LONG-TERM DELIVERY OF A LYSOSOMAL-ENZYME BY GENETICALLY-MODIFIED FIBROBLASTS IN DOGS

We have evaluated the feasibility and efficacy of intraperitoneal impl ants (neo-organs) for protein delivery in large animals. Skin biopsies were taken from four healthy dogs. Primary fibroblast cultures were t ransduced with a retroviral vector coding for the human beta-glucuroni dase. One to six lattices each containing 10(9) skin fibroblasts were implanted into the omentum of the donor animal. Laparotomies performed at regular intervals showed vascularized neo-organs without local inf lammation. Human beta-glucuronidase levels equivalent to 0.8 to 3.1% o f the endogenous canine activity were detected for up to 340 days on l iver biopsy samples. These results indicate that neo-organs can be con sidered for the long-term delivery of therapeutic proteins or enzymes in humans.