title: Cetuximab Reconstitutes Pro-Inflammatory Cytokine Secretions and Tumor-Infiltrating Capabilities of sMICA-Inhibited NK Cells in HNSCC Tumor Spheroids.
abstract: Immunosuppressive factors, such as soluble major histocompatibility complex class I chain-related peptide A (sMICA) and transforming growth factor beta 1 (TGF-β1), are involved in tumor immune escape mechanisms (TIEMs) exhibited by head and neck squamous cell carcinomas (HNSCCs) and may represent opportunities for therapeutic intervention. In order to overcome TIEMs, we investigated the antibody-dependent cellular cytotoxicity (ADCC), cytokine release and retargeted tumor infiltration of sMICA-inhibited patient NK cells expressing Fcγ receptor IIIa (FcγRIIIa, CD16a) in the presence of cetuximab, an anti-epidermal growth factor receptor (HER1) monoclonal antibody (mAb). Compared to healthy controls, relapsed HNSCC patients (n = 5), not currently in treatment revealed decreased levels of circulating regulatory NK cell subsets in relation to increased cytotoxic NK cell subpopulations. Elevated sMICA and TGF-β1 plasma levels correlated with diminished TNFα and IFN-γ release and decreased NKG2D (natural killer group 2 member D)-dependent killing of HNSCC cells by NK cells. Incubation of IL-2-activated patient NK cells with patient plasma containing elevated sMICA or sMICA analogs (shed MICA and recombinant MICA) significantly impaired NKG2D-mediated killing by down-regulation of NKG2D surface expression. Of note, CD16 surface expression levels, pro-apoptotic and activation markers, and viability of patient and healthy donor NK cell subpopulations were not affected by this treatment. Accordingly, cetuximab restored killing activity of sMICA-inhibited patient NK cells against cetuximab-coated primary HNSCC cells via ADCC in a dose-dependent manner. Rapid reconstitution of anti-tumor recognition and enhanced tumor infiltration of treated NK cells was monitored by 24 h co-incubation of HNSCC tumor spheroids with cetuximab (1 μg/ml) and was characterized by increased IFN-γ and TNFα secretion. This data show that the impaired NK cell-dependent tumor surveillance in relapsed HNSCC patients could be reversed by the re-establishment of ADCC-mediated effector cell activity, thus supporting NK cell-based immunotherapy in combination with antineoplastic monoclonal mAbs.
authors.affiliation: Institute of Cellular Therapeutics, Integrated Research and Treatment Center Transplantation (IFB-Tx), Hannover Medical School , Hannover , Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Klöss
authors.affiliation: Department of Oral, Cranio-Maxillofacial and Facial Plastic Surgery, Klinikum Hanau GmbH , Hanau , Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Chambron
authors.affiliation: Institute of Cellular Therapeutics, Integrated Research and Treatment Center Transplantation (IFB-Tx), Hannover Medical School , Hannover , Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Gardlowski
authors.affiliation: Georg-Speyer-Haus Institute for Tumor Biology and Experimental Therapy , Frankfurt , Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Weil
authors.affiliation: Georg-Speyer-Haus Institute for Tumor Biology and Experimental Therapy , Frankfurt , Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Koch
authors.affiliation: Institute of Cellular Therapeutics, Integrated Research and Treatment Center Transplantation (IFB-Tx), Hannover Medical School , Hannover , Germany.
authors.forename: Ruth
authors.initials: R
authors.lastname: Esser
authors.affiliation: Klinik I für Innere Medizin, Uniklinik Köln , Cologne , Germany.
authors.forename: Elke
authors.initials: E
authors.lastname: Pogge von Strandmann
authors.affiliation: Institute of Experimental Haematology, Hannover Medical School , Hannover , Germany.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Morgan
authors.affiliation: Institute of Cellular Therapeutics, Integrated Research and Treatment Center Transplantation (IFB-Tx), Hannover Medical School , Hannover , Germany.
authors.forename: Lubomir
authors.initials: L
authors.lastname: Arseniev
authors.affiliation: Department of Oral, Cranio-Maxillofacial and Facial Plastic Surgery, Klinikum Hanau GmbH , Hanau , Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Seitz
authors.affiliation: Institute of Cellular Therapeutics, Integrated Research and Treatment Center Transplantation (IFB-Tx), Hannover Medical School , Hannover , Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Köhl
keywords: ADCC; HNSCC tumor spheroids; TGF-β1; cetuximab-activated NK cells; soluble MICA