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‐Cw* 1601. The HLA‐Cw* 1601 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.