FIG 5 .

Purified pneumococcal RNA is sufficient to induce IL-12p70 in DCs and can activate TLR3. DCs were transfected with total RNA from T4R with or without prior digestion with RNase A and T1, or transfected with the enzymes alone, and a proportion of these cells were treated with LPS 4 h posttransfection (A). DCs were transfected with total RNA from T4R and treated with a TLR3/dsRNA complex inhibitor (B). IL-12p70 production was measured in the supernatant by ELISA (A and B). HEK293 cells expressing TLR3 or TLR4 were transfected with total RNA from T4R, stimulated with PolyI:C or LPS, and luciferase activity was measured (C). Values represent means ± standard errors of the means for results from 6 (A and B) or 3 (C) experiments. IL-12p70 secretion was measured in the cell supernatant. Statistical analysis was performed using a Wilcoxon matched-pairs signed-rank test (for ELISAs) or using Student’s t test (for the luciferase assay). *, P < 0.05; **, P < 0.005. n.s., not significant.