A prostate stem cell antigen-derived peptide immunogenic in HLA-A24- prostate cancer patients.

We attempted to identify prostate stem cell antigen (PSCA)-derived peptides immunogenic in HLA-A24+ prostate cancer patients. Peripheral blood mononuclear cells (PBMCs) were stimulated in vitro with each of three different PSCA-derived peptides, which were prepared based on the HLA-A24 binding motif, and their peptide-specific and HLA-A24-restricted anti-tumor responses were examined. Plasma levels of immunoglobulin G (IgG) against PSCA peptides were measured by enzyme-linked immunosorbent assay (ELISA). Among three PSCA peptides, the PSCA 76-84 peptide most effectively induced peptide-specific cytotoxic T lymphocytes (CTLs) from PBMCs of HLA-A24+ prostate cancer patients. Cytotoxicity was dependent on peptide-specific and CD8+ T cells. The PSCA 76-84 peptide-stimulated PBMCs showed a significant level of cytotoxicity against prostate cancer cells in an HLA-A24-restricted manner. IgG reactive to the PSCA 76-84 peptide was detected in half of patients. The PSCA 76-84 peptide should be considered for use in clinical trials of immunotherapy for HLA-A24+ patients.

Matsueda S ，Yao A ，Ishihara Y ，Ogata R ，Noguchi M ，Itoh K ，Harada M ... -  《PROSTATE》

Prostate-specific antigen-derived epitopes capable of inducing cellular and humoral responses in HLA-A24+ prostate cancer patients.

We tried to identify prostate-specific antigen (PSA)-derived epitopes immunogenic in HLA-A24+ prostate cancer patients. Peripheral blood mononuclear cells (PBMCs) were in vitro stimulated with each of four different PSA peptides carrying the HLA-A24 binding motif, and their HLA-A24-restricted anti-tumor responses were examined using a parental HLA-A24-negative prostate cancer cell line (PC93) and its HLA-A24-expressing transfectant line (PC93-A24). Serum levels of immunoglobulin G (IgG) against PSA peptides were measured by enzyme-linked immunosorbent assay (ELISA). PBMCs, which were in vitro stimulated with either the PSA(152-160) or PSA(248-257) peptide, showed higher levels of IFN-gamma production and cytotoxicity against the PC93-A24 than against the PC93. IgG against the PSA(248-257) peptide was detected in half of the prostate cancer patients tested. The PSA(152-160) and PSA(248-257) peptides could be appropriate target molecules in use for specific immunotherapy of HLA-A24+ prostate cancer patients.

Harada M ，Kobayashi K ，Matsueda S ，Nakagawa M ，Noguchi M ，Itoh K ... -  《PROSTATE》

Prostate stem cell antigen is a promising candidate for immunotherapy of advanced prostate cancer.

Dannull J ，Diener PA ，Prikler L ，Fürstenberger G ，Cerny T ，Schmid U ，Ackermann DK ，Groettrup M ... -  《CANCER RESEARCH》

Identification of human papillomavirus 16-E6 protein-derived peptides with the potential to generate cytotoxic T-lymphocytes toward human leukocyte antigen-A24+ cervical cancer.

Hara M ，Matsueda S ，Tamura M ，Takedatsu H ，Tanaka M ，Kawano K ，Mochizuki K ，Kamura T ，Itoh K ，Harada M ... -  《INTERNATIONAL JOURNAL OF ONCOLOGY》

Identification of squamous cell carcinoma antigen-derived peptides having the capacity of inducing cancer-reactive CTLs in HLA-A24+ cancer patients.

Homma S ，Harada M ，Yano H ，Ogasawara S ，Shichijo S ，Matsueda S ，Komatsu N ，Shomura H ，Maeda Y ，Sato Y ，Todo S ，Itoh K ... -  《INTERNATIONAL JOURNAL OF ONCOLOGY》