Polymorphonuclear granulocytes are activated by lipopolysaccharide via NF-κB. Polymorphonuclear granulocytes (PMNs) isolated from healthy blood donors were incubated for 3 hours at 37°C in six-well plates with plain cell-culture medium (ctr) or lipopolysaccharide (LPS) from Pseudomonas aeruginosa in the absence or presence of the NF-κB inhibitor EF-24. (A) IL-8 levels measured by ELISA on PMN supernatants. (B) NF-κB activation as measured by the NF-κB (p65) transcription factor assay on PMN nuclear extracts, expressed as increase of absorbance at 450 nm relative to total protein concentration. The increase in absorbance at 450 nm indicates translocation of NF-κB into the nucleus and DNA binding activity in the nuclear extracts. *P <0.05 from corresponding control. #P <0.05, ##P <0.01 from corresponding LPS treatment by one-way analysis of variance (ANOVA) followed by Newman–Keuls multiple comparison test or two-way ANOVA for repeated measures followed by Bonferoni’s post-hoc test.