title: Actin-Related Protein 2 (ARP2) and Virus-Induced Filopodia Facilitate Human Respiratory Syncytial Virus Spread.
abstract: Human respiratory syncytial virus (RSV) is an enveloped RNA virus that is the most important viral cause of acute pediatric lower respiratory tract illness worldwide, and lacks a vaccine or effective antiviral drug. The involvement of host factors in the RSV replicative cycle remains poorly characterized. A genome-wide siRNA screen in human lung epithelial A549 cells identified actin-related protein 2 (ARP2) as a host factor involved in RSV infection. ARP2 knockdown did not reduce RSV entry, and did not markedly reduce gene expression during the first 24 hr of infection, but decreased viral gene expression thereafter, an effect that appeared to be due to inhibition of viral spread to neighboring cells. Consistent with reduced spread, there was a 10-fold reduction in the release of infectious progeny virions in ARP2-depleted cells at 72 hr post-infection. In addition, we found that RSV infection induced filopodia formation and increased cell motility in A549 cells and that this phenotype was ARP2 dependent. Filopodia appeared to shuttle RSV to nearby uninfected cells, facilitating virus spread. Expression of the RSV F protein alone from a plasmid or heterologous viral vector in A549 cells induced filopodia, indicating a new role for the RSV F protein, driving filopodia induction and virus spread. Thus, this study identified roles for ARP2 and filopodia in RSV-induced cell motility, RSV production, and RSV cell-to-cell spread.
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Masfique
authors.identifier: http://orcid.org/0000-0003-1728-3126
authors.initials: M
authors.lastname: Mehedi
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Thomas
authors.initials: T
authors.lastname: McCarty
authors.affiliation: Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Martin
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Cyril
authors.initials: C
authors.lastname: Le Nouën
authors.affiliation: Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America.
authors.forename: Eugen
authors.initials: E
authors.lastname: Buehler
authors.affiliation: Division of Pre-Clinical Innovation, National Center for Advancing Translational Sciences, Rockville, Maryland, United States of America.
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Margery
authors.initials: M
authors.lastname: Smelkinson
authors.affiliation: Biological Imaging Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Sundar
authors.initials: S
authors.lastname: Ganesan
authors.affiliation: Microscopy Unit, Rocky Mountain Laboratories, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America.
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Fischer
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Linda G
authors.initials: LG
authors.lastname: Brock
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Bo
authors.initials: B
authors.lastname: Liang
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Shirin
authors.initials: S
authors.lastname: Munir
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Collins
authors.affiliation: RNA Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
authors.forename: Ursula J
authors.initials: UJ
authors.lastname: Buchholz
mesh_terms: D000072283:A549 Cells; D051377:Actin-Related Protein 2 / Q000378:metabolism*; D015153:Blotting, Western; D005434:Flow Cytometry; D055785:Gene Knockdown Techniques; D006801:Humans; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D011554:Pseudopodia / Q000648:ultrastructure / Q000821:virology*; D060888:Real-Time Polymerase Chain Reaction; D018357:Respiratory Syncytial Virus Infections / Q000821:virology*; D012136:Respiratory Syncytial Viruses / Q000472:pathogenicity*; D053586:Virus Internalization
chemical_list: C495926:ACTR2 protein, human; D051377:Actin-Related Protein 2