Identification Of HLA-A0201-resticted Cytotoxic T Lymphocyte Epitope From Sp17

Immunotherapy is a strategy of promising efficiency in cancer patients. Specific immunotherapy of malignant cancer may be an alternative or be complementary to other approaches for treatment of recurrent or metastasized disease, such as surgical resection, chemotherapy and radiation therapy. Elimination of most tumor by the immune system depends critically on recognition by CD8+ cytotoxic T lymphocytes (CTLs) of tumor antigen-derived peptides presented at the cell surface with self-major histocompatibility complex (MHC) classâ… molecules (HLA-A,B,C in humans). In the early 1990s, Boon and his colleagues reported the first successful coloing of a human tumor antigen, termed melanoma antigen-1 (MAGE-1). Subsequently, many tumor antigens had been identified. The tumor antigens were classified into five groups, such as cancer/testis antigen, tumor differentiation antigen, virus-associated antigen, mutated and overexpressed gene products.The cancer-testis antigen CT antigen family has been an attractive target for tumor immunotherapy because these antigens can be recognized by human CTLs and expressed in a variety of malignant tumors from many kinds of histological origins but not in normal tissues, with the exception of the testis and placenta. The antigenic peptides derived from CT antigens such as MAGE-1, MAGE-3 and NY-ESO-1 have been proven to elicit a CTL response in the context of MHC class I molecules. Some of them are currently tested in cancer clinical trials. . However, expression of CT antigens is heterogeneous among tumors of different histological origins, different patients, and between individual lesions. These characteristics of CT antigen expression suggest that the development of specific immuno-therapy based on as many antigens as possible may be clinically beneficial.The Sp17 antigen, which was initially thought to be a sperm specific protein involved in the acrosome reaction, belongs to a growing class of CT antigen. This gene is found overexpressed in most carcinoma cell lines, hematopoietic and epithelial tumors such as...