The use of cells from ANPEP knockout pigs to evaluate the role of aminopeptidase N (APN) as a receptor for porcine deltacoronavirus (PDCoV)

Stoian, Ana; Rowland, Raymond R.R.; Petrovan, Vlad; Sheahan, Maureen; Samuel, Melissa S.; Whitworth, Kristin M.; Wells, Kevin D.; Zhang, Jianqiang; Beaton, Benjamin; Cigan, Mark; Prather, Randall S.

The coronaviruses, porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis virus (TGEV), and porcine deltacoronavirus (PDCoV) represent important sources of neonatal diarrhea on pig farms. The requirement for aminopeptidase N (APN) as a receptor for TGEV, but not for PEDV, is well established. In this study, the biological relevance of APN as a receptor for PDCoV was tested by using CRISPR/Cas9 to knockout the APN gene, ANPEP, in pigs. Porcine alveolar macrophages (PAMs) from ANPEP knockout (KO) pigs showed resistance to PDCoV infection. However, lung fibroblast-like cells, derived from the ANPEP KO PAM cultures, supported PDCoV infection to high levels. The results suggest that APN is a receptor for PDCoV in PAMs but is not necessary for infection of lung-derived fibroblast cells. The infection of the ANPEP KO pigs with PDCoV further confirmed that APN is dispensable as a receptor for PDCoV.