About 500 young New Zealanders have cystic fibrosis (CF). They suffer from debilitating respiratory infections and have a markedly reduced life expectancy. CF is caused by a faulty protein that makes the lungs susceptible to infections. White blood cells swarm into the lungs to fight infections but destroy the airways with chlorine bleach and digestive enzymes. We found that bleach depletes the antioxidant glutathione and damages proteins in CF airways. We will assess whether lung function declines as airway proteins are damaged. We will also determine whether damaged airway proteins are present in blood and can be used as much needed markers of infection in children with CF. In an animal model of CF, we will establish whether inhibitors of bleach decrease inflammation and infection. This project will enhance our understanding of inflammation in CF airways and enable therapies to be tailored to limit the most debilitating consequences of CF.