Expression of molecules involved in DC migration. (Top panel) DCs were matured for 2 hours as indicated and the expression levels of mRNA encoding CCR-7, MMP)-9, MT-1 MMP, and TIMP-1 were determined by SYBR green-based quantitative RT PCR. The data shown are the mean ± SEM of triplicates and represent 1 of 2 experiments that yielded similar results. (Bottom panel, left) Transwell migration assays. DCs were matured for 48 hours with CD40L and increasing amounts of LTC4 or PGE₂. Migration was assessed in transwell plates with polycarbonate inserts (8 μm pore size) for 2 hours at 37°C. CCL-19 (100 ng/mL) was added to the lower chambers of transwell plates. The data shown represent the mean ± SEM of duplicate cultures and represent 1 of 2 experiments that yielded similar results. (Bottom panel, right) Membranes of transwell inserts were coated with Matrigel (laminin, collagen, proteoglycans, entactin, nidogen) and migration assays were performed using DCs that had been matured as indicated. CCL-19 (100 ng/mL) was added to the lower chambers and migration of DCs was assessed after 6 hours at 37°C/5% CO₂. DC migration in the absence of chemokine was subtracted as background. The data are shown as the mean of duplicate cultures ± SEM and represent 1 of 2 experiments that yielded similar results.