895. Separate rAAV1 Vectors Co-Infect Striatal Neurons Efficiently

Abstract

Top of pageAbstract rAAV is a useful tool for gene therapy, however because of the limited size of the AAV genome large or multicistronic cDNAs are problematic. For example, the tetracycline responsive promoter-transactivator transcriptional regulation system is difficult to package in a single rAAV vector. In instances where more than one gene is required, co-infection by two viruses is necessary and often, both genes must be transferred to the same cell for the system to function properly. To date, the rate at which two mixed viral vectors infect the same cells has not been quantified. We hypothesized that a sequential surgical procedure separated by 24 hr would allow for receptor recycling and increase the number of double-hits. Six adult rats were injected unilaterally in the striatum with a mix of AAV1-GFP and AAV1 DS-Red2. The contralateral striatum was injected with AAV1 DS-Red2 then 24 hours later injected with AAV1-GFP at the same site. In both groups, approximately 75% of cells expressing GFP (direct fluorescence) also expressed dsred2 (indirect fluorescence). However, the number of GFP expressing cells far exceeded that of dsred2 despite very similar titers. In conclusion these results demonstrate that 2 vectors co-transduce striatal neurons at a very high rate even with simple mixing procedure.