scholarly journals The Future of Gene Therapy for Transfusion-Dependent Beta-Thalassemia: The Power of the Lentiviral Vector for Genetically Modified Hematopoietic Stem Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Parin Rattananon ◽  
Usanarat Anurathapan ◽  
Kanit Bhukhai ◽  
Suradej Hongeng
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Lentiviral Vector ◽  
Globin Gene ◽  
Human Leukocyte ◽  
Premature Death ◽  
Beta Thalassemia ◽  
Erythroid Progenitors ◽  
Hematopoietic Stem ◽  
Globin Chains

β-thalassemia, a disease that results from defects in β-globin synthesis, leads to an imbalance of β- and α-globin chains and an excess of α chains. Defective erythroid maturation, ineffective erythropoiesis, and shortened red blood cell survival are commonly observed in most β-thalassemia patients. In severe cases, blood transfusion is considered as a mainstay therapy; however, regular blood transfusions result in chronic iron overload with life-threatening complications, e.g., endocrine dysfunction, cardiomyopathy, liver disease, and ultimately premature death. Therefore, transplantation of healthy hematopoietic stem cells (HSCs) is considered an alternative treatment. Patients with a compatible human leukocyte antigen (HLA) matched donor can be cured by allogeneic HSC transplantation. However, some recipients faced a high risk of morbidity/mortality due to graft versus host disease or graft failure, while a majority of patients do not have such HLA match-related donors. Currently, the infusion of autologous HSCs modified with a lentiviral vector expressing the β-globin gene into the erythroid progenitors of the patient is a promising approach to completely cure β-thalassemia. Here, we discuss a history of β-thalassemia treatments and limitations, in particular the development of β-globin lentiviral vectors, with emphasis on clinical applications and future perspectives in a new era of medicine.

scholarly journals Genetic Engineering in Hematopoietic Stem Cells for Gene Therapy of Hemoglobinopathies

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. SCI-23-SCI-23
Author(s):  
Giuliana Ferrari
Keyword(s):  
Stem Cells ◽  
Gene Therapy ◽  
Hematopoietic Stem Cells ◽  
Conflicts Of Interest ◽  
Globin Gene ◽  
Genetically Modify ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
Globin Genes ◽  
Hematopoietic Stem

Beta-thalassemia and sickle cell disease (SCD) are congenital anemias caused by mutations in the beta-globin gene, resulting in either reduced/absent production of globin chains or abnormal hemoglobin structure. At present, the definitive cure is represented by allogeneic hematopoietic stem cell transplantation, with a probability to find a well-matched donor of <25%. Experimental gene therapy for hemoglobinopathies is based on transplantation of autologous hematopoietic stem cells genetically modified to express therapeutic hemoglobin levels. Approaches to genetically modify HSCs for treatment of hemoglobinopathies include: 1) the addition of globin genes by lentiviral vectors and 2) gene editing by nucleases to reactivate fetal hemoglobin either through inhibition of repressors or by reproducing mutations associated with high fetal hemoglobin levels. The outcomes of early clinical trials are showing the safety and potential efficacy, as well as the hurdles still limiting a general application.Current challenges and improved strategies will be presented and discussed. Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Plerixafor

scholarly journals Beta thalassemia and role of herbals and hematopoietic stem cells in its remedy

2018 ◽  
Vol 6 (5) ◽  
Author(s):  
Pooja Rai ◽  
Kamal Uddin Zaidi ◽  
Vijay Thawani
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
High Efficiency ◽  
Genetic Disorders ◽  
Globin Gene ◽  
Fetal Hemoglobin ◽  
Beta Thalassemia ◽  
The Novel ◽  
Hematopoietic Stem ◽  
Drug Treatments

Genetic disorders caused by mutations in the β-globin gene are widely known as the human β-hemoglobinopathies, in which there is β-thalassemia. In recent years, effort has been made to identify the natural inducers and drug treatments which can increase the synthesis of fetal hemoglobin and promote the expression of fetal γ-globin gene. This review aims to reveal the novel screening platforms for identifying potential herbal inducers with high efficiency and accuracy and to describe the hematopoietic stem cells remedies to provide perspectives in fetal hemoglobin reactivation for treating β-thalassemia.

