Development of gene therapy approaches to beta-hemoglobinopathies

Mégane Brusson (Institut Imagine, Paris)

04 avril 2024


Infos pratiques

12:00 - 13:00
Salle Rosalind Franklin
Accès mobilité réduite

Sickle cell disease (SCD) is due to a mutation in the β-globin gene causing production of the toxic sickle hemoglobin (HbS; α2βS2). Transplantation of autologous hematopoietic stem and progenitor cells (HSPCs) transduced with lentiviral vectors (LVs) expressing an anti-sickling β-globin (βAS) is a promising treatment; however, it is only partially effective, and patients still present elevated HbS levels. Here, we developed a bifunctional LV expressing βAS3-globin and an artificial microRNA (amiRNA) specifically downregulating βS-globin expression with the aim of reducing HbS levels and favoring βAS3 incorporation into Hb tetramers. Efficient transduction of SCD HSPCs by the bifunctional LV led to a substantial decrease of βS-globin transcripts in HSPC-derived erythroid cells, a significant reduction of HbS+ red cells, and effective correction of the sickling phenotype, outperforming βAS gene addition and BCL11A gene silencing strategies. The bifunctional LV showed a standard integration profile, and neither HSPC viability, engraftment, and multilineage differentiation nor the erythroid transcriptome and miRNAome were affected by the treatment, confirming the safety of this therapeutic strategy. In conclusion, the combination of gene addition and gene silencing strategies can improve the efficacy of current LV-based therapeutic approaches without increasing the mutagenic vector load, thus representing a novel treatment for SCD.

Invited by Suzanne Faure-Dupuy, Alberto De la Iglesia and Hugo Barreto, as part of the Post-doc seminar series.

Selected publications

  • Brusson M, Chalumeau A, Martinucci P, et al. Novel lentiviral vectors for gene therapy of sickle cell disease combining gene addition and gene silencing strategies. Mol Ther Nucleic Acids. 2023;32:229-246. doi:10.1016/j.omtn.2023.03.012
  • Pedrazzoli E, Bianchi A, Umbach A, Amistadi S, Brusson M, Frati G, Ciciani M, Badowska KA, Arosio D, Miccio A, Cereseto A, Casini A. An optimized SpCas9 high-fidelity variant for direct protein delivery. Mol Ther. 2023 Jul 5;31(7):2257-2265. doi: 10.1016/j.ymthe.2023.03.007.
  • Antoniou P, Hardouin G, Martinucci P, Frati G, Felix T, Chalumeau A, Fontana L, Martin J, Masson C, Brusson M, Maule G, Rosello M, Giovannangeli C, Abramowski V, de Villartay JP, Concordet JP, Del Bene F, El Nemer W, Amendola M, Cavazzana M, Cereseto A, Romano O, Miccio A. Base-editing-mediated dissection of a γ-globin cis-regulatory element for the therapeutic reactivation of fetal hemoglobin expression. Nat Commun. 2022 Nov 4;13(1):6618. doi: 10.1038/s41467-022-34493-1.
  • Antoniou P, Miccio A, Brusson M. Base and Prime Editing Technologies for Blood Disorders. Front Genome Ed. 2021 Jan 28;3:618406. doi: 10.3389/fgeed.2021.618406.
  • Amendola M, Brusson M, Miccio A. CRISPRthripsis: The Risk of CRISPR/Cas9-induced Chromothripsis in Gene Therapy. Stem Cells Transl Med. 2022 Oct 21;11(10):1003-1009. doi: 10.1093/stcltm/szac064.