RSV vs. rhinovirus bronchiolitis: difference in nasal airway microRNA profiles and NFκB signaling

BACKGROUND: Although rhinovirus infection is associated with increased risks of acute and chronic respiratory outcomes during childhood compared with respiratory syncytial virus (RSV), the underlying mechanisms remain unclear. We aimed to determine the differences in nasal airway microRNA profiles and their downstream effects between infants with rhinovirus and RSV bronchiolitis. METHODS: As part of a multicenter cohort study of infants hospitalized for bronchiolitis, we examined nasal samples obtained from 16 infants with rhinovirus and 16 infants with RSV. We tested nasal airway samples using microarrays to profile global microRNA expression and determine the predicted regulation of targeted transcripts. We also measured gene expression and cytokines for NF kappa B pathway components. RESULTS: Between the virus groups, 386 microRNAs were differentially expressed (false discovery rate (FDR) < 0.05). In infants with rhinovirus, the NF kappa B pathway was highly ranked as a predicted target for these differentially expressed microRNAs compared with RSV. Pathway analysis using measured mRNA expression data validated that rhinovirus infection had upregulation of NF kappa B family (RelA and NF kappa B2) and downregulation of inhibitor kappa B family. Infants with rhinovirus had higher levels of NF kappa B-induced type-2 cytokines (IL-10 and IL-13; FDR<0.01). CONCLUSION: In infants with bronchiolitis, rhinovirus and RSV infections had different nasal airway microRNA profiles associated with NF kappa B signaling.