No abstract

NY-ESO-1 specific humoral responses are frequently observed in patients with various types of NY-ESO-1 antigen expressing tumors. In a large proportion of NY-ESO-1 antibody-positive patients of NY-ESO-1-specific CD8 T-cells can also be detected suggesting that monitoring of the NY-ESO-1 specific humoral immune response may be a relevant and more practical surrogate for estimating the overall immune response against NY-ESO-1 in clinical vaccine studies. We have immunized 9 cancer patients with full length NY-ESO-1 protein formulated with cholesterol-bearing hydrophobized pullulan (CHP-NY-ESO-1) and investigated the humoral immune responses against NY-ESO-1. Seven patients were NY-ESO-1 antibody-negative and 2 patients were positive prior to vaccination. Vaccination with CHP-NY-ESO-1 resulted in the induction or increase of NY-ESO-1 antibody responses in all 9 patients immunized. Epitope analysis revealed 5 regions in the NY-ESO-1 protein molecule that were recognized by antibodies induced after vaccination. The 5 regions were also recognized by antibodies present in nonvaccinated, NY-ESO-1 antibody-positive cancer patients. A peptide spanning amino acids 91-108 was recognized in 6 out of 9 vaccinated patients and in 8 out of 9 nonvaccinated, sero-positive patients, being the most dominant antigenic epitope in NY-ESO-1 for antibody recognition in cancer patients. In conclusion, we showed that CHP-NY-ESO-1 protein vaccination had a potent activity for inducing humoral immune responses against NY-ESO-1 antigen in cancer patients. The antigenic epitopes recognized by antibodies in the vaccinated patients were similar to those recognized in cancer patients with spontaneous humoral immunity against NY-ESO-1.

The spontaneous immune responses against XAGE-1b (GAGED2a) were analyzed in non-small cell lung cancer (NSCLC) patients. An antibody response against XAGE-1b (GAGED2a) was observed in 10% (20/200) of NSCLC patients and in 19% (13/69) of stage IIIB/IV lung adenocarcinoma patients. A CD4 T-cell response was detected in 88% (14/16) and a CD8 T-cell response in 67% (6/9) in the XAGE-1b (GAGED2a) antibody-positive patients examined. Frequent antibody responses and CD4 and CD8 T-cell responses in XAGE-1b (GAGED2a) antibody-positive patients indicate the strong immunogenicity of the XAGE-1b (GAGED2a) antigen in NSCLC patients. We established T-cell clones from PBMCs of antibody-positive patients and determined the DRB1*04:05-restricted XAGE-1b (GAGED2a) 18-31 peptide (14-mer) as a CD4 T cell epitope and the A*02:06-restricted XAGE-1b (GAGED2a) 21-29 peptide (9-mer) as a CD8 T cell epitope. As for peptide recognition, CD4 and CD8 T-cell clones responded to naturally processed antigen. The CD4 T-cell clone recognized DCs pulsed with the synthetic protein or a lysate from XAGE-1b-transfected 293T cells. The CD8 T-cell clone showed cytotoxicity against a tumor expressing XAGE-1b (GAGED2a) and the appropriate HLA class I allele. These findings establish XAGE-1b (GAGED2a) as a promising target for a lung cancer vaccine.More than 70 cancer/testis (CT) antigen gene families have been identified by immunological or genetic approaches. 1-3Several CT antigens such as the NY-ESO-1 antigen etc. have been shown to elicit humoral and cellular immune responses in cancer patients. 4,5 Because of their restricted expression in normal tissues and high immunogenicity, CT antigens are considered attractive targets for cancer vaccines. 6-9XAGE-1 was originally identified by the search for PAGE/ GAGE-related genes using an expression sequence tag database 10 and was shown to exhibit CT antigen characteristics. 11,12 Five identical genes XAGE1A to E have now been identified, located in dispersed fashion in different orientations in a region of approximately 350 kilobases on chromosome Xp11.22.13 They belong to X antigen family genes. The associated protein is designated as G antigen family D member 2 (GAGED2), and GAGED2a and d isoforms have been identified. 10,13 Four transcript variants XAGE-1a, b, c and d have been extensively studied and were shown to be expressed in metastatic melanoma, Ewing sarcoma, and various epithelial tumors such as breast, lung and prostate cancers.14-17 In a serologic search for antigens using recombinant expression cloning (SEREX), we identified XAGE-1b as a dominant antigen recognized by serum from a lung adenocarcinoma patient using an autologous tumor cell line established from malignant pleural effusion as a source of the cDNA library.18 From the analysis with transfected 293T cells using a USO 9-13 mAb specific for XAGE-1b (GAGED2a) protein, we showed that the XAGE-1a and b transcripts code for the 81 amino acid XAGE-1b (GAGED2a) protein. 19 The XAGE-1c transcript codes for 9-and 17-a.a. peptides from an ...

The findings suggested the CCR4 on activated/effector Tregs and non-Tregs was functionally involved in the chemokinetic migration and accumulation of those cells to the tumor site. In vitro findings of efficient elimination of Tregs may give the basis for implementation of a clinical trial to investigate Treg depletion by administration of an anti-hCCR4 mAb to solid cancer patients.

We conducted a phase I clinical trial of a cancer vaccine using a 20-mer NY-ESO-1f peptide (NY-ESO-1 91-110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 lg of NY-ESO-1f peptide mixed with 0.2 KE Picibanil OK-432 and 1.25 ml Montanide ISA-51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY-ESO-1f peptide vaccine was well tolerated. Vaccine-related adverse events observed were fever (Grade 1), injection-site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY-ESO-1f peptide resulted in an increase or induction of NY-ESO-1 antibody responses in nine of ten patients. The sera reacted with recombinant NY-ESO-1 whole protein as well as the NY-ESO-1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine-induced CD4 and CD8 T cells responded to NY-ESO-1 91-108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20-mer NY-ESO-1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY-ESO-1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients.The NY-ESO-1 antigen was originally identified in esophageal cancer by serological expression cloning (SEREX) using autologous patient serum.1,2 NY-ESO-1 expression is observed in a wide range of human malignancies, 3,4 but the expression is restricted to germ cells in the testes in normal adult tissues. 1,3Therefore, NY-ESO-1 has emerged as a prototype of a class of cancer/testis (CT) antigens. 5More than 100 patients with NY-ESO-1-expressing tumors have received the NY-ESO-1 vaccine either as fulllength recombinant protein given as protein alone, with ISCOMATRIX V R or cholesterol-bearing hydrophobized pullulan (CHP), delivered in a recombinant vaccinia or fowlpox vector, or as the NY-ESO-1b peptide given with various adjuvants. [6][7][8][9][10][11] These studies established safety with various preparations of the NY-ESO-1 vaccine, showing toxicity to be limited to Grade 1 or 2 injection-site reactions or flu-like