Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA; Division of Virology and Epidemiology, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
Vet Microbiol. 2018 Jul;221:49-58. doi: 10.1016/j.vetmic.2018.05.019. Epub 2018 May 30.
The porcine small intestinal epithelial cell line, IPEC-J2, is useful to characterize the interactions of enterocytes with enteric viruses in vitro. We investigated whether IPEC-J2 cells are susceptible to porcine deltacoronavirus (PDCoV) infection. We conducted quantification of infectious virus or viral RNA, immunofluorescent (IF) staining for the detection of PDCoV antigens, and TUNEL assay in IPEC-J2 cells inoculated with the strain OH-FD22-P8 grown in LLC-PK cells, and supplemented with 10 μg/ml of trypsin in the cell culture medium. Cytopathic effects (CPE) that consisted of enlarged and rounded cells followed by cell shrinkage and detachment, were identified by the 3rd viral passage in the IPEC-J2 cells. PDCoV antigen was detected in the cells showing CPE. By double IF and TUNEL staining, most PDCoV antigen-positive IPEC-J2 cells failed to show TUNEL-positive signals, indicating that PDCoV-infected IPEC-J2 cells may not undergo apoptosis, but rather necrosis, similar to necrotic cell death of infected enterocytes in vivo. There was increased interleukin-6 in PDCoV-infected IPEC-J2 cell culture supernatants at post-inoculation hour (PIH) 48-96, as evaluated by ELISA, concurrent with increased titers of PDCoV at PIH 24-72. The susceptibility of IPEC-J2 cells to PDCoV infection supports their usefulness to characterize the interactions of enterocytes with PDCoV. We also demonstrated that IPEC-J2 cell culture-passaged PDCoV (OH-FD22-P8-I-P4) was enteropathogenic in 10-day-old gnotobiotic pigs, and induced systemic innate and pro-inflammatory cytokine responses during the acute PDCoV infection.
猪小肠上皮细胞系 IPEC-J2 可用于体外研究肠细胞与肠道病毒的相互作用。我们研究了 IPEC-J2 细胞是否易感染猪德尔塔冠状病毒(PDCoV)。我们通过定量检测感染性病毒或病毒 RNA、免疫荧光(IF)染色检测 PDCoV 抗原以及 TUNEL 检测,研究了在添加 10μg/ml 胰蛋白酶的细胞培养液中,用在 LLC-PK 细胞中生长的 OH-FD22-P8 株感染 IPEC-J2 细胞的情况。在第 3 次病毒传代中,我们在 IPEC-J2 细胞中观察到细胞病变效应(CPE),表现为细胞变大变圆,随后细胞收缩和脱落。在出现 CPE 的细胞中检测到 PDCoV 抗原。通过双重 IF 和 TUNEL 染色,大多数 PDCoV 抗原阳性的 IPEC-J2 细胞未能显示 TUNEL 阳性信号,这表明 PDCoV 感染的 IPEC-J2 细胞可能不会发生凋亡,而是坏死,类似于体内感染肠细胞的坏死性细胞死亡。通过 ELISA 评估,在感染后 48-96 小时(PIH),PDCoV 感染的 IPEC-J2 细胞培养上清中白细胞介素 6 增加,同时在感染后 24-72 小时 PDCoV 滴度增加。IPEC-J2 细胞对 PDCoV 感染的易感性支持其用于研究肠细胞与 PDCoV 的相互作用。我们还证明了在 10 日龄无菌猪中,IPEC-J2 细胞传代的 PDCoV(OH-FD22-P8-I-P4)具有致病性,并在急性 PDCoV 感染期间诱导全身性先天和促炎细胞因子反应。