Efficient CRISPR-Cas9-based genome editing of β-globin gene on erythroid cells from homozygous β039-thalassemia patients (original) (raw)

Co-Treatment of Erythroid Cells from β-Thalassemia Patients with CRISPR-Cas9-Based β039-Globin Gene Editing and Induction of Fetal Hemoglobin

Genes

Gene editing (GE) is an efficient strategy for correcting genetic mutations in monogenic hereditary diseases, including β-thalassemia. We have elsewhere reported that CRISPR-Cas9-based gene editing can be employed for the efficient correction of the β039-thalassemia mutation. On the other hand, robust evidence demonstrates that the increased production of fetal hemoglobin (HbF) can be beneficial for patients with β-thalassemia. The aim of our study was to verify whether the de novo production of adult hemoglobin (HbA) using CRISPR-Cas9 gene editing can be combined with HbF induction protocols. The gene editing of the β039-globin mutation was obtained using a CRISPR-Cas9-based experimental strategy; the correction of the gene sequence and the transcription of the corrected gene were analyzed by allele-specific droplet digital PCR and RT-qPCR, respectively; the relative content of HbA and HbF was studied by high-performance liquid chromatography (HPLC) and Western blotting. For HbF in...

Genetic correction of haemoglobin E in an immortalised haemoglobin E/beta-thalassaemia cell line using the CRISPR/Cas9 system

Scientific Reports

β-thalassaemia is one of the most common genetic blood diseases worldwide with over 300 mutations in the HBB gene affecting red blood cell functions. Recently, advances in genome editing technology have provided a powerful tool for precise genetic correction. Generation of patient-derived induced pluripotent stem cells (iPSCs) followed by genetic correction of HBB mutations and differentiation into haematopoietic stem/progenitor cells (HSPCs) offers a potential therapy to cure the disease. However, the biggest challenge is to generate functional HSPCs that are capable of self-renewal and transplantable. In addition, functional analyses of iPSC-derived erythroid cells are hampered by poor erythroid expansion and incomplete erythroid differentiation. Previously, we generated an immortalised erythroid cell line (SiBBE) with unique properties, including unlimited expansion and the ability to differentiate into mature erythrocytes. In this study, we report a highly efficient genetic corr...

Advances in genome editing: the technology of choice for precise and efficient β-thalassemia treatment

Gene Therapy, 2020

Beta (β)-thalassemia is one of the most significant hemoglobinopathy worldwide. The high prevalence of the β-thalassemia carriers aggravates the disease burden for patients and national economies in the developing world. The survival of βthalassemia patients solely relies on repeated transfusions, which eventually results into multi-organ damage. The fetal γglobin genes are ordinarily silenced at birth and replaced by the adult β-globin genes. However, mutations that cause lifelong persistence of fetal γ-globin, ameliorate the debilitating effects of β-globin mutations. Therefore, therapeutically reactivating the fetal γ-globin gene is a prime focus of researchers. CRISPR/Cas9 is the most common approach to correct disease causative mutations or to enhance or disrupt the expression of proteins to mitigate the effects of the disease. CRISPR/cas9 and prime gene editing to correct mutations in hematopoietic stem cells of β-thalassemia patients has been considered a novel therapeutic approach for effective hemoglobin production. However, genome-editing technologies, along with all advantages, have shown some disadvantages due to either random insertions or deletions at the target site of edition or nonspecific targeting in genome. Therefore, the focus of this review is to compare pros and cons of these editing technologies and to elaborate the retrospective scope of gene therapy for β-thalassemia patients. Clinical implications and disease manifestations of thalassemia The hemoglobinopathies is a term used to describe as a group of disorder and diseases that affect red blood cells. A common hemoglobinopathy, thalassemia a globin gene

Generation of an in vitro model of β‐thalassemia using the CRISPR/Cas9 genome editing system

