title: Human kappa light chain targeted Pseudomonas exotoxin A--identifying human antibodies and Fab fragments with favorable characteristics for antibody-drug conjugate development.
abstract: Antibody-drug conjugates (ADC) represent promising agents for targeted cancer therapy. To allow rational selection of human antibodies with favorable characteristics for ADC development a screening tool was designed obviating the need of preparing individual covalently linked conjugates. Therefore, α-kappa-ETA' was designed as a fusion protein consisting of a human kappa light chain binding antibody fragment and a truncated version of Pseudomonas exotoxin A. α-kappa-ETA' specifically bound to human kappa light chains of human or human-mouse chimeric antibodies and Fab fragments. Antibody-redirected α-kappa-ETA' specifically inhibited proliferation of antigen-expressing cell lines at low toxin and antibody concentrations. Selected antibodies that efficiently delivered α-kappa-ETA' in the novel assay system were used to generate scFv-based covalently linked immunotoxins. These molecules efficiently triggered apoptosis of target cells, indicating that antibodies identified in our assay system can be converted to functional immunoconjugates. Finally, a panel of human epidermal growth factor receptor (EGFR) antibodies was screened--demonstrating favorable characteristics with antibody 2F8. These data suggest that antibodies with potential for Pseudomonas exotoxin A-based ADC development can be identified using the novel α-kappa-ETA' conjugate.
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University, Kiel, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Kellner
authors.forename: W K
authors.initials: WK
authors.lastname: Bleeker
authors.forename: J J
authors.initials: JJ
authors.lastname: Lammerts van Bueren
authors.forename: M
authors.initials: M
authors.lastname: Staudinger
authors.forename: K
authors.initials: K
authors.lastname: Klausz
authors.forename: S
authors.initials: S
authors.lastname: Derer
authors.forename: P
authors.initials: P
authors.lastname: Glorius
authors.forename: A
authors.initials: A
authors.lastname: Muskulus
authors.forename: B E C G
authors.initials: BE
authors.lastname: de Goeij
authors.forename: J G J
authors.initials: JG
authors.lastname: van de Winkel
authors.forename: P W H I
authors.initials: PW
authors.lastname: Parren
authors.forename: T
authors.initials: T
authors.lastname: Valerius
authors.forename: M
authors.initials: M
authors.lastname: Gramatzki
authors.forename: M
authors.initials: M
authors.lastname: Peipp
mesh_terms: D036002:ADP Ribose Transferases / Q000276:immunology* / Q000627:therapeutic use; D000818:Animals; D001427:Bacterial Toxins / Q000276:immunology* / Q000627:therapeutic use; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D066246:ErbB Receptors / Q000276:immunology; D005098:Exotoxins / Q000276:immunology* / Q000627:therapeutic use; D005434:Flow Cytometry; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000627:therapeutic use; D007145:Immunoglobulin kappa-Chains / Q000737:chemistry / Q000302:isolation & purification* / Q000627:therapeutic use; D000922:Immunotoxins / Q000737:chemistry / Q000302:isolation & purification* / Q000627:therapeutic use; D051379:Mice; D008958:Models, Molecular; D009369:Neoplasms / Q000276:immunology / Q000628:therapy; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000627:therapeutic use; D037521:Virulence Factors / Q000276:immunology* / Q000627:therapeutic use; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D066246:ErbB Receptors; D005098:Exotoxins; D007140:Immunoglobulin Fab Fragments; D007145:Immunoglobulin kappa-Chains; D000922:Immunotoxins; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A