NOD-Rag1nullPrf1null Mice Support Long-Term Engraftment of Human Hematopoietic Stem Cells.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1184-1184
Author(s):  
Hitoshi Minamiguchi ◽  
Anne G. Livingston ◽  
John R. Wingard ◽  
Leonard D. Shultz ◽  
Makio Ogawa
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
T Cell ◽  
Cytotoxic Activity ◽  
Nk Cell ◽  
Human Cord Blood ◽  
Hematopoietic Stem ◽  
Cell Engraftment ◽  
Human Hscs

Abstract NOD-scid mice have been widely used as recipients in the xenograft assay for human hematopoietic stem cells (HSCs). One major problem with the strain is the low level of engraftment except when large numbers of cells are injected. This is probably caused by the presence of residual natural killer (NK) cell cytotoxic activity. NOD-scid/beta 2 microglobulin (B2m)null mice have been reported to have reduced NK cell cytotoxic activity and support higher levels of human cell engraftment. However, use of this strain of mice is limited by their difficulty in breeding and short life span caused by early development of lymphomas, which is accelerated by irradiation. Another immune-incompetent mouse model, NOD-recombination activating gene (Rag1)null mice allow longer observation of human cell engraftment than NOD-scid mice and are easier to breed. Genetic crossing of perforin (Prf) structure gene-targeted mutation onto NOD-Rag1null strain results in absence of NK cell cytotoxic function. In these mice, NK cells are not capable of killing target cells because of the absence of Prf, the major mediator of cytotoxic activity. We have tested the use of NOD-Rag1nullPrf1null mice as recipients of long-term xenograft assay for human HSCs by adopting Yoder’s method of conditioning newborn mice with minor modifications. Pregnant NOD-Rag1nullPrf1null dams were treated with 22.5mg/kg busulfan in 20% dimethylsulfoxide in Hank’s BSS on day 17.5 and 18.5 pc via subcutaneous injection. On the day of delivery, mononuclear cells (MNCs) were isolated from human cord blood (n=3) by density gradient centrifugation and T cell-depleted MNCs were separated by using mouse anti-human CD3, CD4, and CD8 antibodies and sheep anti-mouse IgG immunomagnetic beads to prevent preferential T cell engraftment. The busulfan-exposed pups were transplanted with 4–5 million T cell-depleted MNCs via the facial vein. At 6 months post-transplantation, human cells were detected in the bone marrow of 4 out of 10 transplanted mice. The levels of human CD45+ cells in the bone marrow of engrafted mice were 79.9, 69.8, 60.5, and 7.4%, and those in the peripheral blood were 6.3, 5.8, 4.1, and 1.3%. Multilineage engraftment was confirmed by phenotypic analysis. Next, we tested the hypothesis that human cord blood HSCs have dye efflux activity by injecting T cell-depleted Rhodamine 123 (Rho)− or + cells into conditioned newborn NOD-Rag1nullPrf1null mice. Six-month engraftment was found only with the Rho− cells. Thus, conditioned newborn NOD-Rag1nullPrf1null mice provide an excellent model for assaying long-term engrafting human HSCs.

scholarly journals Self-repopulating recipient bone marrow resident macrophages promote long-term hematopoietic stem cell engraftment

Blood ◽  
2018 ◽  
Vol 132 (7) ◽  
pp. 735-749 ◽  
Author(s):  
Simranpreet Kaur ◽  
Liza J. Raggatt ◽  
Susan M. Millard ◽  
Andy C. Wu ◽  
Lena Batoon ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Hematopoietic Stem ◽  
Cell Engraftment ◽  
Key Points ◽  
Bone Marrow Engraftment

Key Points Recipient macrophages persist in hematopoietic tissues and self-repopulate via in situ proliferation after syngeneic transplantation. Targeted depletion of recipient CD169+ macrophages after transplant impaired long-term bone marrow engraftment of hematopoietic stem cells.

