Newborn Cystic Fibrosis Pigs Have a Blunted Early Response to an Inflammatory Stimulus

Rationale: Studies suggest that inappropriate responses to proinflammatory stimuli might contribute to inflammation in cystic fibrosis (CF) lungs. However, technical challenges have made it difficult to distinguish whether altered responses in CF airways are an intrinsic defect or a secondary effect of chronic disease in their tissue of origin. The CF pig model provides an opportunity to study the inflammatory responses of CF airways at birth, before the onset of infection and inflammation. Objectives: To test the hypothesis that acute inflammatory responses are perturbed in porcine CF airways. Methods: We investigated the inflammatory responses of newborn CF and non-CF pig airways following a 4-hour exposure to heat killed Staphylococcus aureus, in vivo and in vitro. Measurements and Main Results: Following an in vivo S. aureus challenge, markers of inflammation were similar between CF and littermate control animals through evaluation of bronchoalveolar lavage and tissues. However, transcriptome analysis revealed genotype-dependent differences as CF pigs showed a diminished host defense response compared with their non-CF counterparts. Furthermore, CF pig airways exhibited an increase in apoptotic pathways and a suppression of ciliary and flagellar biosynthetic pathways. Similar differences were observed in cultured airway epithelia from CF and non-CF pigs exposed to the stimulus. Conclusions: Transcriptome profiling suggests that acute inflammatory responses are dysregulated in the airways of newborn CF pigs.