Genetic and phenotypic characterization of sylvatic dengue virus type 2 strains

• Published in: Virology (New York, N.Y.) N.Y.), 2008-08, Vol.377 (2), p.296-307
• Main Authors: Vasilakis, Nikos, Fokam, Eric B, Hanson, Christopher T, Weinberg, Ethan, Sall, Amadou A, Whitehead, Stephen S, Hanley, Kathryn A, Weaver, Scott C
• Format: Article
• Language: English
• Subjects: 3'-untranslated regions; 5'-untranslated regions; Aedes; Aedes - virology; Animals; Cells, Cultured; conserved sequences; Dengue - transmission; Dengue - virology; Dengue virus; Dengue virus (DENV); Dengue Virus - genetics; Dengue Virus - physiology; Dengue virus type 2; Endemic DENV; genetic variation; Genome, Viral - genetics; genomics; Genotype; human health; Infectious Disease; Insect Vectors; nonstructural genes; open reading frames; Phenotype; phenotypic variation; Phylogenetic and phenotypic analysis; phylogeny; Primates; serotypes; structural genes; Sylvatic DENV; Virus Replication
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/j.virol.2008.04.044

Abstract The four serotypes of endemic dengue viruses (DENV) circulate between humans and peridomestic Aedes mosquitoes. At present endemic DENV infect 100 million people per year, and a third of the global population is at risk. In contrast, sylvatic DENV strains are maintained in a transmission cycle between nonhuman primates and sylvatic Aedes species, and are evolutionarily and ecologically distinct from endemic DENV strains. Phylogenetic analyses place sylvatic strains basal to each of the endemic serotypes, supporting the hypothesis that each of the endemic DENV serotypes emerged independently from sylvatic ancestors. We utilized complete genome analyses of both sylvatic and endemic DENV serotype 2 (DENV-2) to expand our understanding of their genetic relationships. A high degree of conservation was observed in both the 5′- and 3′-untranslated genome regions, whereas considerable differences at the nucleotide and amino acid levels were observed within the open reading frame. Additionally, replication of the two genotypes was compared in cultured cells, where endemic DENV strains produced a significantly higher output of progeny in human liver cells, but not in monkey kidney or mosquito cells. Understanding the genetic relationships and phenotypic differences between endemic and sylvatic DENV genotypes may provide valuable insight into DENV emergence and guide monitoring of future outbreaks.