Influence of signal transduction pathways on MoDC migration. (A) Migration of migratory-type MoDCs to CCL21 in the absence or presence of protein kinase C or protein kinase A agonists. The protein kinase C agonist PMA (1 ng/mL) or the protein kinase A agonist PGE₂ (10 μM) or 8-bromo-cAMP (10 μM) was added to the chemokine-containing side of transwells. Migration in the absence of activators was normalized to 100% (mean ± SEM; n = 3). (B) Migration of MoDC to CCL21 ± ATP in the absence or presence of protein kinase C or protein kinase A or of phospholipase C antagonists. MoDCs were incubated with the protein kinase C inhibitor Ro31-8220 (5 μM) or the protein kinase A inhibitor H-89 (5 μM) for 30 minutes before assessment was made of their migration to CCL21 in the absence or presence of 100 μM ATP. Incubation of MoDCs with the phospholipase C inhibitor U-73122 (0.5 μM) abolished chemokine-directed migration (not shown). Therefore, U-73122 (10 μM) was added to the chemokine-containing side of transwells (± ATP). Migration in the absence of ATP was normalized to 100% (mean ± SEM; n = 3).