Infection of Avian and Swine Cell Lines with Chimeric Porcine Deltacoronaviruses Expressing Sparrow Deltacoronavirus Spike Protein

Moyasar Abdulhameed
Graduate (MS)
Scott P. Kenney
Animal Sciences

Porcine deltacoronavirus (PDCoV) is a newly emerged coronavirus (CoV) causing severe diarrhea and mortality in neonatal piglets. PDCoV belongs to the Coronaviridae family of the genus Deltacoronavirus that consists of avian and mammalian CoVs. Recent studies have shown that PDCoV can infect cell lines of humans, chickens, and swine via the interaction of the spike protein (S) with host aminopeptidase N (APN). Identification of new DCoV strains including sparrow DCoV (SpDCoV), coupled with close contact between sparrows and swine in production facilities may facilitate recombination of DCoVs and drive viral evolution resulting in the emergence of novel CoV variants. We utilized the chimeric viruses, in which the entire S of sparrow HKU17 (icPDCoV-SHKU17) or the receptor-binding domain (RBD) of sparrow ISU73374 (icPDCoV-RBDISU) replaced the PDCoV S or RBD generated using the infectious cDNA clone of PDCoV OH-FD22 strain (icPDCoV) in Dr. Wang's lab, to infect cell lines of 2 species, avian fibroblast origin, DF-1, and porcine kidney origin, LLC-PK, to understand the role of the S protein. We demonstrated that DF-1 and confirmed that LLC-PK cells are susceptible to icPDCoV, icPDCoV-SHKU17, and icPDCoV-RBDISU virus infections. The results demonstrate that chimeric viruses exhibit a broad cell tropism, infecting cells derived from both chicken and swine species.