scholarly journals Partially differentiated ex vivo expanded cells accelerate hematologic recovery in myeloablated mice transplanted with highly enriched long- term repopulating stem cells

Blood ◽  
1996 ◽  
Vol 88 (9) ◽  
pp. 3642-3653 ◽  
Author(s):  
SJ Szilvassy ◽  
KP Weller ◽  
B Chen ◽  
CA Juttner ◽  
A Tsukamoto ◽  
...  

The ability of an infusion of ex vivo expanded hematopoietic cells to ameliorate cytopenia following transplantation of hematopoietic stem cells (HSCs) is controversial. To address this issue, we measured the recovery of circulating leukocytes, erythrocytes, and platelets in lethally irradiated mice transplanted with 10(3) enriched HSCs, with or without their expanded equivalent (EE) generated after 7 days of culture in interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor and Steel Factor. Two HSC populations differing in their content of short-term repopulating progenitors were evaluated. Thy-1loLIN-Sca- 1+ (TLS) bone marrow (BM) is enriched in colony-forming cells (CFCs), day 8 and day 12 spleen colony-forming units (CFU-S) (435 +/- 19, 170 +/- 30, and 740 +/- 70 per 10(3) cells, respectively), and stem cells with competitive long-term repopulating potential (> or = 1 per 43 cells). Thy-1loSca-1+H-2Khl cells (TSHFU) isolated from BM 1 day after treatment of donor mice with 5-fluorouracil (5-FU) are also highly enriched in competitive repopulating units (CRU, > or = 1 per 55 cells), but are depleted of CFCs, day 8 and day 12 CFU-S (171 +/- 8, 0 and 15 +/- 4 per 10(3) cells, respectively). Recipients of 10(3) TLS cells transiently recovered leukocytes to > or = 2,000/microL in 12 days, but sustained engraftment required 25 days. Platelets recovered to > or = 200,000/microL in 15 days, and erythrocytes never decreased below 50% of normal. Mice transplanted with 10(3) TSHFU cells recovered leukocytes in 15 days, and platelets and erythrocytes in 18 days. Recipients of unseparated normal or 5-FU-treated BM cells (containing 10(3) TLS or TSHFU cells) recovered safe levels of blood cells in 9 to 12 days, suggesting that unseparated marrow contains early engrafting cells that were depleted by sorting. Upon ex vivo expansion, total cells, CFCs and day 12 CFU-S were amplified 2,062-,83- and 13-fold, respectively, from TLS cells; and 1,279-, 259- and 708-fold, respectively, from TSHFU cells. Expanded cells could regenerate the majority of lymphocytes and granulocytes in primary (17 weeks) and secondary (26 weeks) hosts and were only moderately impaired compared to fresh HSCs. The EE of TSHFU cells was more potent than that of TLS cells, suggesting that more highly enriched HSCs are more desirable starting populations for this application. When mice were transplanted with 10(3) TSHFU cells and their EE, the duration of thrombocytopenia was shortened from 18 to 12 days, and anemia was abolished. Leukocytes were also elevated on days 9 to 12, although sustained recovery was not accelerated. Anemia was also abrogated in recipients of 10(3) TLS cells and their EE. Early platelet counts were slightly higher than with TLS cells alone, but leukocyte recovery was not improved. These data confirm that TLS cells contribute to early and sustained hematopoiesis, and demonstrate a benefit of ex vivo expanded cells in accelerating engraftment of more primitive TSHFU stem cells depleted of progenitors.

Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 2986-2992 ◽  
Author(s):  
G de Haan ◽  
B Dontje ◽  
C Engel ◽  
M Loeffler ◽  
W Nijhof

Abstract Because of the complexity of appropriate stem cell assays, little information on the in vivo regulation of murine stem cell biology or stemmatopoiesis is available. It is unknown whether and how in vivo the primitive hematopoietic stem cell compartment is affected during a continued increased production of mature blood cells. In this study, we present data showing that prolonged (3 weeks) administration of granulocyte colony-stimulating factor (G-CSF), which is a major regulator of mature granulocyte production, has a substantial impact on both the size and the location of various stem cell subset pools in mice. We have used the novel cobblestone area forming cell (CAFC) assay to assess the effects of G-CSF on the stem cell compartment (CAFC days 7, 14, 21, and 28). In marrow, in which normally 99% of the total number of stem cells can be found, G-CSF induced a severe depletion of particularly the most primitive stem cells to 5% to 10% of normal values. The response after 7 days of G-CSF treatment was an increased amplification between CAFC day 14 and 7. However, this response occurred at the expense of the number of CAFC day 14. It is likely that the resulting gap of CAFC day 14 cell numbers was subsequently replenished from the more primitive CAFC day 21 and 28 compartments, because these cell numbers remained low during the entire treatment period. In the spleen, the number of stem cells increased, likely caused by a migration from the marrow via the blood, leading to an accumulation in the spleen. The increased number of stem cells in the spleen overcompensated for the loss in the marrow. When total body (marrow and spleen) stem cell numbers were calculated, it appeared that a continued increased production of mature granulocytes resulted in the establishment of a higher, new steady state of the stem cell compartment; most committed stem cells (CAFC day 7) were increased threefold, CAFC day 14 were increased 2.3-fold, CAFC-day 21 were increased 1.8-fold, and the most primitive stem cells evaluated, CAFC day 28, were not different from normal, although now 95% of these cells were located in the spleen. Four weeks after discontinuation of the G-CSF treatment, the stem cell reserve in the spleen had returned to a normal level, whereas stem cell numbers in marrow had recovered to values above normal. This study shows that the primitive stem cell compartment is seriously perturbed during an increased stimulation of the production of mature blood cells.(ABSTRACT TRUNCATED AT 400 WORDS)


