Generation of specific HLA-B*5703 tetramers by UV-ligand exchange. Biotinylated, UV-sensitive HLA-B*5703-9MT4 complexes were photoilluminated and rescued in the presence of HLA-B*5703-restricted KAFSPEVIPMF (KF11), TSTLQEQIGW (TW10), HTQGYFPDW (HW9), and QASQEVKGW (QW9) epitopes prior to tetramer generation via conjugation to an extravidin-phycoerythrin (PE)-labeled fluorochrome. (A) The functionality and specificity of UV-exchanged B*5703-KF11 tetramers was confirmed by staining a B*5703-KF11-restricted CD8+ T cell clone with conventional KF11 tetramer and KF11, TW10, and QW9 tetramers produced by UV exchange. Comparable staining was observed using both KF11 tetramers (open boxes), while the irrelevant UV exchange tetramers failed to bind KF11-specifc T cells. (B) The specificities of B*5703-TW10 and HW9 tetramers were evaluated by staining HW9- and TW10-specific CD8+ T cell lines (day 12) derived from a single donor in vitro.