Inhibition of SAA-induced IL-8 secretion and MAP kinase phosphorylation by PTX.
(A) Neutrophils were preincubated with or without either 100 ng/mL or 500 ng/mL pertussis toxin (PTX) at 37°C for 1 hour and then stimulated with 2 μM SAA for 3 hours. The secreted IL-8 was measured by ELISA and expressed as percent of change, with maximal IL-8 (980 pg/mL/106 cells) set as 100%. Data are presented as means ± SEM of 3 independent experiments, each performed in duplicate. (B) Neutrophils (4 × 105 cells) were incubated with or without PTX (400 ng/mL) for 30 minutes, and then stimulated with 2 μM SAA for indicated times. Induction of both ERK1/2 and p38 phosphorylation was determined by Western blotting. Three experiments were performed and a representative set of results is shown.
