A sulfated mimic of the CCR5 N-terminus can inhibit entry of MVC-resistant Envs. NP2-CD4/CCR5 cells were preincubated with increasing concentrations of scrambled, unsulfated or sulfated sCCR51-22 peptide prior to infection with luciferase reporter viruses pseudotyped with Envs from subject 17 (A) or 24 (B). Infections of viruses pseudotyped with 17-Res and 24-Res Envs were also performed in the presence of 10 µM MVC. The data are expressed as the percentage entry of that obtained in cells incubated with no inhibitor. Data points shown are the mean and SEM of triplicates, and are representative of three independent experiments.