FIG. 6.
Comparison of dual-vector heterodimerization between hybrid and homologous ITR vectors. Dual-vector reconstitution of a lacZ minigene was used to evaluate the extent of tail-to-head intermolecular recombination with hybrid and homologous ITR vectors. (A) Schematic representation of the hybrid ITR trans-splicing viral genomes, AV5:2LacZdonor and AV2:5LacZacceptor, which were used to generate AAV-2 serotype viruses AV5:2/2LacZdonor and AV2:5/2LacZacceptor, respectively. The AV2:2/2LacZdonor and AV2:2/2LacZacceptor viruses (not shown) had similar structures but contained AAV-2 ITRs on both ends of the genome. (B to D) HeLa cells were infected at a multiplicity of infection of 2,500 DNase-resistant particles/cell with each virus alone or in combination, as indicated. β-Galactosidase activity was quantified at 3 days postinfection. This analysis was performed with (B) AAV-2-encapsidated viruses and (C) AAV-5-encapsidated viruses. (D) Mixing experiments with combinations of hybrid and homologous ITR donor and acceptor vectors were also performed to assess sequence specificity in ITR recombination. Vector combinations are shown schematically on the graph, with open and solid arrowheads indicating AAV-2 and AAV-5 ITRs, respectively. Data represent the mean (± standard error of the mean) of seven independent infections.