Abstract
Defining the complex dynamics of Zika virus (ZIKV) infection in pregnancy and during transmission between vertebrate hosts and mosquito vectors is critical for a thorough understanding of viral transmission, pathogenesis, immune evasion, and potential reservoir establishment. Within-host viral diversity in ZIKV infection is low, which makes it difficult to evaluate infection dynamics. To overcome this biological hurdle, we constructed a molecularly barcoded ZIKV. This virus stock consists of a “synthetic swarm” whose members are genetically identical except for a run of eight consecutive degenerate codons, which creates approximately 64,000 theoretical nucleotide combinations that all encode the same amino acids. Deep sequencing this region of the ZIKV genome enables counting of individual barcodes to quantify the number and relative proportions of viral lineages present within a host. Here we used these molecularly barcoded ZIKV variants to study the dynamics of ZIKV infection in pregnant and non-pregnant macaques as well as during mosquito infection/transmission. The barcoded virus had no discernible fitness defects in vivo, and the proportions of individual barcoded virus templates remained stable throughout the duration of acute plasma viremia. ZIKV RNA also was detected in maternal plasma from a pregnant animal infected with barcoded virus for 67 days. The complexity of the virus population declined precipitously 8 days following infection of the dam, consistent with the timing of typical resolution of ZIKV in non-pregnant macaques and remained low for the subsequent duration of viremia. Our approach showed that synthetic swarm viruses can be used to probe the composition of ZIKV populations over time in vivo to understand vertical transmission, persistent reservoirs, bottlenecks, and evolutionary dynamics.
| Original language | English (US) |
|---|---|
| Article number | e1006964 |
| Journal | PLoS pathogens |
| Volume | 14 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2018 |
| Externally published | Yes |
Bibliographical note
Funding Information:Funding for this project came from National Institutes of Health grants R21AI131454, R01AI132563, R56AI132563 to MTA; R01AI067380 and R21AI125996 to GDE; and R01AI116382 to DHO; and from P51OD011106 awarded to the Wisconsin National Primate Research Center, Madison, WI. This research was conducted in part at a facility that was constructed with support from Research Facilities Improvement Program Grants RR15459-01 and RR020141-01. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The publication’s contents are solely the responsibility of the authors and do not necessarily represent the official views of the Office of Research Infrastructure Program or the National Institutes of Health; https://www.nih.gov/, http://dpcpsi.nih.gov/orip/index. The authors acknowledge Jens Kuhn and Jiro Wada for preparing silhouettes of macaques used in figures. We thank the Veterinary, Animal Care, Scientific Protocol Implementation, and the Pathology staff at the Wisconsin National Primate Research Center (WNPRC) for their contribution to this study. We also thank Amy Ellis for sequencing efforts and Chelsea Crooks for assistance with tissue viral loads.
Publisher Copyright:
© 2018 Aliota et al.
