scholarly journals Cell and Gene Therapy for Anemia: Hematopoietic Stem Cells and Gene Editing

2021 ◽  
Vol 22 (12) ◽  
pp. 6275
Author(s):  
Dito Anurogo ◽  
Nova Yuli Prasetyo Budi ◽  
Mai-Huong Thi Ngo ◽  
Yen-Hua Huang ◽  
Jeanne Adiwinata Pawitan

Hereditary anemia has various manifestations, such as sickle cell disease (SCD), Fanconi anemia, glucose-6-phosphate dehydrogenase deficiency (G6PDD), and thalassemia. The available management strategies for these disorders are still unsatisfactory and do not eliminate the main causes. As genetic aberrations are the main causes of all forms of hereditary anemia, the optimal approach involves repairing the defective gene, possibly through the transplantation of normal hematopoietic stem cells (HSCs) from a normal matching donor or through gene therapy approaches (either in vivo or ex vivo) to correct the patient’s HSCs. To clearly illustrate the importance of cell and gene therapy in hereditary anemia, this paper provides a review of the genetic aberration, epidemiology, clinical features, current management, and cell and gene therapy endeavors related to SCD, thalassemia, Fanconi anemia, and G6PDD. Moreover, we expound the future research direction of HSC derivation from induced pluripotent stem cells (iPSCs), strategies to edit HSCs, gene therapy risk mitigation, and their clinical perspectives. In conclusion, gene-corrected hematopoietic stem cell transplantation has promising outcomes for SCD, Fanconi anemia, and thalassemia, and it may overcome the limitation of the source of allogenic bone marrow transplantation.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2358-2358
Author(s):  
Ali Nowrouzi ◽  
Africa Gonzales-Murillo ◽  
Anna Paruzynski ◽  
Ariana Jacome ◽  
Paula Rio ◽  
...  

Abstract Improved protocols using lentiviral vectors have been established with minimal cytokine exposure and short transduction times proving more suitable for overcoming the disease-specific challenge in correcting functionally defective hematopoietic stem cells (HSCs) of Fanconi Anemia (FA) patients. Bone marrow (BM) cells from FA patients were transduced ex vivo with lentiviral vectors (LVs) expressing FANCA and/or EGFP using optimized conditions to preserve the repopulating properties of the primitive hematopoietic stem cells (manuscript submitted). In a forward preclinical screening of possible LV-induced side effects we analyzed the insertional inventory in colonies generated by FA BM cells previously transduced with the LVs. We have established and optimized DNA and RNA isolation procedures for minimal cell numbers, suitable for large scale screening of colony forming cell (CFC) derived colonies by linear amplification-mediated PCR (LAM-PCR) and massive parallel pyrosequencing (454 GS Flx system; Roche). This approach is applicable for detecting early indicators of clonal selection, and is based on the analysis of common integration sites (CIS) and non-random distribution of vector insertions in particular genomic loci. From a total of 180 CFC-derived colonies expressing the EGFP LV marker gene, 298 vector insertions could be sequenced and mapped to the human genome. The analysis of vector targeted gene coding regions showed a non-random genomic distribution of LV insertions, with a significant overrepresentation of RefSeq genes that are part of distinct functional categories. Accordingly vector associated genes are predominantly involved in cellular signal cascades regulated by the MAP Kinase family known to be involved in a wide variety of cellular processes such as proliferation, differentiation, transcription regulation and development. Apart from the observed high integration frequency in genes (>80%), partial loss of vector LTR nucleotides was detected in >10% of the integrants (3–25bp). Notably, >20% of the lentiviral insertions were found to be located in CIS of predominantly 2nd order. Further screening assays of LV transduced CFC-derived colonies will allow a deeper investigation in the functional consequences of such CIS targeting in gene therapy protocols of FA. However our results suggest that the LV transduction of FA BM progenitors leads to a relatively high frequency of insertions in CIS which may be indicative of an insertion based (specific) selection mechanism. We herby show that the ex vivo large scale integration site analyses of CFC-derived colonies from patients considered to undergo gene therapeutic treatments constitutes a robust approach, which combined with mouse preclinical biosafety studies will help to improve the safety of clinical gene therapy protocols. The non-random distribution of LV integrations in CIS associated genes and in genes involved in particular cellular pathways may be indicative for the altered biochemical pathways characteristic of FA stem cells, with reported defects in DNA repair and self-renewal.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2590-2590
Author(s):  
Christopher C. Porter ◽  
James DeGregori

