Figure 2.

Displacement of iodinated RANTES by CCR5Δ32 sera, CCR5^+/+ sera and RANTES from transiently transfected COS-7 cells expressing CCR5. As shown, the sera diluted (1:20, 1:50, and 1:500) from the two Δ32 individuals displaced binding of RANTES, in contrast to a panel of CCR5^+/+ sera. Maximally bound iodinated RANTES corresponded to approximately 1,500 cpm. No specific binding was observed with COS-7 transiently transfected with the pTEJ8 eukaryotic expression vector. Nonspecific binding of ¹²⁵I-RANTES was determined by homologues displacement by using 10 μM RANTES (black columns).