AUTOLOGOUS CYTOLYTIC T-LYMPHOCYTES RECOGNIZE A MAGE-1 NONAPEPTIDE ON MELANOMAS EXPRESSING HLA-CW-ASTERISK-1601

Human melanoma cell line MZ2-MEL expresses several antigens recognized by autologous cytolytic T lymphocyte (CTL) clones. We reported previo usly the identification of a gene, named MAGE-1,which codes for antige n 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 antige n recognized by CTL on the MZ2-MEL cells. This antigen, which was name d MZ2-Bb, consists of MAGE-1-encoded peptide SAYGEPRKL bound to major histocompatibility molecule HLA-Cw1601. The HLA-Cw*1601 allele was fo und to be expressed by 7 out of 99 individuals from a Caucasian popula tion. Our results extend the range of tumor patients who could be elig ible for immunization against MAGE antigens.