title: Identification of breast cancer peptide epitopes presented by HLA-A*0201.
abstract: Cellular immune mechanisms detect and destroy cancerous and infected cells via the human leukocyte antigen (HLA) class I molecules that present peptides of intracellular origin on the surface of all nucleated cells. The identification of novel, tumor-specific epitopes is a critical step in the development of immunotherapeutics for breast cancer. To directly identify peptide epitopes unique to cancerous cells, secreted human class I HLA molecules (sHLA) were constructed by deletion of the transmembrane and cytoplasmic domain of HLA A*0201. The resulting sHLA-A*0201 was transferred and expressed in breast cancer cell lines MCF-7, MDA-MB-231, and BT-20 as well as in the immortal, nontumorigenic cell line MCF10A. Stable transfectants were seeded into bioreactors for production of > 25 mg of sHLA-A*0201. Peptides eluted from affinity purified sHLA were analyzed by mass spectroscopy. Comparative analysis of HLA-A*0201 peptides revealed 5 previously uncharacterized epitopes uniquely presented on breast cancer cells. These peptides were derived from intracellular proteins with either well-defined or putative roles in breast cancer development and progression: Cyclin Dependent Kinase 2 (Cdk2), Ornithine Decarboxylase (ODC1), Kinetochore Associated 2 (KNTC2 or HEC1), Macrophage Migration Inhibitory Factor (MIF), and Exosome Component 6 (EXOSC6). Cellular recognition of the MIF, KNTC2, EXOSC6, and Cdk2 peptides by circulating CD8+ cells was demonstrated by tetramer staining and IFN-gamma ELISPOT. The identification and characterization of peptides unique to the class I of breast cancer cells provide putative targets for the development of immune diagnostic tools and therapeutics.
authors.affiliation: University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, Pure Protein, LLC, Oklahoma City, Oklahoma 73104, USA.
authors.forename: Oriana E
authors.initials: OE
authors.lastname: Hawkins
authors.forename: Rodney S
authors.initials: RS
authors.lastname: Vangundy
authors.forename: Annette M
authors.initials: AM
authors.lastname: Eckerd
authors.forename: Wilfried
authors.initials: W
authors.lastname: Bardet
authors.forename: Rico
authors.initials: R
authors.lastname: Buchli
authors.forename: Jon A
authors.initials: JA
authors.lastname: Weidanz
authors.forename: William H
authors.initials: WH
authors.lastname: Hildebrand
mesh_terms: D000595:Amino Acid Sequence; D001943:Breast Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D051357:Cyclin-Dependent Kinase 2 / Q000276:immunology / Q000378:metabolism; D003598:Cytoskeletal Proteins; D018984:Epitopes, T-Lymphocyte / Q000032:analysis* / Q000276:immunology / Q000302:isolation & purification; D005095:Exoribonucleases / Q000276:immunology / Q000378:metabolism; D005260:Female; D015234:HLA-A Antigens / Q000737:chemistry / Q000276:immunology*; D015789:HLA-A2 Antigen; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D019746:Intramolecular Oxidoreductases / Q000276:immunology / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000378:metabolism; D008263:Macrophage Migration-Inhibitory Factors / Q000276:immunology / Q000378:metabolism; D013058:Mass Spectrometry; D009687:Nuclear Proteins / Q000276:immunology / Q000378:metabolism; D009955:Ornithine Decarboxylase / Q000276:immunology / Q000378:metabolism
chemical_list: D003598:Cytoskeletal Proteins; D018984:Epitopes, T-Lymphocyte; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D008263:Macrophage Migration-Inhibitory Factors; C120529:NDC80 protein, human; D009687:Nuclear Proteins; D007371:Interferon-gamma; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D005095:Exoribonucleases; D009955:Ornithine Decarboxylase; D019746:Intramolecular Oxidoreductases; C515598:MIF protein, human