title: [The NS gene--a possible determinant of apathogenicity of a cold-adapted donor of attenuation A /Leningrad/134/47/57 and its reassortants].
abstract: Phenotypical properties of single-gene reassortants of attenuated cold-adapted strain A/Leningrad/135/47/57 (H2N2) and strain A/PR8/34 virulent for laboratory animals were studied. Only the group of reassortants inheriting NS gene from cold-adapted virus was fully attenuated for various animals species, similarly as reassortants with 6/2 genomic formula containing all the 6 internal protein genes from strain A/Leningrad/134/47/57. Reassortant 25A-1 single-gene for NS was temperature-sensitive (ts) on mammalian cells but formed plaques at 40 degrees C on chicken kidney cells. Reassortants with genomic formula 6/2 were temperature-sensitive in all types of cells used. Reassortant 25A-1 could synthesize normal amounts of polypeptides in MDCK cells at 39 degrees C, whereas protein synthesis of reassortants with 6/2 genomic formula was noticeably reduced at this temperature. Hence, a similar level of attenuation of both reassortant groups appears to be due to various molecular mechanisms. Possible role of NS2 gene mutation in attenuation of strain A/Leningrad/134/47/57 and its reassortants is discussed.
authors.forename: A Iu
authors.initials: AIu
authors.lastname: Egorov
authors.forename: L M
authors.initials: LM
authors.lastname: Garmashova
authors.forename: I V
authors.initials: IV
authors.lastname: Lukashok
authors.forename: G N
authors.initials: GN
authors.lastname: Nevedomskaia
authors.forename: G I
authors.initials: GI
authors.lastname: Aleksandrova
authors.forename: A I
authors.initials: AI
authors.lastname: Klimov
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D002335:Carnivora; D002478:Cells, Cultured; D002645:Chickens; D003080:Cold Temperature; D004285:Dogs; D009980:Influenza A virus / Q000235:genetics / Q000276:immunology / Q000472:pathogenicity*; D051379:Mice; D010641:Phenotype; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000096:biosynthesis / Q000235:genetics*; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology; D014774:Virulence / Q000235:genetics
chemical_list: D014613:Vaccines, Attenuated; D017361:Viral Nonstructural Proteins; D014765:Viral Vaccines
vernacular_title: Gen NS--veroiatnaia determinant apatogennosti kholodoadaptirovannogo donora attenuatsii A /Leningrad/134/47/57 i ego reassortantov.