Cdc42 and Rac activation in mature DCs after CCL19 stimulation. BC1 cells treated with LPS for 24 hours were used as mature DCs. The quantity of activated Cdc42 and Rac (GTP-bound form) in the cells was determined by an affinity precipitation assay. (A) Kinetics of Cdc42 and Rac activation following stimulation of mature BC1 cells with CCL19 for 0.5, 1, 2, and 5 minutes. (B) The mean relative intensity ± SE of 3 independent experiments. (C) The effect of PTX on Cdc42 and Rac activity. Mature BC1 cells were pretreated with PTX for 3 hours, then stimulated with CCL19 for 30 seconds. The amount of GTP-bound (GTP) and total (total) Cdc42 (left panel) and Rac (right panel) are each shown. These results are representative of 3 independent experiments with the same results.