Susceptibility of porcine IPI-2I intestinal epithelial cells to infection with swine enteric coronaviruses

Abstract

A B S T R A C TSwine enteric coronavirus (CoV) is an important group of pathogens causing diarrhea in piglets. At least four kinds of swine enteric CoVs have been identified, including transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhea virus (PEDV), porcine deltacoronavirus (PDCoV), and the emerging HKU2-like porcine enteric alphacoronavirus (PEAV). The small intestines, particularly the jejunum and ileum, are the most common targets of these four CoVs in vivo, and co-infections by these CoVs are frequently observed in clinically infected pigs. This study was conducted to investigate the susceptibility of the porcine ileum epithelial cell line, IPI-2I, to different swine enteric CoVs. We found that IPI-2I cells are highly susceptible to TGEV, PDCoV, and PEAV, as demonstrated by cytopathic effect and virus multiplication. However, only a small number of cells could be infected by PEDV, possibly due to the heterogeneity of IPI-2I cells. A homogeneous cell line, designated IPI-FX, obtained from IPI-2I cells by sub-cloning with limited serial dilutions, was found to be highly susceptible to PEDV. Furthermore, IPI-FX cells were also highly susceptible to TGEV, PDCoV, as well as PEAV. Thus, this sub-cloned IPI-FX cell line is an ideal cell model to study the mechanisms of infection, particularly co-infections of swine enteric CoVs.

Porcine deltacoronavirus (PDCoV) modulates calcium influx to favor viral replication

“…To investigate whether PDCoV infection alters the cytosolic Ca 2+ levels, a fluorescence-based flux assay was used to evaluate calcium levels in cells after PDCoV infection. IPI-2I cells, the porcine ileum epithelial cells that are highly susceptible to PDCoV (Wang et al, 2019b), were preloaded with the fluo-3-pentaacetoxymethyl ester (Fluo-3AM), a regent that can freely diffuse into cells and combine with free cytosolic Ca 2+ to produce fluorescence. The preloaded cells were infected with PDCoV at a multiplicity of infection (MOI) of 3 and the fluorescence was measured at 5-min intervals.…”

Identification of a Novel Linear B-Cell Epitope on the Nucleocapsid Protein of Porcine Deltacoronavirus

“…Among them, TGEV, PRCV N protein are identical, because PRCV is a S gene deletion of TGEV [27]. Besides, SADS-CoV also known as swine enteric alphacoronavirus (SeACoV) [28] and porcine enteric alphacoronavirus (PEAV) [29]. The results of I-TASSER server for 3D structure prediction showed that amino acids of EP-4E88 was in close proximity and may be exposed on the surface of the N protein.…”

Low-level contamination of deoxynivalenol: A threat from environmental toxins to porcine epidemic diarrhea virus infection

“…Pig is one of the animals most susceptible to coronavirus infection. Swine coronaviruses mainly include transmissible gastroenteritis virus (TGEV), porcine deltacoronavirus (PDCoV), porcine epidemic diarrhea virus (PEDV) and the emerging HKU2-like porcine enteric alphacoronavirus (PEAV) ( Niederwerder and Hesse, 2018 , Wang et al, 2019b ). Similar to other enteric coronavirus diseases, the porcine epidemic diarrhea (PED) is age-dependent but more destructive ( Lee, 2015 , Li et al, 2011 , Song and Park, 2012 ), causing the intestinal epithelial cells necrosis, villous atrophy, vomit, diarrhea and dehydration in pigs of all ages, even the death of piglets ( Wang et al 2019a ).…”