Rab11a mediates cell-cell spread and reassortment of influenza A virus genomes via tunneling nanotubes

• Type of Material: Article
• Authors: Ketaki Ganti, Emory University; Julianna Han, University of Chicago; Balaji Manicassamy, University of Iowa; Anice Lowen, Emory University
• Language: English
• Date: 2021-09-01
• Publisher: PUBLIC LIBRARY SCIENCE
• Publication Version: Final Published Version
• Copyright Statement: © 2021 Ganti et al
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.ppat.1009321
• Title of Journal or Parent Work: PLOS PATHOGENS
• Volume: 17
• Issue: 9
• Start Page: e1009321
• End Page: e1009321
• Grant/Funding Information: This research project was supported in part by the Emory University Integrated Cellular Imaging Microscopy Core, supported by the Office of the Director, NIH (S10OD028673). The project was funded by NIH/NIAID Centers of Excellence in Influenza Research and Surveillance (CEIRS), contract number HHSN272201400004C (ACL; KG) and NIH R01AI127799 (ACL; KG). JH was partly supported by the NIH Molecular and Cellular Biology training program at The University of Chicago (T32GM007183); JH was partly supported by the NIH Diversity Supplement (R01AI123359- 02S1). BM is supported by NIAID grants (R01AI123359 and R01AI127775). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
• Keywords: MECHANISM; SIGNALS; Virology; COLOCALIZATION; Science & Technology; Life Sciences & Biomedicine; EPITHELIAL-CELLS; TRAFFICKING; MEASLES-VIRUS; Microbiology; TRANSPORT; Parasitology
• Research Categories: Health Sciences, Immunology; Biology, Microbiology

Abstract

Influenza A virus [IAV] genomes comprise eight negative strand RNAs packaged into virions in the form of viral ribonucleoproteins [vRNPs]. Rab11a plays a crucial role in the transport of vRNPs from the nucleus to the plasma membrane via microtubules, allowing assembly and virusproduction. Here, we identify a novel function for Rab11a in the inter-cellular transport of IAV vRNPs using tunneling nanotubes [TNTs]as molecular highways. TNTs are F-Actin rich tubules that link the cytoplasm of nearby cells. In IAV-infected cells, Rab11a was visualized together with vRNPs in these actin-rich intercellular connections. To better examine viral spread via TNTs, we devised an infection system in which conventional, virion-mediated, spread was not possible. Namely, we generated HA-deficient reporter viruses which are unable to produce progeny virions but whose genomes can be replicated and trafficked. In this system, vRNP transfer to neighboring cells was observed and this transfer was found to be dependent on both actin and Rab11a. Generation of infectious virus via TNT transfer was confirmed using donor cells infected with HA-deficient virus and recipient cells stably expressing HA protein. Mixing donor cells infected with genetically distinct IAVs furthermore revealed the potential for Rab11a and TNTs to serve as a conduit for genome mixing and reassortment in IAV infections. These data therefore reveal a novel role for Rab11a in the IAV life cycle, which could have significant implications for within-host spread, genome reassortment and immune evasion.