Figure 2.

(A) Concentration dependence of the effect of RANTES on HIV-1–specific cytolysis. Transformed autologous B cells infected with recombinant vaccinia virus expressing Gag were used as targets. Lysis by HIV-1–specific CTLs was assessed at an E/T ratio of 120:1 in the presence of increasing concentrations of RANTES (closed circles), the antagonist RANTES(9-68) (open circles), or MIP-1α (closed triangles). The data are representative for two experiments. (B) Effect of B. pertussis toxin. The effector cells were pretreated with RANTES in the absence (closed circles) or the presence (open circles) of pertussis toxin, washed, and then mixed with target cells expressing HIV-1 Pol protein. The toxin concentration was 10, 100, 1,000, or 5,000 ng/ml (open circles, top to bottom). The data are representative for four experiments. (C) RANTES acts on the HIV-1–specific CTLs but not on the target cells. Lysis was assessed at a similar E/T ratio after pretreatment of the effector (white bars) or the target cells (hatched bars) with RANTES, MIP-1α (all 25 nM) or without additions. Pretreatment was performed for 1 h at 37°C followed by washing, immediately before the Cr-release assay. The data are representative for two experiments.