Abstract
Purpose: :
Adenovirus vectors (Ad) are efficient gene delivery vehicles and are widely used in pre-clinical and clinical gene therapies. We have previously demonstrated short-term transduction efficiency and intraocular localization of reporter genes delivered by Ad of several serotypes with fiber modification (Ueyama et al. #5194, presented in ARVO 2010). The aim of this study was to evaluate the transduction efficiency of Ad vectors until six months for serotypes 5, 28 and 35 (abbreviation, Ad5, Ad28 and Ad35, respectively).
Methods: :
To determine the time course of luciferase activity, C57BL6 mice received a single subretinal injection of Ad vector containing the construct expressing luciferase at the concentration of 1x10e8 particle units. Naïve animals or animals with intraocular injection of empty adenoviral vectors served as negative controls. Eyes were harvested at the date of 1, 7, 14, 28, 90 and 180 after injection and assayed for luciferase activity.The assessed number of eyes was 4 to 6 eyes at each virus and each timepoint, and the total number was 85.
Results: :
Ad5 expressed strongest within 7 days after injection, but decreased rapidly. Ad28 sustained strong expression until 28 days, but decreased after 90 days. Ad28 had significantly stronger expression than Ad5 at 28 days after injection (P=0.0127). Ad35 expressed strongest within 7 days after injection and sustained throughout the 180 days-observation. Ad35 expressed stronger than Ad5 at the time of 28 days and 180 days after injection (P=0.0127, P=0.033 respectively).
Conclusions: :
The strength and duration of Ad expression differed between serotypes. The prolonged gene expression mediated by Ad28 and Ad35 subretinal injection may provide an advantage in delivering several therapeutic proteins.
Keywords: gene/expression • adenovirus • gene transfer/gene therapy