The last few years have witnessed the publication of a large body of evidence demonstrating conclusively the existence of
tumor-associated
antigens. A large majority of these studies focused on
melanoma-associated
tumor antigens because of the collective evidence that the immune system can influence the pathogenesis of
melanoma, and because of the well-documented, although limited, success of immunotherapeutic modalities in
melanoma patients. This review summarizes what is known about
melanoma-associated antigenic
peptides: their identity, presentation by
human leukocyte antigen class I molecules to cognate
T cell receptors, and their potential to induce an effective immune response. The inability of
melanoma patients to mount an efficacious antitumor response and the distinction between antigenicity (i.e., the ability to express a
tumor antigen) and immunogenicity (i.e., the ability to elicit an effective immune response) are discussed. Recruitment of antigen-presenting cells at the
tumor site is suggested as a way to overcome
tumor-induced immunotolerance. The importance of developing or perfecting laboratory and/or clinical correlates of response to immunotherapeutic modalities is emphasized because of the pressing need for reliable tests that are predictive of clinical outcome.