The favorable prognostic effect of intraepithelial CD8 ؉ TILs did not correlate with concurrent expression of NY-ESO-1 or MAGE antigens. We conclude that intraepithelial CD8 ؉ TILs and a high CD8 ؉ ͞Treg ratio are associated with favorable prognosis in epithelial ovarian cancer.cancer testis antigen ͉ CD8 ϩ T cell

Cancer/testis (CT) antigens, of which more than 40 have now been identified, are encoded by genes that are normally expressed only in the human germ line, but are also expressed in various tumour types, including melanoma, and carcinomas of the bladder, lung and liver. These immunogenic proteins are being vigorously pursued as targets for therapeutic cancer vaccines. CT antigens are also being evaluated for their role in oncogenesis--recapitulation of portions of the germline gene-expression programme might contribute characteristic features to the neoplastic phenotype, including immortality, invasiveness, immune evasion, hypomethylation and metastatic capacity.

Serological analysis of recombinant cDNA expression libraries (SEREX) using tumor mRNA and autologous patient serum provides a powerful approach to identify immunogenic tumor antigens. We have applied this methodology to a case of esophageal squamous cell carcinoma and identified several candidate tumor targets. One of these, NY-ESO-1, showed restricted mRNA expression in normal tissues, with high-level mRNA expression found only in testis and ovary tissues.

Cancer/testis (CT) antigens are a category of tumor antigens with normal expression restricted to male germ cells in the testis but not in adult somatic tissues. In some cases, CT antigens are also expressed in ovary and in trophoblast. In malignancy, this gene regulation is disrupted, resulting in CT antigen expression in a proportion of tumors of various types. Since their initial identification by T-cell epitope cloning, the list of CT antigens has been greatly expanded through serological expression cloning (SEREX) and differential mRNA expression analysis, and approximately 20 CT antigens or antigen families have been identified to date. Characteristics commonly shared by CT antigens, aside from the highly tissue-restricted expression profile, include existence as multigene families, frequent mapping to chromosome X, heterogeneous protein expression in cancer, likely correlation with tumor progression, induction of expression by hypomethylation and/or histone acetylation, and immunogenicity in cancer patients. Spontaneous humoral and cell-mediated immune responses have been demonstrated against several CT antigens, including NY-ESO-1, MAGE-A, and SSX antigens. Since CT antigens are immunogenic and highly restricted to tumors, their discovery has led directly to the development of antigen-specific cancer vaccines, and clinical trials with MAGE-A and NY-ESO-1 are in progress.

Evidence is growing for both humoral and cellular immune recognition of human tumor antigens. Antibodies with specificity for antigens initially recognized by cytotoxic T lymphocytes (CTLs), e.g., MAGE and tyrosinase, have been detected in melanoma patient sera, and CTLs with specificity for NY-ESO-1, a cancer-testis (CT) antigen initially identified by autologous antibody, have recently been identified. To establish a screening system for the humoral response to autoimmunogenic tumor antigens, an enzyme-linked immunosorbent assay (ELISA) was developed using recombinant NY-ESO-1, MAGE-1, MAGE-3, SSX2, Melan-A, and tyrosinase proteins. A survey of sera from 234 cancer patients showed antibodies to NY-ESO-1 in 19 patients, to MAGE-1 in 3, to MAGE-3 in 2, and to SSX2 in 1 patient. No reactivity to these antigens was found in sera from 70 normal individuals. The frequency of NY-ESO-1 antibody was 9.4% in melanoma patients and 12.5% in ovarian cancer patients. Comparison of tumor NY-ESO-1 phenotype and NY-ESO-1 antibody response in 62 stage IV melanoma patients showed that all patients with NY-ESO-1+ antibody had NY-ESO-1+ tumors, and no patients with NY-ESO-1− tumors had NY-ESO-1 antibody. As the proportion of melanomas expressing NY-ESO-1 is 20–40% and only patients with NY-ESO-1+ tumors have antibody, this would suggest that a high percentage of patients with NY-ESO-1+ tumors develop an antibody response to NY-ESO-1.

