title: Characterization of novel murine monoclonal antibodies directed against the extracellular domain of human HER2 tyrosine kinase receptor.
abstract: HER2 proto-oncogene encodes a transmembrane receptor tyrosine kinase overexpressed in a variety of solid tumors. Several mouse monoclonal antibodies (MAbs) have been developed that recognize the extracellular part of HER2; of them two MAbs were humanized and employed for targeted immunotherapy. In this study we aimed to produce murine MAbs that specifically recognize the extracellular domain of human HER2. BALB/c mice were first primed with HER2-transfected NIH-3T3 cells and then boosted with recombinant extracellular part of HER2. Splenocytes from hyperimmunized mice were fused with myeloma cells and growing hybridomas were selected and screened for HER2 reactivity by an indirect ELISA. HER2-specific hybridomas were selected, cloned by limiting dilution assay, and further characterized by Western blotting and flow cytometry techniques. All clones showed positive reactivity to HER2 with binding affinity, ranging from 1.9×10(8) to 5×10(9), and stained HER2-transfected cells and malignant cells overexpressing HER2. None of the MAbs inhibited the binding of trastuzumab (Herceptin(®)) to HER2, indicating recognition of distinct epitopes by these MAbs. Based on these findings, our MAbs could be potentially used for selective targeting of HER2-expressing malignancies.
authors.affiliation: Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Enghelab Ave., Tehran, Iran.
authors.forename: Tohid
authors.initials: T
authors.lastname: Kazemi
authors.forename: Fathollah
authors.initials: F
authors.lastname: Tahmasebi
authors.forename: Ali Ahmad
authors.initials: AA
authors.lastname: Bayat
authors.forename: Neda
authors.initials: N
authors.lastname: Mohajer
authors.forename: Jalal
authors.initials: J
authors.lastname: Khoshnoodi
authors.forename: Mahmood
authors.initials: M
authors.lastname: Jeddi-Tehrani
authors.forename: Hodjatallah
authors.initials: H
authors.lastname: Rabbani
authors.forename: Fazel
authors.initials: F
authors.lastname: Shokri
mesh_terms: D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000737:chemistry; D058846:Antibodies, Monoclonal, Murine-Derived / Q000737:chemistry / Q000378:metabolism*; D000918:Antibody Specificity; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D041681:NIH 3T3 Cells; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D000090063:Proto-Oncogene Mas; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D017186:Titrimetry; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D058846:Antibodies, Monoclonal, Murine-Derived; D000090063:Proto-Oncogene Mas; D018719:Erb-b2 Receptor Tyrosine Kinases; D011994:Recombinant Proteins; D000068878:Trastuzumab; C000715470:MAS1 protein, human; C508053:ERBB2 protein, human