Murine norovirus-1 entry into permissive macrophages and dendritic cells is pH-independent

Virus Res. 2009 Jul;143(1):125-9. doi: 10.1016/j.virusres.2009.03.002. Epub 2009 Mar 14.


Murine norovirus (MNV) is a recently discovered mouse pathogen. Unlike the fastidious human noroviruses that cause the overwhelming majority of non-bacterial gastroenteritis worldwide, MNV readily infects cells in culture. Its replication in primary murine macrophages and dendritic cells and their derived cell lines allows the study of norovirus cell entry for the first time. In this study we determined the role of pH during MNV-1 infection since the low pH environment of endosomes often triggers uncoating of viruses. We demonstrated that MNV-1 viral titers by plaque assay and expression of the non-structural protein VPg by immunofluorescence were not affected by pH in cultured and primary macrophages and dendritic cells in the presence of two known endosome acidification inhibitors, bafilomycin A1 and chloroquine. These data indicate that MNV-1 enters permissive cells in a pH-independent manner.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antirheumatic Agents / pharmacology
  • Caliciviridae Infections / drug therapy*
  • Caliciviridae Infections / metabolism
  • Caliciviridae Infections / virology
  • Cell Culture Techniques
  • Chloroquine / pharmacology
  • Dendritic Cells / chemistry
  • Dendritic Cells / drug effects
  • Dendritic Cells / virology*
  • Endosomes / chemistry
  • Endosomes / drug effects
  • Enzyme Inhibitors / pharmacology
  • Hydrogen-Ion Concentration / drug effects
  • Macrolides / pharmacology
  • Macrophages / chemistry
  • Macrophages / drug effects
  • Macrophages / virology*
  • Male
  • Mice
  • Norovirus / drug effects
  • Norovirus / metabolism
  • Norovirus / physiology*
  • Viral Nonstructural Proteins / biosynthesis
  • Virus Internalization / drug effects*


  • Antirheumatic Agents
  • Enzyme Inhibitors
  • Macrolides
  • Viral Nonstructural Proteins
  • Chloroquine
  • bafilomycin A1