Gene therapy cures the anemia and lethal bone marrow failure in mouse model for RPS19-deficient Diamond-Blackfan anemia

Diamond-Blackfan anemia is a congenital erythroid hypoplasia caused by functional haploinsufficiency of genes encoding ribosomal proteins. Mutations involving the ribosomal protein S19 gene are detected in 25% of patients. Enforced expression of ribosomal protein S19 improves the overall proliferative capacity, erythroid colony-forming potential and erythroid differentiation of hematopoietic progenitors from ribosomal protein S19-deficient patients in vitro and in vivo following xenotransplantation. However, studies using animal models are needed to assess the therapeutic efficacy and safety of the viral vectors. In the present study we have validated the therapeutic potential of gene therapy using mouse models of ribosomal protein S19-deficient Diamond-Blackfan anemia. Using lentiviral gene transfer we demonstrated that enforced expression of ribosomal protein S19 cures the anemia and lethal bone marrow failure in recipients transplanted with ribosomal protein S19-deficient cells. Furthermore, gene-corrected ribosomal protein S19-deficient cells showed an increased pan-hematopoietic contribution over time compared to untransduced cells without signs of vector-mediated toxicity. Our study provides a proof of principle for the development of clinical gene therapy to cure ribosomal protein 19-deficient Diamond-Blackfan anemia.