High-affinity recombinant phage antibodies to the pan-carcinoma marker epithelial glycoprotein-2 for tumour targeting

• Published in: British journal of cancer Vol. 78; no. 11; pp. 1407 - 1416
• Main Authors: ROOVERS, R. C, HENDERIKX, P, HELFRICH, W, VAN DER LINDEN, E, REURS, A, DE BRUÏNE, A. P, ARENDS, J, DE LEIJ, L, HOOGENBOOM, H. R
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.12.1998; Nature Publishing Group|1
• Subjects: Animals; Antibodies, Monoclonal - genetics; Antibodies, Monoclonal - immunology; Antibodies, Monoclonal - metabolism; Antigens, Neoplasm - immunology; Antigens, Neoplasm - metabolism; Base Sequence; Biological and medical sciences; Biomarkers, Tumor - immunology; Biomarkers, Tumor - metabolism; Cell Adhesion Molecules - immunology; Cell Adhesion Molecules - metabolism; Enzyme-Linked Immunosorbent Assay; Epithelial Cell Adhesion Molecule; Genes, Immunoglobulin; Genetic Vectors; Host-tumor relations. Immunology. Biological markers; Humans; Immunoglobulin Fragments - genetics; Immunoglobulin Fragments - immunology; Immunoglobulin Fragments - metabolism; Immunoglobulin Variable Region - genetics; Immunoglobulin Variable Region - immunology; Immunoglobulin Variable Region - metabolism; Medical sciences; Mice; Molecular Sequence Data; Tumors; Radionuclide study; Human; Carcinoma; Tumor associated antigen; Glycoprotein; Tumoral marker; Malignant tumor; Immunoradiodiagnosis; Virus; Immunotherapy; Diagnosis; Single chain antibody; Phage
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.1998.700

The tumour-associated antigen epithelial glycoprotein-2 (EGP-2) is a promising target for detection and treatment of a variety of human carcinomas. Antibodies to this antigen have been successfully used in patients for imaging of small-cell lung cancer and for adjuvant treatment of minimal residual disease of colon cancer. We describe here the isolation and complete characterization of high-affinity single-chain variable fragments (scFv) to the EGP-2 antigen. First, the binding kinetics of four murine whole antibodies directed to EGP-2 (17-1A, 323/A3, MOC-31 and MOC-161) were determined using surface plasmon resonance (SPR). The MOC-31 antibody has the lowest apparent off-rate, followed by MOC-161 and 323/A3. The V-genes of the two MOC hybridomas were cloned as scFv in a phage display vector and antigen-binding phage were selected by panning on recombinant antigen. The scFvs compete with the original hybridoma antibodies for binding to antigen and specifically bind to human carcinomas in immunohistochemistry. MOC-31 scFv has an off-rate which is better than those of the bivalent 17-1A and 323/A3 whole antibodies, providing it with an essential characteristic for tumour retention in vivo. The availability of these high-affinity anti-EGP-2 antibody fragments and of their encoding V-genes creates a variety of possibilities for their future use as tumour-targeting vehicles.