title: Attenuation of highly pathogenic porcine reproductive and respiratory syndrome virus by inserting an additional transcription unit.
abstract: Transcription regulatory sequences (TRSs) play a key role in the synthesis of porcine reproductive and respiratory syndrome virus (PRRSV) subgenomic mRNAs, which resembles similarity-assisted RNA recombination. In this study, genome instability was found when a highly pathogenic PRRSV (HP-PRRSV) strain was inserted by an additional transcription unit in which a foreign gene GFP was expressed from TRS2 while a copy of TRS6 drove ORF2a/b transcription. Structural protein gene-deleted genomes resulted from enhanced RNA recombinations were identified in the recombinant virus rHV-GFP. Moreover, rHV-GFP replicated slower than parental viruses, and caused less cell death in porcine alveolar macrophages. Pigs infected with rHV-GFP survived with no or mild syndromes, whereas all pigs infected with parental viruses died within 12 days. Our data showed that additional transcription unit insertion could confer genome instability and attenuation of HP-PRRSV.
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Lianghai
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Xue-kun
authors.initials: XK
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yihao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Department of Basic Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.affiliation: Beijing Entry-Exit Inspection and Quarantine Bureau, Beijing 100026, China.
authors.forename: Hexiao
authors.initials: H
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China; Ministry of Agriculture Key Laboratory of Soil Microbiology, China Agricultural University, Beijing 100193, China; Department of Microbiology and Immunology, College of Biological Sciences, China Agricultural University, Beijing 100193, China. Electronic address: whfeng@cau.edu.cn.
authors.forename: Wen-hai
authors.initials: WH
authors.lastname: Feng
mesh_terms: D000818:Animals; D001483:Base Sequence; D017353:Gene Deletion; D016679:Genome, Viral; D042822:Genomic Instability; D058977:Molecular Sequence Annotation; D016254:Mutagenesis, Insertional; D009690:Nucleic Acid Conformation; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics; D034421:Sus scrofa; D013552:Swine
chemical_list: D012367:RNA, Viral
keywords: Additional transcription unit; Attenuation; Genome instability; HP-PRRSV