Infection of differentiated airway epithelial cells from caprine lungs by viruses of the bovine respiratory disease complex.

Bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus type 3 (BPIV3) and bovine herpesvirus type 1 (BHV-1) are important pathogens associated with the bovine respiratory disease complex (BRDC). Non-bovine ruminants such as goats may also be infected and serve as a virus reservoir to be considered in the development of control strategies. To evaluate the susceptibility of caprine airway epithelial cells to infection by viruses of BRDC, we established a culture system for differentiated caprine epithelial cells.

Three viruses of the bovine respiratory disease complex apply different strategies to initiate infection.

Bovine respiratory disease complex (BRDC) is the major cause of serious respiratory tract infections in calves. The disease is multifactorial, with either stress or reduced immunity allowing several pathogens to emerge. We investigated the susceptibility of bovine airway epithelial cells (BAEC) to infection by the three major viruses associated with the BRDC: bovine respiratory syncytial virus (BRSV), bovine herpesvirus type 1 (BHV-1) and bovine parainfluenza virus type 3 (BPIV3).

Replication characteristics of swine influenza viruses in precision-cut lung slices reflect the virulence properties of the viruses.

Precision-cut lung slices of pigs were infected with five swine influenza A viruses of different subtypes (A/sw/Potsdam/15/1981 H1N1, A/sw/Bad Griesbach/IDT5604/2006 H1N1, A/sw/Bakum/1832/2000 H1N2, A/sw/Damme/IDT5673/2006 H3N2, A/sw/Herford/IDT5932/2007 H3N2). The viruses were able to infect ciliated and mucus-producing cells. The infection of well-differentiated respiratory epithelial cells by swine influenza A viruses was analyzed with respect to the kinetics of virus release into the supernatant.

Differential sensitivity of differentiated epithelial cells to respiratory viruses reveals different viral strategies of host infection.

To address the initiation of virus infection in the respiratory tract, we established two culture systems for differentiated bovine airway epithelial cells (BAEC). Filter-grown BAEC differentiated under air-liquid interface (ALI) conditions to generate a pseudo-stratified mucociliary epithelium. Alternatively, precision-cut lung slices (PCLS) from the bovine airways were generated that retained the original composition and distribution of differentiated epithelial cells.