Identification of a dengue virus-specific HLA-A*0201-restricted CD8+ T cell epitope.

In this study, a combination of epitope-prediction programs and in vitro assays was used to identify dengue virus (DENV)-specific CD8(+) T cell epitopes. Peripheral blood mononuclear cells (PBMCs) isolated from patients who recovered from dengue fever were stimulated with candidate epitope peptides derived from DENV, which were predicted by using SYFPEITHI and RANKpep epitope-prediction programs. The IFN-gamma ELISpot results and the results of intracellular staining of IFN-gamma showed that peptides NS4b_40 (TLYAVATTI), E_256 (QEGAMHTAL), NS3_205 (LPAIVREAI), NS5_210 (SRNSTHEMY), and NS3_207 (AIVREAIKR) could induce the recall response of CD8(+) T cells. Furthermore, the results of the MHC-peptide complex stabilization assay revealed that peptide NS4b_40 (TLYAVATTI) has a high affinity for HLA-A0201 molecules. The IFN-gamma ELISpot results and staining of intracellular IFN-gamma confirmed that this peptide could induce high-level CD8(+) T cell response in HLA-A0201 positive PBMCs. Peptide NS4b_40 (TLYAVATTI) was identified as a novel DENV-specific HLA-A*0201-restricted CD8(+) T cell epitope.