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Retroviral-mediated transfer of the human acid sphingomyelinase cDNA: correction of the metabolic defect in cultured Niemann-Pick disease cells. Proc Natl Acad Sci U S A 1992 Apr 15;89(8):3227-31

Date

04/15/1992

Pubmed ID

1565614

Pubmed Central ID

PMC48839

DOI

10.1073/pnas.89.8.3227

Scopus ID

2-s2.0-0026607916   29 Citations

Abstract

Types A and B Niemann-Pick disease (NPD) result from inherited deficiencies of the lysosomal hydrolase, acid sphingomyelinase (ASM; sphingomyelin cholinephosphohydrolase, EC 3.1.4.12). To evaluate the feasibility of somatic gene therapy for the treatment of these disorders, retroviral-mediated gene transfer was used to introduce the full-length ASM cDNA into cultured fibroblasts from two unrelated type A NPD patients. The ASM activities in these cells were less than 4% of mean normal levels, and, consequently, they accumulated approximately 3-fold elevated levels of sphingomyelin. After retroviral-mediated transfer of the ASM cDNA, ASM activities in the NPD cells increased to levels up to 16-fold those found in normal fibroblasts. In addition, the sphingomyelin content was reduced to normal levels, indicating that the vector-encoded enzyme was properly targeted to lysosomes, where it was enzymatically active and able to degrade the accumulated substrate. In situ cell-loading studies also were undertaken to evaluate the effects of retroviral-mediated gene transfer on the pathology of NPD fibroblasts. When a pyrene derivative of sphingomyelin was introduced into the lysosomes of cultured fibroblasts from a type A NPD patient by using apolipoprotein E-mediated endocytosis, only approximately 6% of the delivered substrate was degraded. In contrast, normal cells and NPD cells transduced (i.e., "corrected") by retroviral-mediated gene transfer could degrade approximately 80% of the delivered sphingomyelin. These results provided further evidence that retroviral-mediated gene transfer may be used to correct the pathology of NPD cells. Cell-loading studies were also used to develop a selection system for discriminating between NPD cells and those transduced by retroviral-mediated gene transfer. This selection scheme was based on the fluorescence emission of intact NPD cells, which, when loaded with pyrene-labeled sphingomyelin, was 3- to 5-fold that of normal or transduced cells. As a consequence, the NPD and transduced cells could be efficiently sorted by flow cytometry with a fluorescence-activated cell sorter. In addition, the NPD cells could be selectively killed by photosensitization after irradiation with a long-wavelength UV light. These results should permit direct selection of ASM-expressing cells after retroviral-mediated gene transfer without the need to preselect for a cotransferred marker gene.

Author List

Suchi M, Dinur T, Desnick RJ, Gatt S, Pereira L, Gilboa E, Schuchman EH

Author

Mariko Suchi MD, PhD Associate Professor in the Pathology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Cell Survival
Cells, Cultured
DNA
Fibroblasts
Flow Cytometry
Genetic Therapy
Genetic Vectors
Humans
Moloney murine leukemia virus
Niemann-Pick Diseases
Radiation-Sensitizing Agents
Reference Values
Skin
Sphingomyelin Phosphodiesterase
Sphingomyelins
Transfection
Ultraviolet Rays
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a