Fig. 3.
Naturally processed antigen presentation by CEA positive colorectal carcinoma cell lines. a Semi-quantitative mRNA expression analysis of human tumor cell lines. The transcripts for β-actin, CEACAM3, CEACAM4, and CEACAM5 were amplified by RT-PCR from serially diluted reverse-transcribed total RNA extracted from cell lines. b Recognition of human tumor cell lines by CEA694–702L2 no. R1 CD8+ T-cell clone in a chromium release assay. Pulsed targets were loaded with 1 μg/ml of CEA694–702 peptide. c Peptide-dependent recognition of SW403 colon cancer cell line assessed by cold-target inhibition. The ratio cold : hot was 10:1. Cold targets were T2-cells pulsed with either 1 μg/ml of CEA694–702 peptide or 1 μg/ml of FluMA58–66 peptide