ABSTRACT
Summary Recent advances of molecular immunology allowed us to identify genes encoding human tumor-associated antigens (TAAs) and peptides that are recognized by CD8 cytotoxic T lymphocytes (CTLs) of patients with various types of cancers. In this chapter we review the current status of TAAs and their CTL epitopes expressed in epithelial cancers and introduce our recent data concerning seven new TAAs. The first TAAs to be described are cancer-testis antigens which were mainly cloned from melanoma cDNA libraries but were reported to be expressed in various types of epithelial cancers. The second TAAs are non-mutated self-antigens that are over-expressed in both cancer cells and proliferating normal cells. Most TAAs which were identified at out laboratory belong to this group. The third TAAs to be described are mutated antigens which are expressed only in cancer cells but not in normal tissue. The fourth TAAs are some viral antigens which are selectively expressed in tumor cells. In the latter of this review, we introduce six new TAAs that were identified from pancreatic cancer cells. We also introduce that multidrug resistance-associated protein 3 (MRP3) can be a new TAA capable of inducing tumor-reactive CTLs from HLA-A24
patients with epithelial cancers. The majority of human malignant tumors consists of epithelial cancer. We hope that this chapter could provide the update information of molecular basis for CD8 T cell-mediated recognition of epithelial cancer cells, and thereby promote the development of specific cancer immunotherapy.
