FIG 3.

Half-maximal effective concentration (EC₅₀) of a CCR5 antagonist for suppression of infection by chimeric viral variants. TZM-bl cells were infected with the chimeric virus at an MOI of 0.005 and cultured in the presence of the CCR5 antagonist maraviroc at concentrations ranging from 1 × 10⁴ nM to 1 × 10⁻³ nM with 10-fold serial dilutions. The box plots represent the EC₅₀ of maraviroc for each viral variant from the individuals (a), the susceptibilities of viral isolates derived from later and early stages of infection to maraviroc (b), and the susceptibility difference between R5- and R5X6-capable early-transmitted viruses (c). Inhibition data from replicates were plotted using GraphPad Prism software, and EC₅₀ were determined using variable-slope nonlinear regression analysis. Experiments were carried out in triplicate in two biological replicates. The statistical comparisons were performed using the Kruskal-Wallis test (among the individual patients) and the Mann-Whitney test (between groups), and a P value of <0.05 was considered statistically significant. ns, not significant.