Selection and identification of B-cell epitope on NS1 protein of dengue virus type 2

NS1 of dengue virus (DENV) is an important non-structural protein, which plays an important role in DENV replication and dengue infection. In this study, using the phage-displayed peptide library screening method and purified anti-DENV2-NS1 polyclonal antibody immunoglobulin G (IgG) as target, which was generated from the purified recombinant expressed DENV2-NS1 protein immunization on rabbit, seven B-cell epitopes of DENV2-NS1 protein were screened. Considering the results of comprehensive bioinformatic analysis on NS1 B-cell epitopes, possible dominant B-cell epitopes are located in amino acids residues 36–45, 80–89, 103–112, 121–130, 187–196, 295–304, and 315–324 of the NS1, and two epitope-based NS1 protein dodecapeptides corresponding to the predominant epitopes (PA10: 36PESPSKLASA45 and AA10: 187AIKDNRAVHA196) were chosen for synthesis. Results of binding assay and competitive-inhibition assays indicated the two peptides were the specific epitopes of DENV2-NS1 protein. These epitopes could be useful in understanding the pathogenesis of DENV and as dengue vaccine constituents in further study.