scholarly journals Host Conditioning With 5-Fluorouracil and kit-Ligand to Provide for Long-Term Bone Marrow Engraftment

Blood ◽  
1997 ◽  
Vol 89 (7) ◽  
pp. 2376-2383 ◽  
Author(s):  
Ronald van Os ◽  
Donald Dawes ◽  
John M.K. Mislow ◽  
Alice Witsell ◽  
Peter M. Mauch

Abstract Administration of kit-ligand (KL) before and after doses of 5-fluorouracil (5-FU) results in marrow failure in mice, presumably because of enhanced KL-induced cycling of stem cells, which makes them more susceptible to the effects of 5-FU. In attempt to capitalize on this effect on stem cells, we studied the ability of KL and 5-FU to allow stable donor engraftment of congenically marked marrow in a C57BL/6 (B6) mouse model. KL was administered subcutaneously at 50 μg/kg, 21 hours and 9 hours before and 3 hours after each of two doses of 5-FU (125 mg/kg) given 7 days apart to B6-recipients. Animals then received three injections of 107 congenic B6-Gpi-1a-donor bone marrow cells at 24, 48, and 72 hours after the second 5-FU dose. A separate group of animals received a single dose of either 1 × 107 or 3 × 107 donor marrow cells 24 hours after the last 5-FU dose. The level of engraftment was measured from Gpi-phenotyping at 1, 3, 6, and 8 months in red blood cells (RBCs) and at 8 months by phenotyping cells from the thymus, spleen, and marrow. Percent donor engraftment in RBCs appeared stable after 6 months. The percent donor engraftment in RBCs at 8 months was significantly higher in KL + 5-FU prepared recipients (33.0 ± 2.7), compared with 5-FU alone (18.5 ± 2.6, P < .0005), or saline controls (17.8 ± 1.7, P < .0001). In an additional experiment, granulocyte colony-stimulating factor (100 μg/dose) was added to a reduced dose of KL (12.5 μg/dose); engraftment was similar to KL alone. At 8 months after transplantation the levels of engraftment in other tissues such as bone marrow, spleen, and thymus correlated well with erythroid engraftment to suggest that multipotent long-term repopulating stem cells had engrafted in these animals. There are concerns for the toxicity of total body irradiation (TBI)- or busulfan-based regimens in young recipients of syngeneic or transduced autologous marrow who are transplanted for correction of genetic disease. In these recipients complete donor engraftment may not be needed. The results with KL and 5-FU are encouraging for the further refinement of non-TBI, nonbusulfan techniques to achieve stable mixed chimerism.

Blood ◽  
1994 ◽  
Vol 83 (4) ◽  
pp. 939-948 ◽  
Author(s):  
Y Tomita ◽  
DH Sachs ◽  
M Sykes

Abstract We have investigated the requirement for whole body irradiation (WBI) to achieve engraftment of syngeneic pluripotent hematopoietic stem cells (HSCs). Recipient B6 (H-2b; Ly-5.2) mice received various doses of WBI (0 to 3.0 Gy) and were reconstituted with 1.5 x 10(7) T-cell-depleted (TCD) bone marrow cells (BMCs) from congenic Ly-5.1 donors. Using anti-Ly-5.1 and anti-Ly-5.2 monoclonal antibodies and flow cytometry, the origins of lymphoid and myeloid cells reconstituting the animals were observed over time. Chimerism was at least initially detectable in all groups. However, between 1.5 and 3 Gy WBI was the minimum irradiation dose required to permit induction of long-term (at least 30 weeks), multilineage mixed chimerism in 100% of recipient mice. In these mice, stable reconstitution with approximately 70% to 90% donor-type lymphocytes, granulocytes, and monocytes was observed, suggesting that pluripotent HSC engraftment was achieved. About 50% of animals conditioned with 1.5 Gy WBI showed evidence for donor pluripotent HSC engraftment. Although low levels of chimerism were detected in untreated and 0.5-Gy-irradiated recipients in the early post-BM transplantation (BMT) period, donor cells disappeared completely by 12 to 20 weeks post-BMT. BM colony assays and adoptive transfers into secondary lethally irradiated recipients confirmed the absence of donor progenitors and HSCs, respectively, in the marrow of animals originally conditioned with only 0.5 Gy WBI. These results suggest that syngeneic pluripotent HSCs cannot readily engraft unless host HSCs sustain a significant level of injury, as is induced by 1.5 to 3.0 Gy WBI. We also attempted to determine the duration of the permissive period for syngeneic marrow engraftment in animals conditioned with 3 Gy WBI. Stable multilineage chimerism was uniformly established in 3-Gy-irradiated Ly-5.2 mice only when Ly-5.1 BMC were injected within 7 days of irradiation, suggesting that repair of damaged host stem cells or loss of factors stimulating engraftment may prevent syngeneic marrow engraftment after day 7.


