Isolation and Identification of Porcine Epidemic Diarrhea Virus and Its Effect on Host Natural Immune Response
Isolation and Identification of Porcine Epidemic Diarrhea Virus and Its Effect on Host Natural Immune Response
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猪流行性腹泻病毒的分离鉴定及其对宿主自然免疫反应的影响
DOI：
10.3389/fmicb.2019.02272
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发表时间：
2019-10-04
影响因子：
5.2
通讯作者：
Li, Zili
中科院分区：
文献类型：
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作者：
Qian, Shaoju;Zhang, Weida;Li, Zili
猪流行性腹泻(PED)是由猪流行性腹泻病毒(PEDV)引起的一种高度传染性肠道疾病。从江苏省仔猪肠道Vero细胞中分离到一株PEDV，定名为JS-A株。经细胞病理学、免疫荧光、Western blotting、透射电子显微镜和序列分析鉴定为PEDV分离物。对JS-A分离株的全长基因组和S基因的系统分析表明，JS-A属于G2a亚型，与许多国家流行的PEDV有密切的亲缘关系，与现有的许多疫苗不同。动物回归试验表明，口服感染该病毒的仔猪继续出现腹泻，并伴有黄色和难闻的气味。此外，挑战组的仔猪表现出更少的食物消耗和体重减轻，而对照组则没有异常。此外，还对新生猪感染PEDV JS-A株后肠粘膜Toll样受体(TLRs)、RIG-I及其下游介质基因进行了研究。新生儿Fc受体(FcRN)是唯一的免疫球蛋白转运受体，保护免疫球蛋白不被降解。因此，PEDV JS-A感染可能通过下调TLR及其下游信号分子来抑制FcRN的表达。总之，JS-A变异株的分离有助于腹泻病毒的进化分析。实验感染模型的建立为进一步研究疫苗研制和感染仔猪的抗病毒天然免疫反应奠定了基础，有助于我们更好地了解PEDV的致病机理和免疫机制。
Porcine epidemic diarrhea (PED) is a highly infectious intestinal disease caused by porcine epidemic diarrhea virus (PEDV). A PEDV strain was isolated from the piglet intestinal tract in Vero cells in Jiangsu Province, designated as the JS-A strain. PEDV was identified as the isolated virus by cytopathology, immunofluorescence assay, western blotting, transmission electron microscopy, and sequence analysis. The full-length genome of the JS-A isolate and the S gene were systematically analyzed, indicating that PEDV JS-A belongs to the G2a subtype, which is closely related to the prevalent PEDV in many countries and different from many current vaccines. Animal regression tests showed that piglets that are orally infected with the virus continue to develop diarrhea with yellowish and unpleasant odors. Further, piglets showed reduced food consumption and weight loss in the challenged group, while there were no abnormalities in the control group. In addition, Toll-like receptors (TLRs), RIG-I, and the downstream medium gene in the intestinal mucosa of newborn pigs infected with PEDV JS-A strain were studied. The neonatal Fc receptor (FcRn) was the only IgG transport receptor and protected IgG from degradation. Therefore, PEDV JS-A infection might inhibit FcRn expression by downregulating TLRs and downstream signaling molecules. Taken together, isolation of the JS-A variant contributes to evolutionary analysis of the diarrhea virus. Further, the experimental infection model lays a foundation for further research related to vaccine development and the antiviral natural immune response of infected piglets, which helps us to better understand PEDV pathogenesis and immune mechanism.