Many antigens recognized by autologous T lymphocytes have been identified on human
melanoma. Melanoma patients usually mount a spontaneous T cell response against their
tumor. But at some point, the responder T cells become ineffective, probably because of a
local immunosuppressive process occurring at the tumor sites. Therapeutic vaccination of
metastatic melanoma patients with these antigens is followed by tumor regressions only in a
small minority of the patients. The T cell responses to the vaccines show correlation with the …