Growth restriction of negative-strand-RNA viruses in a rat 3Y1 cell line.

A rat fibroblast cell line, 3Y1 is nonpermissive for infection by several negative-strand-RNA viruses including influenza virus A, Sendai virus, Newcastle disease virus and vesicular stomatitis virus (VSV), but not refractory to that of a positive-strand-RNA virus, Sindbis virus. To elucidate the mechanism of the restricted viral growth, we compared the replication pattern of VSV in 3Y1 cells and in baby hamster kidney cells, which are fully permissive for those viruses. The results indicated that the restriction was imposed predominantly on the transcription of the viral RNA. The subsequent steps such as protein synthesis and nucleocapsid assembly appeared to occur normally, although these levels remained low due to the restricted transcription. Virus attachment onto, and penetration into, 3Y1 cells were also not restricted.