scholarly journals Long Term Ex Vivo Culture and Live Imaging of Drosophila Larval Imaginal Discs

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0163744 ◽  
Author(s):  
Chia-Kang Tsao ◽  
Hui-Yu Ku ◽  
Yuan-Ming Lee ◽  
Yu-Fen Huang ◽  
Yi Henry Sun
Blood ◽  
1998 ◽  
Vol 91 (4) ◽  
pp. 1243-1255 ◽  
Author(s):  
Mo A. Dao ◽  
Ami J. Shah ◽  
Gay M. Crooks ◽  
Jan A. Nolta

Abstract Retroviral-mediated transduction of human hematopoietic stem cells to provide a lifelong supply of corrected progeny remains the most daunting challenge to the success of human gene therapy. The paucity of assays to examine transduction of pluripotent human stem cells hampers progress toward this goal. By using the beige/nude/xid (bnx)/hu immune-deficient mouse xenograft system, we compared the transduction and engraftment of human CD34+progenitors with that of a more primitive and quiescent subpopulation, the CD34+CD38− cells. Comparable extents of human engraftment and lineage development were obtained from 5 × 105 CD34+ cells and 2,000 CD34+CD38− cells. Retroviral marking of long-lived progenitors from the CD34+ populations was readily accomplished, but CD34+CD38− cells capable of reconstituting bnx mice were resistant to transduction. Extending the duration of transduction from 3 to 7 days resulted in low levels of transduction of CD34+CD38− cells. Flt3 ligand was required during the 7-day ex vivo culture to maintain the ability of the cells to sustain long-term engraftment and hematopoiesis in the mice.


Blood ◽  
1998 ◽  
Vol 92 (12) ◽  
pp. 4612-4621 ◽  
Author(s):  
M.A. Dao ◽  
K. Hashino ◽  
I. Kato ◽  
J.A. Nolta

Abstract Recent reports have indicated that there is poor engraftment from hematopoietic stem cells (HSC) that have traversed cell cycle ex vivo. However, inducing cells to cycle in culture is critical to the fields of ex vivo stem cell expansion and retroviral-mediated gene therapy. Through the use of a xenograft model, the current data shows that human hematopoietic stem and progenitor cells can traverse M phase ex vivo, integrate retroviral vectors, engraft, and sustain long-term hematopoiesis only if they have had the opportunity to engage their integrin receptors to fibronectin during the culture period. If cultured in suspension under the same conditions, transduction is undetectable and the long-term multilineage regenerative capacity of the primitive cells is severely diminished.


Blood ◽  
1997 ◽  
Vol 90 (2) ◽  
pp. 641-650 ◽  
Author(s):  
Olga I. Gan ◽  
Barbara Murdoch ◽  
Andre Larochelle ◽  
John E. Dick

Abstract Many experimental and clinical protocols are being developed that involve ex vivo culture of human hematopoietic cells on stroma or in the presence of cytokines. However, the effect of these manipulations on primitive hematopoietic cells is not known. Our severe combined immune-deficient mouse (SCID)-repopulating cell (SRC) assay detects primitive human hematopoietic cells based on their ability to repopulate the bone marrow (BM) of immune-deficient non-obese diabetic/SCID (NOD/SCID) mice. We have examined here the maintenance of SRC, colony-forming cells (CFC), and long-term culture-initiating cells (LTC-IC) during coculture of adult human BM or umbilical cord blood (CB) cells with allogeneic human stroma. Transplantation of cultured cells in equivalent doses as fresh cells resulted in lower levels of human cell engraftment after 1 and 2 weeks of culture for BM and CB, respectively. Similar results were obtained using CD34+-enriched CB cells. By limiting dilution analysis, the frequency of SRC in BM declined sixfold after 1 week of culture. In contrast to the loss of SRC as measured by reduced repopulating capacity, the transplanted inocula of cultured cells frequently contained equal or higher numbers of CFC and LTC-IC compared with the inocula of fresh cells. The differential maintenance of CFC/LTC-IC and SRC suggests that SRC are biologically distinct from the majority of these in vitro progenitors. This report demonstrates the importance of the SRC assay in the development of ex vivo conditions that will allow maintenance of primitive human hematopoietic cells with repopulating capacity.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4954-4954
Author(s):  
Ronald L. Brown ◽  
J. Zhang ◽  
L. Qiu ◽  
A. Nett ◽  
G. Almeida-Porada ◽  
...  

