Figure 1.

Effect of specific TLR2, 4, and 7/8 agonist stimulation or of bacterial immune stimulation with and without TLR blockade: dose finding studies for TLR blockade. Supernatant TNF and IL-6 concentrations measured by ELISA after 6 h of incubation of whole blood from healthy volunteers following stimulation with TLR2, 4, or 7/8 agonists or with heat-killed bacteria with and without antibodies directed against TLR2, TLR4, or with chloroquine. Concentrations as indicated. (A) Effects of the TLR2 agonist P₃C. (B) Addition of anti-TLR2 mAb T2.5 30 min prior to the addition of the TLR2 agonist P₃C (10 µg/ml). (C) Effects of the TLR4 agonist LPS : Re595. (D) Addition of anti-TLR4 mAb 3C3 30 min prior to addition of TLR4 agonist LPS : Re595 (0.1 µg/ml). (E) Effects of the endosomal inhibitor chloroquine (CQ) 30 min prior to the addition of TLR7/8 agonist Resiquimod (R848). (F) Addition of the endosomal inhibitor chloroquine (CQ) 30 min prior to addition of the TLR-independent immune stimuli phorbol-12-myristate-13-acetate and Ionomycin (PMA+I) as a toxicity control for CQ; low dose of PMA+I is 0.2 + 0.14 µg/ml, high dose is 1 + 0.7 µg/ml. (G) Addition of the endosomal inhibitor chloroquine (CQ) 30 min prior to the addition of heat-killed S. aureus or E. coli. n.d., not detected. Measurements from 2-3 individuals each. (A–F) single-point graph with means, (G) means with standard deviation.