title: Investigation and molecular mimicry of the antigen involved in the interaction between the monoclonal antibody 5D10 and the human breast cancer cell line MCF-7.
abstract: Monoclonal antibody (mAb) 5D10 is directed against the human breast cancer cell line MCF-7. Biochemical characterization of the antibody epitope was attempted and revealed a complex, most likely carbohydrate-linked nature, which prevented isolation and further studies of the interaction. A major goal of this work was to generate structural mimics of the 5D10 epitope to serve as putative substitutes in such studies. A peptide library displayed on filamentous phage was used to select for mimotope peptide sequences. All positive phage clones selected from the library displayed the amino acid sequence H(2)N-QMNPMYYR-CO(2)H. This peptide sequence, as well as a branched form of the peptide, was found to bind mAb 5D10. Moreover, both peptide sequences were able to inhibit the binding of 5D10 to the MCF-7 cells in a concentration-dependent manner, with an EC(50) value in the range of 65 microM. According to these results, random phage peptide libraries can serve to identify mimotopic peptides for unknown complex cell surface epitopes.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Biotechnologie Chimique, Lausanne, Switzerland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Vandevyver
authors.forename: Stéphane
authors.initials: S
authors.lastname: Canarelli
authors.forename: Claudia
authors.initials: C
authors.lastname: Bossen
authors.forename: Igor
authors.initials: I
authors.lastname: Fisch
authors.forename: Kris
authors.initials: K
authors.lastname: Motmans
authors.forename: Jef
authors.initials: J
authors.lastname: Raus
authors.forename: Ruth
authors.initials: R
authors.lastname: Freitag
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000912:Antibodies, Neoplasm / Q000276:immunology*; D000941:Antigens / Q000276:immunology*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000276:immunology / Q000473:pathology; D045744:Cell Line, Tumor; D002850:Chromatography, Gel; D004279:DNA, Viral / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes; D006801:Humans; D018716:Molecular Mimicry; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D019151:Peptide Library; D017422:Sequence Analysis, DNA
chemical_list: D000911:Antibodies, Monoclonal; D000912:Antibodies, Neoplasm; D000941:Antigens; D004279:DNA, Viral; D000939:Epitopes; D005456:Fluorescent Dyes; D009842:Oligopeptides; D019151:Peptide Library; D016650:Fluorescein-5-isothiocyanate