Tlr7-dependent cytokine induction in FL-DCs by total U1snRNA and oligoribonucleotides derived from U1snRNA. Wild-type and Tlr7^–/– FL-DCs were incubated with 10 μg/mL (0.2 μM) total U1snRNA isolated from U1snRNP, 2 μM oligoribonucleotides derived from the U1snRNA sequence, or 10 μg/mL poly-U RNA in complex with 12.5 μg/mL DOTAP, with DOTAP alone or with 0.5 μM CpG 2216 as positive control stimulus. After 36 hours of incubation, IFN-α and IL-6 were measured in the supernatant by ELISA. Mean values and standard deviations are shown (n = 3). Asterisks indicate significant differences between wild-type and Tlr7^–/– cells (P < .05; 2-tailed paired Student t test).