title: Masking of the contribution of V protein to Sendai virus pathogenesis in an infection model with a highly virulent field isolate.
abstract: Sendai virus V protein is not essential for virus replication in cultured cells but is essential for efficient virus replication and pathogenesis in mice, indicating that the V protein has a luxury function to facilitate virus propagation in mice. This was discovered in the Z strain, an egg-adapted avirulent laboratory strain. In the present study, we reexamined the function of Sendai virus V protein by generating a V-knockout Sendai virus derived from the Hamamatsu strain, a virulent field isolate, which is an appropriate model for studying the natural course of Sendai virus infection in mice. We unexpectedly found that the V-knockout virus propagated efficiently in mice and was as virulent as the wild-type virus. Switching of the functionally important V unique region demonstrated that this region of the Hamamatsu strain was also functional in a Z strain background. It thus appears that the V protein is nonsense in a field isolate of Sendai virus. However, the V protein was required for virus growth and pathogenesis of the Hamamatsu strain in mice when the virulence of the virus was attenuated by introducing mutations that had been found in an egg-adapted, avirulent virus. The V protein therefore seems to be potentially functional in the highly virulent Hamamatsu strain and to be prominent if virus replication is restricted.
authors.affiliation: Department of Virology, Graduate School of Biomedical Sciences, Hiroshima University, Japan. tsaka@hiroshima-u.ac.jp
authors.forename: Takemasa
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Kiyotani
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Cheng
authors.initials: C
authors.lastname: Huang
authors.forename: Noriko
authors.initials: N
authors.lastname: Fukuhara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Fujii
authors.forename: Yukie
authors.initials: Y
authors.lastname: Shimazu
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Sugahara
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Nagai
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D004195:Disease Models, Animal; D017353:Gene Deletion; D008297:Male; D051379:Mice; D010253:Respirovirus Infections / Q000821:virology*; D029082:Sendai virus / Q000235:genetics / Q000472:pathogenicity*; D014764:Viral Proteins / Q000235:genetics*; D014774:Virulence
chemical_list: C111739:V protein, Sendai virus; D014764:Viral Proteins