Functional screening and tetramer staining of CD8^pos HA-1H–specific T-cell clones. HA-1H–specific T-cell clones were stimulated with HLA-A*02:01^pos TAP-deficient T2 cells exogenously loaded with a titration of the HA-1H peptide. IFN-γ production was assessed in a standard enzyme-linked immunosorbent assay (ELISA) (R:S ratio, 1:6). Clones in red were classified as high avidity, clones in green as intermediate avidity, clones in blue as low avidity, and clones in gray as not functional. Results of representative unique clones are depicted. (A) High avidity HA-1H–specific T-cell clones isolated from 3 patients during an in vivo GVL response after alloSCT. (B) HA-1H–specific T-cell clones isolated from 3 HA-1H^neg/HLA-A*02:01^pos healthy donors. (C) HA-1H–specific T-cell clones isolated from 4 HA-1H^pos/HLA*02:01^pos healthy donors. (D) Intensity of HA-1H tetramer staining for a selection of obtained HA-1H–specific T-cell clones. An NY-eso-1-SLL–specific T-cell clone was included as negative control.