title: Attenuation of mouse hepatitis virus by deletion of the LLRKxGxKG region of Nsp1.
abstract: Coronaviruses are a family of large positive-sense RNA viruses that are responsible for a wide range of important veterinary and human diseases. Nsp1 has been shown to have an important role in the pathogenetic mechanisms of coronaviruses in vivo. To assess the function of a relatively conserved domain (LLRKxGxKG) of MHV nsp1, a mutant virus, MHV-nsp1-27D, with a 27 nts (LLRKxGxKG) deletion in nsp1, was constructed using a reverse genetic system with a vaccinia virus vector. The mutant virus had similar growth kinetics to MHV-A59 wild-type virus in 17CI-1 cells, but was highly attenuated in vivo. Moreover, the mutant virus completely protected C57BL/6 mice from a lethal MHV-A59 challenge. To further analyze the mechanism of the attenuation of the mutant virus, changes in reporter gene expression were measured in nsp1- or nsp1-27D-expressing cells; the results showed that nsp1 inhibited reporter gene expression controlled by different promoters, but that this inhibition was reduced for nsp1-27D. The research in vivo and in vitro suggests that the LLRKxGxKG region of nsp1 may play an important role in this process.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Institute of Epidemiology and Microbiology, Academy of Millitary Medical Sciences, Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Lei
authors.forename: Sun
authors.initials: S
authors.lastname: Ying
authors.forename: Luo
authors.initials: L
authors.lastname: Baojun
authors.forename: Yang
authors.initials: Y
authors.lastname: Yi
authors.forename: He
authors.initials: H
authors.lastname: Xiang
authors.forename: Su
authors.initials: S
authors.lastname: Wenli
authors.forename: Sun
authors.initials: S
authors.lastname: Zounan
authors.forename: Guo
authors.initials: G
authors.lastname: Deyin
authors.forename: Zhu
authors.initials: Z
authors.lastname: Qingyu
authors.forename: Liu
authors.initials: L
authors.lastname: Jingmei
authors.forename: Chang
authors.initials: C
authors.lastname: Guohui
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017124:Conserved Sequence; D006801:Humans; D007114:Immunization; D051379:Mice; D008969:Molecular Sequence Data; D006517:Murine hepatitis virus / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: C505227:NSP1 protein, murine hepatitis virus; D017361:Viral Nonstructural Proteins