NEW TUMOR-RESTRICTED MELANOMA ANTIGENS AS DEFINED BY CYTOTOXIC T-CELLRESPONSES

Several tumour antigens have been molecularly defined during the last few years and three main groups of melanoma-associated antigens have b een identified according to their pattern of expression. Despite their wide expression in the Caucasian population, human leukocyte antigen (HLA) class I-presenting molecules, alternate to HLA-A2.1, have receiv ed little attention. To further explore the complexity of HLA class I- presented melanoma epitopes, we looked for the existence of other anti gens recognized by T cells in HLA-A3.1 and HLA-A2.1 restriction. The p attern of recognition identified by HLA-A3.1 or HLA-A2.1-restricted-T- cell lines and clones indicated the existence of a novel category of a ntigens represented by proteins expressed by melanomase but not by mel anocytes.