-derived nucleated peripheral blood cells 3 months posttransplantation in 100% and 22% of the recipients, respectively. When Sca-1+Lin-WGA+ cells were cultured in serum-free medium supplemented with Steel factor, interleukin-6 (IL-6), and erythropoietin (with or without IL-3), a large increase in total cell number, including cells with an Sca-1+Lin-WGA+ phenotype was observed. Single cell cultures showed that 90% to 95% of the input cells underwent at least one division during the first 2 weeks and the remainder died. Interestingly, this proliferative response was not accompanied by a parallel increase in the number of cells with both lymphoid and myeloid repopulating potential in vivo, as quantitation of these by limiting dilution analysis showed they had decreased slightly (1.3-fold) but not significantly below the number initially present. These results demonstrate that Sca-1+Lin-WGA+ cells with long-term repopulating potential can be maintained for 2 weeks in a serum-and stroma cell-free culture, providing a simple in vitro system to study their behavior under well-defined conditions. The observed expansion of Sca-1+Lin-WGA+ cells in vitro without a concomitant increase in reconstituting cells also shows that extensive functional heterogeneity exists within populations of cells with this surface phenotype.

Blood ◽  
1994 ◽  
Vol 83 (1) ◽  
pp. 128-136 ◽  
Author(s):  
VI Rebel ◽  
W Dragowska ◽  
CJ Eaves ◽  
RK Humphries ◽  
PM Lansdorp

Abstract Normal murine bone marrow (BM) cells were sorted on the basis of low forward and orthogonal light scatter properties, Sca-1 expression (Sca-1+), lack of staining with a cocktail of mature hematopoietic lineage markers (Lin-), and binding of wheat germ agglutinin (WGA+). This approach allowed the reproducible isolation of a very small subpopulation (0.037% +/-0.023% of all nucleated BM cells) that was approximately 400-fold enriched in cells capable of reconstituting both lymphoid and myeloid lineages in lethally irradiated recipients. Transplantation of 30 or 10 of these Sca-1+Lin-WGA+ cells resulted in > or = to 20% donor-derived nucleated peripheral blood cells 3 months posttransplantation in 100% and 22% of the recipients, respectively. When Sca-1+Lin-WGA+ cells were cultured in serum-free medium supplemented with Steel factor, interleukin-6 (IL-6), and erythropoietin (with or without IL-3), a large increase in total cell number, including cells with an Sca-1+Lin-WGA+ phenotype was observed. Single cell cultures showed that 90% to 95% of the input cells underwent at least one division during the first 2 weeks and the remainder died. Interestingly, this proliferative response was not accompanied by a parallel increase in the number of cells with both lymphoid and myeloid repopulating potential in vivo, as quantitation of these by limiting dilution analysis showed they had decreased slightly (1.3-fold) but not significantly below the number initially present. These results demonstrate that Sca-1+Lin-WGA+ cells with long-term repopulating potential can be maintained for 2 weeks in a serum-and stroma cell-free culture, providing a simple in vitro system to study their behavior under well-defined conditions. The observed expansion of Sca-1+Lin-WGA+ cells in vitro without a concomitant increase in reconstituting cells also shows that extensive functional heterogeneity exists within populations of cells with this surface phenotype.


2020 ◽  
Author(s):  
Carlota Oleaga ◽  
L. Richard Bridges ◽  
Keisha Persaud ◽  
Christopher W. McAleer ◽  
Christopher J. Long ◽  
...  

Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2525-2532 ◽  
Author(s):  
Xingwei Sui ◽  
Kohichiro Tsuji ◽  
Yasuhiro Ebihara ◽  
Ryuhei Tanaka ◽  
Kenji Muraoka ◽  
...  

