Expression of IL-15/IL-21 receptor components in DCs. Eight-day-cultured DCs (lane 1), IL-15DCs (lane 2), and IL-21DCs (lane 3) were analyzed by RT-PCR for mRNA expression of IL-21R, IL-15Rα, IL-15, IL-21, and IL-2Rα and β chains as well as for the common γ-chain. β-actin message expression was used to normalize the cDNA amount. To exclude contaminations all experiments were run with a mock PCR and found negative (not shown). The correct size of PCR product was assessed with a marker (M). As positive controls (C) for IL-21 and its receptor, cDNA from CD4⁺ T cells from C57BL/6 mice was isolated. For IL-15 and its receptor we used cDNA from L929 fibroblasts, and CTLL-2 cells were the positive reference for all IL-2R chains. One representative experiment of 5 is shown.