GFP Expression after Intraocular Injection of Different Viral Vectors in a Normal Mouse Model

Abstract

Abstract: : Purpose: Evaluation of lentiviral, adenoviral and adeno-associated viral transduction of enhanced green fluorescent protein (e-GFP) in ocular tissues after subretinal and intra-vitreous injections in Balb/c and B10RIII mice. Methods: The virus titers were 1x10E9 infectious unit (IU/ml) for the lentivirus, 3x10E12 IU/ml for the adenovirus and 2x10E9 IU/ml for the recombinant adeno-associated virus (rAAV). Groups of three mice were made for each injection site and for each viral vector. Mice received subretinal (SR) or intra-vitreous (IVT) administration of respectively 1µl or 3µl with a 33 Gauge needle. Ocular e-GFP expression was studied at three and six weeks post-injection. Results: Important inflammatory reaction was observed after IVT or SR adenovirus injection whereas, IVT injection with lentiviruses induced a moderate inflammation. In contrast, no inflammation was detected after IVT or SR injection of rAAV. Expression of e-GFP after subretinal injection of the lentivirus was detectable at six weeks. However, e-GFP was expressed at three and six weeks after adenovirus and rAAV injections. The three types of virus induced an e-GFP expression (i) in ganglion cells after intra-vitreous injection and (ii) in RPE and photoreceptors after subretinal injection. Interestingly, in addition to the previously expression sites with lentiviral vector, e-GFP expression was detectable in RPE, iris, ciliary body and cornea after IVT and SR injections. Conclusions: These results suggest that subretinal and intra-vitreous injections of rAAV or lentiviral vectors target different ocular tissues in normal mice, adjacent to the site of injection. Both subretinal or intravitreous injections of lentiviral vectors are able to transduce the cornea and the anterior uvea. Further studies are needed to analyze the molecular mechanism involved in this form of transduction.

Keywords: gene transfer/gene therapy