Effects of PU.1 on phenotype and function of DCs. (A) Cell-surface expression of DC-related molecules in PU.1-siRNA–introduced BMDCs. Solid line histogram represents cells with each antibody. Dotted line histogram represents negative control with 2.4G2 alone (A and D). Representative results of 3 independent experiments are shown. (B) T cell–stimulation activity of PU.1–knocked-down BMDCs (*P < .05; **P < .005). LPS-stimulated BMDCs (Balb/c) transfected with control siRNA (○) or PU.1 siRNA (●) were used as a stimulator for T cells from B6 mice. Representative results of 2 independent experiments are shown. (C) Cytokine production of PU.1–knocked-down BMDCs in response to LPS stimulation (*P < .05; **P < .005; ***P < .001). Cytokine concentration in the supernatant at 6 hours (for TNF-α and IL6) and at 24 hours (for IL12 p40) after the addition of various concentrations of LPS was measured by ELISA. Results are expressed as means + SD of 2 independent experiments performed in duplicate. (D) Cell-surface expression of DC-related molecules in PU.1-overexpressing hematopoietic stem cells. Lin⁻ cells were transfected by retrovirus vector carrying IG-mock or IG-PU.1 (Figure 5A) and maintained in the same condition as that of Figure 5D with supplementation of IL3, IL6, SCF, TPO, and EPO. Similar results were obtained in 2 additional independent experiments.