Interaction of vMIP-III with chemokine receptors.

(A) Radioligand competition-binding studies were performed on THP-1 cells (which naturally express CCR2), and L1.2 cells were stably transfected with CCR3, CCR4, or CCR5. The radioligand forms of the natural ligands for these receptors were as follows: MCP-1 (THP-1/CCR2), MCP-4 (CCR3), MDC (CCR4), and MIP-1α (CCR5). Competition was performed using either the unlabeled natural ligand (⧫) or vMIP-III (□). (B) The cell lines used for binding studies were used in chemotaxis assays with either the natural ligands for these receptors; MCP-1 (CCR2), eotaxin (CCR3), MDC (CCR4), RANTES (CCR5), (⧫) or vMIP-III (□). (C) IC₅₀ values from A are summarized.