346. The ACE System, a Mammalian Artificial Chromosome Engineering Technology: Delivery and Transgene Expression in Human Adult & Embryonic Stem Cells

The ACE System is a potent biological engineering system consisting of a mammalian artificial chromosome engineered with multiple site-specific integration sites, expression-optimized shuttle vectors to specifically transfer genes, and a proprietary integrase to catalyze specific incorporation of a payload onto the ACE. ACEs are promising gene delivery vehicles for gene-based cell therapies as they are stably maintained, non-integrating, autonomously replicating, and are easily isolated to high purities by flow sorting. We published the first reports of the transfer and stable transgene expression of a mammalian artificial chromosome into hMSCs and hHSCs (Stem Cells 22:324|[ndash]|33, 2004; Exp Hematol 33:1470|[ndash]|1476, 2005). We will update our progress, including an hMSCs enrichment strategy resulting in stable EPO transgene expression, more than 50 days post EPO-ACE transfer, at levels of 100|[ndash]|200 IU/cell/day.