Transient elevation of CCR7 expression and in vitro migratory responsiveness to lymph node–associated chemokines in PGE₂-matured DCs. (A left) Surface CCR7 expression in DCs matured into αDC1s or sDCs in 9 different donors. (A right) In vitro migratory response of αDC1s and sDCs to CCL21, a secondary lymphoid organ chemokine (data from 6 different donors shown as mean ± SD). (B) Surface expression of CCR7 protein on αDC1s and sDCs at 0 (left) and 24 hours after completion of maturation and replating in the absence of the maturation-inducing factors (right). (C) In vitro migratory response to CCL21 of αDC1s and sDCs, directly (left) and 24 hours (right) after removal from the maturation cultures. The numbers in gray boxes represent the ratios between the numbers of sDCs and αDC1 that migrated to each individual concentration of CCL21. Similar data were obtained in 2 independent experiments. (D, left) In vivo migration of αDC1s and sDCs to the lymph nodes. Scintigraphic image of ¹¹¹indium-labeled αDC1 and sDC at intradermal injection site and draining lymph nodes at 48 hours in a single representative patient. (D, right) In vivo migration of αDC1s or sDCs in 6 patients (each pair of dots represents each individual patient).