Dual infections of CD163 expressing NPTr epithelial cells with influenza A virus and PRRSV

In the pig, respiratory co-infections involving various pathogens are far more frequent than single infections. Amongst respiratory viruses, swine influenza type A virus (swIAV) and porcine reproductive and respiratory syndrome virus (PRRSV) are frequently associated. Previously, we performed co-infections with swIAV and PRRSV in porcine alveolar macrophages (PAM) and precision cut lung slices (PCLS). With these two approaches it was practically impossible to have co-infections of the same cells as the main target cell of swIAV is the epithelial cell while the main target of PRRSV is the PAM. This constraint makes the study of interference between the two viruses difficult at the cellular level. In the current report, an epithelial cell line expressing, CD163, the main receptor of PRRSV was generated. This cell line receptive for both viruses was used to assess the interference between the two viruses. Results showed that swIAV as well as PRRSV, even if they interacted differently with the modified epithelial cells, were clearly interfering with each other regarding their replication when they infected a same cell with consequences within the cellular antiviral response. Our modified cell line, receptive to both viruses, can be used as a tool to assess interference between swIAV and PRRSV in a same cell as it probably happens in the porcine host.