Figure 2

Inhibition of HIV-1 entry into CD4+ HeLa cells by gp41-derived recombinant proteins. HIV-1 particles pseudotyped with envelope glycoproteins from either the X4 isolate HIV-1 LAI or the R5 isolate HIV-1 ADA were pre-incubated with increasing concentrations of Rgp41A or Rgp41B before being added to HeLa-CD4-LTR-LacZ cells. For infection with HIV-1 ADA pseudotyped virus, cells were transfected with pCMV-CCR5 48 h before infection. Fourty-eight hours post-infection, viral entry and replication was monitored by measuring luciferase activity in cell extracts. For each experiment, the inhibitory effect of recombinant proteins was compared to the effect of the same volume of solubilization buffer. NLI: Normalized Luciferase Index. The average ± SD of triplicate samples is shown. Results represent the average ± SD of a typical experiment performed in duplicate, representative of at least 3 independent experiments.