June 2015
Volume 56, Issue 7
Free
ARVO Annual Meeting Abstract  |   June 2015
Dose-response effect of RPE65 gene therapy on retinoid levels and correlation with clinical rescue in Rpe65-deficient dogs.
Author Affiliations & Notes
  • Freya Mowat
    Small Animal Clinical Sciences, Michigan State University College of Veterinary Medicine, East Lansing, MI
    UCL Institute of Ophthalmology, London, United Kingdom
  • Kecia L Feathers
    Department of Ophthalmology and Visual Sciences, Department of Biological Chemistry, University of Michigan, Ann Arbor, MI
  • Alexander J Smith
    UCL Institute of Ophthalmology, London, United Kingdom
    National Institute for Health Research Biomedical Research Centre for Ophthalmology at Moorfields, London, United Kingdom
  • Debra A Thompson
    Department of Ophthalmology and Visual Sciences, Department of Biological Chemistry, University of Michigan, Ann Arbor, MI
  • Simon M Petersen-Jones
    Small Animal Clinical Sciences, Michigan State University College of Veterinary Medicine, East Lansing, MI
  • James W B Bainbridge
    UCL Institute of Ophthalmology, London, United Kingdom
    National Institute for Health Research Biomedical Research Centre for Ophthalmology at Moorfields, London, United Kingdom
  • Robin R Ali
    UCL Institute of Ophthalmology, London, United Kingdom
    National Institute for Health Research Biomedical Research Centre for Ophthalmology at Moorfields, London, United Kingdom
  • Footnotes
    Commercial Relationships Freya Mowat, None; Kecia Feathers, None; Alexander Smith, None; Debra Thompson, None; Simon Petersen-Jones, None; James Bainbridge, None; Robin Ali, None
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2015, Vol.56, 2064. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Freya Mowat, Kecia L Feathers, Alexander J Smith, Debra A Thompson, Simon M Petersen-Jones, James W B Bainbridge, Robin R Ali; Dose-response effect of RPE65 gene therapy on retinoid levels and correlation with clinical rescue in Rpe65-deficient dogs.. Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):2064.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract
 
Purpose
 

Although the mouse and dog models of Rpe65 deficiency have been stably rescued and the retinas preserved following AAV vector-mediated gene therapy delivered before degeneration ensues, young human patients treated with identical vectors and doses have incomplete vision recovery, and suffer continued retinal degeneration despite treatment. The purpose of this study was to examine the physiological and clinical effects of different doses of gene therapy in the Rpe65-deficient dog to investigate the effect on visual cycle activity.

 
Methods
 

We treated 12 eyes with 4 different doses of gene therapy, the lowest dose was 8x10^8 vg, the highest dose was 1x10^11 vg. We evaluated electroretinographic responses, vision outcomes, and following euthanasia, we removed retinas under dark-adapted conditions for histology and 11-cis retinal quantification. 11-cis retinal was used as a marker for enzyme activity, as it is a product of normalized RPE65 enzymatic activity.

 
Results
 

Rod and cone rescue was present in the highest two dose groups. Significant improvements in vision were noted in the top 3 dose groups. We detected RPE65 protein expression in the RPE using western blotting and IHC in the highest dose group, and in patchy regions using IHC in the next highest dose group. Significantly higher levels of 11-cis retinal were detected in the highest dose group compared to all other groups. Eyes of the highest dose group contained less than 25% of the 11-cis retinal present in untreated normal dogs' eyes collected in the same manner.

 
Conclusions
 

These results demonstrate that AAV-mediated expression of RPE65 protein can improve vision and electrophysiological responses despite only partial restoration of visual cycle activity.

 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×