1992 ◽  
Vol 176 (2) ◽  
pp. 351-361 ◽  
Author(s):  
H Kodama ◽  
M Nose ◽  
Y Yamaguchi ◽  
J Tsunoda ◽  
T Suda ◽  
...  

The preadipose cell line, PA6, can support long-term hemopoiesis. Frequency of the hemopoietic stem cells capable of sustaining hemopoiesis in cocultures of bone marrow cells and PA6 cells for 6 wk was 1/5.3 x 10(4) bone marrow cells. In the group of dishes into which bone marrow cells had been inoculated at 2.5 x 10(4) cells/dish, 3 of 19 dishes (16%) contained stem cells capable of reconstituting erythropoiesis of WBB6F1-W/Wv mice, indicating that PA6 cells can support the proliferation of primitive hemopoietic stem cells. When the cocultures were treated with an antagonistic anti-c-kit monoclonal antibody, ACK2, only a small number of day 12 spleen colony-forming units survived; and hemopoiesis was severely reduced. However, when the cocultures were continued with antibody-free medium, hemopoiesis dramatically recovered. To examine the proliferative properties of the ACK2-resistant stem cells, we developed a colony assay system by modifying our coculture system. Sequential observations of the development of individual colonies and their disappearance demonstrated that the stem cells having higher proliferative capacity preferentially survive the ACK2 treatment. Furthermore, cells of subclones of the PA6 clone that were incapable of supporting long-term hemopoiesis expressed mRNA for the c-kit ligand. These results suggest that a mechanism(s) other than that involving c-kit receptor and its ligand plays an important role in the survival and proliferation of primitive hemopoietic stem cells.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1577-1577
Author(s):  
Yaoyu Chen ◽  
Sullivan Con ◽  
Yiguo Hu ◽  
Linghong Kong ◽  
Cong Peng ◽  
...  

Abstract Abstract 1577 Hematopoiesis is a tightly regulated biological process that relies upon complicated interactions between the blood cells and their microenvironment. Adhesion molecules like P-selectin are essential to hematopoiesis, and their dysregulation has been implicated in leukemogenesis. We have previously shown a role for P-selectin in chronic myeloid leukemia and demonstrated that in its absence the disease process accelerates. Recently, there has also been speculation that P-selectin may play a role in the aging hematopoietic stem cells (HSCs), as its expression in upregulated as a mouse ages. In this study, we show that the loss of P-selectin function dysregulates the balance of stem cells and progenitors and that these differences become more pronounced with age. We compared the percentages of HSCs, long-term (LT)-HSCs, short-term (ST)-HSCs, multipotent progenitors (MPPs), CMPs, GMPs and MEPs in bone marrow by flow cytometry between wild type (WT) and Selp-/- mice. An age-dependent LT-HSC expansion was observed in WT mice. However, this expansion was prevented by the loss of Selp as observed in Selp-/-mice. Further, we demonstrate that with age LT-HSCs in particular express more elevated levels of P-selectin. LT-HSCs and ST-HSC/MPPs were isolated from the bone marrow of young (2 months old) and old (15 months old) WT mice and examined P-selectin expression by FACS. A significant increase in P-selectin expression was observed in LT-HSCs of old mice, and this increase was not observed in the ST-HSC+MPP subpopulations. We also show that the loss of P-selectin gene has profound effects of stem cell function, altering the capacity of these cells to home. Despite impaired homing capacity, stem cells lacking P-selectin possess a competitive advantage over their wild type counterparts. Using a stem cell competition assay, HSCs derived from Selp-/- mice (CD45.2+) and WT control mice (CD45.2+GFP+) were mixed in 1:1 ratio and transplanted into irradiated WT recipients (CD45.1). The initial findings were potentially indicative of the ability of cells derived from GFP mice to more efficiently home and engraft. Despite this initial advantage, cells derived from Selp-/- eventually exhibited a competitive and statistically significant advantage over the cells derived from GFP mice. At 30 days post-transplant, 49.9±1.4% of the CD45.2 subpopulation was GFP+. At 86 days post-transplant, 25.7±3.3 % of the CD45.2 cells derived from the peripheral blood were GFP+. Similarly, 23.0±3.7% of the CD45.2 cells derived from the bone marrow of these mice were GFP+. Indeed, we demonstrate that recipients of P-selectin deficient bone marrow cells more efficiently repopulate the bone marrow than controls and that this advantage extends and expands in the long-term. Finally, we demonstrate that recipients of leukemic cells lacking P-selectin develop a more accelerated form of leukemia accompanied by significant increases in stem and progenitor cells. Bone marrow cells from donor WT and Selp-/- mice were infected with retrovirus expressing BCR-ABL-GFP, and irradiated WT recipients were transplanted with 2×105 of these transduced donor cells. At 14 days post-transplant, recipient mice from each of the groups were sacrificed, and bone marrow cells were harvested and analyzed by flow cytometry. Recipients of leukemic Selp-/- cells possessed 3.5-fold more LSCs than recipients of wild-type cells. There were 3.1-fold more LT-LSCs and 3.8-fold more ST-LSCs and MPPs in recipients of Selp-/- cells than WT cells. In addition, recipients of leukemic Selp-/- cells possessed significantly more CMP (16.9-fold) and MEP (4.5-fold) cells. Because P-selectin expression increases with age on LT-HSCs, we sought to determine the role that age plays in CML development and progression. Bone marrow cells derived from 15-month-old donor Selp-/- and WT mice were transduced with BCR-ABL, respectively, followed by transplantation of the transduced cells into recipient mice. All recipients of BCR-ABL transduced Selp-/- cells died by 23 days after induction of CML and had a median survival of 19 days, whereas recipients of the transduced WT cells survived significantly longer. This pro-leukemic role for cells lacking P-selectin expression is leukemic stem cell-specific rather than stromal cell-specific and supports an essential role for P-selectin on leukemic stem cells. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
1991 ◽  
Vol 78 (2) ◽  
pp. 310-317 ◽  
Author(s):  
JF Apperley ◽  
BD Luskey ◽  
DA Williams

