Mapping Attenuation Determinants in Enterovirus-D68

Viruses. 2020 Aug 8;12(8):867. doi: 10.3390/v12080867.


Enterovirus (EV)-D68 has been associated with epidemics in the United Sates in 2014, 2016 and 2018. This study aims to identify potential viral virulence determinants. We found that neonatal type I interferon receptor knockout mice are susceptible to EV-D68 infection via intraperitoneal inoculation and were able to recapitulate the paralysis process observed in human disease. Among the EV-D68 strains tested, strain US/MO-14-18949 caused no observable disease in this mouse model, whereas the other strains caused paralysis and death. Sequence analysis revealed several conserved genetic changes among these virus strains: nucleotide positions 107 and 648 in the 5'-untranslated region (UTR); amino acid position 88 in VP3; 1, 148, 282 and 283 in VP1; 22 in 2A; 47 in 3A. A series of chimeric and point-mutated infectious clones were constructed to identify viral elements responsible for the distinct virulence. A single amino acid change from isoleucine to valine at position 88 in VP3 attenuated neurovirulence by reducing virus replication in the brain and spinal cord of infected mice.

Keywords: VP3; enterovirus; enterovirus-D68; infectious clones; mouse model; paralysis; virulence determinant.

Publication types

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

MeSH terms

  • 5' Untranslated Regions
  • Amino Acid Substitution
  • Animals
  • Brain / virology
  • Capsid Proteins / chemistry
  • Capsid Proteins / genetics*
  • Cell Line
  • Cell Line, Tumor
  • Disease Models, Animal
  • Enterovirus D, Human / genetics*
  • Enterovirus D, Human / pathogenicity*
  • Enterovirus D, Human / physiology
  • Enterovirus Infections / virology*
  • Genes, Viral
  • Humans
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Models, Molecular
  • Molecular Dynamics Simulation
  • Receptor, Interferon alpha-beta / genetics
  • Spinal Cord / virology
  • Virulence
  • Virus Replication


  • 5' Untranslated Regions
  • Capsid Proteins
  • Receptor, Interferon alpha-beta