Editing a ?-globin repressor binding site restores fetal hemoglobin synthesis and corrects the sickle cell disease phenotype.

ABSTRACT: Sickle cell disease (SCD) is caused by a single amino acid change in the adult hemoglobin (Hb) ? chain that causes Hb polymerization and red blood cell (RBC) sickling. The co-inheritance of mutations causing fetal ?-globin production in adult life hereditary persistence of fetal Hb (HPFH) reduces the clinical severity of SCD. HPFH mutations in the HBG ?-globin promoters disrupt binding sites for the repressors BCL11A and LRF. We used CRISPR-Cas9 to mimic HPFH mutations in the HBG promoters by generating insertions and deletions, leading to disruption of known and putative repressor binding sites. Editing of the LRF-binding site in patient-derived hematopoietic stem/progenitor cells (HSPCs) resulted in ?-globin derepression and correction of the sickling phenotype. Xenotransplantation of HSPCs treated with gRNAs targeting the LRF-binding site showed a high editing efficiency in repopulating HSPCs. This study identifies the LRF-binding site as a potent target for genome-editing treatment of SCD.

SUBMITTER: Weber L 

PROVIDER: S-EPMC7015694 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature