Extremely high-avidity T cells expressing CD4+ T cell-derived TCRβ chains, which can be stained by an A2/MART1 monomer complex, possess broader cross-reactivity.
(a) Jurkat 76 and Jurkat 76/CD8 transfectants were stained with 50 μg/ml non-multimerized A2/MART1 or control monomer along with anti-CD3 mAb or anti-CD8 mAb. Data for monomer staining of 6 representative CD8+ T-cell-derived TCRβ transfectants and 7 representative CD4+ T-cell-derived TCRβ transfectants are shown. Data for monomer staining of the remaining transfectants are shown in Supplementary Fig. 4a,b. (b) A2/MART1 monomer positivity was compared in Jurkat 76/CD8 transfectants expressing CD8+ or CD4+ T-cell-derived TCRβ chains. The data represent the means ± SD in each group. *p < 0.05, two-tailed Welch’s t test. (c) A2/MART1 monomer positivity in Jurkat 76/CD8 transfectants expressing CD4+ T-cell-derived TCRβ chains is shown according to the number of MART1-related peptides recognized. (d) A2/MART1 monomer positivity was compared in Jurkat 76/CD8 transfectants expressing CD4+ T-cell-derived TCRβ chains that recognized the indicated number of MART1-related peptides. The data represent the means ± SD in each group. *p < 0.05, two-tailed Welch’s t test. The data shown are representative of three independent experiments.