scholarly journals Gene Therapy: Where We Started and Where the Field Is Going

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. SCI-19-SCI-19
Author(s):  
Philip D. Gregory
Keyword(s):  
Stem Cells ◽  
Gene Therapy ◽  
Hematopoietic Stem Cells ◽  
Gene Editing ◽  
Lentiviral Vector ◽  
Globin Gene ◽  
Hematopoietic Stem ◽  
New Genes ◽  
Therapeutic Benefits ◽  
Hsc Transplantation

In the more than 20 years since the first successful gene transfer was performed in a human subject (Blaese, R.M. et al. Science 1995; 270, 475-480), the promise of gene therapy has been at once tantalizingly close and just out of reach. Today, gene-modified therapies are being used to treat a variety of diseases, and direct manipulation of the human genome for therapeutic effect is becoming a reality. While many advances in gene-based therapeutics have come in the oncology space, non-malignant hematologic and primary immune disorders remain important targets for these approaches. The ability to manipulate hematopoietic stem cells (HSCs) ex vivo and return the modified HSCs to the patient offers many potential advantages over allogeneic HSC transplantation. Additionally, the potential to introduce new genes with therapeutic potential, or to modify genes to modulate protein expression, may open new avenues for transformative therapies for genetic diseases. The progress of gene therapy for hemoglobinopathies - from the γ-retroviral vector technology that established the field, to the accumulating clinical experience with lentiviral vector-based gene therapy and the potential for gene editing-based approaches to address these diseases - provides insight into the development of genetic therapeutics. Transfusion-dependent β-thalassemia (TDT) and sickle cell disease (SCD) result from pathogenic mutations in the β-globin gene, HBB . Addition of functional HBB genes into autologous hematopoietic stem cells has the potential to offer the long-term therapeutic benefits of allogeneic HSC transplantation without the complications of graft vs host disease. The first human proof of concept of this approach came in a study of the HPV569 lentiviral vector coding for therapeutic β-globin, which was successfully introduced into the HSCs of patients with TDT and resulted in sustained clinical benefit in some patients (Cavazzana-Calvo et al., Nature 2010; 467(7313):318-22). Beyond restoring normal β-globin production, studies with HPV569 and its improved variant BB305, have shown that it is possible to drive expression of a β-globin variant with a point mutation, T87Q, designed to mimic the anti-sickling effect of γ-globin. This innovation may have important implications for patients with SCD, where introduction of normal β-globin may be insufficient to ameliorate the red blood cell sickling and polymerization that can cause painful and damaging vaso-occlusive crises. It has taken more than 20 years for HSC gene addition to reach safety and efficacy thresholds that may allow it to be used routinely for patients with hemoglobinopathies, but this approach is now nearing maturity. Important refinements in LVV architecture and advances in HBB gene cassette design have yielded promising results in multiple clinical studies of TDT and SCD (e.g. Ribeil J.A. et al., N Engl J Med 2017; 376:848-855). There is also significant excitement about the potential for gene editing approaches to address the hemoglobinopathies even as these technologies are just beginning to transition from lab to clinic. Critical questions of both efficacy and safety remain regarding the path forward for nuclease-based editing technologies such as CRISPR, ZFN, and megaTALs. Key lessons from the development of clinical gene addition therapies in the hemoglobinopathies may help chart the path forward for gene editing technologies. Disclosures Gregory: bluebirdbio: Employment; Merck KGaA: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Hematopoietic Stem Cells Are Endowed with Erythroid Signature in Beta-Thalassemia

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 31-31
Author(s):  
Maria Rosa Lidonnici ◽  
Giulia Chianella ◽  
Francesca Tiboni ◽  
Matteo Barcella ◽  
Ivan Merelli ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Gene Set Enrichment Analysis ◽  
Lineage Commitment ◽  
Erythroid Cell ◽  
Beta Thalassemia ◽  
Hematopoietic Stem ◽  
Multipotent Progenitors

