Time course of transgene expression after intrastriatal pseudotyped rAAV2/1, rAAV2/2, rAAV2/5, and rAAV2/8 transduction in the rat

Document Type

Article

Abstract

In vivo recombinant adeno-associated viral vector (rAAV)-mediated transduction of various tissues including brain has been characterized by slow onset and gradual increase in gene expression before reaching stable long-term protein levels. The early time course of transgene expression has not been quantified using newly available rAAV capsid serotypes. In this experiment, the onset of expression of green fluorescent protein (GFP) after intrastriatal injection of rAAV2-based pseudotyped vectors (rAAV1, rAAV5, and rAAV8 capsids) was quantified. Native GFP fluorescence displayed a delayed onset of expression of at least 7 days for all the pseudotyped rAAV vectors. However, GFP immunohistochemical staining revealed significant transgene expression by 4 days after transduction for all serotypes and stable GFP+ neuronal populations mediated by all serotypes within 14 days post transduction at the latest. rAAV2/1 and rAAV2/2 displayed no time-dependent increase of GFP+ striatal neurons; reaching maximal striatal cell GFP+ counts at 4 days after injection. All serotypes displayed peak transgene expression by 4 weeks post injection where native GFP+ neurons were equal to immunostained striatal GFP+ neurons. The inflammatory response to these rAAV vectors was present up to 4 weeks after transduction but was not apparent 9 months post injection. Thus, rAAV-mediated transgene expression begins earlier than previously thought.

Publication Date

8-1-2007

Publication Title

Molecular Therapy

ISSN

15250016

E-ISSN

15250024

Volume

15

Issue

8

First Page

1504

Last Page

1511

PubMed ID

17565350

Digital Object Identifier (DOI)

10.1038/sj.mt.6300227

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