(A, D) HEK293 stably expressing human TLR3 (HEK293-hTLR3) or control HEK293 cells (HEK ctl) were transfected with the TLR3 ligand poly(I:C) (5 μg), the Tlr13 ligand oligoribonucleotide SA19 (5 μg), S. pyogenes RNA (5 μg) using DOTAP or stimulated with human TNF (10 ng/ml). IL-8 release was measured in supernatants 24 h post stimulation by ELISA (A) or the levels of IL8 mRNA were determined by qRT-PCR (normalized to HPRT) (D). Mean values ± SD are shown (n ≥ 3). (B, C, E, F) HEK293XL cells stably expressing human TLR7 (B, E) or TLR8 (C, F) or control HEK293XL cells were transfected with SA19 (5 μg), S. pyogenes RNA (5 μg) or stimulated with the TLR7 and TLR8 ligand R848 (5 μg/ml) or human TNF (10 ng/ml). IL-8 release was measured in supernatants 24 h post stimulation by ELISA (B, C) or the levels of IL8 mRNA were determined by qRT-PCR (normalized to HPRT) (E, F). Mean values ± SD are shown (n ≥ 3).