Novel approach to recognition of predicted HIV-1 Gag B*3501-restricted CD8 T-cell epitopes by HLA-B*3501⁺ patients: Confirmation by quantitative ELISpot analyses and characterisation using multimers

Exploring the intricacies of CD8⁺ T-cell epitope recognition using emerging technologies to combine assessment of affinity, phenotype and resulting polyfunctional efficacy advances our understanding of HIV-1 immunopathogenesis and disease progression. Complexities within T-cell antigen recognition, such as epitope:MHC binding, stability and affinity, appear to influence the distinction between protective and ineffective anti-HIV-1 immune responses, which are thought to govern rate of disease progression. This study utilises the novel ProImmune REVEAL and ProVE® technology of rapid peptide synthesis, binding and affinity assays, and pentamer synthesis in conjunction with flow cytometry and simultaneous assessment of multiple CD8⁺ T-cell effector functions in response to HLA-B*3501-restricted HIV-1 Gag peptides, to discover new T-cell epitopes. The predicted HLA-B*3501-restricted peptides, HPVHAGPIA and YPLTSLRSL, and relevant pentamers were used in parallel to validate T-cell epitopes on clinical HIV-1⁺ samples, confirming correlation between the expected superior immunogenicity of newly discovered epitopes and the ex vivo T-cell response. Such a platform should be employed in prophylactic and therapeutic vaccine settings.