scholarly journals Hematopoietic Stem Cell and Gene Therapy Corrects Primary Neuropathology and Behavior in Mucopolysaccharidosis IIIA Mice

2012 ◽  
Vol 20 (8) ◽  
pp. 1610-1621 ◽  
Author(s):  
Alexander Langford-Smith ◽  
Fiona L Wilkinson ◽  
Kia J Langford-Smith ◽  
Rebecca J Holley ◽  
Ana Sergijenko ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Hematopoietic Stem ◽  
Cell And Gene Therapy ◽  
And Behavior

Hematopoietic Stem Cell Expansion, without Exhaustion or Transformation, by Stable Microrna Antagonism in Vivo

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 30-30
Author(s):  
Bernhard Gentner ◽  
Alice Giustacchini ◽  
Eric Lechman ◽  
Peter van Galen ◽  
Francesco Boccalatte ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Stem Cell ◽  
Steady State ◽  
Hematopoietic Stem Cell ◽  
Pi3k Pathway ◽  
Cellular Functions ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Cell And Gene Therapy

Abstract Abstract 30 The precise mechanisms controlling hematopoietic stem cell (HSC) quiescence, self renewal and differentiation remain incompletely understood, and HSC expansion remains a long sought after goal for cell- and gene therapy. Genetic manipulation of single transcription factors and signal transduction pathways has so far failed to provide sustained HSC expansion, often resulting in stem cell exhaustion or the emergence of malignancy. MicroRNAs (miRNAs) post-transcriptionally regulate multiple genes in a coordinated fashion, making them attractive targets to manipulate signaling networks and complex cellular functions. We have systematically manipulated miR-126, a miRNA enriched in the primitive hematopoietic compartment, in mouse and human HSC by stably knocking down its activity with a sponge lentiviral vector (126/KD LV) or forcing its overexpression by a 126/OE LV. Hematochimeric mice were generated by transplanting 126/OE LV- or 126/KD LV- transduced progenitors into congenic mice (murine HSC) or NSG mice (human HSC), and the effects of altered miR-126 levels on hematopoiesis were investigated in vivo. Steady state hematopoiesis was comparatively normal, with no alterations in complete blood cell counts except a minor skewing towards or against lymphopoiesis upon 126/OE or 126/KD, respectively. Strikingly, under stress conditions such as 5-fluorouracil exposure, secondary transplantation or the NSG xenograft environment, 126/OE resulted in a progressive loss of HSC, while 126/KD increased HSC numbers as measured by immunophenotype and functional output upon competitive transplantation into secondary recipients. Limiting dilution analysis confirmed a 3–4 fold expansion of mouse and human HSC upon miR-126/KD, and the competitive advantage of 126/KD HSC was maintained long-term including post tertiary transplantation. To study the mechanism by which miR-126 regulates HSC numbers, cell cycle analysis was performed on 126/KD- or 126/OE progenitors isolated from steady state bone marrow. Human CD34+CD38-CD90+ and murine Lineage-Kit+Sca+CD150+ HSC were shifted towards the S/G2/M or the G0 phase upon 126/KD or 126/OE, respectively, indicating that miR-126 antagonism increased cycling while excessive levels of miR-126 favoured HSC quiescence within the niche microenvironment. Interestingly, this effect was highly specific for HSC and the most primitive progenitors. An in vitro culture model of HSC-enriched cord blood cells was set up to study the molecular basis of miR-126 mediated control of HSC cycling. This model reproduced key aspects of the HSC phenotype observed in vivo, i.e. increased or decreased proliferation of primitive progenitors upon 126/KD or 126/OE, respectively. Transcriptome analysis indicated that miR-126 manipulation altered several cellular functions and pathways, most significantly the PI3K/AKT/GSK3β signalling axis. We confirmed PIK3R2 and CRKII as direct miR-126 targets in CB CD34+38- cells and show enhanced PI3K pathway activation as reflected by increased AKT and GSK3β phosphorylation upon 126/KD, while 126/OE caused opposite effects. Pharmacologic inhibition of the beta subunit of PI3K abrogated the 126/KD phenotype, indicating that miR-126 mainly acts through the PI3K pathway. In contrast to published studies showing HSC expansion upon hyperactivation of the PI3K pathway using various genetic approaches, miR-126/KD did not cause HSC exhaustion or leukemogenesis. On the contrary, evidence will be provided that 126/OE is oncogenic in hematopoietic cells. Thus, miR-126 represents a principle target for HSC expansion for cell and gene therapy applications. In summary, we propose that in vivo HSC pool size is influenced by endogenous levels of miR-126 through modulation of the HSC quiescence/proliferation equilibrium. Disclosures: No relevant conflicts of interest to declare.

Long-term hematopoietic stem cell gene therapy corrects neuromuscular manifestations in preclinical study of Pompe mice

2021 ◽  
Vol 132 (2) ◽  
pp. S107
Author(s):  
Niek P. van Til ◽  
Yildirim Dogan ◽  
Cecilia Barese ◽  
Zeenath Unnisa ◽  
Swaroopa Guda ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Preclinical Study ◽  
Hematopoietic Stem ◽  
Cell Gene ◽  
Stem Cell Gene ◽  
Stem Cell Gene Therapy

Sickle Cell Disease Hematopoietic Stem Cell gene therapy with globin gene addition is promising

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Gene Therapy ◽  
Stem Cell ◽  
Sickle Cell Disease ◽  
Hematopoietic Stem Cell ◽  
Sickle Cell ◽  
Globin Gene ◽  
Autologous Transplantation ◽  
Gene Repair ◽  
Cell Disease ◽  
Hematopoietic Stem

Autologous transplantation of gene-modified HSCs might be used to treat Sickle Cell Disease (SCD) once and for all. Hematopoietic Stem Cell (HSC) gene therapy with lentiviral-globin gene addition was optimized by HSC collection, vector constructs, lentiviral transduction, and conditioning in the current gene therapy experiment for SCD, resulting in higher gene marking and phenotypic correction. Further advancements over the next decade should allow for a widely approved gene-addition therapy. Long-term engraftment is crucial for gene-corrected CD34+ HSCs, which might be addressed in the coming years, and gene repair of the SCD mutation in the-globin gene can be achieved in vitro using genome editing in CD34+ cells. Because of breakthroughs in efficacy, safety, and delivery strategies, in vivo gene addition and gene correction in BM HSCs is advancing. Overall, further research is needed, but HSC-targeted gene addition/gene editing therapy is a promising SCD therapy with curative potential that might be widely available soon.

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