Abstract Ex-vivo expansion regimens for cord blood (CB) CD34+ cells that maintain their long term engrafting ability hold great promise for adult transplantation but have been met with relatively little success. Data presented delineate the development of a cell cu1ture system composed of clinical grade serum-free medium (QBSF 60) and a cytokine combination that not only yields large numbers of CD34+ cell populations but also supports the long term engraftment of these cells. CBCD34+ cells were cultured for over 14 days in QBSF 60 medium supplemented with the following cytokine combination a.) SCF, Flt-3 and TPO, b.) SCF, Flt-3 and IL-6, c.) SCF, Flt-3 TPO and IL-3, d.) SCF Flt-3, TPO and IL-6, e.) SCF, Flt-3, TPO and IL-11, f.) SCF, Flt-3, TPO, IL-3, IL-6 and IL-11, g.) SCF, Flt-3, TPO, IL-3, IL-6, IL-11, G-CSF, and EPO. The following cytokine concentrations was used for each of the above combinations: SCF (50 ng/ml), Flt-3 (100 ng/ml), TPO (100 ng/ml), IL-3 (20 ng/ml), IL-6 (50 ng/ml), IL-11 (50 ng/ml), G-CSF (50 ng/ml) and EPO (10U), or 10 times lower concentrations of each cytokine. The ex vivo cultured were evaluated for the following cell populations: total nucleated cells, CD34+ cells, CD34+ CD38− cells, CFU-C, HPP-CFU, and LTC-IC. In all cases those combinations of cytokines containing either IL-3 and/or IL-6 yielded higher quantities of all the cellular populations studied. Those culture conditions having the fewest cytokines that yielded large quantities of total cells, CD34+ cells and/or CD34+ CD38− cells were subsequently examined after 14 days of culture for their long-term engrafting ability in the fetal sheep model for human hematopoiesis. Typically, after 14 days of ex vivo culture CD34+ cells fail to engraft long-term, therefore, all our cultures were maintained for at least this time frame. Based on these criteria, CD34+ cells cultured in the presence of the higher concentration of cytokines a, b d and f were examined. The cultured CD 34+ cells from all four cytokine combinations engraft and undergo multilineage differentiation in primary recipients (short-term engraftment) examined 63 days post-transplant. By contrast the secondary recipients (long-term engraftment) after 61 days post-transplant showed no engraftment from cells cultured in cytokine combinations a and f, very few human cells were found in secondary recipients engrafted with cells from cytokine concentration b, but cells cultured in cytokine combination d (SCF, Flt-3, TPO and IL-6) maintained their long-term engrafting ability and undergo multilineage differentiation. In conclusion, cytokine combinations of TPO and IL-6 with SCF and Flt-3 yielded successful long-term engraftment. The presence of IL-3 in any of there combinations supported excellent cellular proliferation and the increase in the various cell populations but failed to support engraftment. These studies suggest that it is possible to maintain/expand long-term engrafting CB stem cells after 14 days under clinically relevant culture conditions.


Blood ◽  
1997 ◽  
Vol 89 (3) ◽  
pp. 1089-1099 ◽  
Author(s):  
Andromachi Scaradavou ◽  
Luis Isola ◽  
Pablo Rubinstein ◽  
Yelena Galperin ◽  
Vesna Najfeld ◽  
...  

Abstract The purposes of the research reported here were first to explore a murine model for human placental and umbilical cord blood transplantation and second to evaluate the engraftment ability of ex vivo cultured hematopoietic cells. Murine near-term fetal and neonatal peripheral blood (FNPB) cells, genetically marked with the human multiple drug resistance transgene (MDR1) were used for syngeneic transplants into sublethally irradiated adult mice. Donor cells were transplanted either fresh and untreated, or after ex vivo culture in the presence of the hematopoietic growth factors recombinant murine stem cell factor, recombinant human interleukin-3 (rHu IL-3), and rHu IL-6, in a liquid culture system. To evaluate, count, and characterize FNPB progenitor cell-derived colonies, neonatal mouse mononuclear cells were cultured directly in methylcellulose with growth factors. To assess their ex vivo expansion ability, FNPB mononuclear cells were first cultured in liquid medium for 3 to 8 days and then transferred to semisolid assay plates. Evaluation of the cell counts after liquid culture showed a 1.4- to 11.6-fold increase, and the numbers of colonies observed in methylcellulose were similar to those produced by fresh FNPB cells. Donor-type engraftment was demonstrated by polymerase chain reaction (PCR) amplification of the human MDR1 transgene in the peripheral blood of all surviving animals (5 of 7 recipients of the fresh, and 3 of 8 recipients of the ex vivo–cultured cells) 2 to 4 months after transplantation. The proportion of donor leukocytes in the peripheral blood of the recipients (chimerism) was evaluated using fluorescence in situ hybridization (FISH) analysis 4 to 6 months after transplantation and ranged from 2% to 26%. In addition, bone marrow cultures were obtained from two recipient animals: one had received fresh-untreated cells and was evaluated 8 months after transplant, the other had received ex vivo cultured cells and was tested 14 months after grafting. The derived hematopoietic colonies were tested by PCR and the transgene was detected, conclusively proving long-term engraftment of donor cells. These results indicate that FNPB transplants can be successfully performed in sublethally irradiated mice with and without ex vivo culture. Long-term donor-type engraftment with sustained chimerism has been demonstrated. Thus, murine neonatal blood grafts can be used as an animal model for cord blood transplantation for gene therapy studies where complete myeloablation is not desirable and partial replacement of defective marrow may be sufficient. Furthermore, the possibility of numerically expanding hematopoietic progenitor cells contained in neonatal blood without affecting their engraftment ability could facilitate use of cord blood grafts in adult recipients.


Blood ◽  
2001 ◽  
Vol 97 (11) ◽  
pp. 3441-3449 ◽  
Author(s):  
Ian D. Lewis ◽  
Graca Almeida-Porada ◽  
Jingbo Du ◽  
Ihor R. Lemischka ◽  
Kateri A. Moore ◽  
...  

This report describes stroma-based and stroma-free cultures that maintain long-term engrafting hematopoietic cells for at least 14 days ex vivo. Umbilical cord blood (UCB) CD34+ cells were cultured in transwells above AFT024 feeders with fetal-liver-tyrosine-kinase (FL) + stem cell factor (SCF) + interleukin 7 (IL-7), or FL + thrombopoietin (Tpo). CD34+ progeny were transplanted into nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice or preimmune fetal sheep. SCID repopulating cells (SRC) with multilineage differentiation potential were maintained in FL-SCF-IL-7 or FL-Tpo containing cultures for up to 28 days. Marrow from mice highly engrafted with uncultured or expanded cells induced multilineage human hematopoiesis in 50% of secondary but not tertiary recipients. Day 7 expanded cells engrafted primary, secondary, and tertiary fetal sheep. Day 14 expanded cells, although engrafting primary and to a lesser degree secondary fetal sheep, failed to engraft tertiary recipients. SRC that can be transferred to secondary recipients were maintained for at least 14 days in medium containing glycosaminoglycans and cytokines found in stromal supernatants. This is the first demonstration that ex vivo culture in stroma-noncontact and stroma-free cultures maintains “long-term” engrafting cells, defined by their capacity to engraft secondary or tertiary hosts.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 170-170
Author(s):  
Stephanie Zhi-Juan Xie ◽  
Laura Garcia Prat ◽  
Veronique Voisin ◽  
Alex Murison ◽  
Olga I. Gan ◽  
...  

