FIG. 1.

Postentry HIV-1 infection in primary monocytes is enhanced by macrophage differentiation. (A) Kinetics of HIV-1 infection of freshly isolated monocytes. Primary monocytes and Hut/CCR5 cells were infected with HIV-Luc/VSV-G (VSV-G) or the same p24 amounts of HIV-1 particles devoid of envelope protein (No Env). (B) Macrophage differentiation stimulates HIV-1 infection in monocytes. Monocytes were infected with HIV-Luc/VSV-G (MOI, 0.5) and cultured in the presence of M-CSF to induce macrophage differentiation. (C) Macrophages continuously support robust HIV-1 infection. Macrophages were differentiated from monocytes by M-CSF treatment for 7 days and then were infected with HIV-Luc/VSV-G (MOI, 0.5). HIV-1-infected cells were lysed at the indicated times for the detection of luciferase activity. cps, counts per second. All data are means ± standard deviations of triplicate samples. One representative experiment out of at least three is shown. Multiple different donors' monocytes were used in the repeat experiments.