Induction of fetal hemoglobin synthesis by CRISPR/Cas9-mediated editing of the human β-globin locus.
Antoniani C, Meneghini V, Lattanzi A, Felix T, Romano O, Magrin E, Weber L, Pavani G, El Hoss S, Kurita R, Nakamura Y, Cradick TJ, Lundberg AS, Porteus M, Amendola M, El Nemer W, Cavazzana M, Mavilio F, Miccio A.
2019 May 14
Naturally occurring, large deletions in the β-globin locus result in hereditary persistence of fetal hemoglobin, a condition that mitigates the clinical severity of sickle cell disease (SCD) and β-thalassemia. We designed a clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) (CRISPR/Cas9) strategy to disrupt a 13.6-kb genomic region encompassing the δ- and β-globin genes and a putative γ-δ intergenic fetal hemoglobin (HbF) silencer. Disruption of just the putative HbF silencer results in a mild increase in γ-globin expression, whereas deletion or inversion of a 13.6-kb region causes a robust reactivation of HbF synthesis in adult erythroblasts that is associated with epigenetic modifications and changes in chromatin contacts within the β-globin locus. In primary SCD patient-derived hematopoietic stem/progenitor cells, targeting the 13.6-kb region results in a high proportion of γ-globin expression in erythroblasts, increased HbF synthesis, and amelioration of the sickling cell phenotype. Overall, this study provides clues for a potential CRISPR/Cas9 genome editing approach to the therapy of β-hemoglobinopathies.