Double-stranded RNA impairs epithelial barrier formation by redirecting airway basal cell differentiation

Background Viral double-stranded RNA disrupts the airway epithelial barrier, but its specific impact on progenitor basal cells remains unknown. In this study, we stimulated undifferentiated normal human bronchial epithelial cells and VA10 cells, which function as basal cells, with the Toll-like receptor 3 (TLR3) ligand polycytidylic acid (poly I:C). The cells were subsequently cultured at an air-liquid interface (ALI) to evaluate airway epithelial barrier integrity and perform global gene expression analysis. Results Poly I:C stimulation significantly decreased trans-epithelial electrical resistance and reduced the expression of barrier-related genes. This barrier dysfunction was improved by silencing TLR3 or TIR-domain-containing adapter-inducing interferon-β. Transcriptomic analysis revealed a biphasic response to poly I:C. During the late phase, the transcriptional landscape shifted toward sustained inflammation and abnormal tissue remodeling. During the early phase, the transcriptomic profile suggests the initial prioritization of an antiviral state, which may affect essential epithelial differentiation and barrier genes. Conclusions Exposure of airway basal cells to double-stranded RNA triggered a TLR3/ TIR-domain-containing adapter-inducing interferon β-mediated biphasic response. An initial prioritization of antiviral defence compromises epithelial differentiation, which is followed by a late phase of unresolved chronic inflammation and abnormal remodeling. This cascade may provide a potential mechanistic explanation for how viral infections induce persistent airway barrier vulnerability and chronic dysfunction.