FIG. 4.

Inhibition of HIV-1 entry into normal and CCR5-deficient macrophages. Macrophages were isolated from individuals homozygous for the wild-type CCR5 allele (w/w) or the ccr5Δ32 allele (Δ/Δ). After 7 days in culture they were infected with 20 ng of p24 antigen of the dual-tropic isolate 89.6, the T-tropic strain NL43, or the M-tropic strain SF162. The indicated wells were incubated for 1 h prior to and throughout the infection with the anti-CD4 MAb no. 19 (#19), the anti-CXCR-4 MAb 12G5, or the control antibody B33.1 or with SDF, MCP-1 and MCP-3, or eotaxin. Three days after infection the cells were lysed and subjected to PCR amplification with primers that detect conserved regions of the HIV-1 LTR, followed by Southern blotting. Infections were done in duplicate and amplified in independent PCR reactions, both of which are shown. Amplification with β-globin primers showed a positive signal in all wells (data not shown). HIV plasmid DNA was used as a positive control (+) for amplification. Data are representative of replicate experiments with cells from three ccr5Δ32-homozygous donors.