AAV2-CAG-FLPo

AAV2 was the first AAV isolate to be developed as a recombinant vector for transgene delivery. Initially, adenoviral helper functions were used directly to produce AAV2, which raised concerns about contamination of AAV2 stocks with adenoviral capsids. Significant advances have been made in the production of AAV2 over the past decade. Plasmid-based protocols, which involve plasmids containing the Ad gene rather than using adenovirus, have been primarily used for AAV production. Currently, production of AAV2 vectors requires transfection of the following components into host 293 cells: (1) a vector genome containing a transgene expression cassette flanked by two ITRs, (2) expression of the Rep and Cap proteins provided in trans by a helper plasmid, and (3) adenoviral genes encoding E1, E2A, E4, and viral-associated RNAs. Because transfection methods are generally considered unsuitable for large-scale production, infection of cell lines stably expressing Rep and Cap with adenovirus carrying the vector genome provides an alternative for scaling up production. Alternatively, infection of proviral cell lines with adenoviral or herpes simplex virus vectors carrying the Rep and Cap expression cassettes is also a viable alternative.