Characterization of a novel bat-HKU2-like swine enteric alphacoronavirus (SeACoV) infection in cultured cells and development of a SeACoV infectious clone

• Published in: Virology (New York, N.Y.) N.Y.), 2019-10, Vol.536, p.110-118
• Main Authors: Yang, Yong-Le, Liang, Qi-Zhang, Xu, Shu-Ya, Mazing, Evgeniia, Xu, Guo-Han, Peng, Lei, Qin, Pan, Wang, Bin, Huang, Yao-Wei
• Format: Article
• Language: English
• Subjects: Alphacoronavirus - genetics; Alphacoronavirus - metabolism; Alphacoronavirus - pathogenicity; Animals; Antibodies, Viral - biosynthesis; Antibodies, Viral - chemistry; Antigens, Viral - chemistry; Antigens, Viral - immunology; Base Sequence; Cell Membrane - ultrastructure; Cell Membrane - virology; Chiroptera; Chlorocebus aethiops; Clone Cells; Coronavirus Infections - diagnosis; Coronavirus Infections - veterinary; Coronavirus Infections - virology; DNA, Complementary - genetics; DNA, Complementary - metabolism; Electron microscopy (EM); Infectious clone; Microscopy, Electron; Nucleocapsid - chemistry; Nucleocapsid - immunology; Rabbits; RNA, Messenger - genetics; RNA, Messenger - metabolism; RNA, Viral - genetics; RNA, Viral - metabolism; RNA-Dependent RNA Polymerase - chemistry; RNA-Dependent RNA Polymerase - immunology; Spike Glycoprotein, Coronavirus - chemistry; Spike Glycoprotein, Coronavirus - immunology; Subgenomic mRNAs; Swine; Swine Diseases - diagnosis; Swine Diseases - virology; Swine enteric alphacoronavirus (SeACoV); Vero Cells; Viral antibodies; Viral Nonstructural Proteins - chemistry; Viral Nonstructural Proteins - immunology; Virus Replication
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2019.08.006

Swine enteric alphacoronavirus (SeACoV), also known as swine acute diarrhea syndrome coronavirus (SADS-CoV), belongs to the species Rhinolophus bat coronavirus HKU2. Herein, we report on the primary characterization of SeACoV in vitro. Four antibodies against the SeACoV spike, membrane, nucleocapsid and nonstructural protein 3 capable of reacting with viral antigens in SeACoV-infected Vero cells were generated. We established a DNA-launched SeACoV infectious clone based on the cell adapted passage-10 virus and rescued the recombinant virus with a unique genetic marker in cultured cells. Six subgenomic mRNAs containing the leader-body junction sites, including a bicistronic mRNA encoding the accessory NS7a and NS7b genes, were experimentally identified in SeACoV-infected cells. Cellular ultrastructural changes induced by SeACoV infection were visualized by electron microscopy. The availability of the SeACoV infectious clone and a panel of antibodies against different viral proteins will facilitate further studies on understanding the molecular mechanisms of SeACoV replication and pathogenesis. •Generation of four antibodies to distinct SeACoV protein for detection of SeACoV infection.•Development of a DNA-launched reverse genetics system for SeACoV.•Recombinant SeACoV with a genetic marker had similar growth kinetics to the parental virus.•Identification of all SeACoV subgenomic mRNAs containing the leader-body junction sites.•SeACoV infection induces cellular ultrastructural changes.