Journal of Cellular Biochemistry, 2019

β-Thalassemia is a common monogenic disease characterized by defective β-globin chains synthesis. In vitro β-thalassemia-related research on increasing β-like globin genes or identification of factors reducing the severity of the disease, has been performed on mouse erythroleukaemia or K562 cell lines. The aim of this study was the production of an in vitro model of β-thalassemia using the highly efficient CRISPR-Cas9 system. Embryonic stem (ES) cells were nucleofected with guide RNA (gRNA)-Cas9 expression vectors. Molecular testing was done on extracted DNA to assess Hbb-b1 mutation. Analysis of transcription factors and hemoglobin genes were evaluated using quantitative reverse transcription-polymerase chain reaction following erythroid differentiation of ES cells. Sequencing data confirmed Hbb-b1 knockout alleles. Significant expression of erythroid transcription factors was observed in wild-type, Hbb-b1 +/− and Hbb-b1 −/− groups (P < .001). Compared with the wild-type group, the absolute number of Hbb-b1 mRNA in Hbb-b1 +/− group significantly decreased from 6.44 × 10 6 to 3.23 × 10 6 copy number (P < .01), whereas in Hbb-b1 −/− group had zero expression. The CRISPR/Cas9-mediated Hbb-b1 knockout in ES cells provides accessibility to an in vitro thalassemia model following erythroid differentiation. Considering the need for in vitro and mouse models to investigate the molecular basis of β-thalassemia which also enables testing of therapeutic approaches, this method can be utilized to produce a mouse model of β-thalassemia intermedia (Hbbth1/th1).

Correction of Hemoglobin E/Beta-Thalassemia Patient-Derived iPSCs Using CRISPR/Cas9

Methods in molecular biology, 2021

HbE/β-thalassemia is one of the most common thalassemic syndromes in Southeast Asia and Thailand. Patients have mutations in β hemoglobin (HBB) gene resulting in decreased and/or abnormal production of β hemoglobin. Here, we describe a protocol for CRISPR/Cas9-mediated gene correction of the mutated hemoglobin E from one allele of the HBB gene by homology-directed repair (HDR) in HbE/β-thalassemia patient-derived induced pluripotent stem cells (iPSCs) using a CRISPR/Cas9 plasmid-based transfection method and a single-stranded DNA oligonucleotide (ssODN) repair template harboring the correct nucleotides. Our strategy allows the seamless HbE gene correction with the editing efficiency (HDR) up to 3%, as confirmed by Sanger sequencing. This protocol provides a simple one-step genetic correction of HbE mutation in the patient-derived iPSCs. Further differentiation of the corrected iPSCs into hematopoietic stem/progenitor cells will provide an alternative renewable source of cells for th...

CRISPR-Cas9 Gene Editing for Sickle Cell Disease and β-Thalassemia

New England Journal of Medicine, 2021

Transfusion-dependent β-thalassemia (TDT) and sickle cell disease (SCD) are severe monogenic diseases with severe and potentially life-threatening manifestations. BCL11A is a transcription factor that represses γ-globin expression and fetal hemoglobin in erythroid cells. We performed electroporation of CD34+ hematopoietic stem and progenitor cells obtained from healthy donors, with CRISPR-Cas9 targeting the BCL11A erythroid-specific enhancer. Approximately 80% of the alleles at this locus were modified, with no evidence of off-target editing. After undergoing myeloablation, two patients-one with TDT and the other with SCD-received autologous CD34+ cells edited with CRISPR-Cas9 targeting the same BCL11A enhancer. More than a year later, both patients had high levels of allelic editing in bone marrow and blood, increases in fetal hemoglobin that were distributed pancellularly, transfusion independence, and (in the patient with SCD) elimination of vaso-occlusive episodes. (Funded by CRISPR Therapeutics and Vertex Pharmaceuticals; ClinicalTrials.gov numbers, NCT03655678 for CLIMB THAL-111 and NCT03745287 for CLIMB SCD-121.) T ransfusion-dependent β-thalassemia (TDT) and sickle cell disease (SCD) are the most common monogenic diseases worldwide, with an annual diagnosis in approximately 60,000 patients with TDT and 300,000 patients with SCD. 1-3 Both diseases are caused by mutations in the hemoglobin β subunit gene (HBB). Mutations in HBB that cause TDT 4 result in reduced (β +) or absent (β 0) β-globin synthesis and an imbalance between the α-like and β-like globin (e.g., β, γ, and δ) chains of hemoglobin, which causes ineffective erythropoiesis. 5,6 Sickle hemoglobin is the result of a point mutation in HBB that replaces glutamic acid with valine at amino acid position 6. Polymerization of deoxygenated sickle hemoglobin causes erythrocyte deformation, hemolysis, anemia, painful vaso-occlusive episodes, irreversible end-organ damage, and a reduced life expectancy. 5 Treatment options primarily consist of transfusion and iron chelation in patients with TDT 7 and pain management, transfusion, and hydroxyurea in those with SCD. 8 Recently approved therapies, including luspatercept 9 and crizanlizumab, 10 have reduced transfusion requirements in patients with TDT and the incidence of vaso-occlusive episodes in those with SCD, respectively, but neither treatment addresses the underlying cause of the disease nor fully ameliorates disease manifestations. Allogeneic bone marrow transplantation can cure both TDT and