Hybrid AAV6/2-Mediated Human β-Globin Expression in β-Thalassemia Patient Hematopoietic Stem Cells Transplanted Into Irradiated BALB/c Nude Mouse

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4715-4715
Author(s):  
Mengqun Tan ◽  
Zhenqing Liu ◽  
Juan Zhang ◽  
Zhiyan Li ◽  
Liujiang Song ◽  
...  
Keyword(s):  
Stem Cells ◽  
Gene Therapy ◽  
Bone Marrow ◽  
Globin Gene ◽  
Blood Transfusions ◽  
Rt Pcr ◽  
Thalassemia Patient ◽  
Hematopoietic Stem ◽  
Human Hscs

Abstract Abstract 4715 β -Thalassemia is one of the most common worldwide monogenic human diseases,caused by molecular defects in the human β -globin gene cluster leading to decrease or absence of β-globin. Loss of β -globin chains causes ineffective production of oxygen-carrying hemoglobin and therefore results in severe anemia. The treatment for β -Thalassemia major usually includes lifelong blood transfusions but chronic blood transfusion often causes iron overload, and accumulated iron produces tissue damage in multiple organs, so that iron chelating treatment is also needed. Bone marrow transplantation is another effective therapy, which can eliminate a patient's dependence on blood transfusions, however, it is difficult to find a matching donor for most patients; therefore it is only available for a minority of patients. Gene therapy is one potential novel therapy for treatment of inherited monogenic disorders. The long–term therapeutic strategy for this disease is to replace the defective β-globin gene via introduction of a functional gene into hematopoietic stem cells (HSCs). Adeno-associated virus type 2 (AAV), a nonpathogenic human parvovirus, has gained attention as a potentially useful vector for human gene therapy. AAV can infect both dividing and non-dividing cells and wild AAV integrates preferentially at a specific site on human chromosome 19. In the absence of helper virus, recombinant AAV will stably integrate into the host cell genome, mediating long-term and stable expression of the transgene. In this study, we used a hybrid rAAV6/2 vector carrying the human β-globin gene to transduce HSCs from a β -Thalassemia patient, followed by transplantation into irradiated BALB/c nude mice. One month post-transplantation, Hb was prepared from peripheral blood and analyzed by Western Blot and HPLC respectively. RNA and DNA were isolated from bone marrow cells (BMCs) from recipient mice transplanted with mock-infected or hybrid rAAV–globin-infected cells and analyzed by RT-PCR and PCR respectively. The results showed: 1. Human β-actin and β-globin transcripts were detected by RT-PCR in BMCs from all recipient mice, indicating that human HSCs were successfully transplanted in these mice and that the human β-globin gene was transcriptionally active in the donor cells. 2. The level of human hemoglobin expressed in peripheral red blood cells of recipient mice as measured by HPLC (ratio of β/α) was increased to 0.3 from 0.05 of pre-transplantation levels. Expression of human β-globin was also confirmed in recipient mice by Western Blot; a 2–3-fold increase compared with that of controls. Our results indicate that human HSCs from a β-Thalassemia patient can be efficiently transduced by a hybrid rAAV6/2-β-globin vector followed by expression of normal human β-globin protein. This study provides a proof-of-concept that rAAV6/2-mediated gene transfer into human HSCs might be a potential approach for gene therapy of β-Thalassemia. Disclosures: No relevant conflicts of interest to declare.

Identification of Single Human Hematopoietic Stem Cells Capable of Long-Term Multilineage Engraftment and Self-Renewal.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 816-816
Author(s):  
Faiyaz Notta ◽  
Sergei Doulatov ◽  
John E. Dick
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cord Blood ◽  
Conflicts Of Interest ◽  
Single Cells ◽  
Human Cord Blood ◽  
Hematopoietic Stem ◽  
Human Hscs ◽  
Insight Into

