Antigen-presenting capacity of ES-DCs.

(A) Graded numbers of ES-DCs (○) and BM-DCs (▵) were incubated with PCC protein (50 μg/mL) for 6 hours, and subsequently 2B4 hybridoma cells were added (5 × 10⁴/well). ES-DCs (●) and BM-DCs (⋄) were also tested in the absence of the protein. After 24 hours, culture supernatant was collected and IL-2 produced by the hybridoma was measured by proliferation of CTLL-20 cells. (B) ES-DCs (○) and BM-DCs (▵) were plated (3 × 10⁴/well) and incubated with graded doses of PCC protein for 6 hours and subsequently added with 2B4 cells. IL-2 production by 2B4 was measured as in panel A. (C) ES-DCs fixed with glutaraldehyde or left unfixed were plated (3 × 10⁴/well) and incubated with PCC protein (50 μg/mL, prot.) or PCC_88-104 peptide (10 μM, pep.) for 6 hours, and subsequently 2B4 hybridoma cells were added. Results were expressed as mean cpm of triplicate (A-B) or duplicate (C) cultures ± standard deviation.