Abstract We have recently shown that stimulation of glycoprotein (gp) 130, the membrane-anchored signal transducing receptor component of IL-6, by a complex of human soluble interleukin-6 receptor (sIL-6R) and IL-6 (sIL-6R/IL-6), potently stimulates the ex vivo expansion as well as erythropoiesis of human stem/progenitor cells in the presence of stem cell factor (SCF). Here we show that sIL-6R dose-dependently enhanced the generation of megakaryocytes (Mks) (IIbIIIa-positive cells) from human CD34+ cells in serum-free suspension culture supplemented with IL-6 and SCF. The sIL-6R/IL-6 complex also synergistically acted with IL-3 and thrombopoietin (TPO) on the generation of Mks from CD34+ cells, whereas the synergy of IL-6 alone with TPO was barely detectable. Accordingly, the addition of sIL-6R to the combination of SCF + IL-6 also supported a substantial number of Mk colonies from CD34+ cells in serum-free methylcellulose culture, whereas SCF + IL-6 in the absence of sIL-6R rarely induced Mk colonies. The addition of monoclonal antibodies against gp130 to the suspension and clonal cultures completely abrogated the megakaryopoiesis induced by sIL-6R/IL-6 in the presence of SCF, whereas an anti-TPO antibody did not, indicating that the observed megakaryopoiesis by sIL-6R/IL-6 is a response to gp130 signaling and independent of TPO. Furthermore, human CD34+ cells were subfractionated into two populations of IL-6R–negative (CD34+ IL-6R−) and IL-6R–positive (CD34+ IL-6R+) cells by fluorescence-activated cell sorting. The CD34+IL-6R− cells produced a number of Mks as well as Mk colonies in cultures supplemented with sIL-6R/IL-6 or TPO in the presence of SCF. In contrast, CD34+ IL-6R+cells generated much less Mks and lacked Mk colony forming activity under the same conditions. Collectively, the present results indicate that most of the human Mk progenitors do not express IL-6R, and that sIL-6R confers the responsiveness of human Mk progenitors to IL-6. Together with the presence of functional sIL-6R in human serum and relative unresponsiveness of human Mk progenitors to IL-6 in vitro, current results suggest that the role of IL-6 may be mainly mediated by sIL-6R, and that the gp130 signaling initiated by the sIL-6R/ IL-6 complex is involved in human megakaryopoiesis in vivo.


Blood ◽  
2008 ◽  
Vol 112 (3) ◽  
pp. 560-567 ◽  
Author(s):  
David G. Kent ◽  
Brad J. Dykstra ◽  
Jay Cheyne ◽  
Elaine Ma ◽  
Connie J. Eaves

Abstract Hematopoietic stem cells (HSCs) regenerated in vivo display sustained differences in their self-renewal and differentiation activities. Variations in Steel factor (SF) signaling are known to affect these functions in vitro, but the cellular and molecular mechanisms involved are not understood. To address these issues, we evaluated highly purified HSCs maintained in single-cell serum-free cultures containing 20 ng/mL IL-11 plus 1, 10, or 300 ng/mL SF. Under all conditions, more than 99% of the cells traversed a first cell cycle with similar kinetics. After 8 hours in the 10 or 300 ng/mL SF conditions, the frequency of HSCs remained unchanged. However, in the next 8 hours (ie, 6 hours before any cell divided), HSC integrity was sustained only in the 300 ng/mL SF cultures. The cells in these cultures also contained significantly higher levels of Bmi1, Lnk, and Ezh2 transcripts but not of several other regulators. Assessment of 21 first division progeny pairs further showed that only those generated in 300 ng/mL SF cultures contained HSCs and pairs of progeny with similar differentiation programs were not observed. Thus, SF signaling intensity can directly and coordinately alter the transcription factor profile and long-term repopulating ability of quiescent HSCs before their first division.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2392-2392
Author(s):  
Malwina Suszynska ◽  
Daniel Pedziwiatr ◽  
Magdalena J Kucia ◽  
Mariusz Z Ratajczak ◽  
Janina Ratajczak

