p53, a potential target for tumor-directed T cells.

Cell lineage-specific cellular proteins, oncogenes from viral or cellular origin and tumor suppressor genes encode tumor-specific/associated antigens. Such antigens can elicit an major compatibility complex (MHC) class I-restricted cytotoxic T lymphocyte (CTL) response, either naturally in cancer patients or following appropriate immunostimulation (in vitro or in vivo). The reported immune responses in humans to the melanoma-associated MAGE gene products, GP100 and tyrosinase, all self-proteins, support the idea to use wild-type p53 products as targets for T cells. An important step towards this goal is identification of potential p53 CTL epitopes. We identified the wild-type p53 peptides with the highest affinity to the HLA-A*0201 molecule using two assays: the previously described MHC peptide-binding assay and the peptide competition assay. We obtained CTL against four p53 peptides with a high affinity for the HLA-A*0201 molecule. These findings are discussed next to a short review concerning the p53 literature.