BACKGROUND: Rhinovirus infections are a major risk factor for asthma exacerbations. We sought to investigate in an in vitro system whether infection with human rhinovirus reduces the integrity and barrier function of a respiratory epithelial cell layer and thus may influence allergen penetration. METHODS: We cultured the human bronchial epithelial cell line 16HBE14o- in a transwell culture system as a surrogate of respiratory epithelium. The cell monolayer was infected with human rhinovirus 14 at 2 different doses. The extent and effects of transepithelial allergen penetration were assessed using transepithelial resistance measurements and a panel of (125)I-labeled purified recombinant respiratory allergens (rBet v 1, rBet v 2, and rPhl p 5). RESULTS: Infection of respiratory cell monolayers with human rhinovirus decreased transepithelial resistance and induced a pronounced increase in allergen penetration. CONCLUSIONS: Our results indicate that infection with rhinovirus damages the respiratory epithelial barrier and allows allergens to penetrate more efficiently into the subepithelial tissues where they may cause increased allergic inflammation.