Mature CD34⁺-derived int-DCs migrate in response to chemokines and activated naive T cells.

(A) Unstimulated and stimulated CD34⁺-derived int-DCs were tested for chemotactic migration in response to CCL20, CCL19, and CCL21. Each assay was performed in duplicate, and the results are expressed as the means ± SD of migrating cells per 2 fields. (B) Naive T cell stimulatory ability of unstimulated or stimulated CD34⁺-derived int-DCs and CD14⁺ precursor cell–derived mature CD1a⁺ DCs, generated in the presence of GMCSF and TNFα. Graded doses of DCs were seeded with 2 × 10⁴ cord blood–purified T cells in microtest culture plates in RPMI medium containing 10% FCS. T-cell proliferation was measured after 5 days of culture following an overnight incubation with 1 μCi (0.037 MBq) of [³H]thymidine. Results are expressed as mean cpm ± SD of triplicate cultures.