title: Novel method for differentiation between Trastuzumab and host adaptive response.
abstract: Humoral immune response to human epidermal growth factor receptor 2 (HER-2/neu or ErbB-2) has been detected in sera of breast cancer patients and shown to be an appropriate prognostic marker (Taylor et al., 2007). However, since Trastuzumab (Herceptin) is a widely used monoclonal antibody as cancer therapy agent for tumors over-expressing HER-2, there is a need for an efficient way to detect host-generated antibodies against HER-2 without the confounding effect of Herceptin. Here we describe a screening method developed to decipher between host antibodies against HER-2 and that of Herceptin. By producing a series of truncation mutants within the epitope of Herceptin, we were able to inhibit this binding. We demonstrated also that by a three amino acid substitution (PPF→SSS) we were able to abrogate Herceptin binding while generating a highly conserved HER-2 extracellular domain (ECD). By producing a stable cell line that expresses this mutated form of the human HER-2 ECD, we have a source of this protein to probe patient sera. Our method represents a proof of principle that mutated HER-2 which we constructed could be used to distinguish between a host response against HER-2 and the monoclonal antibody Herceptin targeting the same protein.
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton L8N 3Z5, Canada. galina.denisova@gmail.com
authors.forename: Galina
authors.initials: G
authors.lastname: Denisova
authors.forename: Kristina
authors.initials: K
authors.lastname: Jenkins
authors.forename: Carole
authors.initials: C
authors.lastname: Evelegh
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bramson
mesh_terms: D056704:Adaptive Immunity; D000911:Antibodies, Monoclonal / Q000097:blood* / Q000627:therapeutic use; D061067:Antibodies, Monoclonal, Humanized; D000915:Antibody Affinity; D000970:Antineoplastic Agents / Q000097:blood / Q000627:therapeutic use; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy / Q000276:immunology; D005260:Female; D006403:Hematologic Tests / Q000379:methods*; D006801:Humans; D009154:Mutation; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D001323:Autoantibodies; D001324:Autoantigens; D018719:Erb-b2 Receptor Tyrosine Kinases; D011994:Recombinant Proteins; D000068878:Trastuzumab; C508053:ERBB2 protein, human