Fig. 2.

Establishment and specificity of T-cell clones. Individual T-cell clones were established from peptide-reactive T-cell lines by limiting dilution. T-cell clones (3×10⁴ cells/well) from CEA₁₁₆-, CEA₁₇₆-, and CEA₆₂₄-positive T-cell lines were restimulated in triplicate with autologous PBMC-derived DCs (1.5×10³ cells/well) pulsed with the same concentration (20 μg/ml) of corresponding peptides or irrelevant peptide control in the presence of anti-HLA-DR or anti-HLA-ABC (20 μg/ml). T-cell proliferation was measured by [³H]-thymidine incorporation assays. The proliferation of each T-cell clone cocultured with corresponding peptide was significantly higher than the proliferation with medium control and with the addition of HLA-DR antibody (p<0.01). Mean and standard deviation (SD) are shown for triplicate wells. The data shown are representative of three repeated experiments