An External Loop Region of Domain III of Dengue Virus Type 2 Envelope Protein Is Involved in Serotype-Specific Binding to Mosquito but Not Mammalian Cells

DOI Web Site 6 Citations
  • Jan-Jong Hung
    Institute of Molecular Biology, Academia Sinica, Nankang
  • Meng-Ti Hsieh
    Institute of Molecular Biology, Academia Sinica, Nankang
  • Ming-Jer Young
    Institute of Molecular Biology, Academia Sinica, Nankang
  • Chuan-Liang Kao
    Graduate Institute of Medical Technology
  • Chwan-Chuen King
    Institue of Epidemiology, College of Public Health, National Taiwan University, Taipei, Taiwan, Republic of China
  • Wen Chang
    Institute of Molecular Biology, Academia Sinica, Nankang

Abstract

<jats:title>ABSTRACT</jats:title> <jats:p>Dengue virus (DV) is a flavivirus and infects mammalian cells through mosquito vectors. This study investigates the roles of domain III of DV type 2 envelope protein (EIII) in DV binding to the host cell. Recombinant EIII interferes with DV infection to BHK21 and C6/36 cells by blocking dengue virion adsorption to these cells. Inhibition of EIII on BHK21 cells was broad with no serotype specificity; however, inhibition of EIII on C6/36 cells was relatively serotype specific. Soluble heparin completely blocks binding of EIII to BHK21 cells, suggesting that domain III binds mainly to cell surface heparan sulfates. This suggestion is supported by the observation that EIII binds very weakly to gro2C and sog9 mutant mammalian cell lines that lack heparan sulfate. In contrast, heparin does not block binding of EIII to mosquito cells. Furthermore, a synthetic peptide that includes amino acids (aa) 380 to 389 of EIII, IGVEPGQLKL, inhibits binding of EIII to C6/36 but not BHK21 cells. This peptide corresponds to a lateral loop region on domain III of E protein, indicating a possible role of this loop in binding to mosquito cells. In summary, these results suggest that EIII plays an important role in binding of DV type 2 to host cells. In addition, EIII interacts with heparan sulfates when binding to BHK21 cells, and a loop region containing aa 380 to 389 of EIII may participate in DV type 2 binding to C6/36 cells.</jats:p>

Journal

  • Journal of Virology

    Journal of Virology 78 (1), 378-388, 2004-01

    American Society for Microbiology

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