Figure 2

Coreceptor use by R5X4 HIV-1 on indicator cell lines and primary CD4+ lymphocytes. (A) Coreceptor use on U87 indicator cells by R5X4 HIV-1. U87 CD4, CD4/CCR5 or CD4/CXCR4 cells were infected with HIV-1 pseudotype viruses (5ng p24 Gag antigen). Three days after infection, cells were lysed and luciferase activity was measured. Results are means sem of two experiments performed in triplicate. (B) Coreceptor-specific entry into CD4+ T lymphocytes. Purified CD4+ lymphocytes were isolated by negative selection, stimulated with PHA for 3 days, infected with 5ng of HIV-1 pseudotype viruses in the absence or presence of coreceptor antagonists as described in Figure 1, maintained with IL-2 and lysed four days later for measurement of luciferase expression. Results represent normalized infection through each coreceptor and are means +/- sem of infections done using cells from three different donors, each performed in duplicate.