Abstract Abstract 816 A fundamental tenet that has guided our insight into the biology of hematopoietic stem cells (HSCs) over the past 50 years is the principle that an HSC can only be assayed by functional repopulation of an irradiated host1. In its strictest definition, only a HSC can provide long-term reconstitution of all the major lineages following single cell transplantation. However, the existing strategies for human HSC isolation lack quantitation and do not submit to this rigorous standard, thus precluding further biological analysis. Here, we report the prospective and quantitative analysis of human cord blood (CB) HSCs transplanted into female NOD/SCID/IL-2Rgcnull mice. We identify integrin a6 (CD49f) as a novel marker of cord blood (CB) HSCs and report that single Lin-CD34+CD38-CD90+CD45RA-RholoCD49fhi cells can reconstitute myeloid, B-, and T-cell lineages for 18 weeks. 5 of 29 mice transplanted with single cells gave rise to human cells indicating that approximately 20% of cells in this fraction are HSCs. This advance finally enables utilization of near-homogeneous populations of human HSCs to gain insight into their biology and to harness them for stem cell-based therapeutics. Disclosures: No relevant conflicts of interest to declare.

Plxdc2 Marks Hematopoietic Stem Cells and Th2 Cytokine-Producing Innate Lymphocytes in Adult Bone Marrow

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1278-1278
Author(s):  
Yasushi Kubota ◽  
Ivo Lieberam ◽  
Shinya Kimura ◽  
Thomas M Jessell ◽  
Shin-Ichi Nishikawa
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
T Cell ◽  
Cell Surface ◽  
Hematopoietic Stem Cells ◽  
Cell Population ◽  
Specific Marker ◽  
Simple Method ◽  
Hematopoietic Stem

Abstract Abstract 1278 Hematopoietic stem cells (HSCs) have been highly enriched using combinations of more than 10 surface markers. However the simple method using a few positive markers is preferable to identify HSCs location in tissue section. We performed a stringent comparative gene expression profiling analysis to find genes preferentially expressed in the HSC population, and identified a total of 63 genes that are highly expressed in HSC among various hematopoietic cell population. In order to find HSC-specific marker we focused on genes encoding cell surface protein, and found that plexin domain containing 2 (Plxdc2) is highly expressed in CD34—c-Kit+Sca-1+Lineage−(CD34−KSL) HSC population using Plxdc2::GFP knock-in mice. Only 0.2% of whole bone marrow cells were Plxdc2+, and competitive repopulation assay clearly showed that all HSCs are included in the Plxdc2+ fraction. These results identify Plxdc2 as a new marker of HSCs. Plxdc2+ population contain not only HSCs but uncharacterized c-Kitlow/−Sca-1+Lineage−cells. To further purify HSCs, we investigated the additional positive marker. Throughout the screening of various known HSC-related marker, CD150 was selected. CD150 is already recognized as a positive HSC marker (Kiel, et al. Cell 2005). The Plxdc2+CD150+ fraction represented only 0.1%±0.002% in whole bone marrow, and 6% in c-Kit+Sca-1+Lineage− cells, respectively. To test whether the combination of Plxdc2 and CD150 with or without other markers can highly enrich long-term HSCs, we competitively reconstituted irradiated mice with single Plxdc2+CD150+ cells or single Plxdc2+CD150+c-Kit+Sca-1+Lineage− cells. One out of every 4.6 Plxdc2+CD150+ cells (22%), and one out of 2.2 Plxdc2+CD150+c-Kit+Sca-1+Lineage− cells (44%) engrafted and gave long-term multi-lineage reconstitution. The simple combination of Plxdc2 and CD150 significantly increased HSC purity. In addition, we found robust levels of PLXDC2 transcripts in purified human cord blood CD34+ HSCs. Next, we attempted to characterize the another Plxdc2+ fraction which is c-Kitlow/−Sca-1+Lineage−. Multicolor flowcytometric analysis revealed that Plxdc2+c-Kitlow/−Sca-1+Lineage− cells uniformly express CD45, IL7Rα, Thy-1.2, CD27, T1/ST2 (IL1RL1, a subunit of IL33R) and CD25. These cell surface phenotype indicated that this population is probably of lymphoid lineage. However, culturing Plxdc2+ c-Kit low/−Sca-1+Lineage− cells on OP9-DL1, which supports the development of T-cell progenitors to mature T-cells, did not induce T-cell differentiation. Plxdc2+c-Kitlow/−Sca-1+Lineage−cells also did not differentiate into B cells when co-cultured with OP9 stroma cell line. Furthermore Plxdc2+c-Kitlow/−Sca-1+Lineage− cells produce IL-5 and IL-13 in response to IL-33 or a combination of IL-2 and IL-25. These characteristics resemble that of “natural helper (NH) cells”, a recently identified cell population capable of producing large amounts of Th2 cytokines in fat-associated lymphoid clusters (Moro, et al. Nature 2010). Immunohistochemical staining of bone section to detect HSCs, and functional analyses to clarify why Plxdc2 specifically express in HSCs and bone marrow “NH cells” using Plxdc2-deficient mice are our ongoing tasks. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Left or right? Directions to stem cell engraftment

