Identification of Dengue-specific B-Cell Epitopes by Phage-display Random Peptide Library

Background: Dengue is the most important human viral disease transmitted by arthropod vectors. The availability of random peptide libraries (RPL) displayed on phage has provided a powerful tool for selecting sequences that mimic epitopes from microorganisms that are useful for diagnostic and vaccine development purposes. In this paper, we describe peptides that resemble the antigenic structure of B-cell epitopes of dengue virus identified from a phage-peptide library using human sera containing polyclonal antibodies against dengue virus. Materials and Methods: Eighteen phage clones were isolated from the phage-display peptide library, J404, by affinity selection using human antisera against dengue virus type 3. These clones were tested for reactivity by ELISA with a panel of hyperimmune ascitic fluids (HAFs) containing antibodies either against all four dengue serotypes, West Nile virus (WNV) or Eastern equine encephalitis virus (EEEV) with control ascitic fluid (NAF) used as a negative control. Results: Eight clones were recognized by HAFs against the four dengue serotypes, of which four significantly inhibited binding of anti-dengue antibodies to the virus. Two peptides with similar sequences to regions of NS3 and NS4B non-structural dengue virus proteins were identified. Conclusion: Our results suggest that these peptides could be used for the development of diagnostic tools for the detection of dengue virus infection and for a potential vaccine against this pathogen.