Original article
The envelope glycoprotein domain III of dengue virus serotypes 1 and 2 inhibit virus entry
J.F.L. China, J.J.H. Chua and M.L. Ng
aFlavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597, Singapore
Received 28 July 2006; accepted 30 September 2006. Available online 6 December 2006.
Abstract
Dengue virus (DV) is a flavivirus and its urban transmission is maintained largely by its mosquito vectors and vertebrate host, often human. In this study, investigation was carried out on the involvement of domain III of the envelope (E) glycosylated protein of dengue virus serotypes 1 and 2 (DV-1 and DV-2 DIII) in binding to host cell surfaces, thus mediating virus entry. Domain III protein of flavivirus can also serve as an attractive target in inhibiting virus entry. The respective DV DIII proteins were expressed as soluble recombinant fusion proteins before purification through enzymatic cleavage and affinity purification. The purified recombinant DV-1 and DV-2 DIII proteins both demonstrated the ability to inhibit the entry of DV-1 and DV-2 into HepG2 cells and C6/36 mosquito cells. As such, the DV DIII protein is indeed important for the interaction with cellular receptors in both human and mosquito cells. In addition, this protein induced antibodies that completely neutralized homologous dengue serotypes although not with the same efficiency among the heterologous serotypes. This observation may be of importance when formulating a generic vaccine that is effective against all dengue virus serotypes.
Keywords: Flavivirus; Virus entry; Vaccine; Neutralizing antibodies
