Effects of rhinovirus infection on hydrogen peroxideinduced alterations of barrier function in the cultured human tracheal epithelium

To investigate whether rhinovirus infection impairs epithelial barrier functions, human rhinovirus 14 (HRV-14) was infected to primary cultures of human tracheal epithelial cells and experiments were performed on Day 2 after HRV-14 infection. Hydrogen peroxide (H₂O₂; 3 x 10^-4 M) increased electrical conductance (G) across the epithelial cell sheet measured with Ussing's chamber methods. Exposure of the epithelial cells to HRV-14 had no effect on H₂O₂-induced increases in G and [³H]mannitol flux through the cultured epithelium in the control condition, but it markedly potentiated H₂O₂induced increases in both parameters in IL-1β (100 U/ml) pretreated condition. However, pretreatment with TNF-α (100 U/ml) was without effect. IL-1β enhanced the intercellular adhesion molecule-1 (ICAM-1) expression assessed by immunohistochemical analysis and susceptibility of epithelial cells to HRV-14 infection. An antibody to ICAM-1 inhibited HRV-14 infection of epithelial cells and abolished H₂O₂-induced increases in G and [³H]mannitol flux in IL-lβ-pretreated epithelial cells with HRV-14 infection. These results suggest that rhinovirus infection may reduce barrier functions in the airway epithelium in association with upregulation of ICAM- 1 expression.