REGULATION OF GENE-EXPRESSION IN-VIVO FOLLOWING TRANSDUCTION BY 2 SEPARATE RAAV VECTORS

Control of gene expression is important to gene therapy for purposes o f both dosing and safety. In vivo regulation of gene expression was de monstrated following co-injection of two separate recombinant adeno-as sociated virus vectors, one encoding an inducible murine erythropoieti n transgene and the other a transcriptional activator, directly into t he skeletal muscle of adult immunocompetent mice. Transcription was co ntrolled by systemic administration or withdrawal of tetracycline over an 18 week period, demonstrating that the two vectors were capable of transducing the same cell. Cellular or humoral immune responses again st the transactivator protein were not detected.