Successful gene therapy of Diamond-Blackfan anemia in a mouse model and human CD34 + cord blood hematopoietic stem cells using a clinically applicable lentiviral vector

• Published in: Haematologica (Roma) Vol. 107; no. 2; pp. 446 - 456
• Main Authors: Liu, Yang, Dahl, Maria, Debnath, Shubhranshu, Rothe, Michael, Smith, Emma M, Grahn, Tan Hooi Min, Warsi, Sarah, Chen, Jun, Flygare, Johan, Schambach, Axel, Karlsson, Stefan
• Format: Journal Article
• Language: English
• Published: Italy Fondazione Ferrata Storti 01.02.2022; Ferrata Storti Foundation
• Subjects: Anemia, Diamond-Blackfan - genetics; Anemia, Diamond-Blackfan - metabolism; Anemia, Diamond-Blackfan - therapy; Animals; Clinical Medicine; Fetal Blood - metabolism; Genetic Therapy; Hematologi; Hematology; Hematopoietic Stem Cells - metabolism; Humans; Klinisk medicin; Medical and Health Sciences; Medicin och hälsovetenskap; Mice; Mutation; Ribosomal Proteins - genetics; RNA, Small Interfering - genetics
• ISSN: 0390-6078; 1592-8721; 1592-8721
• DOI: 10.3324/haematol.2020.269142

Diamond-Blackfan anemia (DBA) is an inherited bone marrow failure disorder in which pure red blood cell aplasia is associated with physical malformations and a predisposition to cancer. Twentyfive percent of patients with DBA have mutations in a gene encoding ribosomal protein S19 (RPS19). Our previous proof-of-concept studies demonstrated that DBA phenotype could be successfully treated using lentiviral vectors in Rps19-deficient DBA mice. In our present study, we developed a clinically applicable single gene, self-inactivating lentiviral vector, containing the human RPS19 cDNA driven by the human elongation factor 1a short promoter, which can be used for clinical gene therapy development for RPS19-deficient DBA. We examined the efficacy and safety of the vector in a Rps19-deficient DBA mouse model and in human primary RPS19-deficient CD34+ cord blood cells. We observed that transduced Rps19-deficient bone marrow cells could reconstitute mice long-term and rescue the bone marrow failure and severe anemia observed in Rps19-deficient mice, with a low risk of mutagenesis and a highly polyclonal insertion site pattern. More importantly, the vector can also rescue impaired erythroid differentiation in human primary RPS19-deficient CD34+ cord blood hematopoietic stem cells. Collectively, our results demonstrate the efficacy and safety of using a clinically applicable lentiviral vector for the successful treatment of Rps19-deficient DBA in a mouse model and in human primary CD34+ cord blood cells. These findings show that this vector can be used to develop clinical gene therapy for RPS19-deficient DBA patients.