title: A Complement-Optimized EGFR Antibody Improves Cytotoxic Functions of Polymorphonuclear Cells against Tumor Cells.
abstract: Complement-dependent cytotoxicity (CDC) has been suggested to be an important mechanism of action of tumor-targeting Abs. However, single unmodified epidermal growth factor receptor (EGFR)-targeting IgG1 Abs fail to trigger efficient CDC. For the current study, we generated a CDC-optimized variant of the EGFR Ab matuzumab (H425 wt) by introducing amino acid substitutions K326A/E333A (H425 mt). This Ab was then used to elucidate the impact of complement activation on the capacity of effector cells such as mononuclear cells (MNC) and polymorphonuclear cells (PMN) to exert Ab-dependent cell-mediated cytotoxicity (ADCC). H425 mt, but not H425 wt, significantly induced complement deposition, release of anaphylatoxins, and CDC against distinct tumor cell lines, whereas no differences in ADCC by MNC or PMN were detected. Notably, stronger cytotoxicity was induced by H425 mt than by H425 wt in whole blood assays and in experiments in which MNC or PMN were combined with serum. Although MNC-ADCC was not affected by C5 cleavage, the cytotoxic activity of PMN in the presence of serum strongly depended on C5 cleavage, pointing to a direct interaction between complement and PMN. Strong cell surface expression of C5a receptors was detected on PMN, whereas NK cells completely lacked expression. Stimulation of PMN with C5a led to upregulation of activated complement receptor 3, resulting in enhanced complement receptor 3-dependent PMN-ADCC against tumor cells. In conclusion, complement-optimized EGFR Abs may constitute a promising strategy to improve tumor cell killing by enhancing the interaction between humoral and cellular effector functions in Ab-based tumor therapy.
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University and University Hospital Schleswig-Holstein, 24105 Kiel, Germany; Medical Department 1, University Hospital Schleswig-Holstein, Campus Lübeck, 23538 Lübeck, Germany; Stefanie.Derer@uksh.de.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Derer
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University and University Hospital Schleswig-Holstein, 24105 Kiel, Germany;
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0003-4251-6462
authors.initials: M
authors.lastname: Cossham
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University and University Hospital Schleswig-Holstein, 24105 Kiel, Germany;
authors.forename: Thies
authors.initials: T
authors.lastname: Rösner
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University and University Hospital Schleswig-Holstein, 24105 Kiel, Germany;
authors.forename: Christian
authors.identifier: http://orcid.org/0000-0002-2562-6902
authors.initials: C
authors.lastname: Kellner
authors.affiliation: Genmab, 3584 CM Utrecht, the Netherlands; and.
authors.forename: Frank J
authors.identifier: http://orcid.org/0000-0002-7165-5771
authors.initials: FJ
authors.lastname: Beurskens
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University and University Hospital Schleswig-Holstein, 24105 Kiel, Germany;
authors.forename: Ralf
authors.initials: R
authors.lastname: Schwanbeck
authors.affiliation: Institute of Virology, Saarland University Medical Center, 66424 Homburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Lohse
authors.affiliation: Medical Department 1, University Hospital Schleswig-Holstein, Campus Lübeck, 23538 Lübeck, Germany;
authors.forename: Christian
authors.initials: C
authors.lastname: Sina
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University and University Hospital Schleswig-Holstein, 24105 Kiel, Germany;
authors.forename: Matthias
authors.initials: M
authors.lastname: Peipp
authors.affiliation: Division of Stem Cell Transplantation and Immunotherapy, 2nd Department of Medicine, Christian-Albrechts-University and University Hospital Schleswig-Holstein, 24105 Kiel, Germany;
authors.forename: Thomas
authors.identifier: http://orcid.org/0000-0001-9181-8067
authors.initials: T
authors.lastname: Valerius
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D000912:Antibodies, Neoplasm / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D045744:Cell Line, Tumor; D015936:Complement C5a / Q000276:immunology*; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology; D006801:Humans; D007962:Leukocytes / Q000276:immunology*; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D044087:Receptor, Anaphylatoxin C5a / Q000276:immunology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000912:Antibodies, Neoplasm; C488033:C5AR1 protein, human; D044087:Receptor, Anaphylatoxin C5a; D015936:Complement C5a; C512478:EGFR protein, human; D066246:ErbB Receptors; C520777:matuzumab