Autologous cytolytic T lymphocytes recognize a MAGE-1 nonapeptide on melanomas expressing HLA-Cw*1601.

Human melanoma cell line MZ2-MEL expresses several antigens recognized by autologous cytolytic T lymphocyte (CTL) clones. We reported previously the identification of a gene, named MAGE-1, which codes for antigen MZ2-E which is presented by HLA-A1. Gene MAGE-1 is expressed in many tumors of several types but not in normal tissues except for testis. We show here that gene MAGE-1 directs the expression of another antigen recognized by CTL on the MZ2-MEL cells. This antigen, which was named MZ2-Bb, consists of MAGE-1-encoded peptide SAYGEPRKL bound to major histocompatibility molecule HLA-Cw1601. The HLA-Cw1601 allele was found to be expressed by 7 out of 99 individuals from a Caucasian population. Our results extend the range of tumor patients who could be eligible for immunization against MAGE antigens.