Figure 1. CCX8037 is a potent and selective antagonist of CCR9.

CCL25-induced chemotaxis was measured on Molt-4 cells and murine thymocytes by using a DNA intercalating fluorescent dye (CyQUANT) to quantify responding cells and is labeled as the “migration signal”, as the relative fluorescence of the migrated population is proportional to the number of cells that migrated. Six to eight replicates were performed per data point. Calcium flux was measured on Molt-4 cells or IL-2-cultured lymphocytes loaded with Indo-1AM dye and exposed to IC₅₀ concentrations of the chemokines indicated. A) CCX8037 inhibits CCL25-induced Molt-4 chemotaxis in buffer (0.1% BSA in HBSS) with an IC₅₀ of 12 nM (n = 31). B) CCX8037 inhibits CCL25-induced Molt-4 chemotaxis in the presence of 100% human AB serum with an IC₅₀ of 32 nM (n = 9). C) CCX8037 inhibits CCL25-mediated mobilization of intracellular Ca2+ in Molt-4 cells with an IC₅₀ of 19 nM (n = 3). D) CCX8037 (blue trace; 10 uM) does not inhibit chemokine induced mobilization of intracellular Ca2+ to EC₅₀ concentrations of CCL4(CCR5), CCL15 (CCR1) on IL-2 activated lymphocytes. E) CCX8037 inhibits CCL25-induced murine thymocyte chemotaxis in buffer with an IC₅₀ of 2.5 nM (n = 2).