Neutrophils augment LPS-mediated pro-inflammatory signaling in human lung epithelial cells

► We investigate the influence of a pre-existing neutrophilic inflammation on airway epithelial defense. ► Neutrophils increase IL-8 and ROS productions by human lung epithelial cells. ► The interaction involves ERK1/2 and NF-κB signaling in the epithelial cells. ► The interaction depends on a functional neutrophilic NADPH oxidase. ► Neutrophilic inflammation augments the response to inflammatory triggers.