Serotonin Receptor Agonist 5-Nonyloxytryptamine Alters the Kinetics of Reovirus Cell Entry

J Virol. 2015 Sep;89(17):8701-12. doi: 10.1128/JVI.00739-15. Epub 2015 Jun 24.


Mammalian orthoreoviruses (reoviruses) are nonenveloped double-stranded RNA viruses that infect most mammalian species, including humans. Reovirus binds to cell surface glycans, junctional adhesion molecule A (JAM-A), and the Nogo-1 receptor (depending on the cell type) and enters cells by receptor-mediated endocytosis. Within the endocytic compartment, reovirus undergoes stepwise disassembly, which is followed by release of the transcriptionally active viral core into the cytoplasm. In a small-molecule screen to identify host mediators of reovirus infection, we found that treatment of cells with 5-nonyloxytryptamine (5-NT), a prototype serotonin receptor agonist, diminished reovirus cytotoxicity. 5-NT also blocked reovirus infection. In contrast, treatment of cells with methiothepin mesylate, a serotonin antagonist, enhanced infection by reovirus. 5-NT did not alter cell surface expression of JAM-A or attachment of reovirus to cells. However, 5-NT altered the distribution of early endosomes with a concomitant impairment of reovirus transit to late endosomes and a delay in reovirus disassembly. Consistent with an inhibition of viral disassembly, 5-NT treatment did not alter infection by in vitro-generated infectious subvirion particles, which bind to JAM-A but bypass a requirement for proteolytic uncoating in endosomes to infect cells. We also found that treatment of cells with 5-NT decreased the infectivity of alphavirus chikungunya virus and coronavirus mouse hepatitis virus. These data suggest that serotonin receptor signaling influences cellular activities that regulate entry of diverse virus families and provides a new, potentially broad-spectrum target for antiviral drug development.

Importance: Identification of well-characterized small molecules that modulate viral infection can accelerate development of antiviral therapeutics while also providing new tools to increase our understanding of the cellular processes that underlie virus-mediated cell injury. We conducted a small-molecule screen to identify compounds capable of inhibiting cytotoxicity caused by reovirus, a prototype double-stranded RNA virus. We found that 5-nonyloxytryptamine (5-NT) impairs reovirus infection by altering viral transport during cell entry. Remarkably, 5-NT also inhibits infection by an alphavirus and a coronavirus. The antiviral properties of 5-NT suggest that serotonin receptor signaling is an important regulator of infection by diverse virus families and illuminate a potential new drug target.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antiviral Agents
  • Biological Transport / drug effects
  • Cell Line
  • Cell Survival / drug effects
  • Chikungunya virus / drug effects
  • Chikungunya virus / pathogenicity
  • Chlorocebus aethiops
  • Cholera Toxin / metabolism
  • Cricetinae
  • Cytoskeleton / drug effects
  • Endosomes / physiology
  • Endosomes / virology
  • HeLa Cells
  • Humans
  • Interferon-gamma / biosynthesis
  • L Cells
  • Methiothepin / pharmacology
  • Mice
  • Murine hepatitis virus / drug effects
  • Murine hepatitis virus / pathogenicity
  • Reoviridae / drug effects
  • Reoviridae / pathogenicity*
  • Reoviridae / physiology
  • Reoviridae Infections / drug therapy*
  • Serotonin Antagonists / pharmacology*
  • Transferrin / metabolism
  • Tryptamines / pharmacology*
  • Vero Cells
  • Virus Assembly / drug effects
  • Virus Attachment / drug effects
  • Virus Internalization / drug effects*


  • Antiviral Agents
  • Serotonin Antagonists
  • Transferrin
  • Tryptamines
  • 5-(nonyloxy)tryptamine
  • Methiothepin
  • Interferon-gamma
  • Cholera Toxin