Long‐term real‐time monitoring of adeno‐associated virus‐mediated gene expression in the rat retina

Abstract

These results confirm the importance of this direct visualization system to study vector transgene expression in vivo and support the use of AAV for diseases treatable by targeting RPE cells.

Photoreceptor Protection by Adeno-Associated Virus–Mediated LEDGF Expression in the RCS Rat Model of Retinal Degeneration: Probing the Mechanism

“…However, preliminary follow-up on a single RCS animal injected at 3 weeks of age showed ERG functional protection at 11 and at 15 weeks, but the protection effect did not persist at 19 and 23 weeks (data not shown). It was reported that, in the rat eye, maximum expression of a protein delivered by AAV via subretinal injection occurs 8 weeks after injection, as our present results also suggest, and that expression gradually decreases thereafter,49 with need for reapplication. In humans however, wild-type AAV integrates stably into a site-specific chromosomal locus50 and long-term protein expression is expected.…”

Adeno-Associated Virus Encoding Green Fluorescent Protein as a Label for Retinal Pigment Epithelium

“…48,51,53,55 These in vivo studies showed that RPE are highly permissive to AAV-mediated gene transfer, and reporter gene expression (e.g., LacZ or GFP) in transduced RPE can be detected for up to 1 year after subretinal injection. 52 In a study by Grant et al, 53 reporter gene expression of RPE cells in some areas approached 100%.…”

“…AAV, as measured by reporter gene expression, has been demonstrated in RPE cells for up to 1 year after subretinal injection. 52 In addition, AAV has been shown to cause minimal inflammatory response 48 and has no toxic effects on the retina after subretinal delivery. 53,54 To determine whether AAV-GFP is an appropriate marker for cultured RPE cells, we studied the long-term stability of AAV-GFP in transduced cells and the preservation of label after cell division.…”

Combined Effect of Cyclosporine and Sirolimus on Improving the Longevity of Recombinant Adenovirus–Mediated Transgene Expression in the Retina

“…24 In our own hands, recombinant adenoassociated virus-mediated GFP expression remained relatively consistent for up to 18 months. 25 These facts indicate that the rAd-induced immune responses are related to the presence of rAd vector rather than GFP protein. Previous studies have demonstrated that the mechanisms involved in elimination of the rAd vector by host responses include (1) innate immunity, (2) major histocompatibility complex class I-restricted cytotoxic T-cell responses, and (3) types 1 and 2 helper T-cell-mediated cellular and humoral immune responses.…”