FIG. 1.

Dualtropic and T-tropic viruses use Apj or CCR9 as coreceptors. Cf2Th-CD4 cells were transfected with either the pcDNA3 vector only or pcDNA3 plasmids encoding CCR5, CXCR4, Apj, or CCR9. The transfected cells were incubated with recombinant CAT-expressing viruses containing the envelope glycoproteins of the M-tropic HIV-1 ADA, JR-FL, or YU2; the dualtropic HIV-1 89.6; the primary T-tropic HIV-1 ELI, or UG21; the laboratory-adapted T-tropic HIV-1 MN or HXBc2; or the SIV isolates SIVmac239 or SIVmac316. Entry was quantitated as the ratio of the acetylated forms of chloramphenicol (upper spots) to the unacetylated form (bottom spot). Samples in which conversion is greater than 60% were diluted 1:10 and reassayed for quantitative comparisons. Entry of viruses pseudotyped with 89.6, ELI, UG21, MN, or HXBc2 envelope glycoproteins into cells expressing Apj was 5.6 ± 0.2, 10.2 ± 0.1, 7.7 ± 0.4, 1.5, and 0.3% ± 0.1%, respectively, of that of the same viruses entering cells expressing CXCR4. The entry of the virus pseudotyped with the envelope glycoproteins of SIVmac316 into cells expressing Apj was 21.9% ± 4.7% of that observed for cells expressing CCR5. Entry of virus pseudotyped with UG21 envelope glycoproteins into cells expressing CCR9 was 6.2% ± 1.9% of that observed for cells expressing CXCR4.