Gene therapy for neurodegenerative and ocular diseases using lentiviral vectors

Gene therapy holds great promise for the treatment of a wide range of inherited and acquired disorders. The development of viral vector systems to mediate safe and long-lasting expression of therapeutic transgenes in specific target cell populations is continually advancing. Gene therapy for the nervous system is particularly challenging due to the post-mitotic nature of neuronal cells and the restricted accessibility of the brain itself. Viral vectors based on lentiviruses provide particularly attractive vehicles for delivery of therapeutic genes to treat neurological and ocular diseases, since they efficiently transduce non-dividing cells and mediate sustained transgene expression. Furthermore, novel routes of vector delivery to the nervous system have recently been elucidated and these have increased further the scope of lentiviruses for gene therapy application. Several studies have demonstrated convincing therapeutic efficacy of lentiviral-based gene therapies in animal models of severe neurological disorders and the push for progressing such vectors to the clinic is ongoing. This review describes the key features of lentiviral vectors that make them such useful tools for gene therapy to the nervous system and outlines the major breakthroughs in the potential use of such vectors for treating neurodegenerative and ocular diseases.