Differential Sensitivity of Differentiated Epithelial Cells to Respiratory Viruses Reveals Different Viral Strategies of Host Infection

Abstract

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. With both systems, epithelial cells were readily infected by bovine parainfluenza virus 3 (BPIV3). Ciliated cells were the most prominent cell type affected by BPIV3. Surprisingly, differentiated BAEC were resistant to infection by bovine respiratory syncytial virus (BRSV), when the virus was applied at the same multiplicity of infection that was sufficient for infection by BPIV3. In the case of PCLS, infection by BRSV was observed in cells located in lower cell layers but not in epithelial cells facing the lumen of the airways. The identity of the infected cells could not be determined because of a lack of specific antibodies. Increasing the virus titer 30-fold resulted in infection of the ALI cultures of BAEC, whereas in PCLS the ciliated epithelium was still refractory to infection by BRSV. These results indicate that differentiated BAEC are readily infected by BPIV3 but rather resistant to infection by BRSV. Disease caused by BRSV may require that calves encounter environmental stimuli that render BAEC susceptible to infection.

Investigations on the protective role of passively transferred antibodies against avian metapneumovirus infection in turkeys

“…It has been reported that bovine respiratory syncytial virus and human respiratory syncytial virus additionally possess the ability to replicate in leukocytes, such as monocytes and alveolar macrophages (Panuska et al, 1990;Midulla et al, 1993;Schrijver et al, 1995;Sharma & Woldehiwet, 1996). In vitro experiments of Goris et al (2009) in primary bovine lung organ cultures demonstrated that bovine respiratory syncytial virus initially replicates in subepithelial cells, possibly dendritic cells, whereas the respiratory epithelium was infected only at high inoculation titres. Preliminary results of Sharma et al (2004) indicated that aMPV replication in macrophages may also play a role in the pathogenesis of aMPV in turkeys.…”

Mutations during the Adaptation of H9N2 Avian Influenza Virus to the Respiratory Epithelium of Pigs Enhance Sialic Acid Binding Activity and Virulence in Mice

“…PCLS were prepared from lungs of 3-month-old healthy crossbred pigs as described previously (32,33,63,64).…”

“…Slices which showed 100% ciliary activity at the beginning were selected for the experiments. From selected samples, the slices were analyzed for bronchoconstriction by addition of 10 Ϫ4 M methacholine (acetyl-ß-methylcholine chloride; Sigma-Aldrich) as described previously (32,64). The integrity of the cells was also determined by applying a Live/Dead viability/cytotoxicity assay kit (FPBE4710; Fluo Probes) (32,33).…”

Dynamic Virus-Bacterium Interactions in a Porcine Precision-Cut Lung Slice Coinfection Model: Swine Influenza Virus Paves the Way for Streptococcus suis Infection in a Two-Step Process

“…The animals had a good health status and no clinical symptoms. The cranial, middle, and intermediate lobes of the fresh lungs were carefully removed and filled with 37°C low-melting-point agarose (Gerbu) as previously described (4,23,24). After the agarose became solidified on ice, the tissue was stamped out as cylindrical portions (8-mm tissue coring tool), and approximately 250-m-thick slices were prepared by using a Krumdieck tissue slicer (model MD4000-01; TSE Systems) with a cycle speed of 60 slices/min.…”