Objectives/hypothesis: Manifestations of rhinovirus (RV) infections include mucus overproduction, increased vascular permeability, and secondary bacterial infection. These effects may reflect disrupted epithelial barrier functions, which are mainly regulated by intercellular junctions, referred to as tight junctions (TJs) and adherens junctions (AJs). The objective of this study was to investigate changes in the components of TJs (ZO-1, occluding, and claudin-1) and AJs (E-cadherin) after RV infection in cultured nasal epithelial cells.
Methods: Primary human nasal epithelial cells grown at an air-liquid interface were infected apically with RV. RV-induced changes in the expression of epithelial TJ and AJ proteins were determined using real-time reverse transcriptase-polymerase chain reaction, confocal microscopy, and Western blot analyses. Functional changes in the integrity of junctional proteins were assessed by measuring transepithelial resistance (TER) using a voltmeter.
Results: RV infection decreased mRNA levels of ZO-1, occludin, claudin-1, and E-cadherin to 64.2%, 51.8%, 56.2%, and 56.3%, respectively, of those in controls (P < .05). Decreases in ZO-1, occludin, claudin-1, and E-cadherin protein levels in RV-infected cells were evident in immunofluorescent confocal microscopic images. Expression levels of these proteins were also lower in the RV-infected group in Western blot analyses. RV infection reduced the mean TER from 143.1 Omega/cm(2) (controls) to 122.6 Omega/cm(2).
Conclusions: RV infection decreased the expression of TJ and AJ components and reduced TER in primary cultured human nasal epithelial cells, indicating that RV infection may exert a harmful effect on nasal epithelial barrier function.