Abstract Inefficient transduction, poor long term expression, and engraftment failure of ex vivo manipulated cells have slowed the practical advancement of gene therapy trials. Thus, the ability to select for or amplify a population of cells that has been modified to express a gene of interest might enhance the effectiveness of gene therapy. Strategies for in vivo expansion of genetically modified cells that have been studied to date have relatively high toxicity or low efficacy in selection of hematopoietic stem cells. We hypothesized that resistance to the purine analog 6-thioguanine (6TG) could be programmed via lentiviruses, and that treatment with 6TG would allow for selection of genetically modified cells in vitro and in vivo. Using short hairpin RNAs, we achieved efficient knockdown of hypoxanthine phosphoribosyl transferase (HPRTkd), the enzyme required for 6TG cytotoxicity, in the murine hematopoietic progenitor cell line FL5.12. In so doing we were able to provide Fl5.12 cells with resistance to 6TG. In the presence of 6TG, HPRTkd cells continued to proliferate for at least 30 days, whereas control transduced cells ceased proliferating after 7-10 days. 6TG treatment of mixed cultures of GFP+-HPRTkd cells and untransduced cells resulted in selective outgrowth of HPRTkd cells. Knockdown of HPRT in FL5.12 cells was found to attenuate the checkpoint activation, cell cycle arrest and apoptosis seen in control transduced cells when treated with 6TG. Knockdown of HPRT in murine primary hematopoietic cells also allowed for selection of transduced cells with 6TG ex vivo. Furthermore, and most importantly, after transduction of whole bone marrow and transplantation into sub-lethally irradiated recipient mice, a single, short course of treatment with 6TG resulted in up to 12 fold greater percentages of circulating transduced granulocytes as compared to untreated controls. These results suggest that genetically modified hematopoietic stem cells can be selected in vivo using 6TG. This strategy may be useful for therapy of a variety of hematopoietic diseases, particularly those that affect hematopoietic progenitors. The benefits of this strategy include the following: 1) the use of a lentivirus with a self inactivating long terminal repeat, 2) a very short cassette encoding drug resistance, making the vector easier to manipulate, and 3) a very well tolerated and relatively non-toxic medication for selection.


Blood ◽  
2008 ◽  
Vol 112 (13) ◽  
pp. 4853-4861 ◽  
Author(s):  
Paula Río ◽  
Néstor W. Meza ◽  
África González-Murillo ◽  
Susana Navarro ◽  
Lara Álvarez ◽  
...  

AbstractFanconi anemia (FA) is an inherited recessive DNA repair disorder mainly characterized by bone marrow failure and cancer predisposition. Studies in mosaic FA patients have shown that reversion of one inherited germ-line mutation resulting in a functional allele in one or a few hematopoietic stem cells (HSCs) can lead to the proliferation advantage of corrected cells, thus over time normalizing the hematologic status of the patient. In contrast to these observations, it is still unclear whether ex vivo genetic correction of FA HSCs also provides a similar proliferation advantage to FA HSCs. Using an FA mouse model with a marked hematopoietic phenotype, the FA-D1 (Brca2Δ27/Δ27) mice, we demonstrate that the lentivirus-mediated gene therapy of FA HSCs results in the progressive expansion of genetically corrected clones in mild-conditioned FA-D1 recipients. Consistent with these data, hematopoietic progenitors from FA recipients progressively became mitomycin C resistant and their chromosomal instability was reverted. No evidence of myelodysplasia, leukemias, or abnormal clonal repopulation was observed at multiple time points in primary or secondary recipients. Our results demonstrate that ectopic expression of BRCA2 confers a beneficial in vivo proliferation advantage to FA-D1 HSCs that enables the full hematopoietic repopulation of FA recipients with genetically corrected 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.


Blood ◽  
2012 ◽  
Vol 119 (1) ◽  
pp. 83-94 ◽  
Author(s):  
Terumasa Umemoto ◽  
Masayuki Yamato ◽  
Jun Ishihara ◽  
Yoshiko Shiratsuchi ◽  
Mika Utsumi ◽  
...  

AbstractThroughout life, one's blood supply depends on sustained division of hematopoietic stem cells (HSCs) for self-renewal and differentiation. Within the bone marrow microenvironment, an adhesion-dependent or -independent niche system regulates HSC function. Here we show that a novel adhesion-dependent mechanism via integrin-β3 signaling contributes to HSC maintenance. Specific ligation of β3-integrin on HSCs using an antibody or extracellular matrix protein prevented loss of long-term repopulating (LTR) activity during ex vivo culture. The actions required activation of αvβ3-integrin “inside-out” signaling, which is dependent on thrombopoietin (TPO), an essential cytokine for activation of dormant HSCs. Subsequent “outside-in” signaling via phosphorylation of Tyr747 in the β3-subunit cytoplasmic domain was indispensable for TPO-dependent, but not stem cell factor-dependent, LTR activity in HSCs in vivo. This was accompanied with enhanced expression of Vps72, Mll1, and Runx1, 3 factors known to be critical for maintaining HSC activity. Thus, our findings demonstrate a mechanistic link between β3-integrin and TPO in HSCs, which may contribute to maintenance of LTR activity in vivo as well as during ex vivo culture.


1990 ◽  
Vol 171 (5) ◽  
pp. 1407-1418 ◽  
Author(s):  
G Keller ◽  
R Snodgrass

The findings reported in this study highlight several important features of the development of hematopoietic stem cells after transplantation into irradiated recipients. First, they demonstrate the existence of a class of primitive multipotential stem cells that can function for a significant portion of the lifetime of a mouse (15 mo). In addition, they clearly show that these primitive stem cells can be infected with recombinant retroviruses and thus would be appropriate targets for gene therapy in somatic tissues. Second, our data indicate that the progeny of some, but not all, of the primitive stem cells have fully expanded into the various hematopoietic lineages by 2 mo after reconstitution. Finally, our analysis of the secondary recipients provides strong evidence suggesting that the primitive stem cell population can actually clonally expand. Our current experiments are aimed at determining the extent to which this expansion can occur and whether or not this expansion can be influenced by exogenous factors.


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