CD86 up-regulation by U1snRNP/anti–Sm complexes in FL-DCs. FL-DCs (untreated or pretreated with IFN-β) were incubated with Y12 antibody (50 μg/mL) alone or in complex with U1snRNP (20 μg/mL) for 40 hours. CD11b and CD86 expression were measured by flow cytometry. Low CD11b expression correlated with high B220 expression (not shown). Percentages are indicated in the quadrants. Results of 1 of 4 representative independent experiments are shown.