scAAV6-Cre

Various preclinical studies using experimental animal models have demonstrated the efficacy of recombinant adeno-associated viral (AAV) vectors for various diseases. Adeno-associated virus (AAV) is a small non-enveloped virus with a single-stranded genomic DNA of approximately 4.7 kb. Inverted terminal repeats (ITRs) flank the coding sequence. All AAV serotypes can efficiently package single-stranded DNA (ssDNA) genomes up to 6 kb, with an optimal packaging capacity of 5.23 kb. The single-stranded DNA (ssDNA) genome carrying the gene of interest requires host cells to synthesize complementary DNA strands to form double-stranded DNA for mRNA transcription. This secondary strand synthesis is the rate-limiting step for transgene expression. This pitfall can be circumvented by using self-complementary AAV (scAAV) vectors.

Self-complementary AAV vectors package double-stranded DNA (dsDNA) and do not require DNA synthesis or base pairing of two single-stranded complementary viral vectors. scAAV vectors contain a dimeric inverted repeat genome folded into dsDNA. Despite their limited transgene carrying capacity, scAAV vectors offer higher transduction efficiency. Recent studies have shown that scAAV can effectively infect retinal pigment epithelial cells (RPE) and photoreceptor cells. scAAV vectors have higher transduction efficiency and longer transgene expression in these ocular cells.