antibody, CD4 and CD8 T-cell resoponse against XAGE-1b (GAGED2a) in non-small cell lung cencer patients*
Cancer/testis (CT) antigen is a promising target for cancer vaccine due to their immunogenicity and restricted expression. We previously demonstrated that XAGE-1b (GAGED2a), one of the CT-like antigens, was predominantly expressed in lung adenocarcinoma by immunohistochemistry using XAGE-1b (GAGED2a) mAb (clone USO 9-13). In this study, we investigated humoral and cellular immune responses against XAGE-1b in patients with nonsmall cell lung cancer (NSCLC). Sera and PBMCs were obtained from NSCLC patients who visited Kawasaki Medical School Hospital between 2005 and 2011. Antibody response to XAGE-1b was analyzed by ELISA using synthesized XAGE-1b protein. CD4 and CD8 T-cell responses against XAGE-1b were examined by IFN- γ ELISA and/or capture assay using 17 16- or 17-mer XAGE-1b-overlapping peptides (OLPs) spanning the entire XAGE-1b (GAGED2a) protein by FACS in antibody-positive patients. Antibody positive frequencies of 362 NSCLC, 220 lung adenocarcinoma and 85 lung squamous cell carcinoma patients were 8.8% (32/362), 12.7% (28/220) and 1.2% (1/85), respectively. In patient KLU187 who is antibody positive, CD4 and CD8 T-cell responses against XAGE-1b (GAGED2a) were observed. Our findings indicate that CT antigen XAGE-1b (GAGED2a) is highly immunogenic in NSCLC patients inducing antibody, and CD4 and CD8 T-cell responses. XAGE-1b (GAGED2a) is a promising target antigen for immunotherapy against lung adenocarcinoma. (Accepted on October 24, 2011)