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1267-1267
Author(s):  
Elisa Tomellini ◽  
Iman Fares ◽  
Bernhard Lehnertz ◽  
Jalila Chagraoui ◽  
Nadine Mayotte ◽  
...  

Abstract Hematopoietic stem cell (HSC) transplantation constitutes one of the most effective therapeutic strategies to treat numerous hematological diseases. Cord blood (CB) is one of the most attractive donor sources of stem cells for this procedure due to its rapid availability, HLA mismatches tolerance and low associated risk of chronic graft-versus-host disease. However, these advantages are offset by the limited cell dose in CB units, which can contribute to delayed hematopoietic engraftment following transplantation. Mastering ex vivo HSC expansion is therefore of great interest for clinical purposes and for genetic manipulation. HSCs can be functionally defined as either long-term (LT-HSC), providing life-long hematopoiesis and characterized by delayed engraftment pattern, or short-term repopulating stem cells (ST-HSC), providing early and transient hematopoietic recovery. Major hurdles hindering the study of these cell populations is the current inability to evaluate their content in cultured samples and the lack of understanding of the molecular mechanisms regulating stem cell self-renewal ex vivo. Those issues highly benefited from the discovery by our laboratory of the small molecule UM171, which promote HSC expansion ex vivo, as well as from the identification of EPCR as one of the most reliable surface markers for cultured HSCs. We now describe the identification of Integrin-α3 (ITGA3) as a novel marker for cultured HSCs. ITGA3 expression was found to be sufficient to split the primitive EPCR+CD90+CD133+CD34+CD45RA- HSC population in two functionally distinct fractions presenting only short-term (ITGA3-) and both short-term and long-term (ITGA3+) repopulating potential. ITGA3+ cells, as opposed to the ITGA3- fraction, exhibited robust multilineage differentiation potential and serial reconstitution ability in immunocompromised mice. This combination of markers identifies repopulating HSCs in culture by FACS beyond what is currently possible with other approaches, with a frequency of LT-HSC found in the ITGA3+ population estimated at 1:38 in day 7 UM171 expanded CB-cells. Moreover, lentiviral-mediated ITGA3 knockdown was shown to compromise the LT repopulating activity of cultured HSC in vivo. Gene expression profiling revealed striking molecular similarity between ITGA3+ and ITGA3- cells, showing overrepresentation of genes involved in fundamental hematopoietic programs known to govern HSC specification and function in both of these populations. However, ITGA3+ and ITGA3- subsets clearly clustered separately by principle component analysis, indicating broad differences in gene expression. Concordantly with their primitive phenotype, stem cell markers and cell quiescence are gene sets enriched in ITGA3+ cells, while progenitor markers, DNA replication, M/G1 and G2/M checkpoints, mRNA processing, reduction of hypoxia and Myc targets were significantly downregulated in these cells. Altogether, our results indicate that ITGA3 is a reliable marker for cultured HSCs, improving the accuracy of prospective HSC identification in culture. Deciphering the function of genes upregulated in primitive ITGA3+ HSCs will represent an invaluable resource for dissecting the genetic programs that govern hematopoietic stem cells biology. Disclosures Sauvageau: ExCellThera: Employment, Equity Ownership.


Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1989-1993
Author(s):  
Fumihito Tajima ◽  
Takashi Sato ◽  
Joseph H. Laver ◽  
Makio Ogawa

Controversy has existed about CD34 expression by hematopoietic stem cells. We recently reported that CD34 expression reflects the activation state of stem cells by using a murine transplantation model. It has been generally held that mobilized blood stem cells express CD34.However, it has also been reported that mobilized stem cells and progenitors are in G0/G1 phases of the cell cycle. To address the state of CD34 expression by the mobilized stem cells, we again used the mouse transplantation model. We prepared CD34− and CD34+ populations of nucleated blood cells from granulocyte colony-stimulating factor–treated Ly-5.1 mice and assayed each population for long-term engrafting cells in lethally irradiated Ly-5.2 mice. The majority of the stem cells were in the CD34+population. The CD34 expression by mobilized stem cells was reversible because re-transplantation of Ly-5.1 CD34− marrow cells harvested from the Ly-5.2 recipients of CD34+-mobilized stem cells 8 months posttransplantation revealed long-term engraftment. These results may support the use of total CD34+ cells in mobilized blood as a predictor for engraftment and CD34 selection for enrichment of human stem cells.


