title: Recognition of HLA-A2-restricted mammaglobin-A-derived epitopes by CD8+ cytotoxic T lymphocytes from breast cancer patients.
abstract: A breast cancer-associated antigen, mammaglobin-A, is specifically expressed in 80% of primary breast tumors. The definition of immune responses against this highly expressed breast cancer-specific antigen should be of great value in the development of new therapeutic strategies for breast cancer. Thus, the purpose of this study was to identify HLA-A2-restricted mammaglobin-A-derived epitopes recognized by CD8+ cytotoxic T lymphocytes (CTL). We identified seven mammaglobin-A-derived candidate epitopes that bind the HLA-A2 molecule (Mam-A2.1-7) by means of a HLA class I-peptide binding computer algorithm from the Bioinformatics & Molecular Analysis Section of the National Institutes of Health. Subsequently, we determined that CD8+ CTLs from breast cancer patients reacted to the Mam-A2.1 (83-92, LIYDSSLCDL), Mam-A2.2 (2-10, KLLMVLMLA), Mam-A2.3 (4-12, LMVLMLAAL), Mam-A2.4 (66-74, FLNQTDETL), and Mam-A2.7 (32-40, TINPQVSKT) epitopes using an IFN-gamma ELISPOT assay. Interestingly, healthy individuals also showed high reactivity to the Mam-A2.2 epitope. Two CD8+ CTL lines generated in vitro against TAP-deficient T2 cells loaded with the candidate epitopes showed significant cytotoxic activity against the Mam-A2.1-4 epitopes. These CD8+CTL lines recognized a HLA-A2+breast cancer cell line expressing the Mam-A2.1 epitope. In addition, DNA vaccination of HLA-A2+/human CD8+ double-transgenic mice with a DNA construct encoding the Mam-A2.1 epitope and the HLA-A2 molecule induced a significant expansion of epitope-specific CD8+ CTLs that recognize the same HLA- A2+/Mam-A2.1+ breast cancer cell line. In conclusion, these results demonstrate the immunotherapeutic potential of mammaglobin-A for the treatment and prevention of breast cancer.
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA. jaramilloa@wustl.edu
authors.forename: André
authors.initials: A
authors.lastname: Jaramillo
authors.forename: Kishore
authors.initials: K
authors.lastname: Narayanan
authors.forename: Lacey G
authors.initials: LG
authors.lastname: Campbell
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Benshoff
authors.forename: Lonnie
authors.initials: L
authors.lastname: Lybarger
authors.forename: Ted H
authors.initials: TH
authors.lastname: Hansen
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Fleming
authors.forename: Jill R
authors.initials: JR
authors.lastname: Dietz
authors.forename: T
authors.initials: T
authors.lastname: Mohanakumar
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology* / Q000473:pathology; D000818:Animals; D000951:Antigens, Neoplasm; D001943:Breast Neoplasms / Q000276:immunology* / Q000473:pathology; D000939:Epitopes; D005260:Female; D015789:HLA-A2 Antigen / Q000032:analysis; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D060785:Mammaglobin A; D051379:Mice; D008822:Mice, Transgenic; D009363:Neoplasm Proteins / Q000032:analysis / Q000276:immunology*; D009374:Neoplasms, Experimental; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014407:Tumor Cells, Cultured; D014598:Uteroglobin / Q000032:analysis / Q000276:immunology*; D019444:Vaccines, DNA
chemical_list: D000951:Antigens, Neoplasm; D000939:Epitopes; D015789:HLA-A2 Antigen; D060785:Mammaglobin A; D009363:Neoplasm Proteins; C556448:SCGB2A2 protein, human; D019444:Vaccines, DNA; D014598:Uteroglobin