title: Correction of mucopolysaccharidosis type IIIb fibroblasts by lentiviral vector-mediated gene transfer.
abstract: Mucopolysaccharidosis type IIIB (MPS IIIB; or Sanfilippo syndrome type B) is a lysosomal disease, due to glycosaminoglycan storage caused by mutations on the alpha-N-acetylglucosaminidase (NAGLU) gene. The disease is characterized by neurological dysfunction but relatively mild somatic manifestations. No effective treatment is available for affected patients. In the present study, we evaluated the role of a lentiviral vector as the transducing agent of NAGLU cDNA in MPS IIIB fibroblasts. The vector expressed high transduction efficiency and high levels of enzymic activity, 20-fold above normal levels, persisting for at least 2 months. PCR experiments confirmed the integration of the viral vector into the target genome. The NAGLU activity restored by virus infection was sufficient to normalize glycosaminoglycan accumulation, which is directly responsible for the disease phenotype. Metabolic labelling experiments on transduced fibroblasts exhibited, in the medium and in cellular lysates, polypeptide forms of 84 and 80 kDa respectively related to the precursor and mature forms of the enzyme. The enzyme secreted by transduced MPS IIIB fibroblasts was endocytosed in deficient cells by the mannose 6-phosphate system. Thus we show that lentiviral vectors may provide a therapeutic approach for the treatment of MPS IIIB disease.
authors.affiliation: Department of Biochemistry and Medical Biotechnologies, University of Naples, Frederico II, via Sergio Pansini 5, 80131 Naples, Italy.
authors.forename: Guglielmo R D
authors.initials: GR
authors.lastname: Villani
authors.forename: Antonia
authors.initials: A
authors.lastname: Follenzi
authors.forename: Borghina
authors.initials: B
authors.lastname: Vanacore
authors.forename: Carmela
authors.initials: C
authors.lastname: Di Domenico
authors.forename: Luigi
authors.initials: L
authors.lastname: Naldini
authors.forename: Paola
authors.initials: P
authors.lastname: Di Natale
mesh_terms: D000118:Acetylglucosaminidase / Q000096:biosynthesis / Q000235:genetics*; D002478:Cells, Cultured; D017931:DNA Primers; D005347:Fibroblasts / Q000201:enzymology; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D007700:Kinetics; D016086:Lentivirus / Q000235:genetics*; D009084:Mucopolysaccharidosis III / Q000235:genetics* / Q000628:therapy; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000378:metabolism; D013462:Sulfur Radioisotopes; D014161:Transduction, Genetic; D016662:Virus Integration
chemical_list: D017931:DNA Primers; D011994:Recombinant Proteins; D013462:Sulfur Radioisotopes; D000118:Acetylglucosaminidase