ADENOASSOCIATED VIRUS 2-MEDIATED GENE-TRANSFER AND FUNCTIONAL EXPRESSION OF THE HUMAN GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR

It is becoming increasingly clear that the adeno-associated virus 2 (A AV)-based vector system may prove to be useful for high-efficiency gen e transfer in human cells as well as for potential gene therapy in hum ans. A recombinant AAV vector containing the gene for a human hematopo ietic growth factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), was constructed and used to infect COS-1 cells, a monkey kid ney cell line. COS-1 cells infected with the recombinant virus, but no t mock-infected cells, expressed high levels of the human GM-CSF gene transcripts. Furthermore, in co-cultivation experiments with the recom binant virus-infected cells, but not in those with mock-infected cells , active proliferation of a GM-CSF-dependent human megakaryocytic leuk emia cell line, M07e, could be obtained in the absence of exogenously added GM-CSF. The recombinant GM-CSF protein released into the superna tant was biologically active in progenitor cell assays carried out wit h primary human hematopoietic cells, and this activity was specificall y abrogated by treatment of the supernatant with anti-GM-CSF antibodie s. This recombinant virus may be potentially useful in the management and gene therapy of a variety of malignant disorders in the human hema topoietic system.