Long-term correction of ammonia metabolism and prolonged survival in ornithine transcarbamylase-deficient mice following liver-directed treatment with adeno-associated viral vectors.
The purpose of this study was to determine the efficacy of novel recombinant adeno-associated viral (AAV) vector constructs in correcting metabolic defects in the liver in two strains of ornithine transcarbamylase (OTC)-deficient mice (spf and spf-ash). AAV vectors expressing mouse OTC were produced with capsids from AAV2 and the novel serotypes AAV7, 8, and 9. OTC-deficient mice were infused with these vectors as well as a control AAV2/8 vector expressing LacZ. In vivo activity of OTC was assessed by measuring a surrogate marker, urine orotate. The novel vectors restored orotate levels to virtually normal 15 days after infusion, and each persisted to 1 year posttreatment. Liver OTC enzyme activity in spf mice was substantially higher in animals receiving novel vectors compared to those receiving AAV2 vectors. Animals receiving novel OTC-expressing vectors lived longer than those treated with AAV2 OTC or untreated controls, and they were tolerant to a challenge with NH3 at 21 days and beyond, which caused severe morbidity in control OTC-deficient animals. Numerous mice, representative of all treatment groups followed for +250 days, were observed to have either nodules or discrete tumors in the liver, the etiology of which is the subject of a companion paper.
Moscioni
David
D
Gene Therapy Program, Division of Medical Genetics, Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Morizono
Hiroki
H
McCarter
Robert J
RJ
Stern
Adam
A
Cabrera-Luque
Juan
J
Hoang
Albert
A
Sanmiguel
Julio
J
Wu
Di
D
Bell
Peter
P
Gao
Guang-Ping
GP
Raper
Steven E
SE
Wilson
James M
JM
Batshaw
Mark L
ML