IPCs derived from HPCs in FLT3-L/TPO cultures have functional properties similar to those of peripheral blood IPCs. (A) Sorted IPCs and CD11c⁺ immature DCs from HPCs in FLT3-L/TPO culture were activated by HSV for 48 hours. Culture supernatants were collected and assayed for IFN-α production using ELISA. Data shown are aggregate results from 3 independent experiments and are expressed as means ± SD. (B) Sorted CD11c⁺ immature DCs and (C) sorted IPCs from FLT3-L/TPO cultures were cultured in media with or without CD40L for 3 days and were used as stimulators in graded doses to 2 × 10⁵ purified allogeneic CD3⁺ T cells in an MLR assay. (D) Sorted IPCs from FLT3-L/TPO cultures were cultured in media with or without CpG ODN 2006 at 3 μg/mL for 3 days and were used as stimulators in graded doses to 2 × 10⁵ purified allogeneic CD3⁺ T cells in an MLR assay. [³H]-Thymidine was added to each well 18 hours before harvesting, and [³H]-thymidine incorporation (cpm) was determined. MLR data are representative results from 1 of 3 independent experiments and are expressed as means ± SD.