title: Evaluation of a novel human IgG1 anti-claudin3 antibody that specifically recognizes its aberrantly localized antigen in ovarian cancer cells and that is suitable for selective drug delivery.
abstract: Membrane protein claudin3 has been recently suggested as a marker for biologically aggressive tumors and a possible target for the therapeutic delivery of active anti-cancer compounds. Claudin3-binding molecules such as the Clostridium perfringens enterotoxin (CPE), CPE-related molecules, and murine and chimeric antibodies have shown promising antitumor efficacy in preclinical oncological settings. We first engineered a fully human anti-claudin3 IgG1 antibody (IgGH6) by fusing the human IgG1 Fc-domain to the anti-claudin3 scFvH6 previously isolated from a pre-immune phage display library. The construct was expressed in mammalian cells and specifically targeted claudin3 endogenously expressed on the surface of different human ovarian cancer cell lines. No detectable cross-reactivity with other homologous claudins was observed. The epitope recognized by IgGH6 is located within the minor extracellular domain of claudin3 and becomes accessible only in tumor cells characterized by incomplete junction formation. Confocal microscopy experiments demonstrated that IgGH6 was actively internalized in tumor cells after binding to native claudin3 and co-localized, likely within intracellular vesicles, with the C-CPE peptide. Preliminary results indicate that IgGH6 accumulated in vivo in free claudin3 ovarian carcinoma xenografts. For its selective uptake in tumor cells and its human nature, IgGH6 represents a valuable candidate for antibody-drug conjugate therapeutic applications in ovarian cancer patients.
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Romani
authors.affiliation: Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT, USA.|Department of Molecular and Translational Medicine, Brescia, Italy.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Cocco
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Eliana
authors.initials: E
authors.lastname: Bignotti
authors.affiliation: Laboratory of Genetic Disorders of Childhood, Angelo Nocivelli Institute for Molecular Medicine, Spedali Civili, Brescia, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Moratto
authors.affiliation: Department of Pathology, University of Brescia, Brescia, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Bugatti
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Todeschini
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Bandiera
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Renata
authors.initials: R
authors.lastname: Tassi
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Zanotti
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Pecorelli
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Sartori
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Franco E
authors.initials: FE
authors.lastname: Odicino
authors.affiliation: Department of Biomedical Science and Engineering, University of Nova Gorica, Vipava, Slovenia.
authors.forename: Ario
authors.initials: A
authors.lastname: de Marco
authors.affiliation: Department of Molecular and Translational Medicine, Brescia, Italy.
authors.forename: Alessandro Davide
authors.initials: AD
authors.lastname: Santin
authors.affiliation: "Angelo Nocivelli" Institute for Molecular Medicine, Division of Gynecologic Oncology, University of Brescia, Brescia, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Ravaggi
authors.affiliation: Department of Pathology, University of Brescia, Brescia, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Mitola
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000494:pharmacology*; D000915:Antibody Affinity; D000970:Antineoplastic Agents / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D062465:Claudin-3 / Q000276:immunology*; D004337:Drug Carriers / Q000494:pharmacology; D016503:Drug Delivery Systems / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology*; D051379:Mice; D016513:Mice, SCID; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010051:Ovarian Neoplasms / Q000276:immunology*; D034741:RNA, Small Interfering; D060888:Real-Time Polymerase Chain Reaction; D020349:Surface Plasmon Resonance; D014162:Transfection; D023041:Xenograft Model Antitumor Assays
chemical_list: D000912:Antibodies, Neoplasm; D000970:Antineoplastic Agents; C568122:CLDN3 protein, human; D062465:Claudin-3; D004337:Drug Carriers; D007074:Immunoglobulin G; D034741:RNA, Small Interfering
keywords: claudins; human antibody; therapeutic target; tight junction