title: Molecular basis for adaptation of a chimeric dengue type-4/Japanese encephalitis virus to Vero cells.
abstract: The premembrane and envelope (E) genes of a full-length cDNA clone of the dengue type-4 (DEN4) virus 814669 strain were replaced with those of the Japanese encephalitis (JE) virus JaOH0566 strain. The in vitro-synthesized RNA transcripts prepared from chimeric cDNA were used to transfect mosquito C6/36 cells. A viable chimeric virus (designated DEN4/JE) was recovered. Unexpectedly, DEN4/JE exhibited restricted growth in Vero cells. After a serial passage in Vero cells, the Vero-adapted chimeras were obtained (two clones, designated Strain I and Strain II, respectively). The entire genomes of DEN4/JE, Strain I, and Strain II were sequenced and compared. There were multiple mutations, but amino acid substitutions occurred only in E and nonstructural (NS) protein NS4B. Our findings in this study indicate that the 5' nontranslated region, E, and NS4B may be involved in Vero cell adaptation in this chimeric system.
authors.affiliation: Department of Infectious Diseases, Faculty of Medicine, Oita University, Japan.
authors.forename: Wei-Feng
authors.initials: WF
authors.lastname: Tang
authors.forename: Yuki
authors.initials: Y
authors.lastname: Eshita
authors.forename: Masayuki
authors.initials: M
authors.lastname: Tadano
authors.forename: Kouichi
authors.initials: K
authors.lastname: Morita
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Makino
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D002460:Cell Line; D002678:Chimera / Q000235:genetics / Q000502:physiology; D002522:Chlorocebus aethiops; D009033:Culicidae; D003716:Dengue Virus / Q000145:classification / Q000235:genetics* / Q000502:physiology; D004664:Encephalitis Virus, Japanese / Q000235:genetics* / Q000502:physiology; D005814:Genes, Viral; D006801:Humans; D014162:Transfection; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000235:genetics; D017361:Viral Nonstructural Proteins / Q000235:genetics
chemical_list: D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins