A nox2 / cybb zebrafish mutant with defective neutrophil ROS production displays normal initial neutrophil recruitment to sterile tail injuries

Reactive oxygen species (ROS) are important effectors and modifiers of the acute inflammatory response, recruiting neutrophils to sites of tissue injury. In turn, neutrophils are both consumers and producers of reactive oxygen species. Stimulated neutrophils generate reactive oxygen species in an oxidative burst through the activity of a multimeric phagocytic NADPH oxidase complex. Mutations in the NOX2/CYBB (previously gp91phox) NADPH oxidase subunit are the commonest cause of chronic granulomatous disease, a disease characterized by infection susceptibility and an inflammatory phenotype. To model chronic granulomatous disease, we made a nox2/cybb zebrafish (Danio rerio) mutant and demonstrated it to have severely impaired neutrophil ROS production. Reduced early survival of nox2 mutant embryos indicated an essential requirement for nox2 during early development. In nox2/cybb zebrafish mutants, the dynamics of initial neutrophil recruitment to both mild and severe surgical tailfin wounds was normal, suggesting that excessive neutrophil recruitment at the initiation of inflammation is not the primary cause of the "sterile" inflammatory phenotype of chronic granulomatous disease patients. This nox2 zebrafish mutant adds to existing in vivo models for studying neutrophil reactive oxygen species function in development and disease.