1. ¹Gene Therapy Program, Institute of Human Genetics, Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
2. ²Department of Neurosurgery, University of Minnesota, Minneapolis, MN 55455, USA
3. ³Department of Research Animal Resources, University of Minnesota, Minneapolis, MN 55455, USA
4. ⁴Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA

Correspondence: R. Scott McIvor, Department of Genetics, Cell Biology and Development, University of Minnesota, 6-160 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA. Fax: (612) 625-9810. E-mail: mcivor@mail.med.umn.edu

Received 26 August 2003; Accepted 15 March 2004.

Abstract

Murine models of lysosomal storage diseases provide an opportunity to evaluate the potential for gene therapy to prevent systemic manifestations of the disease. To determine the potential for treatment of mucopolysaccharidosis type I using a gene delivery approach, a recombinant adeno-associated virus (AAV) vector, vTRCA1, transducing the human iduronidase (IDUA) gene was constructed and 1 10¹⁰ particles were injected intravenously into 1-day-old Idua^-/- mice. High levels of IDUA activity were present in the plasma of vTRCA1-treated animals that persisted for the 5-month duration of the study, with heart and lung of this group demonstrating the highest tissue levels of gene transfer and enzyme activity overall. vTRCA1-treated Idua^-/- animals with measurable plasma IDUA activity exhibited histopathological evidence of reduced lysosomal storage in a number of tissues and were normalized with respect to urinary GAG excretion, craniofacial bony parameters, and body weight. In an open field test, vTRCA1-treated Idua^-/- animals exhibited a significant reduction in total squares covered and a trend toward normalization in rearing events and grooming time compared to control-treated Idua^-/- animals. We conclude that AAV-mediated transduction of the IDUA gene in newborn Idua^-/- mice was sufficient to have a major curative impact on several of the most important parameters of the disease.