Adeno-associated viruses (AAVs) are replication-deficient parvoviruses, which have traditionally required co-infection with a helper adenovirus or herpes virus for productive infection. The AAV Helper-Free System allows the production of infectious recombinant human adeno-associated virus-2 (AAV-2) virions without the use of a helper virus.
In the AAV Helper-Free System, most of the adenovirus gene products required for the production of infective AAV particles are supplied on the plasmid helper that is co-transfected into cells with human AAV-2 vector DNA. The remaining adenoviral gene product is supplied by the AAV-293 host cells, which stably express the adenovirus E1 gene. The AAV Helper-Free System includes AAV-293 cells, which are HEK293-derived cells with improved adeno-associated virus production capabilities. By eliminating the requirement for live helper virus, the AAV Helper-Free System provides a safer, purer and more convenient alternative to retroviral and adenoviral gene delivery systems.