scAAV3-Cre

Adeno-associated virus (AAV) vectors are widely used to stably transfer genes into terminally differentiated or quiescent cells, such as myofibers, hepatocytes, neurons, retinal cells, etc. These vectors, derived from a non-pathogenic, replication-defective parvovirus with a small single-stranded (ss) DNA genome, have recently been successfully used for clinical gene transfer for inherited blindness and also show promise for the treatment of other diseases. In recent years, many alterations of the capsid and vector genome have been developed in an attempt to improve gene transfer efficiency and potentially evade immunity. Modifications of the recombinant AAV genome can also improve transduction rates. As ss, the ssAAV genome must be converted to a double-stranded form in the nucleus of infected cells for transgene expression. To overcome this rate-limiting step, self-complementary (sc)AAV vectors were developed by eliminating the terminal cleavage site in one of the inverted terminal repeats (ITRs). In order to package such a genome into the capsid, the size of the expression cassette must be further reduced to not exceed the packaging limit.