Viral vectors based on bidirectional cell-specific mammalian promoters and transcriptional amplification strategy for use in vitro and in vivo

Abstract
Using cell-type-specific promoters to restrict gene expression to particular cells is an attractive approach for gene therapy, but often hampered by insufficient transcriptional activity of these promoters. Previous studies have shown that transcriptional amplification strategy (TAS) can be used to enhance the activity of such promoters without loss of cell type specificity. Originally TAS involved the use of two copies of a cell-specific promoter leading to generation of large expression cassettes, which can be hard to use given the space limitations of the conventional viral gene expression vectors.