Abstract Background . Almost 20 years ago, a "mystery" population of small stem cells with many of the phenotypic characteristics attributed to resting hematopoietic stem cells was identified in murine bone marrow (BM) (Stem Cells 1998, 16, 38-48). These cells expressed high levels of Sca-1, H-2K, and CD38 and low levels of Thy-1.1; they expressed CD45 antigen but were lineage-negative (lin-) for other hematopoietic markers. These cells incorporated only low levels of Rh123 and were resistant to the cytotoxic effects of 5-fluorouracil. The only phenotypic characteristic that distinguishes these cells from Sca-1+, Lin-, CD45+ Thy-1.1low long-term-reconstituting hematopoietic stem cell population is the lack of c-kit expression. In sum, this "mystery" population of small Sca-1+, lin-, c-kit- but CD45+ stem cells do not respond to hematopoietic growth factors in vitro, form in vivo spleen colonies, or reconstitute lethally irradiated mice. With our discovery of Sca-1+ Lin- CD45- very small embryonic-like stem cells (VSELs) in murine bone marrow (BM) (Leukemia 2006, 20, 857-869), we became interested in this "mystery" population of stem cells. VSELs, like the "mystery" population, are c-kit - and, if freshly isolated from BM, do not show any hematopoietic activity in standard in vitro and in vivo assays. In order to become specified to hematopoiesis, they need to be expanded over an OP-9 stromal support (Exp Hematol 2011;39:225-237). Hypothesis. Since (1) very small CD45- VSELs can be specified in OP-9 co-cultures into long-term reconstituting CD45+ HSCs, (2) the size of the "mystery" population is intermediate between VSELs and HSCs, and (3) VSELs and HSCs differ in cell surface receptor expression, we hypothesized that the "mystery" population is a missing developmental intermediate between VSELs and HSCs. Materials and Methods . Multicolor FACS analysis was employed to compare size and expression of surface markers between murine BM HSCs, the unknown population of stem cells, and VSELs. Next, the populations of small Sca-1+ H2-K+ lin- c-kit+ CD38+/- CD45+ cells (HSCs), smaller Sca-1+ H-2K+ lin- c-kit- CD38+ CD45+ cells (the "mystery" population), and very small in size Sca-1+ H-2K+ lin- c-kit- CD38+/- CD45- cells (VSELs) were purified by FACS from BM (Figure 1) and tested for in vitro colony formation. All these cell populations were primed/expanded over OP-9 support and subsequently evaluated for their hematopoietic potential after passaging in consecutive methylocellulose cultures (passages 1-4). RQ-PCR analysis was employed for detection of pluripotency marker expression as well as hematopoietic gene expression. Results . We found that, in contrast to HSCs, neither freshly sorted stem cells from the "mystery" BM population nor, as expected, VSELs grew hematopoietic colonies in standard methylcellulose cultures. This was also an important step in excluding contamination of our sorted populations with clonogenic cells. We also found that, while VSELs highly expressed Oct-4, this transcription factor was expressed at very low levels in the "mystery" population and was not detectable in HSCs. The most important observation was that the "mystery" population of stem cells became specified in OP-9-supported cultures into clonogenic HSPCs, and this specification occurred faster than the delayed specification of VSELs. VSELs first became enriched for HSPCs after acquiring CD45 antigen expression. Conclusions . Based on the results presented, we propose that the "mystery" population in murine BM is a population of stem cells intermediate between the most primitive population of BM-residing stem cells (VSELs) and the population of stem cells already specified to lympho-hematopoietic development (HSCs). Disclosures No relevant conflicts of interest to declare.


Blood ◽  
1999 ◽  
Vol 93 (8) ◽  
pp. 2525-2532 ◽  
Author(s):  
Xingwei Sui ◽  
Kohichiro Tsuji ◽  
Yasuhiro Ebihara ◽  
Ryuhei Tanaka ◽  
Kenji Muraoka ◽  
...  

