Table 1

Binding constants of selected CXC-chemokines for the HHV8-encoded ORF74 receptor using different radiolabeled ligands. The ORF-74 receptor was transiently transfected in COS-7 cells and competition binding experiments were performed as described under Experimental Procedures. IC₅₀ values were determined either in competition against ¹²⁵I-GROα (B _max = 44 ± 10 fmol/10⁵ cell), ¹²⁵I-IL8 (B _max = 42 ± 12 fmol/10⁵ cell), or¹²⁵I-IP-10 (B _max = 28 ± 5 fmol/10⁵ cell). Shown are mean ± S.E. of the indicated number of experiments (n). The “fold difference” measured in affinity when using ¹²⁵I-GROα or¹²⁵I-IP-10 versus ¹²⁵I-IL8 as radioactive ligand is listed in a separate column.