title: Evolution of attenuating mutations in dengue-2 strain S16803 PDK50 vaccine and comparison of growth kinetics with parent virus.
abstract: A live-attenuated dengue-2 virus strain S16803 vaccine candidate that is immunogenic and safe in humans was derived by 50 passages in primary dog kidney (PDK) cells. To identify mutations associated with attenuation of the dengue-2 PDK50 vaccine strain, we determined the nucleotide changes that arose during PDK passage of the dengue-2 virus. Thirteen mutations distinguished the PDK50 virus from low-passage parent resulting in amino acid substitutions in the premembrane (E89G), envelope (E202K, N203D), nonstructural proteins NS1 (A43T), NS2A (L181F), NS2B (I26V), and NS4B (I/T108T, L112F). In addition, the PDK50 virus contained a C to T change of nucleotide 57 in the 5' non-coding region and four silent mutations of nucleotides 591, 987, 6471, and 8907. An infectious PDK50 cDNA clone virus was produced and characterized for growth kinetics in monkey (LLC-MK(2), Vero) and mosquito (C6/36) cells. Identification of mutations in the vaccine strain and availability of an infectious clone will permit systematic analysis of the importance of individual or collective mutations on attenuation of dengue virus.
authors.affiliation: Division of Virus Diseases, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA. eileen.kelly@amedd.army.mil
authors.forename: Eileen P
authors.initials: EP
authors.lastname: Kelly
authors.forename: Stephanie
authors.initials: S
authors.lastname: Polo
authors.forename: Wellington
authors.initials: W
authors.lastname: Sun
authors.forename: Barry
authors.initials: B
authors.lastname: Falgout
mesh_terms: D000330:Aedes; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D002460:Cell Line; D053059:Dengue Vaccines / Q000235:genetics*; D003716:Dengue Virus / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D000882:Haplorhini; D008969:Molecular Sequence Data; D017354:Point Mutation; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D012692:Serial Passage; D014613:Vaccines, Attenuated / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics; D014774:Virulence; D014776:Virus Cultivation
chemical_list: D053059:Dengue Vaccines; D012367:RNA, Viral; D014613:Vaccines, Attenuated; D014764:Viral Proteins