Figure 4From: Extracellular Hsp72, an endogenous DAMP, is released by virally infected airway epithelial cells and activates neutrophils via Toll-like receptor (TLR)-4 Exogenous Hsp72 activates IL-8 production in HL-60 cells in an endotoxin-independent manner. Differentiated HL-60 cells were pretreated with polymyxin B (50 μg/ml) for 1 h prior to treatment with Hsp72 (100 ng/ml) or LPS (100 ng/ml). In some cases, cells were treated with Hsp72 or LPS which had been boiled for 1 hr. Supernatants were harvested, clarified and run on IL-8 ELISA. Data represent means ± SEM for 4 experiments and differences pinpointed by ANOVA (compared to untreated control *p = 0.002, **p < 0.001).Back to article page