The NB protein of influenza B virus is not necessary for virus replication in vitro.
The NB protein of influenza B virus is thought to function as an ion channel and therefore would be expected to have an essential function in viral replication. Because direct evidence for its absolute requirement in the viral life cycle is lacking, we generated NB knockout viruses by reverse genetics and tested their growth properties both in vitro and in vivo. Mutants not expressing NB replicated as efficiently as the wild-type virus in cell culture, whereas in mice they showed restricted growth compared with findings for the wild-type virus. Thus, the NB protein is not essential for influenza B virus replication in cell culture but promotes efficient growth in mice.
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
Masato
M
Hatta
Yoshihiro
Y
Kawaoka
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004285:Dogs; D005260:Female; D006801:Humans; D009981:Influenza B virus / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D007251:Influenza, Human / Q000821:virology; D007473:Ion Channels / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009154:Mutation; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
D007473:Ion Channels; D014764:Viral Proteins