The potency of the immune response has still to be harnessed effectively to combat human cancers. However, the discovery of T-cell targets in melanomas and other tumors has raised the possibility that cancer vaccines can be used to induce a therapeutically effective immune response against cancer. The targets, cancer-testis (CT) antigens, are immunogenic proteins preferentially expressed in normal gametogenic tissues and different histological types of tumors. Therapeutic cancer vaccines directed against CT antigens are currently in late-stage clinical trials testing whether they can delay or prevent recurrence of lung cancer and melanoma following surgical removal of primary tumors. CT antigens constitute a large, but ill-defined, family of proteins that exhibit a remarkably restricted expression. Currently, there is a considerable amount of information about these proteins, but the data are scattered through the literature and in several bioinformatic databases. The database presented here, CTdatabase (http://www.cta.lncc.br), unifies this knowledge to facilitate both the mining of the existing deluge of data, and the identification of proteins alleged to be CT antigens, but that do not have their characteristic restricted expression pattern. CTdatabase is more than a repository of CT antigen data, since all the available information was carefully curated and annotated with most data being specifically processed for CT antigens and stored locally. Starting from a compilation of known CT antigens, CTdatabase provides basic information including gene names and aliases, RefSeq accession numbers, genomic location, known splicing variants, gene duplications and additional family members. Gene expression at the mRNA level in normal and tumor tissues has been collated from publicly available data obtained by several different technologies. Manually curated data related to mRNA and protein expression, and antigen-specific immune responses in cancer patients are also available, together with links to PubMed for relevant CT antigen articles.

No abstract

A nalysis of spontaneous immune responses against cancer in humans has led to the identification of a large number of tumor antigens (1). The majority of these antigens can be classified into one of the following categories according to their expression pattern, function, or origin: cancer-testis (CT) antigens, e.g., MAGE (2, 3) and NY-ESO-1 (4), which are aberrantly expressed in tumor cells but that, with the exception of germ cells, are silent in normal cells; differentiation antigens of the melanocyte lineage, e.g., Melan A͞MART-1 (5, 6), tyrosinase (7), and gp100 (8, 9); mutational antigens, e.g., MUM-1 (10), p53 (11, 12), and CDK4 (13); overexpressed ''self'' antigens, e.g., HER2͞neu (14) and p53 (12); and viral antigens, e.g., HPV (15) and EBV (16). Spontaneous immune responses elicited by these antigens are either predominantly cellular, e.g., tyrosinase (17, 18) and Melan A͞MART-1 (9, 19), or are associated with a strong humoral immune component, e.g., NY-ESO-1 (20) and p53 (12).NY-ESO-1 is a highly immunogenic CT antigen, inducing simultaneous cellular and humoral immune responses in a high percentage of patients with advanced NY-ESO-1-expressing tumors (20,21). Detectable NY-ESO-1 serum antibody depends on the presence of NY-ESO-1-expressing tumor, and antibody titers correlate with the clinical development of disease (20,22). NY-ESO-1-specific CD8ϩ T-cell responses were detected in more than 90% of NY-ESO-1 antibody-positive patients, whereas NY-ESO-1 antibody-negative patients showed no detectable NY-ESO-1-specific T-cell reactivity (23).The present study was initiated to evaluate the effects of active immunization with NY-ESO-1 peptides in NY-ESO-1 antibodynegative and -positive patients. Three naturally processed NY-ESO-1 peptides presented by HLA-A2 were used for intradermal immunization, first alone and then in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) as a systemic adjuvant. The following parameters were monitored in this trial: (i) peptide-specific CD8ϩ T-cell responses; (ii) delayed-type hypersensitivity (DTH) reactivity; (iii) NY-ESO-1-specific antibody responses; and (iv) disease status. MethodsImmunization Protocol. Twelve HLA-A2ϩ patients with progressing NY-ESO-1-expressing metastatic tumors of different types and meeting predefined entry criteria were selected for immunization in the LUD97-008 protocol sponsored by the Ludwig Institute for Cancer Research. Immunizations were performed with three HLA-A2-binding NY-ESO-1 peptides derived from NY-ESO-1 and initially identified by the T-cell line NW38-IVS-1 (21). The NY-ESO-1 peptide sequences were: p157-167 (SLLM-WITQCFL), p157-165 (SLLMWITQC), and p155-163 (QLSLLMWIT). The HLA-A2-presented influenza matrix peptide p58-66 (GILGFVFTL) was used as a positive control for immune responses in vitro and in vivo. Peptides (Ͼ90% purity) were manufactured according to good manufactorial practice guidelines (Multiple Peptide Systems, San Diego) and solubilized in 100% DMSO. Intradermal injection of the 100% DMSO͞pepti...