Adeno-associated virus vectors for human gene therapy

Figure 2 Diagram of adeno-associated virus vector production. A: The expression cassette containing promoter, intron, target gene, and polyadenylation sequence is flanked with adeno-associated virus (AAV) inverted terminal repeats (ITRs); B: AAV rep and cap sequences without ITRs are provided in trans; C: helper virus can be adenovirus, herpes simplex virus (HSV), or baculovirus depending on the production system used. Once these three components are introduced into a host cell under proper conditions, AAV vectors will be produced.