2017 ◽  
Vol 215 (1) ◽  
pp. 13-15 ◽  
Author(s):  
Mirjam E. Belderbos ◽  
Leonid Bystrykh ◽  
Gerald de Haan
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
T Cell ◽  
Hematopoietic Stem Cells ◽  
Hematopoietic Stem ◽  
Cell Production ◽  
Cell Engraftment ◽  
Genetic Barcoding ◽  
Asymmetrically Distributed

In this issue of JEM, Wu et al. (https://doi.org/10.1084/jem.20171341) use genetic barcoding of macaque hematopoietic stem cells to demonstrate that, after transplantation, HSCs are very asymmetrically distributed and uncover a thymus-independent pathway for mature T cell production in the bone marrow.

Robo4/Magic Roundabout Is a Novel Surface Marker for Murine and Human Hematopoietic Stem Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 682-682
Author(s):  
Fumi Shibata ◽  
Yuko Goto-Koshino ◽  
Miyuki Ito ◽  
Yumi Fukuchi ◽  
Yoshihiro Morikawa ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Cell Surface ◽  
Hematopoietic Stem Cells ◽  
Surface Markers ◽  
Hematopoietic Stem ◽  
Hematopoietic System ◽  
Cd34 Cells ◽  
Human Hscs

Abstract A variety of cell surface markers such as c-Kit, Sca-1, CD34 and Flt-3 have been utilized to prospectively isolate murine or human hematopoietic stem cells (HSCs). While murine HSCs were shown to be highly enriched in CD34−c-Kit+Sca-1+Lineage- (CD34−KSL) fraction, this population is still not homogeneous for long-term HSCs. In human, CD34+ cells are regarded as crude HSC fraction and used for clinical applications. However, quiescent human HSCs are also found in CD34− fraction, indicating that CD34 is not a bona fide marker for human HSC. Thus, novel surface markers that can be used to purify human or murine HSCs to homogeneity need to be identified. Roundabout (Robo) family proteins are immunoglobulin-type cell surface receptors that are predominantly expressed in nervous system. Slit2, a ligand for Robo, is a large leucine-rich repeat-containing secreted protein that is also expressed in brain. By binding with Robo, Slit2 acts as a repellant for axon guidance of developing neurons and they are critical for correct wiring of neuronal network. Robo family comprises four family members, Robo1 – Robo4, and Robo4 is distinct in that it is expressed specifically in endothelial cells, but not in brain. In this study, we investigated Robo4 for its possible application for HSC identification in murine and human hematopoietic system. By RT-PCR, Robo4 was specifically expressed in murine KSL fraction, and was not expressed in lineage positive cells and various progenitors such as common myeloid progenitor (CMP), granulocyte-monocyte progenitor (GMP), megakaryocyte/erythroid progenitor (MEP) and common lymphoid progenitor (CLP). Moreover, the expression of Robo4 was highest in side population of KSL cells (KSL-SP), and moderate in KSL-main population (KSL-MP) cells. Monoclonal antibody raised against Robo4 identified its high expression in KSL cells by FACS. FACS analysis of human cord blood cells revealed that Robo4 is highly expressed in CD34+ cells, and CD34+Robo4high population fell into CD38− fraction, which enriches human HSCs. Bone marrow transplantation experiments revealed that Robo4+ fraction of murine KSL cells had long-term repopulating activity, while Robo4−KSL cells not. Although both Robo4+ and Robo4− CD34−KSL cells repopulated murine hematopoietic system for long-term, Robo4+CD34−KSL cells achieved higher chimerism after repopulation compared with Robo4−CD34−KSL. To investigate the physiological role of Robo4 in HSC homeostasis, we next examined the expression of Slit2 in hematopoietic system. Interestingly, Slit2 is specifically expressed in bone marrow stromal cells, but not in hematopoietic cells. Moreover, Slit2 is induced in osteoblasts, a critical cellular component composing HSC niche, in response to myelosuppressive stress such as 5FU treatment. These results indicate that Robo4 is expressed in murine and human hematopoietic HSCs and useful for HSC purification, and Robo4 - Slit2 system may play a role in HSC physiology in niche environment under hematopoietic stress.

