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CD8+ T Cell Epitopes (cd8+ t + cell_epitope)
Selected AbstractsIdentification of a dengue virus-specific HLA-A*0201-restricted CD8+ T cell epitopeJOURNAL OF MEDICAL VIROLOGY, Issue 4 2010Jinsheng Wen Abstract 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-, ELISpot results and the results of intracellular staining of IFN-, 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-A*0201 molecules. The IFN-, ELISpot results and staining of intracellular IFN-, confirmed that this peptide could induce high-level CD8+ T cell response in HLA-A*0201 positive PBMCs. Peptide NS4b_40 (TLYAVATTI) was identified as a novel DENV-specific HLA-A*0201-restricted CD8+ T cell epitope. J. Med. Virol. 82:642,648, 2010. © 2010 Wiley-Liss, Inc. [source] Immune hierarchy among HIV-1 CD8+ T cell epitopes delivered by dendritic cells depends on MHC-I binding irrespective of mode of loading and immunization in HLA-A*0201 miceAPMIS, Issue 11 2009HENRIK N. KLOVERPRIS Recent human immunodeficiency virus type 1 (HIV-1) vaccination strategies aim at targeting a broad range of cytotoxic T lymphocyte (CTL) epitopes from different HIV-1 proteins by immunization with multiple CTL epitopes simultaneously. However, this may establish an immune hierarchical response, where the immune system responds to only a small number of the epitopes administered. To evaluate the feasibility of such vaccine strategies, we used the human leukocyte antigen (HLA)-A*0201 transgenic (tg) HHD murine in vivo model and immunized with dendritic cells pulsed with seven HIV-1-derived HLA-A*0201 binding CTL epitopes. The seven peptides were simultaneously presented on the same dendritic cell (DC) or on separate DCs before immunization to one or different lymphoid compartments. Data from this study showed that the T-cell response, as measured by cytolytic activity and ,-interferon (IFN-,)-producing CD8+ T cells, mainly focused on two of seven administered epitopes. The magnitude of individual T-cell responses induced by immunization with multiple peptides correlated with their individual immunogenicity that depended on major histocompatibility class I binding and was not influenced by mode of loading or mode of immunization. These findings may have implications for the design of vaccines based on DCs when using multiple epitopes simultaneously. [source] Both CD4+ and CD8+ T cell epitopes fused to heat shock cognate protein 70 (hsc70) can function to eradicate tumorsCANCER SCIENCE, Issue 5 2008Shusaku Mizukami Vaccination with heat shock proteins (HSP) protects mice from challenge with the tumor from which the HSP were isolated. The antigenicity of HSP vaccination is thought to result from HSP-associated endogenous major histocompatibility complex class I peptides or their precursors. The vaccination effect can be achieved in an adjuvant-free manner and is mediated by CD8+ T cells, indicating that HSP can act as a natural adjuvant and cross-prime T cells in vivo. We previously devised a recombinant vaccine composed of a CD8+ T cell epitope fused to the carboxyl-terminus of hsc70 and demonstrated efficient generation of antigen-specific cytotoxic T lymphocyte (CTL) after vaccination with a few micrograms of the hsc70-CTL epitope fusion protein. The present study aimed to determine if the fusion protein vaccine could control tumor growth in vivo and whether simultaneous fusion of a CD4+ T cell epitope to the amino terminus of the hsc70-CTL epitope would be a more potent vaccine compared to the CTL epitope alone. Ovalbumin (OVA),derived 8 mer peptide, OVA257-264, and 16mer peptide, OVA265-280, were used as CD8+ and CD4+ T cell epitopes, respectively. Vaccination with hsc70-OVA257-264 generated peptide specific CTL more effectively than a peptide plus incomplete Freund's adjuvant combination, and suppressed growth of OVA expressing EL4 (E.G7) and B16 melanoma tumor cells. Addition of OVA265-280 to the amino-terminus of hsc70-OVA257-264 (OVA265-280 -hsc70-OVA257-264) enhanced the generation of the OVA257-264 -specific CTL population, leading to better eradication of MO5 lung metastasis compared to hsc70-OVA257-264. Our results suggest that fusion of both CD4+ and CD8+ T cell epitopes to hsc70 enhances tumor immunity beyond the effect of the CD8+ T cell epitope alone. (Cancer Sci 2008; 99: 1008,1015) [source] | ||||||||||