A Full-Length Infectious cDNA Clone of Zika Virus from the 2015 Epidemic in Brazil as a Genetic Platform for Studies of Virus-Host Interactions and Vaccine Development

Konstantin A Tsetsarkin,Konstantin Chumakov,Heather Kenney,Stephen S Whitehead,Alexander G Pletnev,Guangping Liu,Majid Laassri,Hasmik Manukyan,Rubing Chen,Peter Palese

doi:10.1128/mbio.01114-16

Abstract

ABSTRACTAn arthropod-borne virus, Zika virus (ZIKV), has recently emerged as a major human pathogen. Associated with complications during perinatal development and Guillain-Barré syndrome in adults, ZIKV raises new challenges for understanding the molecular determinants of flavivirus pathogenesis. This underscores the necessity for the development of a reverse genetic system based on an epidemic ZIKV strain. Here, we describe the generation and characterization in cell cultures of an infectious cDNA clone of ZIKV isolated from the 2015 epidemic in Brazil. The cDNA-derived ZIKV replicated efficiently in a variety of cell lines, including those of both neuronal and placental origin. We observed that the growth of cDNA-derived virus was attenuated compared to the growth of the parental isolate in most cell lines, which correlates with substantial differences in sequence heterogeneity between these viruses that were determined by deep-sequencing analysis. Our findings support the role of genetic diversity in maintaining the replicative fitness of viral populations under changing conditions. Moreover, these results indicate that caution should be exercised when interpreting the results of reverse-genetics experiments in attempts to accurately predict the biology of natural viruses. Finally, a Vero cell-adapted cDNA clone of ZIKV was generated that can be used as a convenient platform for studies aimed at the development of ZIKV vaccines and therapeutics.

Highlights

An arthropod-borne virus, Zika virus (ZIKV), has recently emerged as a major human pathogen
Two of three selected clones contained a common nt substitution, C¡T, at nt position 5680, leading to a Ser356Phe mutation in the NS3 protein. To demonstrate that this mutation increases the fitness of clonederived virus in Vero cells, we introduced it into the ZIKV-1 cDNA plasmid and generated the ZIKV-NS3m plasmid
Contrary to single-stranded RNA viruses from many other families, the development of a reverse-genetics system for viruses belonging to the Flavivirus family has often been problematic due to toxicity of viral cDNA in bacterial systems

Summary

Introduction

An arthropod-borne virus, Zika virus (ZIKV), has recently emerged as a major human pathogen. Associated with complications during perinatal development and Guillain-Barré syndrome in adults, ZIKV raises new challenges for understanding the molecular determinants of flavivirus pathogenesis This underscores the necessity for the development of a reverse genetic system based on an epidemic ZIKV strain. Recent large-scale outbreaks of Zika virus (ZIKV) that were linked to complications during perinatal development and Guillain-Barré syndrome in adults emphasize the urgency for the development of a reverse-genetics system based on an epidemic ZIKV strain. The availability of appropriate genetic tools and laboratory models typically determines the progress in understanding the mechanisms of virus emergence and severity of disease caused by virus infection Such tools are instrumental for studies aimed at the development of effective vaccines and therapeutics. We developed and characterized a full-length ICD clone of a ZIKV isolate obtained in 2015 from a patient in Brazil

Methods

Results

Conclusion