GPI-80 Defines Primitive Human Cord Blood-Derived CD34-Positive and Negative Hematopoietic Stem Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2365-2365
Author(s):  
Yoshikazu Matsuoka ◽  
Keisuke Sumide ◽  
Hiroshi Kawamura ◽  
Ryusuke Nakatsuka ◽  
Tatsuya Fujioka ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Stem Cell ◽  
Human Cord Blood ◽  
Differentiation Potential ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Nog Mice ◽  
High Level

Abstract Background. We identified very primitive CD34-negative (CD34-) severe combined immunodeficiency (SCID)-repopulating cells (SRCs) in human cord blood (CB) using the intra-bone marrow injection (IBMI) method (Blood 2003:101;2924). These CD34- SRCs possess myeloid-biased differentiation potential, which suggests that they are a distinct class of primitive hematopoietic stem cell (HSC) and that they reside at the apex of the human HSC hierarchy (Blood Cancer J 2015:5;e290). We recently developed high-resolution purification methods for CD34- SRCs using 18 Lineage (18Lin)-specific antibodies, which can enrich CD34- SRC at the 1/1,000 level in 18Lin- CD34- fractions (Exp Hematol 2011:39:203). In addition, we previously identified CD133 as a positive marker for CD34- SRCs as well as for CD34+ SRCs (Leukemia 2014:28;1308). The results showed that CD34+/- SRCs were enriched to approximately 1/100 and 1/140 in 18Lin- CD34+/- CD133+ fractions, respectively. Aim. In order to further elucidate the details of the characteristics of human CD34+/- HSCs, we aimed to identify additional positive markers for the high-level purification of CB-derived CD34+/- SRCs. Materials and Methods. First, weextensively analyzed the candidate positive markers, including cell adhesion molecules and homing receptors that are expressed on 18Lin- CD34+ CD38- and 18Lin- CD34- cells by multicolor FACS. Finally, we discovered that glycosylphosphatidylinositol-anchored protein GPI-80, which has recently been reported as a marker for human fetal liver hematopoietic stem/progenitor cells (HSPCs) (Cell Stem Cell 2015:16;80), was also expressed on human full-term CB-derived 18Lin- CD34+ CD38- and 18Lin- CD34- cells. Next, we sorted 18Lin- CD34+ CD38- GPI-80+/- and 18Lin- CD34- GPI-80+/- cells from human CB. The HSPC characteristics of the 18Lin- CD34+ CD38- GPI-80+/- and 18Lin- CD34- GPI-80+/- cells were assessed as follows: (1) the in vitro maintenance/production capacities of CD34+ and CD34+ CD38- cells were examined in co-cultures with mesenchymal stroma cells (MSCs) established from human bone marrow-derived CD45- Lin- CD271+ SSEA-4+ cells (Stem Cells 2015:33;1554); (2) an SRC assay was performed using NOD/Shi-scid/IL-2Rγcnull (NOG) mice; (3) limiting dilution analyses (LDAs) were performed to determine the SRC frequencies in these four fractions of cells. Results. In the CB-derived 18Lin- CD34+ CD38- and 18Lin- CD34- fractions, 10.1% and 14.4% of cells expressed GPI-80, respectively. The 18Lin- CD34+ CD38- GPI-80+/- and 18Lin- CD34- GPI-80+/- cells were then co-cultured with human MSCs for 7 days in the presence of SCF and TPO. As a result, the 18Lin- CD34+ CD38- GPI-80+ cells maintained significantly higher percentages of CD34+ (86.4%) and CD34+ CD38- cells (24.8%) in comparison to 18Lin- CD34+ CD38- GPI-80- cells (78.7% and 14.3%, respectively). However, 18Lin- CD34- GPI-80+/- cells produced comparable levels of CD34+ (50.3% and 50.8%) and CD34+ CD38- cells (4.4% and 5.3%). These four fractions of cells were then transplanted into NOG mice using the IBMI method. All of these four fractions of cells showed long-term repopulating SRC activities with multi-lineage differentiation potential in mouse bone marrow. However, LDAs demonstrated that the frequencies of SRC in the 18Lin- CD34+ CD38- GPI-80+/- and 18Lin- CD34- GPI-80+/- fractions were 1/21, 1/35 and 1/28, 1/874, respectively. These data clearly demonstrate that both CD34+/- SRCs are enriched in GPI-80+ fractions. Surprisingly, a number of mice received a limited number of 18Lin- CD34+ CD38- GPI-80+ (2 cells) and 18Lin- CD34- GPI-80+ cells (10 cells), and thus also showed multi-lineage long-term human hematopoietic cell repopulation. Conclusion. These observations clearly demonstrated that GPI-80 defines CB-derived human primitive HSCs. Furthermore, these results indicate that GPI-80 is a useful marker for the high-level purification of human CB-derived CD34+/- SRCs (HSCs). Disclosures No relevant conflicts of interest to declare.

