Aronovich EL, Bell JB, Belur LR, Gunther R, Koniar B, Erickson DCC, Schachern PA, Matise I, McIvor RS, Whitley CB, Hackett PB. Prolonged expression of a lysosomal enzyme in mouse liver after Sleeping Beauty transposon-mediated gene delivery: implications for non-viral gene therapy of mucopolysaccharidoses.
J Gene Med 2007;
9:403-15. [PMID:
17407189 PMCID:
PMC1868578 DOI:
10.1002/jgm.1028]
[Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND
The Sleeping Beauty (SB) transposon system is a non-viral vector system that can integrate precise sequences into chromosomes. We evaluated the SB transposon system as a tool for gene therapy of mucopolysaccharidosis (MPS) types I and VII.
METHODS
We constructed SB transposon plasmids for high-level expression of human beta-glucuronidase (hGUSB) or alpha-L-iduronidase (hIDUA). Plasmids were delivered with and without SB transposase to mouse liver by rapid, high-volume tail-vein injection. We studied the duration of expressed therapeutic enzyme activity, transgene presence by PCR, lysosomal pathology by toluidine blue staining and cell-mediated immune response histologically and by immunohistochemical staining.
RESULTS
Transgene frequency, distribution of transgene and enzyme expression in liver and the level of transgenic enzyme required for amelioration of lysosomal pathology were estimated in MPS I and VII mice. Without immunomodulation, initial GUSB and IDUA activities in plasma reached > 100-fold of wild-type (WT) levels but fell to background within 4 weeks post-injection. In immunomodulated transposon-treated MPS I mice plasma IDUA persisted for over 3 months at up to 100-fold WT activity in one-third of MPS I mice, which was sufficient to reverse lysosomal pathology in the liver and, partially, in distant organs. Histological and immunohistochemical examination of liver sections in IDUA transposon-treated WT mice revealed inflammation 10 days post-injection consisting predominantly of mononuclear cells, some of which were CD4- or CD8-positive.
CONCLUSIONS
Our results demonstrate the feasibility of achieving prolonged expression of lysosomal enzymes in the liver and reversing MPS disease in adult mice with a single dose of therapeutic SB transposons.
Collapse