Figure 2.

Nef mutations provide resistance against siRNA-Nef. The Nef mutations shown in Figure 1B were cloned in the HIV-1 LAI molecular clone. Virus stocks were produced in transiently transfected C33A cells and used to infect SupT1 cells stably expressing siRNA-Nef. Virus replication was monitored by determining the level of CA-p24 in the culture supernatant. Similar results were obtained in independent infection experiments. The R7 variant was excluded from further analysis since it contained a complete deletion of the siRNA-Nef target sequence very similar to the R1 variant. The wild-type LAI virus that does not replicate on these SupT1-siRNA-Nef cells replicates efficiently on control SupT1 cells [results not shown, see also (28)].