INDUCTION OF ANTIGEN-SPECIFIC CYTOLYTIC T-CELLS IN-SITU IN HUMAN-MELANOMA BY IMMUNIZATION WITH SYNTHETIC PEPTIDE-PULSED AUTOLOGOUS ANTIGEN-PRESENTING CELLS

Human melanoma cells can process the MAGE-1 gene product and present t he processed nonapeptide EADPTGHSY on their major histocompatibility c omplex class I molecules, HLA-A1, as a determinant for cytolytic T lym phocytes (CTLs), Considering that autologous antigen presenting cells (APCs) pulsed with the synthetic nonapeptide might, therefore, be immu nogenic, melanoma patients whose tumor cells express the MAGE-1 gene a nd who are HLA-A1(+) were immunized with a vaccine made of cultured au tologous APCs pulsed with the synthetic nonapeptide. Analyses of the n ature of the in vivo host immune response to the vaccine revealed that the peptide-pulsed APCs are capable of inducing autologous melanoma-r eactive and the nonapeptide-specific CTLs in situ at the immunization site and at distant metastatic disease sites.