FIG. 5.

PSC-RANTES blocks primary R5 HIV infection of LC without promoting infection of LC by primary X4 HIV. LC within skin explants were preincubated with 100 nM PSC-RANTES for 20 min, simultaneously exposed to relatively equal amounts (MOI of 0.01 for each) of both B2 HIV (an R5 HIV primary isolate) and B4 HIV (an X4 HIV primary isolate) for 2 h, and cultured for 3 days. DNA was then extracted from LC and amplified by PCR using env-specific primers (A) and used in a heteroduplex tracking assay (B) as described in Materials and Methods. (C) Additional competitions between B2 HIV and B4 HIV were performed in PBMC. DNA was extracted after 10 days in these experiments. The percent growth of B2 HIV relative to B4 HIV is plotted for both PBMC and LC experiments.