FIG. 3.

Use of CXCR4⁻ SupT1 cells to assess CXCR4 use. Growth curves are shown for 239-ST1.2-32 Long CT (A) and SIVmac239 (B) in parental SupT1 cells, CD4⁺ CXCR4⁻ CCR5⁻ SupX4⁻ cells, CD4⁺ CXCR4⁻ CCR5⁺ SupX4⁻R5⁺ cells, and SupX4⁻ cells that were complemented with stable CXCR4 expression (SupX4⁺ cells). RT activity in culture supernatants was measured at the indicated time points. Results from a representative experiment are shown for each panel.