Local irradiation enhances congenic donor pluripotent hematopoietic stem cell engraftment similarly in irradiated and nonirradiated sites

Blood ◽  
2004 ◽  
Vol 103 (5) ◽  
pp. 1949-1954 ◽  
Author(s):  
Hiroshi Ito ◽  
Yasuo Takeuchi ◽  
Juanita Shaffer ◽  
Megan Sykes
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Local Irradiation ◽  
Short Term ◽  
Hematopoietic Stem ◽  
Donor Chimerism ◽  
Cell Engraftment ◽  
High Bone ◽  
Bone Marrow Doses

AbstractLong-term multilineage chimerism is achieved in CD45 congenic mice receiving high bone marrow doses with or without mediastinal irradiation (MI). Increased donor chimerism results in MI-treated compared with nonirradiated animals, suggesting that MI makes “space” for engraftment of donor pluripotent hematopoietic stem cells (PHSCs). We have now examined whether space is systemic or whether increased engraftment of donor marrow in locally irradiated mice is confined to the irradiated bones. While increased donor chimerism was observed in irradiated bones compared with nonirradiated bones of MI-treated animals 4 weeks following bone marrow transplantation (BMT), these differences were minimal by 40 weeks. MI-treated chimeras contained more adoptively transferable donor PHSCs in the marrow of both irradiated and distant bones compared with non-MI–treated chimeras. Similar proportions of donor PHSCs were present in irradiated and nonirradiated bones of locally irradiated mice at both 4 and 40 weeks. Irradiated bones contained more donor short-term repopulating cells than distant bones at 4 weeks, but not 40 weeks, after BMT. Our study suggests that local proliferation of donor PHSCs in mice receiving local irradiation rapidly leads to a systemic increase in donor PHSC engraftment.

