Assessment of alloreactivity of TCR-transduced PBMCs against single MHC allele–expressing cells. 1D3 TCR–transduced cells were incubated with 21 single MHC allele-expressing cell lines for a period of 5 hours. T2 cells and A02.01 K562 cells loaded with the Mart-1_(26-35) peptide were used as a positive control. After incubation, cells were stained with anti-CD8 and PE CD4, and intracellular cytokine production was determined using anti-IFN-γ. The percentage of IFN-γ⁺ CD8⁺ cells (■) and CD4⁺ cells (□) is depicted. Bars represent range (n = 2).