Development and utilization of an infectious clone for porcine deltacoronavirus strain USA/IL/2014/026.

• 影响指数: 3.513
• 发表时间: 01 2021 15
• 来源期刊: Virology
• DOI: 10.1016/j.virol.2020.11.002
• PMID: 33220618
• 文章类型: Journal Article
• 中科院分区: Q3
• 方向: 医学
• 作者列表: Deng X,Buckley AC,Pillatzki A,Lager KM,Baker SC,Faaberg KS

关键词: Coronavirus infectious clone; Coronavirus pathogenesis; Endoribonuclease; Enteric coronavirus; Infection of piglets; Interferon antagonist; NS6; Porcine deltacoronavirus

Mesh: Animals; Clone Cells; Coronavirus Infections / pathology; DNA, Complementary / isolation & purification; Deltacoronavirus / genetics pathogenicity physiology; Endoribonucleases / physiology; Interferons / antagonists & inhibitors; Swine / virology; Virus Replication

Abstract

We report the generation of a full-length infectious cDNA clone for porcine deltacoronavirus strain USA/IL/2014/026. Similar to the parental strain, the infectious clone virus (icPDCoV) replicated efficiently in cell culture and caused mild clinical symptoms in piglets. To investigate putative viral interferon (IFN) antagonists, we generated two mutant viruses: a nonstructural protein 15 mutant virus that encodes a catalytically-inactive endoribonuclease (icEnUmut), and an accessory gene NS6-deletion virus in which the NS6 gene was replaced with the mNeonGreen sequence (icDelNS6/nG). By infecting PK1 cells with these recombinant PDCoVs, we found that icDelNS6/nG elicited similar levels of type I IFN responses as icPDCoV, however icEnUmut stimulated robust type I IFN responses, demonstrating that the deltacoronavirus endoribonuclease, but not NS6, functions as an IFN antagonist in PK1 cells. Collectively, the construction of a full-length infectious clone and the identification of an IFN-antagonistic endoribonuclease will aid in the development of live-attenuated deltacoronavirus vaccines.