Mitwasi et al. stably transduced NK-92 cells with ‘universal’ (Uni)CARs comprising an scFv specific for (intracellular antigen) peptide E5B9, a CD28 transmembrane, and a CD28-CD3ζ signaling domain, and built soluble E5B9-tagged anti-disialoganglioside (GD2)-scFV and IgG4 targeting molecules (TMs). FACS showed TMs bind to GD2+ neuroblastoma/melanoma cells and to UniCAR-NK cells via E5B9. TM-bridging of GD2+ tumors to UniCAR-NK cells rapidly induced NK cell secretion of IFNγ and enhanced GD2+ tumor cytolysis in vitro (<1 nM EC50). Injecting nude mice s.c. with UniCAR-NK cells and anti-GM2 TMs inhibited GD2+ neuroblastoma growth.
Contributed by Paula Hochman
Antigen-specific redirection of immune effector cells with chimeric antigen receptors (CARs) demonstrated high therapeutic potential for targeting cancers of different origins. Beside CAR-T cells, natural killer (NK) cells represent promising alternative effectors that can be combined with CAR technology. Unlike T cells, primary NK cells and the NK cell line NK-92 can be applied as allogeneic off-the-shelf products with a reduced risk of toxicities. We previously established a modular universal CAR (UniCAR) platform which consists of UniCAR-expressing immune cells that cannot recognize target antigens directly but are redirected by a tumour-specific target module (TM). The TM contains an antigen-binding moiety fused to a peptide epitope which is recognized by the UniCAR molecule, thereby allowing an on/off switch of CAR activity, and facilitating flexible targeting of various tumour antigens depending on the presence and specificity of the TM. Here, we provide proof of concept that it is feasible to generate a universal off-the-shelf cellular therapeutic based on UniCAR NK-92 cells targeted to tumours expressing the disialoganglioside GD2 by GD2-specific TMs that are either based on an antibody-derived single-chain fragment variable (scFv) or an IgG4 backbone. Redirected UniCAR NK-92 cells induced specific killing of GD2-expressing cells in vitro and in vivo, associated with enhanced production of interferon-gamma. Analysis of radiolabelled proteins demonstrated that the IgG4-based format increased the in vivo half-life of the TM markedly in comparison to the scFv-based molecule. In summary, UniCAR NK-92 cells represent a universal off-the-shelf platform that is highly effective and flexible, allowing the use of different TM formats for specific tumour targeting.
Author Info: (1) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. (2) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of R
Author Info: (1) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. (2) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. (3) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. (4) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. (5) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. (6) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. German Cancer Consortium (DKTK), partner site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany. (7) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. National Center for Tumor Diseases (NCT), University Hospital 'Carl Gustav Carus', TU Dresden, Dresden, Germany. (8) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. Semmelweis University, Department of Biophysics and Radiation Biology, Budapest, Hungary. (9) Semmelweis University, Department of Biophysics and Radiation Biology, Budapest, Hungary. (10) Semmelweis University, Department of Biophysics and Radiation Biology, Budapest, Hungary. (11) University of Pannonia, Veszprem, Hungary. (12) Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main, Germany. German Cancer Consortium (DKTK), partner site Frankfurt/Mainz, and German Cancer Research Center (DKFZ), Heidelberg, Germany. (13) Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main, Germany. German Cancer Consortium (DKTK), partner site Frankfurt/Mainz, and German Cancer Research Center (DKFZ), Heidelberg, Germany. (14) Department of Hematology and Oncology, Krankenhaus Nordwest, Frankfurt am Main, Germany. (15) Institute of Medical Immunology, Martin-Luther-University Halle-Wittenberg, Halle, Germany. (16) Department of Pediatric Hematology and Oncology, University Children s Hospital Munster, Munster, Germany. (17) German Cancer Consortium (DKTK), partner site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany. National Center for Tumor Diseases (NCT), University Hospital 'Carl Gustav Carus', TU Dresden, Dresden, Germany. Department of Neurosurgery, Section Experimental Neurosurgery and Tumor Immunology, University Hospital 'Carl Gustav Carus', TU Dresden, Dresden, Germany. (18) Expermintal Transfusion Medicine, Medical Faculty 'Carl Gustav Carus', TU Dresden, Dresden, Germany. (19) German Cancer Consortium (DKTK), partner site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany. Expermintal Transfusion Medicine, Medical Faculty 'Carl Gustav Carus', TU Dresden, Dresden, Germany. Center for Regenerative Therapies Dresden, Dresden, Germany. (20) German Cancer Consortium (DKTK), partner site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany. National Center for Tumor Diseases (NCT), University Hospital 'Carl Gustav Carus', TU Dresden, Dresden, Germany. Center for Regenerative Therapies Dresden, Dresden, Germany. Institute of Immunology, Medical Faculty 'Carl Gustav Carus', TU Dresden, Dresden, Germany. (21) Department of Dermatology and National Center for Tumor Diseases (NCT), University Hospital Heidelberg, Heidelberg, Germany. (22) Department of Medical Oncology, National Center for Tumor Diseases (NCT), University Medical Center Heidelberg, Heidelberg, Germany. (23) Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main, Germany. German Cancer Consortium (DKTK), partner site Frankfurt/Mainz, and German Cancer Research Center (DKFZ), Heidelberg, Germany. Frankfurt Cancer Institute, Goethe University, Frankfurt am Main, Germany. (24) Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Dresden, Germany. m.bachmann@hzdr.de. German Cancer Consortium (DKTK), partner site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany. m.bachmann@hzdr.de. National Center for Tumor Diseases (NCT), University Hospital 'Carl Gustav Carus', TU Dresden, Dresden, Germany. m.bachmann@hzdr.de. Tumor Immunology, University Cancer Center (UCC) 'Carl Gustav Carus', TU Dresden, Dresden, Germany. m.bachmann@hzdr.de.
