Figure 1.

Schematic diagram of HPV16 pseudovirus production. The packaging plasmid encoding the L1 and L2 capsid proteins (pink) is transfected into 293TT cells along with a pseudogenome encoding the green fluorescent protein (GFP; shown in green), resulting in “pseudovirus-producing” 293TT cells. The pseudogenome carries a SV40 origin of replication (SV40 Ori), allowing high expression in 293TT cells. These cells synthesize L1 and L2 capsids that assemble into virus particles carrying the pseudogenome. These pseudoviruses can then be used to infect 293TT cells, which in turn express GFP encoded by the pseudogenome, which can then be visualized under a microscope, as shown in Figure 2.