A Virulent PEDV Strain FJzz1 with Genomic Mutations and Deletions at the High Passage Level Was Attenuated in Piglets via Serial Passage In Vitro  

作　　者：Pengfei Chen Xiongwei Zhao Shuting Zhou Tianxing Zhou Xiangmei Tan Xia Wu Wu Tong Fei Gao Lingxue Yu Yifeng Jiang Hai Yu Zhibiao Yang Guangzhi Tong Yanjun Zhou 

机构地区：[1]Department of Swine Infectious Diseases,Shanghai Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Shanghai 200241,China [2]Shanghai Key Laboratory of Veterinary Biotechnology,School of Agriculture and Biology,Shanghai JiaoTong University,Shanghai 200240,China [3]College of Biological Science and Technology,Beijing Forestry University,Beijing 100083,China [4]Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses,Yangzhou University,Yangzhou 225009,China

出　　处：《Virologica Sinica》2021年第5期1052-1065,共14页中国病毒学（英文版）

基　　金：supported by the National Program on Key Research Project of China(2016YFD0500100);the Shanghai Youth Scientific and Technological Yang Fan Program Grant(20YF1457800);the National Natural Science Foundation of China(31472207);the earmarked fund for Modern Agro-industry Technology Research System of China(CARS-36);the China Postdoctoral Science Foundation(2020M670555);Shanghai Minhang District talent development special funds。

摘　　要：Highly virulent porcine epidemic diarrhea virus(PEDV)strains re-emerged and circulated in China at the end of 2010,causing significant economic losses in the pork industry worldwide.To understand the genetic dynamics of PEDV during its passage in vitro,the PEDV G2 strain FJzzl was serially propagated in Vero cells for up to 200 passages.The susceptibility and adaptability of the FJzzl strain increased gradually as it was serially passaged in vitro.Sequence analysis revealed that amino acid(aa)changes were mainly concentrated in the S glycoprotein,which accounted for 72.22%-85.71%of all aa changes.A continuous aa deletion(^(55)I^(56)G^(57)E→^(55)K^(56)Δ^(57)Δ)occurred in the N-terminal domain of S1(Sl-NTD).To examine how the aa changes affected its virulence,FJzzl-F20 and FJzzl-F200 were selected to simultaneously evaluate their pathogenicity in suckling piglets.All the piglets in the FJzzl-F20-infected group showed typical diarrhea at 24 h postinfection,and the piglets died successively by 48 h postinfection.However,the clinical signs of the piglets in the FJzzl-F200-infected group were significantly weaker,and no deaths occurred.The FJzzl-F200-infected group also showed a lower level of fecal viral shedding and lower viral loads in the intestinal tissues,and no obvious histopathological lesions.TypeⅠandⅢinterferon were induced in the FJzzl-F200 infection group,together with pro-inflammatory cytokines,such as TNF-α,IL-1βand IL-8.These results indicate that the identified genetic changes may contribute to the attenuation of FJzzl strain,and the attenuated FJzzl-F200 may have the potential for developing PEDV live-attenuated vaccines.

关 键 词：Porcine epidemic diarrhea virus(PEDV) Serially passage Genetic variation Pathogenicity 

分 类 号：S852.651[农业科学—基础兽医学]