scholarly journals Targeted, homology-driven gene insertion in stem cells by ZFN-loaded ‘all-in-one’ lentiviral vectors

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Yujia Cai ◽  
Anders Laustsen ◽  
Yan Zhou ◽  
Chenglong Sun ◽  
Mads Valdemar Anderson ◽  
...  

Biased integration remains a key challenge for gene therapy based on lentiviral vector technologies. Engineering of next-generation lentiviral vectors targeting safe genomic harbors for insertion is therefore of high relevance. In a previous paper (<xref ref-type="bibr" rid="bib2">Cai et al., 2014a</xref>), we showed the use of integrase-defective lentiviral vectors (IDLVs) as carriers of complete gene repair kits consisting of zinc-finger nuclease (ZFN) proteins and repair sequences, allowing gene correction by homologous recombination (HR). Here, we follow this strategy to engineer ZFN-loaded IDLVs that insert transgenes by a homology-driven mechanism into safe loci. This insertion mechanism is driven by time-restricted exposure of treated cells to ZFNs. We show targeted gene integration in human stem cells, including CD34+ hematopoietic progenitors and induced pluripotent stem cells (iPSCs). Notably, targeted insertions are identified in 89% of transduced iPSCs. Our findings demonstrate the applicability of nuclease-loaded ‘all-in-one’ IDLVs for site-directed gene insertion in stem cell-based gene therapies.

2021 ◽  
Vol 1 (1) ◽  
pp. 4-24
Author(s):  
Jun Ochiai ◽  
Yutaka Niihara ◽  
Joan Oliva

Cell and gene therapies have been developing dramatically over the past decade. To face and adapt to the development of these new therapies, the Food and Drug Administration (FDA) wrote and updated new guidelines from 2016 and keep updating them. Mesenchymal stem cells (MSCs) are the most used cells for treatment, far ahead from the induced pluripotent stem cells (iPSCs), based on registered clinical trials at clinicaltrials.gov. They are widely used because of their differentiation capacity and their anti-inflammatory properties, but some controversies still require clear answers. Additional studies are needed to determine the dosage, the number, and the route of injections (location and transplantation method), and if allogenic MSCs are safe compared to autologous MSC injection, including their long-term effect. In this review, we summarize the research our company is conducting with the adipose stromal cells in engineering cell sheets and their potential application.


Author(s):  
Andreia Gianotti Sommer ◽  
Sarah S. Rozelle ◽  
Spencer Sullivan ◽  
Jason A. Mills ◽  
Seon-Mi Park ◽  
...  

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 703-703
Author(s):  
Naoya Takayama ◽  
Shinji Hirata ◽  
Ryoko Jono-Ohnishi ◽  
Sou Nakamura ◽  
Sho-ichi Hirose ◽  
...  

Abstract Abstract 703 Patient-specific, induced pluripotent stem cells (iPSCs) enable us to study disease mechanisms and drug screening. To clarify the phenotypic alterations caused by the loss of c-MPL, the thrombopoietin (TPO) receptor, we established iPSCs derived from skin fibroblasts of a patient who received curative bone marrow transplantation for congenital amegakarycytic thrombocytopenia (CAMT) caused by the loss of the TPO receptor gene, MPL. The resultant CAMT-iPSCs exhibited mutations corresponding to the original donor skin. Then using an in vitro culture system yielding hematopoietic progenitor cells (HPCs), we evaluated the role of MPL on the early and late phases of human hematopoiesis. Although CAMT-iPSCs generated CD34+ HPCs, per se, their colony formation capability was impaired, as compared to control CD34+ HPCs. Intriguingly, both Glycophorin A (GPA)+ erythrocyte development and CD41+ megakaryocyte yields from CAMT-iPSCs were also impaired, suggesting that MPL is indispensable for MEP (megakaryocyte erythrocyte progenitors) development. Prospective analysis along with the hematopoietic hierarchy revealed that, in CAMT-iPSCs but not control iPSCs expressing MPL, mRNA expression and phosphorylation of putative signaling molecules downstream of MPL are severely impaired, as is the transition from CD34+CD43+CD41-GPA- MPP (multipotent progenitors) to CD41+GPA+ MEP. Additional analysis also indicated that c-MPL is required for maintenance of a consistent supply of megakaryocytes and erythrocytes from MEPs. Conversely, complimentary transduction of MPL into CAMT-iPSCs using a retroviral vector restored the defective erythropoiesis and megakaryopoiesis; however, excessive MPL signaling appears to promote aberrant megakaryopoiesis with CD42b (GPIba)-null platelet generation and impaired erythrocyte production. Taken together, our findings demonstrate the usefulness of CAMT-iPSCs for validation of functionality in the human hematopoiesis system. For example, it appears that MPL is not indispensable for the emergence of HPCs, but is indispensible for their maintenance, and for subsequent MEP development. Our results also strongly indicate that an appropriate expression level of an administered gene is necessary to achieve curative gene correction / therapy using patient-derived iPSCs. Disclosures: No relevant conflicts of interest to declare.


2015 ◽  
Vol 5 (4) ◽  
pp. 558-568 ◽  
Author(s):  
Tui Neri ◽  
Sharon Muggeo ◽  
Marianna Paulis ◽  
Maria Elena Caldana ◽  
Laura Crisafulli ◽  
...  

2016 ◽  
Vol 24 ◽  
pp. S139
Author(s):  
Brian Truong ◽  
Patrick C. Lee ◽  
Agustin Vega-Crespo ◽  
William B. Gilmore ◽  
Kip Hermann ◽  
...  

Author(s):  
Marita L. Rodriguez ◽  
Charles E. Murry ◽  
Nathan J. Sniadecki

Cardiovascular stem cell therapies have shown increasing promise as a potential therapeutic means for reversing the effects of a myocardial infarction [1]. Out of the currently available sources of human stem cells, human induced pluripotent stem cells (hiPSCs) are very promising in that: the number of cell lines that can be induced to the pluripotent state is extremely vast, they serve as a potential source for patient-specific cardiomyocytes, and their use is non-controversial. However, before they can be used feasibly in a clinical setting, the functional engraftment of these cells into the host tissue must be improved [2]. It is hypothesized that the structural and functional maturity of the stem-cell derived cardiomyocytes prior to implantation, may significantly affect the ability of these cells to engraft with resident heart tissue [3]. One of the most important functional characteristics of a cardiomyocyte is its ability to produce contractile forces. However, assessing the contractile properties of single iPS-CMs is a difficult task. iPS-CMs generally have relatively unorganized cytoskeletons, with stress fibers in multiple directions. This trait renders one or two-point force assays ineffectual in determining total cell forces. Furthermore, iPS-CMs don’t spread well on tissue culture surfaces, which make two-dimensional force measurements almost impossible.


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