Blood ◽  
1995 ◽  
Vol 86 (8) ◽  
pp. 2986-2992 ◽  
Author(s):  
G de Haan ◽  
B Dontje ◽  
C Engel ◽  
M Loeffler ◽  
W Nijhof

Because of the complexity of appropriate stem cell assays, little information on the in vivo regulation of murine stem cell biology or stemmatopoiesis is available. It is unknown whether and how in vivo the primitive hematopoietic stem cell compartment is affected during a continued increased production of mature blood cells. In this study, we present data showing that prolonged (3 weeks) administration of granulocyte colony-stimulating factor (G-CSF), which is a major regulator of mature granulocyte production, has a substantial impact on both the size and the location of various stem cell subset pools in mice. We have used the novel cobblestone area forming cell (CAFC) assay to assess the effects of G-CSF on the stem cell compartment (CAFC days 7, 14, 21, and 28). In marrow, in which normally 99% of the total number of stem cells can be found, G-CSF induced a severe depletion of particularly the most primitive stem cells to 5% to 10% of normal values. The response after 7 days of G-CSF treatment was an increased amplification between CAFC day 14 and 7. However, this response occurred at the expense of the number of CAFC day 14. It is likely that the resulting gap of CAFC day 14 cell numbers was subsequently replenished from the more primitive CAFC day 21 and 28 compartments, because these cell numbers remained low during the entire treatment period. In the spleen, the number of stem cells increased, likely caused by a migration from the marrow via the blood, leading to an accumulation in the spleen. The increased number of stem cells in the spleen overcompensated for the loss in the marrow. When total body (marrow and spleen) stem cell numbers were calculated, it appeared that a continued increased production of mature granulocytes resulted in the establishment of a higher, new steady state of the stem cell compartment; most committed stem cells (CAFC day 7) were increased threefold, CAFC day 14 were increased 2.3-fold, CAFC-day 21 were increased 1.8-fold, and the most primitive stem cells evaluated, CAFC day 28, were not different from normal, although now 95% of these cells were located in the spleen. Four weeks after discontinuation of the G-CSF treatment, the stem cell reserve in the spleen had returned to a normal level, whereas stem cell numbers in marrow had recovered to values above normal. This study shows that the primitive stem cell compartment is seriously perturbed during an increased stimulation of the production of mature blood cells.(ABSTRACT TRUNCATED AT 400 WORDS)


Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1989-1993 ◽  
Author(s):  
Fumihito Tajima ◽  
Takashi Sato ◽  
Joseph H. Laver ◽  
Makio Ogawa

Abstract Controversy has existed about CD34 expression by hematopoietic stem cells. We recently reported that CD34 expression reflects the activation state of stem cells by using a murine transplantation model. It has been generally held that mobilized blood stem cells express CD34.However, it has also been reported that mobilized stem cells and progenitors are in G0/G1 phases of the cell cycle. To address the state of CD34 expression by the mobilized stem cells, we again used the mouse transplantation model. We prepared CD34− and CD34+ populations of nucleated blood cells from granulocyte colony-stimulating factor–treated Ly-5.1 mice and assayed each population for long-term engrafting cells in lethally irradiated Ly-5.2 mice. The majority of the stem cells were in the CD34+population. The CD34 expression by mobilized stem cells was reversible because re-transplantation of Ly-5.1 CD34− marrow cells harvested from the Ly-5.2 recipients of CD34+-mobilized stem cells 8 months posttransplantation revealed long-term engraftment. These results may support the use of total CD34+ cells in mobilized blood as a predictor for engraftment and CD34 selection for enrichment of human stem cells.


Author(s):  
Fatima Aerts-Kaya

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Wen-Ching Tzaan ◽  
Hsien-Chih Chen

Intervertebral disc (IVD) degeneration is a multifactorial process that is influenced by contributions from genetic predisposition, the aging phenomenon, lifestyle conditions, biomechanical loading and activities, and other health factors (such as diabetes). Attempts to decelerate disc degeneration using various techniques have been reported. However, to date, there has been no proven technique effective for broad clinical application. Granulocyte colony-stimulating factor (GCSF) is a growth factor cytokine that has been shown to enhance the availability of circulating hematopoietic stem cells to the brain and heart as well as their capacity for mobilization of mesenchymal bone marrow stem cells. GCSF also exerts significant increases in circulating neutrophils as well as potent anti-inflammatory effects. In our study, we hypothesize that GCSF can induce bone marrow stem cells differentiation and mobilization to regenerate the degenerated IVD. We found that GCSF had no contribution in disc regeneration or maintenance; however, there were cell proliferation within end plates. The effects of GCSF treatment on end plates might deserve further investigation.


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