Cytotoxic T-lymphocyte clones, established by stimulation with the HLA-A2 binding p53(65-73) wild type peptide loaded on dendritic cells in vitro, specifically recognize and lyse HLA-A2 tumour cells overexpressing the p53 protein

Mutations in the tumour suppressor gene p53 are among the most frequent gen etic alterations in human malignancies, often associated with an accumulati on of the p53 protein in the cytoplasm. We have generated a number of cytot oxic T lymphocyte (CTL) clones that specifically recognize the HLA-A*0201 p 53 wild type peptide RMPEAAPPV [65-73], designated R9V, by the in vitro sti mulation of CD8 enriched peripheral blood lymphocytes from a healthy HLA-A* 0201 donor using peptide loaded autologous dendritic cells. A total of 22 C TL clones were generated from the same bulk culture and demonstrated to car ry identical T-cell receptors. The CTL clone, 2D9, was shown to specificall y lyse the HLA-A*0201(+) squamous carcinoma cell line SCC9 and the breast c ancer cell line MDA-MB-468. Our data demonstrate that human peripheral bloo d lymphocytes from normal healthy individuals comprise T cells capable of r ecognizing p53 derived wild type (self) peptides. Furthermore, the capacity of R9V specific T cell clones to exert HLA restricted cytotoxicity, argues that the R9V peptide is naturally presented on certain cancer cells. This supports the view that p53 derived wild type peptides might serve as candid ate target antigens for the immunotherapeutic treatment of cancer.