Fig. 2.

Sensitivity to small-molecule CCR5 inhibitors of T/F HIV-1 Envs in cell–cell fusion. QT6 effector cells were prepared by infection with vTF1.1 for 1 h followed by transfection with Env expression constructs. Target QT6 cells were transfected with CD4 and CCR5 in pcDNA3, and a construct encoding luciferase under the transcriptional control of T7 promoter. At 16–18 h post-transfection, target cells were pre-treated with serially diluted CCR5 inhibitor maraviroc (a), CMPD-167 (b) or SCH-412147 (c) for 30 min before mixing with effector cells. The luciferase activity of cell lysates was determined approximately 8 h later. The fusogenic activity in medium alone was arbitrarily set to 100 % for each Env. Data are representative of three independent experiments, with each determination performed in triplicate (mean±sd).