58-11A5 recognizes an LMP1-derived peptide in an HLA-A∗02:01–restricted manner. (A) Coculture of 58-11A5 with U266B1 loaded with EBV protein–spanning peptide pools (PepTivator). Frequencies of GFP⁺ among all 58α⁻β⁻ were measured to detect T-cell activation. The plot shows median ± standard deviation from n = 3 independent experiments. (B) CD34^+exp of an independent individual were incubated with 58-11A5 in presence of blocking antibodies against HLA-ABC, HLA-BC, or HLA-A2. (C) HLA-class I–deficient HEK293T were transfected with all HLA-class I alleles, 1 at a time, of patient 230 (median recombinant HLA-expression: 54%; range, 37.3%-66.2%), loaded with LMP1 PepTivator, and incubated with 58-11A5. The plot shows median ± standard deviation from n = 3 replicates. (D) LMP1 or LMP2A expressing L-363 were cocultured with 58-11A5 (median LMP1 and LMP2A expression: 7.5%; range, 3.5%-15.3%). The plot shows median ± standard deviation from 6 replicates of n = 2 independent experiments. (E) Coculture of HLA-A∗02:01⁺ (A2⁺) or A2⁻ miniLCLs with 58-11A5. The plot shows median ± standard deviation from n = 3 replicates. All plots show frequencies of GFP⁺ as percentage of 58α⁻β⁻ cells. “Control” indicates coculture with nontreated/nontransfected cells as negative control. “Unstimulated” indicates 58-11A5 alone. (F) Only WQLLAFFLA of the LMP1 PepTivator pool activated 58-11A5. All other LMP1 PepTivator pool peptides did not activate 58-11A5 as shown for ALLVLYSFA as a representative example.