Time course of TLR agonist-induced IL-8 expression. Human neutrophils were isolated and stimulated, with or without 90 minutes of pretreatment with GM-CSF. Cells were harvested at the indicated time points for RNA. Expression of IL-8 was determined by QPCR and depicted as the number of copies of IL-8 message per copies of the control mRNA β₂-microglobulin. Data are representative of 3 similar experiments conducted on 2 donors.