Abstract
BackgroundZika virus (ZIKV) is an arthropod-borne virus (arbovirus) with an urban transmission cycle that primarily involves humans and Aedes aegypti. Evidence suggests that the evolution of some arboviruses is constrained by their dependency on alternating between disparate (vertebrate and invertebrate) hosts. The goals of this study are to compare the genetic changes that occur in ZIKV after serial passaging in mosquito or vertebrate cell lines or alternate passaging in both cell types and to compare the replication, dissemination, and transmission efficiencies of the cell culture-derived viruses in Ae. aegypti.MethodsAn isolate of ZIKV originally acquired from a febrile patient in Yucatan, Mexico, was serially passaged six times in African green monkey kidney (Vero) cells or Aedes albopictus (C6/36) cells or both cell types by alternating passage. A colony of Ae. aegypti from Yucatan was established, and mosquitoes were challenged with the cell-adapted viruses. Midguts, Malpighian tubules, ovaries, salivary glands, wings/legs and saliva were collected at various times after challenge and tested for evidence of virus infection.ResultsGenome sequencing revealed the presence of two non-synonymous substitutions in the premembrane and NS1 regions of the mosquito cell-adapted virus and two non-synonymous substitutions in the capsid and NS2A regions of both the vertebrate cell-adapted and alternate-passaged viruses. Additional genetic changes were identified by intrahost variant frequency analysis. Virus maintained by continuous C6/36 cell passage was significantly more infectious in Ae. aegypti than viruses maintained by alternating passage and consecutive Vero cell passage.ConclusionsMosquito cell-adapted ZIKV displayed greater in vivo fitness in Ae. aegypti compared to the other viruses, indicating that obligate cycling between disparate hosts carries a fitness cost. These data increase our understanding of the factors that drive ZIKV adaptation and evolution and underscore the important need to consider the in vivo passage histories of flaviviruses to be evaluated in vector competence studies.Graphical abstract
Highlights
Zika virus (ZIKV) is an arthropod-borne virus with an urban transmission cycle that primar‐ ily involves humans and Aedes aegypti
Genetic characterization of the host‐cell adapted viruses ZIKV was sequentially passaged six times in Vero or C6/36 cells or alternately between both cell types, and the viruses harvested from the final cultures were designated as ZIKV-6V, ZIKV-6C and ZIKV-6A, respectively
When ZIKV was released from alternate host cell replication by sequential in vitro passaging, the mosquito cell-adapted virus exhibited similar in vivo fitness in its principal mosquito vector compared to the input virus and greater in vivo fitness than the alternate-passaged virus
Summary
Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) with an urban transmission cycle that primar‐ ily involves humans and Aedes aegypti. The goals of this study are to compare the genetic changes that occur in ZIKV after serial passaging in mosquito or vertebrate cell lines or alternate passaging in both cell types and to compare the replication, dissemination, and transmission efficiencies of the cell culture-derived viruses in Ae. aegypti. Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) that belongs to the genus Flavivirus (family Flaviviridae). ZIKV was first isolated from a febrile rhesus monkey in Zika Forest, Uganda, in 1947, with subsequent isolations made from Aedes africanus in the same region the following year [1]. ZIKV emerged in the Pacific Islands in 2007, causing an explosive outbreak of febrile illness on Yap Island, with infections occurring in most inhabitants [5].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