Abstract The hematopoietic stem cells (HSC) field has long been perplexed by how the blood system d (~10e12 cells produced daily) - yet hematologic malignancies remain relatively rare. The risk of malignancy is mitigated in part by a complex hierarchy in which the quiescent long-term hematopoietic stem cells (LT-HSC) with high self-renewal capacity undergo a restricted number of cell divisions. Nonetheless, such a high production demand over a lifetime raises an inherent risk of malignancy due to DNA replication errors, misfolded proteins and metabolic stress that cause cellular damage in HSC. Previously, HSC dormancy, largely thought to be controlled by transcription factor networks, was held responsible for preventing mutation acquisition. However, recent studies suggest that LT-HSC contain critical cellular networks centered around the coordination of distinct HSC metabolic programs with proteostasis, which serve as crucial decision nodes to balance persistence or culling of HSC for lifelong blood production. While HSC culling mechanisms are known, the linkage between cellular stress programs and the self-renewal properties that underlie human HSC persistence remains unknown. Here, we ask how this HSC fate choice is influenced by lipid biosynthesis - an underexplored area of HSC metabolism. We observed a distinct sphingolipid transcriptional signature in human HSC and examined the consequences of sphingolipid perturbation in human cord blood (CB) stem cells during ex vivo activation. DEGS1 (Delta 4-Desaturase, Sphingolipid 1) is the final enzyme in de novo sphingolipid synthesis, converting dihydroceramide (dhCer) to ceramide (Cer); ablation of DEGS1 either genetically or by treatment with the synthetic retinoid fenretinide/N-(4-hydroxyphenyl) retinamide (4HPR) is sufficient to activate autophagy in mouse cells and human cell lines. DEGS1 gene expression was higher in HSC than in progenitors and was significantly increased in LT-HSC following 6 hours of cytokine stimulation, suggesting that it plays a role in cellular activation. Sphingolipid composition was altered in CB cultured with 4HPR for 8 days with an increase in dhCer levels and decrease in Cer levels shown by lipidomics. Remarkably, 4HPR treatment significantly increased in vitro colony forming efficiency from LT-HSC (50% over control), but not from short-term HSC or granulocyte-macrophage progenitors. Ex vivo 4HPR treatment of CB followed by serial xenotransplantation resulted in a 2.5-fold increase in long-term repopulation cell (LTRC) frequency over control-treated cells, suggesting that 4HPR treatment affects HSC self-renewal. RNA-seq analysis showed that 4HPR activates a set of proteostatic quality control (QC) programs that coalesce around the unfolded protein response (UPR) and autophagy, the latter confirmed by immunofluorescence and flow cytometry in CB stem cells. Ex vivo culture perturbs these programs and results in loss of chromatin accessibility at sites associated with uncultured LT-HSC as determined by ATAC-Seq. Addition of 4HPR to the culture activates these proteostatic programs to sustain immunophenotypic and functional HSC. These results suggest that ceramide, the central component to all sphingolipids, may act as a "lipid biostat" for measuring cellular stress and activating stress responses. We further asked if 4HPR could synergize with known compounds to enhance HSC self-renewal. Treatment of CB with a combination of 4HPR plus CD34+ agonists UM171 and StemRegenin-1 during ex vivo culture maintains a chromatin state more similar to uncultured LT-HSC as demonstrated by ATAC-seq, and led to a 4-fold increase in serial repopulating ability in xenotransplant assays over treatment with UM171 and SR1 alone. These results suggest that sphingolipid perturbation not only activates proteostatic mechanisms that protect HSC organelles from damage incurred during cellular activation, but also regulates the landscape of chromatin accessibility in cultured HSC when combined with CD34+ agonists. This work identifies a new linkage between sphingolipid metabolism, proteostatic QC systems and HSC self-renewal, and identifies novel strategies by which to expand HSC numbers and improve HSC quality for clinical applications. Disclosures Takayama: Megakaryon co. Ltd.: Research Funding.


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