Bat Severe Acute Respiratory Syndrome-Like Coronavirus WIV1 Encodes an Extra Accessory Protein, ORFX, Involved in Modulation of the Host Immune Response

摘要: ABSTRACT Bats harbor severe acute respiratory syndrome (SARS)-like coronaviruses (SL-CoVs) from which the causative agent of 2002-2003 SARS pandemic is thought to have originated. However, despite fact that a large number genetically diverse SL-CoV sequences been detected in bats, only two strains (named WIV1 and WIV16) successfully cultured vitro . These differ SARS-CoV containing an extra open reading frame (ORF) ORFX), between ORF6 ORF7, has no homology any known protein sequences. In this study, we constructed full-length cDNA clone (rWIV1), ORFX deletion mutant (rWIV1-ΔX), green fluorescent (GFP)-expressing (rWIV1-GFP-ΔX). Northern blotting fluorescence microscopy indicate was expressed during infection. A virus infection assay showed rWIV1-ΔX replicated as efficiently rWIV1 Vero E6, Calu-3, HeLa-hACE2 cells. Further study could inhibit interferon production activate NF-κB. Our results demonstrate for first time unique strain functional gene involving modulation host immune response but not essential viral replication. IMPORTANCE SARS-like (SL-CoVs), some them potential interspecies transmission. (ORFX) identified genomes recently isolated bat (WIV1 -16). It will therefore be critical clarify whether how contributes virulence Here revealed involved provide important information further exploration function future. Moreover, reverse genetics system helpful pathogenesis group viruses develop therapeutics future control emerging infections.