Identification of DC-stimulatory compounds in the NCI library. (A) Six hits were identified by screening 1986 compounds in the NCI library with the DC biosensor system. The XS106-pIL1-YFP DC clone was incubated for 16 hours with individual hit compounds at the indicated concentrations and then examined for YFP expression. Data shown are the delta MFI values representing the YFP fluorescent signals above the baseline level detected in the absence of added stimuli (mean ± SD; n = 3). *P < .01 (compared with vehicle-treated samples). (B) BM-DCs were incubated for 24 hours with compound 3667-7B at the indicated concentrations and then examined for the surface expression of MHC II (circles), CD40 (triangles), and CD80 (squares) (mean ± SD; n = 3). *P < .05, **P < .01 (compared with vehicle-treated samples). (C-D) The supernatants of the same BM-DC cultures were examined for secretion of IL-1β (C), IL-6 (D, ○), and IL-12 p40 (D, •) (mean ± SD; n = 3). *P < .05, **P < .01 (compared with vehicle-treated samples). (E) BM-DCs were incubated for 24 hours with compound 3667-7B (1 μM), LPS (10 ng/mL), or vehicle alone and then examined for the production of indicated factor (mean ± SD; n = 3). **P < .01 (compared with vehicle-treated samples). (F) XS106 DCs were incubated for 5 hours with compound 3667-7B at the indicated concentrations and then examined for activation of NF-κB p65 (•) and c-Rel (○) (mean ± SD; n = 3). **P < .01 (compared with vehicle-treated samples).