Fig. 8.

Sensitivity of viruses with wild-type and variant HIV-1_JR-FL Envs to neutralization by antibodies and activation by CD4-mimetic molecules. (A) Recombinant, luciferase-expressing viruses with the wild-type HIV-1_JR-FL Env or variant Envs with adaptation-associated changes were incubated with antibody at room temperature. The virus-antibody mixtures were then incubated with Cf2Th-CD4/CCR5 cells for 2 days prior to cell lysis and measurement of luciferase activity. Viral infection is shown as a percentage of the luciferase activity observed in the absence of antibody. The means and standard deviations from duplicate samples in a typical experiment are shown. (B) Recombinant viruses with the wild-type HIV-1_JR-FL Env or the adapted virus Envs were incubated with CD4-negative Cf2Th-CCR5 cells in the presence of the indicated concentrations of sCD4 or the CD4-mimetic compound DMJ-I-228. Luciferase activity was measured in the cells two days later and is reported as the percentage of the maximum luciferase activity observed for each virus variant.