We have recently shown that stimulation of glycoprotein (gp) 130, the membrane-anchored signal transducing receptor component of IL-6, by a complex of human soluble interleukin-6 receptor (sIL-6R) and IL-6 (sIL-6R/IL-6), potently stimulates the ex vivo expansion as well as erythropoiesis of human stem/progenitor cells in the presence of stem cell factor (SCF). Here we show that sIL-6R dose-dependently enhanced the generation of megakaryocytes (Mks) (IIbIIIa-positive cells) from human CD34+ cells in serum-free suspension culture supplemented with IL-6 and SCF. The sIL-6R/IL-6 complex also synergistically acted with IL-3 and thrombopoietin (TPO) on the generation of Mks from CD34+ cells, whereas the synergy of IL-6 alone with TPO was barely detectable. Accordingly, the addition of sIL-6R to the combination of SCF + IL-6 also supported a substantial number of Mk colonies from CD34+ cells in serum-free methylcellulose culture, whereas SCF + IL-6 in the absence of sIL-6R rarely induced Mk colonies. The addition of monoclonal antibodies against gp130 to the suspension and clonal cultures completely abrogated the megakaryopoiesis induced by sIL-6R/IL-6 in the presence of SCF, whereas an anti-TPO antibody did not, indicating that the observed megakaryopoiesis by sIL-6R/IL-6 is a response to gp130 signaling and independent of TPO. Furthermore, human CD34+ cells were subfractionated into two populations of IL-6R–negative (CD34+ IL-6R−) and IL-6R–positive (CD34+ IL-6R+) cells by fluorescence-activated cell sorting. The CD34+IL-6R− cells produced a number of Mks as well as Mk colonies in cultures supplemented with sIL-6R/IL-6 or TPO in the presence of SCF. In contrast, CD34+ IL-6R+cells generated much less Mks and lacked Mk colony forming activity under the same conditions. Collectively, the present results indicate that most of the human Mk progenitors do not express IL-6R, and that sIL-6R confers the responsiveness of human Mk progenitors to IL-6. Together with the presence of functional sIL-6R in human serum and relative unresponsiveness of human Mk progenitors to IL-6 in vitro, current results suggest that the role of IL-6 may be mainly mediated by sIL-6R, and that the gp130 signaling initiated by the sIL-6R/ IL-6 complex is involved in human megakaryopoiesis in vivo.


Blood ◽  
1995 ◽  
Vol 85 (6) ◽  
pp. 1472-1479 ◽  
Author(s):  
CL Li ◽  
GR Johnson

Murine bone marrow cells were fractionated by fluorescence-activated cell sorting into Rh123lo Lin- c-kit+ Ly6A+, Rh123hi Lin-c-kit+ Ly6A+, and Lin- c-kit+ Ly6A- populations within which most, if not all, of the hematopoietic activities of the marrow resided. The Rh123lo Lin- c- kit+Ly6A+ cells, which consist exclusively of small- or medium-sized lymphocyte-like cells, are highly enriched for long-term hematopoietic in vivo repopulating cells. The enrichment factor for these cells from the marrow was estimated as 2,000-fold. The Rh123hi Lin- c-kit+ Ly6A+ cells, although also highly enriched for day-12 spleen colony-forming units, were relatively depleted of long-term in vivo repopulation capacity. Most, if not all Lin- c-kit+ Ly6A- cells were Rb123hi. In contrast to both Rh123lo and Rh123hi Lin- c-kit+ Ly6A+ stem cell populations, the Lin- c-kit+ Ly6A- cells can be stimulated to proliferate in vitro in the presence of single cytokines, which is a characteristic of committed progenitor cells. No marked synergistic interactions between individual cytokines were observed with this cell population. Both Rh123hi Lin- c-kit+ Ly6A+ mature stem cell and Lin- c- kit+ Ly6A- progenitor cell populations displayed in vivo repopulation kinetics resembling those of the putative short-term hematopoietic repopulating cells.


Blood ◽  
2003 ◽  
Vol 102 (9) ◽  
pp. 3120-3128 ◽  
Author(s):  
Kim Klarmann ◽  
Mariaestela Ortiz ◽  
Meghan Davies ◽  
Jonathan R. Keller