Retroviral-mediated gene transfer of human adenosine deaminase (hADA) provides a model system for the development of somatic gene therapy as a therapy for diseases of bone marrow-derived cells. We have previously demonstrated that hADA can be observed in all hematopoietic lineages in a minority of mice transplanted with bone marrow cells infected with a simplified retroviral vector, ZipPGK-ADA. Here we report a majority of mice (six of eight) demonstrate expression of hADA in the peripheral blood at least 6 months after transplantation with bone marrow infected with this simplified retroviral vector, which contains no selectable marker. The failure to express hADA in two of eight mice was associated with the absence of the recombinant retroviral provirus in DNA prepared from bone marrow cells of these mice apparently due to failure to efficiently infect the reconstituting hematopoietic stem cell. In an effort to preselect bone marrow stem cells containing proviral integrations, we incorporated the selectable marker neo phosphotransferase (NEO) into a retroviral vector encoding hADA, N2/ZipPGK-ADATKNEO, and used G418 selection of infected bone marrow cells before transplantation. In contrast to the simplified retroviral vector, hADA expression in these recipients was short lived (less than 8 weeks), despite the continued presence of intact provirus in DNA prepared from bone marrow of these mice. To determine whether the preselection of bone marrow using G418 was responsible for the lack of sustained hADA expression, we repeated the infection with the N2/ZipPGK- ADATKNEO vector but omitted the G418 selection step. Again, the majority of recipient mice failed to express hADA long term, although the continued presence of provirus in DNA prepared from peripheral blood cell mononuclear cells was clearly demonstrated. Finally, we demonstrate clonal fluctuation of infected stem cells, and observe a temporal correlation between cessation of expression of hADA and the emergence of a dominant stem cell clone between 14 and 20 weeks posttransplantation in one recipient. These data suggest that inclusion of a second transcriptional unit that includes neo phosphotransferase sequences in this simplified vector is associated with decreased expression of the nonselectable ADA sequences.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2304-2304
Author(s):  
Cheng Li ◽  
Daniel R. George ◽  
Nichole M. Havey ◽  
Jeffery M. Klco ◽  
Timothy J. Ley

