Abstract
Purpose: :
To determine whether adeno–associated virus (AAV) vectors transduced into iris pigment epithelium (IPE) cells and transplanted into the subretinal space of rats will transfer the AAV genome to the host cells, and whether the vectors are disseminated systemically.
Methods: :
Recombinant AAVs (rAAV) were transduced into rat IPE and transplanted into the subretinal space of rats. For control, rAAVs alone were injected subretinally. The transplanted IPE cells were detected by LacZ staining. Immunohistochemistry, electronmicroscopy, electroretinography, and fluorescein–dextran angiography were performed. DNA was extracted from various organs and blood and examined for AAV genome by polymerase chain reaction.
Results: :
No toxicities of rAAV transduction were observed in vitro. LacZ was expressed in the transplanted cells 1 and 2 weeks after transplantation. At 4 and 12 weeks, fewer transplanted cells were detected than that at 1 week, and LacZ expression was occasionally detected at the level of host retinal pigment epithelium (RPE) cells. Expression was also detected in ciliary body epithelial cells. The electroretinograms and fluorescein–dextran angiography were only mildly altered. Significantly lower levels of AAV genome was detected in the organs and blood of rats transplanted with rAAV–IPE than with direct intravenous injection of AAV vectors.
Conclusions: :
AAV–mediated LacZ was expressed in the transplanted cells after subretinal transplantation, and the transplanted IPE cells may transfer the rAAV to host tissues, such as RPE cells, long after the transplantation. This method of gene delivery did not lead to systemic dissemination of the vectors.
Keywords: retinal pigment epithelium • transplantation