Detection of intact rAAV particles up to 6 years after successful gene transfer in the retina of dogs and primates.
Gene transfer to the retina using recombinant adeno-associated viral (rAAV) vectors has proven to be an effective option for the treatment of retinal degenerative diseases in several animal models and has recently advanced into clinical trials in humans. To date, intracellular trafficking of AAV vectors and subsequent capsid degradation has been studied only in vitro, but the fate of AAV particles in transduced cells following subretinal injection has yet to be elucidated. Using electron microscopy and western blot, we analyzed retinas of one primate and four dogs that had been subretinally injected with AAV2/4, -2/5, or -2/2 serotypes and that displayed efficient gene transfer over several years. We show that intact AAV particles are still present in retinal cells, for up to 6 years after successful gene transfer in these large animals. The persistence of intact vector particles in the target organ, several years postadministration, is totally unexpected and, therefore, represents a new and unanticipated safety issue to consider at a time when gene therapy clinical trials raise new immunological concerns.
Stieger
Knut
K
INSERM U649, CHU-Hotel Dieu, Nantes, France.
Schroeder
Josef
J
Provost
Nathalie
N
Mendes-Madeira
Alexandra
A
Belbellaa
Brahim
B
Le Meur
Guylène
G
Weber
Michel
M
Deschamps
Jack-Yves
JY
Lorenz
Birgit
B
Moullier
Philippe
P
Rolling
Fabienne
F
D000818:Animals; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D000229:Dependovirus / Q000235:genetics* / Q000648:ultrastructure; D004285:Dogs; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics*; D016253:Microscopy, Immunoelectron; D011323:Primates / Q000235:genetics* / Q000378:metabolism*; D012160:Retina / Q000378:metabolism*; D013997:Time Factors; D014771:Virion / Q000235:genetics*
D036022:Capsid Proteins