Sensitivity of XLP and healthy donor derived CD8⁺T-cell clones assayed against peptide sensitized fibroblasts and B-cell targets. (A) HLA-B*2705 fibroblasts (top panel) or B-cell blasts (bottom panel) were sensitized with 10-fold dilutions of KRP-peptide, incubated overnight with KRP-specific T-cell clones derived from XLP1 or healthy donors and recognition assessed by measuring IFN-γ secreted by the T cells. (B) HLA-A*0201 fibroblasts (top panel) or LCLs (bottom panel) were sensitized with 10-fold dilutions of YVL-peptide, incubated overnight with YVL-specific T-cell clones derived from XLP8 or healthy donors, and recognition assessed by measuring IFN-γ secreted by the T cells.