Cytokine-mediated induction of MHC class II in human neutrophils is dependent on NADPH oxidase activity

In response to selected cytokines, neutrophils are induced to express MHC class II and acquire properties of antigen-presenting cells. Here we show that (a) GM-CSF- and IFN-γ-mediated induction of MHC class II in human neutrophils is associated with intracellular ROS up-regulation, (b) cell-permeable ROS scavengers MnTMPyP and polyethylene glycol-conjugated superoxide dismutase and NADPH oxidase inhibitors diphenylene iodonium and apocynin abrogate both the cytokine-mediated ROS elevation and the induction of MHC class II and (c) neutrophils from chronic granulomatous disease patients which lack NADPH oxidase activity fail to express MHC class II in response to the cytokines. Thus, NADPH oxidase activity is required for the cytokine-mediated induction of MHC class II expression in neutrophils.