17-Res and 24-Res Envs exhibit a similar altered recognition of the CCR5 ECLs. Luciferase reporter viruses pseudotyped with Envs from subject 17 (A) or 24 (B) were used to infect NP2-CD4 cells expressing equivalent amounts of WT CCR5 or CCR5 with mutations in the ECL1, ECL2 and ECL3 regions. Infections were performed in the absence or presence of 10 µM MVC. Viral entry in cells expressing CCR5 mutants was normalized to entry obtained in cells expressing an equivalent amount of WT CCR5. In these experiments, MVC completely inhibited the entry of 17-Sens and 24-Sens Envs, regardless of the Env mutant tested (data not shown). The data shown are the means and SEM from a compilation of 3 independent experiments. **p<0.05 for increases in the dependence on a particular residue compared to respective resistant Envs in the absence of drug (unpaired t-test).