U83A-N inhibits HIV-1 infection in human PBMC. (A) Flow cytometry for CD14 and CCR5. Cells were cultured for 72 hours allowing monocytic/macrophage differentiation, confirmed by flow cytometry which showed CD14 and CCR5 expression, but not CCR2, CCR3, CCR1, or CCR8. (B) R5 HIV-1 strain SF162 was cultured at an MOI of 0.01, in these cells for 6 days in the presence of U83A-N (gray line) or CCL5/RANTES (black line), and virus was then titrated on MAGI-CCR5 cells as described. Greater than 95% inhibition was demonstrated with U83A-N at 0.1 nM and above. Means ± SDs of duplicates.