Effect of SCH 546738 on human Activated T cell chemotaxis induced by CXCL10, CXCL9, CXCL11 and CCL19. Human peripheral blood lymphocytes were prepared by Ficoll-Hypaque centrifugation, depleted of monocytes, and stimulated by PHA/IL-2. After 7-9 days of stimulation, activated T cell chemotaxis assay was carried out as described in Methods. The medium containing 20% fetal bovine serum was used for all dilutions of chemokines and compounds. Various concentrations of each indicated chemokine were added to the bottom wells in the presence of fixed concentrations of SCH 546738 (1, 10, 100 nM) (added both on the filter with cells and in the bottom wells). Chemotaxis of each sample is expressed relative to spontaneous response (without chemokines) as chemotactic index.