RESUMEN
In this study, we set out to identify dengue virus serotype 2 (DENV-2)-specific HLA-A*2402-restricted epitopes and determine the characteristics of T cells generated to these epitopes. We screened the full-length amino-acid sequence of DENV-2 to find potential epitopes using the SYFPEITHI algorithm. Twelve putative HLA-A*2402-binding peptides conserved in hundreds of DENV-2 strains were synthesized, and the HLA restriction of peptides was tested in HLA-A*2402 transgenic mice. Nine peptides (NS4b(228-237), NS2a(73-81), E(298-306), M(141-149), NS4a(96-105), NS4b(159-168), NS5(475-484), NS1(162-171), and NS5(611-620)) induced high levels of peptide-specific IFN-γ-secreting cells in HLA-A*2402 transgenic mice. Apart from IFN-γ, NS4b(228-237-), NS2a(73-81-) and E(298-306)-specific CD8(+) cells produced TNF-α and IL-6 simultaneously, whereas M(141-149-) and NS5(475-484-) CD8(+) cells produced only IL-6. Moreover, splenic mononuclear cells (SMCs) efficiently recognized and killed peptide-pulsed splenocytes. Furthermore, each of nine peptides could be recognized by splenocytes from DENV-2-infected HLA-A*2402 transgenic mice. The SMCs from HLA-A*2402 transgenic mice immunized with nine immunogenic peptides efficiently killed DENV-2-infected splenic monocytes. The present identified epitopes have the potential to be new diagnostic tools for characterization of T-cell immunity in DENV infection and may serve as part of a universal epitope-based vaccine.
Asunto(s)
Virus del Dengue/inmunología , Dengue/inmunología , Epítopos/inmunología , Antígenos HLA-A/inmunología , Secuencia de Aminoácidos , Animales , Línea Celular , Citocinas/metabolismo , Dengue/metabolismo , Virus del Dengue/clasificación , Modelos Animales de Enfermedad , Mapeo Epitopo , Epítopos/química , Epítopos de Linfocito T/química , Epítopos de Linfocito T/inmunología , Femenino , Humanos , Inmunización , Inmunofenotipificación , Ratones Transgénicos , Péptidos/química , Péptidos/inmunología , Serogrupo , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismoRESUMEN
Squamous cell carcinoma antigen (SCCA) is overexpressed in many squamous cell cancers and SCCAderived peptide-specific CD8(+) cytotoxic T lymphocytes can display cytotoxicity against tumor cells. In the present study, we screened the SCCA amino acid sequence for potential HLA-A*0201-binding CD8(+) Tcell epitopes using two predictive computational algorithms. Seven epitope candidates were selected of which SCCA(246-254)(llpneidgl), SCCA(223-231)(sledvqakv), SCCA(328336)(vlhkafvev) and SCCA(324332)(vlsgvlhka) significantly stabilized HLA-A*0201 molecules on T2 cells. Both SCCA(328336) and SCCA(324-332) induced CD8(+) IFN-γ(+) Tcell responses in HLA-A*0201-positive peripheral blood mononuclear cells as assessed by intracellular cytokine staining. Consistent with this, immunization with either SCCA(328-336) or SCCA(324332) effectively elicited CD8(+) IFN-γ(+) T cells in HLA-A*0201 transgenic mice as visualized by IFN-γ ELISPOT assay and intracellular cytokine staining. Furthermore, CD8(+) T cells induced in vitro or in vivo by SCCA(328-336) or SCCA(324-332) demonstrated in vitro cytotoxicity against peptide-pulsed T2 cells and splenocytes, respectively. These novel SCCAderived CD8(+) Tcell epitopes described, herein, may be potentially important components for diagnostic reagents and immunotherapeutic vaccines for the treatment of squamous cell carcinomas.