Recombinant aden-associated virus (AAV) production
Several systems exist to produce recombinant adeno-associated virus (AAV). The most common system is based on a 3 plasmid co-transfection (Figure 1) of HEK293 cells as the packaging cell line. Following lipid based co-transfection, cells are harvested by lysis, and the virus is purified for infection of target cells (Figure 2).
Figure 1: Plasmids required for AAV production. The viral plasmid encodes for the replication (Rep) and Capsid (Cap) proteins. The helper plasmid encodes for the essential factors E4, E2a, and VA. Without those factors, no replication would occur. Finally, a third plasmid is co-transfected the therapeutic gene cDNA (shown here in yellow).
Figure 2: Co-transfection procedure