High-throughput transcriptional analysis of gene therapy viral vectors effects on brain cells

The gene therapy approach using viral vectors currently represents one of the best hopes for treating numerous genetic and acquired brain disorders. Different viral vector platforms have been extensively studied and utilised in clinical trials on the Central Nervous System (CNS), by taking advantage of the specific viral features. However, the improvement of viral systems to mediate safe and long-lasting expression of therapeutic transgenes in brain is particularly challenging due to the post-mitotic nature of nervous cells, the high level of compartmentalisation of the CNS, the potential toxicity and the alteration of the neuronal physiology triggered by the virus. Although many studies have proved the efficacy of the viral sources in transducing the brain in vivo, little is known on neuronal cells perturbations following the vector interaction. To address this issue, we have analysed the global transcriptome of differentiated midbrain-derived human neuronal progenitor cells transduced in vitro with HIV-1-, AAV9-, Helper Dependent human adenoviral (HD hAd)- and Helper Dependent canine adenoviral (HD CAV-2)- vectors, at early and late time points. In particular, canine adenovectors have proved to be an interesting alternative to the human Ad, because of their efficiency in transducing human cells and the absence of CAV-specific neutralizing antibodies in human serum, that inhibit the vector effect. This study intends to provide insights in vector development for CNS, consisting in the ability to predict the neuronal functions altered by the vectors and the possibility to act on these with tools aimed at improving the efficacy and reducing the toxicity.