Viral Vectors for Gene Therapy

The selection of the delivery system is one of the most critical points for the success (and safety) of gene therapy. First, the chosen vector must ensure that the gene is delivered to the correct target cells, or at least predominantly to those cells. Second, the introduced transgene has to be activated, that is, it must go to the nucleus, be transcribed, and then translated. In a one-time cure setting, ideally the transgene should be integrated into the host genome or endure episomally, ensuring a long-term persistent expression. The ideal delivery system should meet several criteria,including (i) a good safety profile; (ii) easy production; (iii) good stability in target cells, and (iv) a high transgene capacity. As mentioned, the delivery systems can be roughly divided into two main categories: non-viral and viral systems. The non-viral methods were described in the previous chapter, whereas in this chapter the viral vectors used in gene therapy will be explained.