CMV-Luc AAV (Serotype BR1)

AAV was first discovered as a contaminant of simian adenovirus preparations and was initially thought to be defective particles because they were not replication competent on their own. However, these particles are antigenically distinct and were later classified as dependent parvoviruses. AAV replication is dependent on the presence of a helper virus, such as adenovirus, herpes simplex virus (HSV), human papillomavirus (HPV), or vaccinia virus (VACV). Furthermore, although most humans are seropositive for AAV, AAV has not been definitively associated with any human disease. The genome of AAV is approximately 4.7 kb in length and contains 2 genes, rep and cap, which are very similar to other members of the parvovirus family. The genome of AAV is flanked by symmetrical inverted terminal repeats (ITRs), each 165 bp long, which self-anneal to a T-shaped hairpin structure. The rep gene encodes four nonstructural genes, Rep78, Rep68, Rep52, and Rep40, which are named based on their molecular weight. These genes are produced by expression driven by 2 different promoters, p5 and p19, as well as by alternative splicing. Rep78 and Rep68 have DNA binding activity and have been shown to be important in regulating the activity of the p5, p19, and p40 promoters. In addition, Rep78 and Rep68 play a key role in site-specific integration and subsequent rescue of the AAV genome into and out of human chromosome 19 at a site called AAVS1. Both Rep 52 and Rep40 have DNA helicase activity and have been shown to be required for packaging of DNA into AAV capsids. The cap gene encodes three VP subunits, VP1, VP2, and VP3, all driven by the p40 promoter. A single VP is generated by alternative splicing as well as alternative start codons. VPs assemble into capsids in a VP1:VP2:VP3 ratio of approximately 1:1:10, with 60 VPs constituting a complete capsid containing 5 copies each of VP1 and VP2, and 50 copies of VP3.