AbstractOur laboratory recently identified a quiescent class of pluripotent hematopoietic stem cells (PHSCs) that are lineage negative (Linneg), lack c-Kit, and are able to give rise to c-Kit–positive (c-Kitpos) PHSCs in vivo. This population fails to proliferate in vitro but has delayed reconstituting activity in vivo. In this study, we purified these cells to enrich for the PHSCs and we identified in vitro conditions capable of supporting their maturation. The c-Kit–negative (c-Kitneg) cells exhibited differential expression of Sca-1, CD34, CD43, CD45, and Thy 1.2. We purified the cells based on Sca-1, as it is expressed on active PHSCs. We detected pre–colony-forming unit spleen (pre–CFU-s) activity in both the Sca-1neg and Sca-1pos populations, indicating the presence of primitive PHSCs in both populations. However, our in vitro studies suggest that the Sca-1pos population is enriched for PHSCs. The in vitro systems that support the growth of these dormant cells include a modified long-term marrow culture and various stromal cell lines. In modified long-term bone marrow cultures, c-Kitneg cells gave rise to c-Kitpos PHSCs, with long-term reconstitution activity in vivo. Thus we have established an in vitro system to examine PHSC maturation that will allow us to study the mediators of the c-Kitneg to c-Kitpos transition.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1719-1719
Author(s):  
Edward F. Srour ◽  
Tamara L. Horvath

Abstract Murine bone marrow-derived cells expressing Sca-1+c-kit+lin− (KSL), as well as subfractions of these cells, represent an enriched population of hematopoietic stem cells (HSC) capable of long-term reconstitution of lethally irradiated recipients. Commitment to the hematopoietic lineage is invariably associated with expression of the pan-leukocyte marker CD45 which is also expressed on KSL cells. Whether KSL cells are the most primitive population of HSC present in the bone marrow (BM) is not fully resolved. We hypothesized that putative HSC that are more primitive than KSL cells may not express CD45 or genetic elements that mark early hematopoietic specification and commitment, but may mature under appropriate conditions into CD45+ cells capable of hematopoietic differentiation in conditioned hosts. BM cells from 8 to 10-week old BoyJ mice were collected by flushing and erythrocytes were lysed. The remaining cells were stained and sorted to yield CD45+ Sca-1+ c-kit+ (CD45+HSC) and CD45− Sca-1+ c-kit− (CD45−) cells which represented approximately 0.02% of total cells analyzed. PCR analysis of both cell populations revealed that CD45+HSC expressed CD45 and SCL but not PU.1 while CD45− cells did not express any of these genes. Directly after sorting, CD45+HSC, but not CD45− cells contained clonogenic cells that gave rise to hematopoietic colonies in progenitor cell assays. Similarly, while fresh CD45+HSC were able to respond to exogenous hematopoietic cytokines including SCF, TPO, and FL in liquid suspension cultures as evidenced by expansion and differentiation, their CD45− counterparts failed to proliferate under these conditions and none survived beyond 7 days of culture. When transplanted competitively into lethally irradiated congenic recipients, only freshly isolated CD45+HSC sustained donor-derived hematopoiesis, whereas hematopoiesis in mice injected with freshly isolated CD45− cells was sustained long term by competitor cells and endogenous host-derived stem cells. Both groups of CD45+HSC and CD45− cells could be expanded on irradiated M210B4 stromal cells when supplemented with SCF, TPO, and FL, with CD45− cells giving rise to cobblestone foci of small, round translucent cells beginning on day 7 of culture. Cultured CD45+HSC continued to express CD45 and SCL and, depending on the length of culture, also expressed PU.1. Interestingly, after 15 days in culture, CD45− cells expressed CD45 by RT-PCR and FACS (in addition to Sca-1) and also expressed mRNA for SCL. Given the ability of CD45− cells to expand under these conditions and to acquire CD45 expression, we next compared the repopulating potential of fresh and cultured CD45+HSC and CD45− cells using lethally irradiated C57Bl/6 recipients. As expected, fresh CD45+HSC sustained donor-derived engraftment and culture of these cells over M210B4 for 15 days reduced their repopulating potential more than 7-fold. In contrast, CD45− cells maintained on M210B4 (the expansion equivalent of 750 cells seeded) contributed to hematopoietic engraftment, albeit at low levels (under 5% chimerism). These data demonstrate that CD45− Sca-1+ c-kit− cells may be marrow resident precursors of hematopoietic stem cells and suggest that early stages of the HSC hierarchy may include CD45− cells. Whether these CD45− cells also posses endothelial differentiation potential and can give rise to CD45+HSC in vivo is now under investigation.


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