Figure 2
Effect of blocking antibodies on endotoxin-dependent IL-8 release by PBMC. Freshly isolated human PBMC (~1.0 × 106 total cells/well, 100,000 monocytes) were prepared as described in Methods in 100 μl of incubation buffer containing 100 ng/ml LBP, and (A) 1 μg/well of non-immune mouse IgG or MEM-18 (anti-CD14), or (B) 2 μg/well non-immune mouse IgG or HTA-125 (anti-TLR4). Cultures were then pre-incubated at 37°C for 30 min, and 100 μl of 2× the final endotoxin concentration in incubation buffer was added to the wells. Cultures were incubated at 37°C for 6 h. At the end of the incubation period, samples were collected and frozen for subsequent IL-8 analysis by ELISA. Data are expressed as the mean ± S.E.M. of triplicate samples; error bars for some conditions were so small they are obscured by the symbols. (A) *p < 0.05, **p < 0.001 for mouse IgG values relative to MEM-18 values for the same LPS concentration. (B) *p < 0.05, **p < 0.001 for mouse IgG values relative to HTA-125 values for the same LPS concentration. Similar results were seen in 3 independent experiments.