Updated FTP location. Bovine respiratory epithelial cells have different susceptibility to bovine respiratory syncytial virus infection. The cells derived from the lower respiratory tract were significantly more susceptible to the virus than those derived from the upper respiratory tract. Pre-infection with virus of lower respiratory tract with increased adherence of P. multocida; this was not the case for upper tract. However, the molecular mechanisms of enhanced bacterial adherence are not completely understood. To investigate whether virus infection regulates the cellular adherence receptor on bovine trachea-, bronchus- and lung-epithelial cells, we performed proteomic analyses.