Apoptotic cells induce migration of mature DCs toward the LN chemokines CCL19 and CCL21. Immature DCs were exposed, in 10% autologous complete serum, to apoptotic Jurkat cells for 4 hours before the addition of TNF-α (250 U/mL). Migration capacity of DCs toward CCL19 (300 ng/mL) or CCL21 (250 ng/mL) was tested 2 days later using the Transwell migration assay. (A) Migration of DCs alone (1:0/0) plus TNF-α (1:0/TNF) or treated with apoptotic cells at different DC/ApoC ratios (1:1, 1:2, 1:4, 1:8). Error bars represent the SD of 2 counts. (B) Mean ± SD of 5 to 8 independent experiments. Statistical analyses were performed using the Student t test. PGE2 (1 μg/mL) was added simultaneously with TNF-α. Unless otherwise stated, differences were not significant. The migration difference between no attractant and CCL21 was significant for the condition PGE2/TNF-α (P < .01) and for the condition 1:8/TNF (P < .02). The difference between 1:8/TNF with CCL21 and 0/TNF with CCL21 was significant (P < .05). (C) CD83 and CCR7 co-expression (top) or CCR7 expression (bottom) after 48-hour incubation in various conditions. Experimental conditions and DC/ApoC ratios are similar to those in panels A and B. Histograms are representative of more than 7 experiments. (Top) Percentages of cells in each quadrant are given. (Bottom) Percentages of CCR7-positive cells as defined using isotype control (dashed line) are given.