ADENOASSOCIATED VIRUS TYPE 2-MEDIATED TRANSDUCTION OF MURINE HEMATOPOIETIC-CELLS WITH LONG-TERM REPOPULATING ABILITY AND SUSTAINED EXPRESSION OF A HUMAN GLOBIN GENE IN-VIVO

Adeno-associated virus type 2 (AAV), a nonpathogenic human parvovirus, is gaining attention as a vector for potential use in human gene ther apy. We and others have described AAV-mediated beta-globin gene transf er and expression in established human and murine erythroleukemia cell lines in vitro. However, successful AAV-mediated globin gene transduc tion of hematopoietic stem cells and long-term expression in vivo in p rogeny cells have not been documented. We report here that infection o f murine hematopoietic bone marrow cells ex vivo with a recombinant AA V vector containing the genomic copy of a normal human globin gene fol lowed by transplantation of these cells into lethally irradiated conge nic mice resulted in efficient gene transfer into hematopoietic cells with long-term repopulating ability as detected by the presence of the human globin gene sequences in bone marrow and spleen in primary reci pient mice for at least 6 months. Long-term expression of the human gl obin gene was also detected in bone marrow, but not in spleen, in prim ary recipient mice, Furthermore, in secondary-transplant experiments, we were also able to document the presence as well as expression of th e transduced human globin gene in mouse bone marrow for up to 3 months , These results provide further support for potential use of the AAV-b ased vector system in gene therapy of human hemoglobinopathies in gene ral and sickle-cell anemia and beta-thalassemia in particular.