Abstract Abstract 2304 Despite two decades of effort, deriving long-term repopulating hematopoietic stem/progenitor cells (HSPCs) from embryonic stem cells (ESCs) has proven to be extremely difficult. Both embryoid body (EB)-based and stroma-based methods have been extensively explored. However, robust production of HSPCs from C57BL/6J-derived mouse ESCs (mESCs) has not yet been reported. Furthermore, in vivo engraftment of mES-derived HSCs (from any strain) has been achieved only with forced expression of HoxB4 or related oncogenes, which creates significant limitations for most studies. Here, we describe a stroma-based co-culture method to differentiate HSCs and progenitor populations from C57BL/6J-derived mESCs. After simple co-culture on OP9 stroma cells for one week, C57BL/6J-derived mESC lines differentiate into cells that mark as HSCs, CMPs, GMPs, and MEPs (by immunophenotyping); these cells are capable of giving rise to erythrocytes, monocytes, and mast cells (by morphology and immunophenotyping) after another week of culture in methylcellulose with hematopoietic cytokines (SCF, IL-3, IL-6, and Epo). Similar in vitro hematopoietic differentiation has been achieved in several different C57BL/6J-derived mESCs (B6/Blu, B6-GFP, LK1, and B6 albino), B6/SVJ129 mESCs (R1), various SVJ129-derived mESCs (SWT16, EDJ22, and SCC10), and five independent C57BL/6J mouse embryonic fibroblast (MEF)-derived induced pluripotent stem cell (iPSC) lines. C57BL/6J ESCs derived from CAGGS-GFP transgenic mice (B6-GFP ESCs, which express high levels of GFP in all hematopoietic lineages) were used to determine whether we could obtain long-term engraftment of the OP9 differentiated ESCs. B6-GFP ESCs cultured for 7 days on OP9 cells were sorted by Kit+ surface staining. Sorted cells (1×105, 2×105, 4×105) were transferred into immunocompromised NSG mice via retro orbital injection (n=1 mouse per dose). Peripheral blood from the recipients injected with 2×105 and 4×105 cells showed 5% GFP positivity in the peripheral blood at weeks 12 and 16 post-transplant, while recipients injected with 1×105 cells had no detectable GFP+ cells in the periphery. Bone marrow cells and spleens were harvested at week 22. The recipient injected with 4×105 cells showed 5% GFP positivity in the bone marrow and 20% in the spleen. Engraftment was multi-lineage. Myeloid compartments (CD34+, CD11b+, Kit+, and Gr-1+) showed similar or less GFP positivity than overall bone marrow and spleen cells. Lymphoid (CD3+ and B220+) and erythroid (Ter119+) compartments also showed similar GFP positivity compared to overall bone marrow cells. However, lymphoid and erythroid compartments contained significantly higher GFP positivity (30–60%) than overall spleen cells. We have now modified the procedure to transfer 1×106 unfractionated B6-GFP ESCs grown for 7 days on OP9 stroma directly into NSG recipients. We have detected short-term engraftment 4 weeks post-injection in the peripheral blood of one recipient and multilineage splenic engraftment 8 weeks post-injection in two recipients, confirming that short-term repopulating cells are indeed generated by this method. Secondary transplants using the GFP+ bone marrow cells from the long-term engrafted mouse have been performed. This approach could be a valuable tool for studying the hematopoietic development of a variety of mESC lines, and potentially, iPSC lines as well. Disclosures: No relevant conflicts of interest to declare.


1992 ◽  
Vol 175 (1) ◽  
pp. 175-184 ◽  
Author(s):  
N Uchida ◽  
I L Weissman

Hematopoietic stem cells (HSCs) are defined in mice by three activities: they must rescue lethally irradiated mice (radioprotection), they must self-renew, and they must restore all blood cell lineages permanently. We initially demonstrated that HSCs were contained in a rare (approximately 0.05%) subset of bone marrow cells with the following surface marker profile: Thy-1.1lo Lin- Sca-1+. These cells were capable of long-term, multi-lineage reconstitution and radioprotection of lethally irradiated mice with an enrichment that mirrors their representation in bone marrow, namely, 1,000-2,000-fold. However, the experiments reported did not exclude the possibility that stem cell activity may also reside in populations that are Thy-1.1-, Sca-1-, or Lin+. In this article stem cell activity was determined by measuring: (a) radioprotection provided by sorted cells; (b) long-term, multi-lineage reconstitution of these surviving mice; and (c) long-term, multi-lineage reconstitution by donor cells when radioprotection is provided by coinjection of congenic host bone marrow cells. Here we demonstrate that HSC activity was detected in Thy-1.1+, Sca-1+, and Lin- fractions, but not Thy-1.1-, Sca-1-, or Lin+ bone marrow cells. We conclude that Thy-1.1lo Lin- Sca-1+ cells comprise the only adult C57BL/Ka-Thy-1.1 mouse bone marrow subset that contains pluripotent HSCs.


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