Background Beta-thalassemia (Bthal) is a genetic disorder due to mutations in the ß-globin gene, leading to a reduced or absent production of HbA, which interferes with erythroid cell maturation and limits normal red cell production. Patients are affected by severe anemia, hepatosplenomegaly, and skeletal abnormalities due to rapid expansion of the erythroid compartment in bone marrow (BM) caused by ineffective erythropoiesis. In a classical view of hematopoiesis, the blood cell lineages arise via a hierarchical scheme starting with multipotent stem cells that become increasingly restricted in their differentiation potential through oligopotent and then unipotent progenitors. In human, novel purification strategies based on differential expression of CD49f and CD90 enrich for long-term (49f+) and short-term (49f−) repopulating hematopoietic stem cells (HSCs), with distinct cell cycle properties, but similar myeloid (My) and lymphoid (Ly) potential. In this view, it has been proposed that erythroid (Ery) and megakaryocytic (Mk) fates branch off directly from CD90-/49f− multipotent progenitors (MPPs). Recently, a new study suggested that separation between multipotent (Ery/My/Ly) long-term repopulating cells (Subset1, defined as CLEC9AhighCD34low) and cells with only My/Ly and no Ery potential (Subset2, defined as CLEC9AlowCD34high)occurs within the phenotypic HSC/MPP and CD49f+ HSCs compartment. Aims A general perturbed and stress condition is present in the thalassemic BM microenvironment. Since its impact on the hematopoietic cell subpopulations is mostly unknown, we will investigate which model of hematopoiesis/erythropoiesis occurs in Bthal. Moreover, since Beta-Thalassemia is an erythropoietic disorder, it could be considered as a disease model to study the 'erythroid branching' in the hematopoietic hierarchy. Methods We defined by immunophenotype and functional analysis the lineage commitment of most primitive HSC/MPP cells in patients affected by this pathology compared to healthy donors (HDs). Furthermore, in order to delineate the transcriptional networks governing hematopoiesis in Beta-thalassemia, RNAseq analysis was performed on sorted hematopoietic subpopulations from BM of Bthal patients and HDs. By droplet digital PCR on RNA purified from mesenchymal stromal cells of Bthal patients, we evaluated the expression levels of some niche factors involved in the regulation of hematopoiesis and erythropoiesis. Moreover, the protein levels in the BM plasma were analyzed by performing ELISA. Results Differences in the primitive compartment were observed with an increased proportion of multipotent progenitors in Bthal patients compared to HDs. The Subset1 compartment is actually endowed with an enhanced Ery potential. Focusing on progenitors (CD34+ CD38+) and using a new sorting scheme that efficiently resolved My, Ery, and Mk lineage fates, we quantified the new My (CD71-BAH1-/+) and Ery (CD71+ BAH1-/+) subsets and found a reduction of Ery subset in Bthal samples. We can hypothesize that the erythroid-enriched subsets are more prone to differentiate quickly due to the higher sensitivity to Epo stimuli or other bone marrow niche signals. Gene set enrichment analysis, perfomed on RNAseq data, showed that Bthal HSC/MPP presented negative enrichment of several pathways related to stemness and quiescence. Cellular processes involved in erythropoiesis were found altered in Bthal HSC. Moreover, some master erythroid transcription factors involved were overrepresented in Bthal across the hematopoietic cascade. We identified the niche factors which affect molecular pathways and the lineage commitment of Bthal HSCs. Summary/Conclusions Overall, these data indicate that Bthal HSCs are more cycling cells which egress from the quiescent state probably towards an erythroid differentiation, probably in response to a chronic BM stimulation. On the other hand,some evidences support our hypothesis of an 'erythroid branching' already present in the HSC pool, exacerbated by the pathophysiology of the disease. Disclosures No relevant conflicts of interest to declare.

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