Human CD34+ hematopoietic stem cells capable of multilineage engrafting NOD/SCID mice express flt3: distinct flt3 and c-kit expression and response patterns on mouse and candidate human hematopoietic stem cells

Blood ◽  
2003 ◽  
Vol 102 (3) ◽  
pp. 881-886 ◽  
Author(s):  
Ewa Sitnicka ◽  
Natalija Buza-Vidas ◽  
Staffan Larsson ◽  
Jens M. Nygren ◽  
Karina Liuba ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Cord Blood ◽  
Severe Combined Immunodeficiency ◽  
Scid Mice ◽  
Striking Difference ◽  
Hematopoietic Stem ◽  
Human Hscs

Abstract The cytokine tyrosine kinase receptors c-kit and flt3 are expressed and function in early mouse and human hematopoiesis. Through its ability to promote ex vivo expansion and oncoretroviral transduction of primitive human hematopoietic progenitors, the flt3 ligand (FL) has emerged as a key stimulator of candidate human hematopoietic stem cells (HSCs). However, recent studies in the mouse suggest that though it is present on short-term repopulating cells, flt3 is not expressed on bone marrow long-term reconstituting HSCs, the ultimate target for the development of cell replacement and gene therapy. Herein we demonstrate that though only a fraction of human adult bone marrow and cord blood CD34+long-term culture-initiating cells (LTC-ICs) express flt3, most cord blood lymphomyeloid HSCs capable of in vivo reconstituting nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice are flt3+. The striking difference in flt3 and c-kit expression on mouse and candidate human HSCs translated into a corresponding difference in flt3 and c-kit function because FL was more efficient than SCF at supporting the survival of candidate human HSCs. In contrast, SCF is far superior to FL as a viability factor for mouse HSCs. Thus, the present data provide compelling evidence for a contrasting expression and response pattern of flt3 and c-kit on mouse and human HSCs.

scholarly journals Thymus reconstitution by c-kit-expressing hematopoietic stem cells purified from adult mouse bone marrow.

1992 ◽  
Vol 176 (6) ◽  
pp. 1503-1509 ◽  
Author(s):  
P de Vries ◽  
K A Brasel ◽  
H J McKenna ◽  
D E Williams ◽  
J D Watson
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
T Cell ◽  
Hematopoietic Stem Cells ◽  
Cell Lineage ◽  
Lag Phase ◽  
Mouse Bone Marrow ◽  
Hematopoietic Stem ◽  
Colony Forming Units

The introduction of clonal assays and long-term culture systems has resulted in considerable progress in the understanding of the early events that control self-renewal and commitment to differentiation of pluripotent hematopoietic stem cells (PHSC). Relatively little is known about the factors that control the commitment of PHSC to the lymphoid lineages, especially the T cell lineage. In the present study, the expression of the proto-oncogene c-kit was used to isolate and study the capacity of highly purified day 14 colony-forming units-spleen (CFU-S) to reconstitute the thymus of sublethally irradiated Thy-1 congenic recipient mice. We demonstrate here that one c-kit positive (c-kitpos) stem cell upon intrathymic transfer can effectively reconstitute the thymus of a sublethally irradiated recipient. After a lag phase of 15 d, high levels of donor-derived thymocytes (Thy-1.1pos) could be detected until 65 d after transplantation in Thy-1.2pos host mice. Donor-derived cells were only detected in the lobe of the thymus in which cells were previously injected and not in the noninjected lobe. These data suggest that c-kitpos stem cells do not migrate from one lobe to another and that they do not re-seed the thymus after having migrated to the bone marrow. The level and duration of reconstitution was found to be cell dose dependent, suggesting that, over time, endogenous stem cells compete with donor stem cells for available sites in the thymus microenvironment. The data presented in this paper demonstrate that commitment of purified adult bone marrow-derived c-kitpos stem cells to the T cell differentiation pathway can occur in the thymus and does not have to happen in the bone marrow.

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