Gene Editing for Inherited Red Blood Cell Diseases

Abstract

Today gene therapy is a real therapeutic option to address inherited hematological diseases that could be beneficial for thousands of patients worldwide. Currently, gene therapy is used to treat different monogenic hematological pathologies, including several red blood cell diseases such as β-thalassemia, sickle cell disease and pyruvate kinase deficiency. This approach is based on addition gene therapy, which consists of the correction of hematopoietic stem cells (HSCs) using lentiviral vectors, which integrate a corrected version of the altered gene. Lentivirally-corrected HSCs generate healthy cells that compensate for the deficiency caused by genetic mutations. Despite its successful results, this approach lacks both control of the integration of the transgene into the genome and endogenous regulation of the therapeutic gene, both of which are important aspects that might be a cause for concern. To overcome these limitations, gene editing is able to correct the altered gene through more precise and safer approaches. Cheap and easy-to-design gene editing tools, such as the CRISPR/Cas9 system, allow the specific correction of the altered gene without affecting the rest of the genome. Inherited erythroid diseases, such as thalassemia, sickle cell disease and Pyruvate Kinase Deficiency, have been the test bed for these gene editing strategies, and promising results are currently being seen. CRISPR/Cas9 system has been successfully used to manipulate globin regulation to re-activate fetal globin chains in adult red blood cells and to compensate for hemoglobin defects. Knock-in at the mutated locus to express the therapeutic gene under the endogenous gene regulatory region has also been accomplished successfully. Thanks to the lessons learned from previous lentiviral gene therapy research and trials, gene editing for red blood cell diseases is rapidly moving from its proof-of-concept to its first exciting results in the clinic. Indeed, patients suffering from β-thalassemia and sickle cell disease have already been successfully treated with gene editing, which will hopefully inspire the use of gene editing to cure erythroid disorders and many other inherited diseases in the near future.

Combined approaches for increasing fetal hemoglobin (HbF) and de novo production of adult hemoglobin (HbA) in erythroid cells from β-thalassemia patients: treatment with HbF inducers and CRISPR-Cas9 based genome editing

“…As for other human pathologies and rare diseases, most of the new innovative approaches for developing protocols of possible interest for future treatments of β-thalassemias are focusing on personalized treatments on one hand, and precise targeting on the other. In order to reach these objectives, an exciting strategy recently proposed for β-thalassemia (and other genetic diseases) is genome editing of human hematopoietic stem and progenitor cells (HSPC) ( Boulad et al, 2018 ; Magrin et al, 2019 ; Ernst et al, 2020 ; Ali et al, 2021 ; Ferrari et al, 2021 ; Karamperis et al, 2021 ; Rosanwo and Bauer, 2021 ; Quintana-Bustamante et al, 2022 ; Eckrich and Frangoul, 2023 ; Khiabani et al, 2023 ). In this respect, the Clustered Regularly Interspaced Palindromic Repeats (CRISPR)-Cas9 nuclease system should be considered among the most studied gene editing strategies ( Dever et al, 2016 ; Hu, 2016 ; Lau, 2018 ; Papasavva et al, 2019 ).…”

Specific correction of pyruvate kinase deficiency-causing point mutations by CRISPR/Cas9 and single-stranded oligodeoxynucleotides

“…Despite the promising results of the PKD lentiviral gene therapy, the ideal gene therapy approach should be based on the specific correction of the mutated gene. Gene editing allows the specific correction of the affected gene with a very limited genotoxic effect and entails the elimination of the mutated protein, which can interfere with the function of the therapeutic protein (Quintana-Bustamante et al, 2022). Gene editing has changed the therapeutical landscape of inherited hematopoietic diseases, from promising preclinical data to its success in clinical trials, mainly for hemoglobinopathies, such as β-thalassemia and sickle cell disease.…”

“…Gene editing has changed the therapeutical landscape of inherited hematopoietic diseases, from promising preclinical data to its success in clinical trials, mainly for hemoglobinopathies, such as β-thalassemia and sickle cell disease. In this therapeutic option, patient's HSPCs are mobilized from their bone marrow niches to peripheral blood, purified, and ex vivo genetically modified, and then reinfused into the patient after being preconditioned to favor the engraftment of the gene edited cells (Quintana-Bustamante et al, 2022). Ex vivo gene editing of patient's HSPCs has been shown promising results to correct red blood cell diseases (Canver et al, 2015;Brendel et al, 2016;Dever et al, 2016;Hoban et al, 2016;Ye et al, 2016;Lux et al, 2019;Fañanas-Baquero et al, 2021;Lattanzi et al, 2021;Wilkinson et al, 2021) and others inherited hematopoietic disorders (De Ravin et al, 2016Pavel-Dinu et al, 2019;Román-Rodríguez et al, 2019;Schiroli et al, 2019;Ferrari et al, 2020;Rai et al, 2020) in preclinical research.…”