Gene therapy of RAG-2−/− mice: sustained correction of the immunodeficiency

• Published in: Blood Vol. 100; no. 12; pp. 3942 - 3949
• Main Authors: Yates, Frank, Malassis-Séris, Michèle, Stockholm, Daniel, Bouneaud, Cécile, Larousserie, Frédérique, Noguiez-Hellin, Patricia, Danos, Olivier, Kohn, Donald B., Fischer, Alain, de Villartay, Jean-Pierre, Cavazzana-Calvo, Marina
• Format: Journal Article
• Language: English
• Published: Washington, DC Elsevier Inc 01.12.2002; The Americain Society of Hematology
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Applied cell therapy and gene therapy; B-Lymphocytes - cytology; B-Lymphocytes - immunology; Biological and medical sciences; Bone Marrow Cells - metabolism; Bone Marrow Transplantation; Cell Division; Cell Lineage; DNA-Binding Proteins - administration & dosage; DNA-Binding Proteins - genetics; Female; Genetic Therapy - methods; Male; Medical sciences; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Knockout; Receptors, Antigen, T-Cell; Retroviridae - genetics; Severe Combined Immunodeficiency - therapy; T-Lymphocytes - cytology; T-Lymphocytes - immunology; Transduction, Genetic; Transfusions. Complications. Transfusion reactions. Cell and gene therapy; Virus Integration; Immunopathology; Animal model; Severe combined immunodeficiency; Stem cell; Rodentia; Hematopoietic cell; Congenital disease; Genetic transfer; Vertebrata; Autograft; Mammalia; Treatment; Mouse; Animal; Bone marrow; Graft; Transduction; Combined immune deficiency; Gene therapy
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2002-03-0782

Patients with mutations of either RAG-1 or RAG-2 genes suffer from severe combined immunodeficiency (SCID) characterized by the lack of T and B lymphocytes. The only curative treatment today consists of hematopoietic stem cell (HSC) transplantation, which is only partially successful in the absence of an HLA genoidentical donor, thus justifying research to find an alternative therapeutic approach. To this end, RAG-2–deficient mice were used to test whether retrovirally mediated ex vivo gene transfer into HSCs could provide long-term correction of the immunologic deficiency. Murine RAG-2−/−Sca-1+ selected bone marrow cells were transduced with a modified Moloney leukemia virus (MLV)–based MND (myeloproliferative sarcoma virus enhancer, negative control region deleted, dl587rev primer-binding site substituted) retroviral vector containing the RAG-2 cDNA and transplanted into RAG-2−/− sublethally irradiated mice (3Gy). Two months later, T- and B-cell development was achieved in all mice. Diverse repertoire of T cells as well as proliferative capacity in the presence of mitogens, allogeneic cells, and keyhole limpet hemocyanin (KLH) were shown. B-cell function as shown by serum Ig levels and antibody response to a challenge by KLH also developed. Lymphoid subsets and function were shown to be stable over a one-year period without evidence of any detectable toxicity. Noteworthy, a selective advantage for transduced lymphoid cells was evidenced by comparative provirus quantification in lymphoid and myeloid lineages. Altogether, this study demonstrates the efficiency of ex vivo RAG-2 gene transfer in HSCs to correct the immune deficiency of RAG-2−/− mice, constituting a significant step toward clinical application.