Induction of cytolytic T lymphocytes by immunization of mice with an adenovirus containing a mouse homolog of the human MAGE-A genes

The genes of the MAGE-A family code for antigens that are strictly tumor-sp ecific and are shared by many human tumors. Melanoma patients have been imm unized against these antigens and some tumor regressions have been observed . However, no unequivocal evidence of cytolytic T cell responses has been o btained by analyzing the blood lymphocytes of these patients. Hence it was considered worthwhile to examine in mouse systems whether or not immunizati on against antigens derived from the mouse Mage homologs can produce cytoly tic T cell responses. We have identified an antigenic peptide encoded by mo use gene Mage-a2, and here we show that immunization of DBA/2 mice with st recombinant adenovirus containing either just the sequence encoding this pe ptide or a large part of the Mage-a2 coding sequence produces strong cytoly tic T cell responses. The Mage-a2 system should prove useful for the compar ison of vaccination modalities that could be applied to human patients in t herapeutic vaccination trials with MAGE antigens.