Intracellular Diversity of WNV within Circulating Avian Peripheral Blood Mononuclear Cells Reveals Host-Dependent Patterns of Polyinfection

Authors

Dalit Talmi-Frank, Colorado State University, Fort Collins,
Alex D. Byas, Colorado State University, Fort Collins,
Reyes Murrieta, Colorado State University, Fort Collins,
James Weger-Lucarelli, Colorado State University, Fort Collins,
Claudia Rückert, University of Nevada, Reno
Emily N. Gallichotte, Colorado State University, Fort Collins,
Janna A. Yoshimoto, Colorado State University, Fort Collins,
Chris Allen, Colorado State University, Fort Collins,
Angela M. Bosco-Lauth, Colorado State University, Fort Collins,
Barbara Graham, Colorado State University, Fort Collins,
Todd A. Felix, USDA APHIS Wildlife Services
Aaron C. Brault, Centers for Disease Control and Prevention, Fort Collins, CO
Gregory D. Ebel, Colorado State University, Fort Collins,Follow

Date of this Version

2023

Citation

Talmi-Frank, D.; Byas, A.D.; Murrieta, R.;Weger-Lucarelli, J.; Rückert, C.; Gallichotte, E.N.; Yoshimoto, J.A.; Allen, C.; Bosco-Lauth, A.M.; Graham, B.; et al. Intracellular Diversity of WNV within Circulating Avian Peripheral Blood Mononuclear Cells Reveals Host-Dependent Patterns of Polyinfection. Pathogens 2023, 12, 767. https://doi.org/10.3390/ pathogens12060767

Comments

Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license

Abstract

Arthropod-borne virus (arbovirus) populations exist as mutant swarms that are maintained between arthropods and vertebrates. West Nile virus (WNV) population dynamics are host-dependent. In American crows, purifying selection is weak and population diversity is high compared to American robins, which have 100- to 1000-fold lower viremia. WNV passed in robins leads to fitness gains, whereas that passed in crows does not. Therefore, we tested the hypothesis that high crow viremia allows for higher genetic diversity within individual avian peripheral blood mononuclear cells (PBMCs), reasoning that this could have produced the previously observed hostspecific differences in genetic diversity and fitness. Specifically, we infected cells and birds with a molecularly barcoded WNV and sequenced viral RNA from single cells to quantify the number of WNV barcodes in each. Our results demonstrate that the richness of WNV populations within crows far exceeds that in robins. Similarly, rare WNV variants were maintained by crows more frequently than by robins. Our results suggest that increased viremia in crows relative to robins leads to the maintenance of defective genomes and less prevalent variants, presumably through complementation. Our findings further suggest that weaker purifying selection in highly susceptible crows is attributable to this higher viremia, polyinfections and complementation.