Figure 6.
Evasin-1 neutralizes the antagonistic effect of CCL18 on CCR3. (A) Equilibrium competition binding assay of 125I-CCL18 on L1.2/CCR3 transfectants using an increasing concentration of CCL11 and the CCL18-binding proteins Evasin-1, -3, and -4. Data are expressed in cpm ± SEM. Data points are in triplicate. Inhibitory activity of CCL11 (IC50: 4.99 nM), Evasin-1 (IC50: 7.94 nM), and -4 (IC50: 0.03 nM) on 125I-CCL18 binding to CCR3. (B) Inhibition of chemotaxis using L1.2/CCR3 transfectants. Migration of L1.2/CCR3 transfectants to a constant concentration of 1 nM CCL11 was inhibited by an increasing concentration of CCL18 (IC50: 556.8 nM). The effect of Evasin-1 on the antagonistic activity of CCL18 on CCR3 was assessed by the incubation of CCL18 with a twofold access of Evasin-1. Evasin-3 (IC50: 421 nM) was used as a control. Data are expressed as chemotaxis index ± SEM. Data points are in triplicate. One representative experiment out of two is shown.