FIG. 4.

Infection of macrophages by SI primary isolates that use CXCR4 but not CCR5 in heterologous systems. Macrophages from CCR5 wild-type donors (A, C, and E) or Δ32 homozygous donors (B, D, and E) were infected with the primary isolate tybe (A and B) and two clade D primary isolates, UG021 (C and D) and UG024 (E and F). Infections were done in the presence or absence of the CXCR4 inhibitor AMD3100 (1 μg/ml) as described in the legend to Fig. 1, and supernatant was sampled periodically for p24 antigen. Data are means of duplicate wells and are representative of three independent experiments.