AdCCL-21-DC augments PBL chemotaxis. Ad-CCL-21-DC, AdCV, NTDC, and recombinant CCL-21 were used to investigate the induction of migration of PBL in response to AdCCL-21-DC. 2 × 105 freshly isolated PBL were labeled with 5 μm cell tracker™ green 5-chloromethylfluorescein diacetate and loaded in the upper chamber of a Transwell apparatus fitted with 3 μm pre size membrane inserts. Supernatant from NTDC, AdCCL21-DC (producing 20 ng/ml/106 cells/48 hours CCL-21 protein) and AdCV-DC were added to the lower chamber. The OD of migrated cells was measured after 2 hours incubation at 37°C by a fluorescence plate reader. Values are expressed as relative migration versus control (10% AB medium). The bar on the far right indicates chemotaxis to recombinant CCL-21 at 100 ng/ml. Results are representative of three independent experiments.