(Best Abstract Best-2) Identification of HIV-1 CD8 T cell epitopes presented by HLA-A2601

Since HLA-A*26 is one of the most common alleles in Asia where approximately 20% people have this allele, identification of HIV-1CD8 T cell epitopes presented by HLA-A*26 is necessary for studies of immunopathogenesis in AIDS and vaccine development in Asian. We therefore tried to identify HIV-1CD8 T cell epitopes presented by HLA-A*2601. We employed reverse immunogenetics to identify the HIV-1 epitopes presented by HLA-A*2601. We selected 124 peptides that consist of 8-mer to 11-mer carrying V, T, I, F or L at P2 and Y or F at the C-terminus from HIV-1 SF2 sequence, and then synthesized these peptides. The ability of the peptides to bind the HLA-A*2601 molecules was tested by a HLA-A*2601 stabilization assay using RMA-S-A*2601 cells. 27 peptides bound to HLA-A*2601. The ability of these HLA-A*2601-binding peptides to induce peptide-specific CD8 T cells was tested by stimulating PBL from HIV-1-infected individuals having HLA-A*2601. Stimulated PBL was cultured for approximately 2 weeks and then the ability of the cultured cells to produce IFN-γ was tested by stimulation with C1R-A*2601 cells pulsed with the peptides. 5 of 27 HLA-A*2601-binding peptides induced peptide-specific CD8 T cells. Of CD8 T cells specific for 5 peptides, those specific for 3 peptides showed IFN-γ production after stimulation with C1R-A*2601 cells infected with HIV-1 recombinant vaccinia virus. These results indicate that these three peptides are HIV-1 CD8 T cell epitopes presented by HLA-A*2601. This study will contribute to studies of AIDS immunopathogenesis and vaccine development.