Figure 3

Binding of Fc-gp120 chimeras to cellular CCR5. A) Inhibition of Fc-gp120-sCD4 complex binding to CCR5 by RANTES (1 μg/ml), TAK779 (0.5 μg/ml) and 2G12. Binding inhibition was assessed by FACS analysis and is expressed as a percentage calculated with reference to m.f.i. data using Fc-gp120-sCD4 complexes alone (0% inhibition value) and background with nothing added (100% inhibition value). Results are the means of triplicates. B) Inhibition assays were performed using Fc-gp120 complexed with 1 or 10 μg/ml of sCD4 and mAbs 2G12 or b12 at 10 or 25 μg/ml. Inhibition of binding was expressed as a percentage, as above. Results are the means of duplicates.