CD19-specific triplebody SPM-1 engages NK and γδ T cells for rapid and efficient lysis of malignant B-lymphoid cells.
Triplebodies are antibody-derived recombinant proteins carrying 3 antigen-binding domains in a single polypeptide chain. Triplebody SPM-1 was designed for lysis of CD19-bearing malignant B-lymphoid cells through the engagement of CD16-expressing cytolytic effectors, including NK and γδ T cells.SPM-1 is an optimized version of triplebody ds(19-16-19) and includes humanization, disulfide stabilization and the removal of potentially immunogenic sequences. A three-step chromatographic procedure yielded 1.7 - 5.5 mg of purified, monomeric protein per liter of culture medium. In cytolysis assays with NK cell effectors, SPM-1 mediated potent lysis of cancer-derived B cell lines and primary cells from patients with various B-lymphoid malignancies, which surpassed the ADCC activity of the therapeutic antibody Rituximab. EC50-values ranged from 3 to 86 pM. Finally, in an impedance-based assay, SPM-1 mediated a particularly rapid lysis of CD19-bearing target cells by engaging and activating both primary and expanded human γδ T cells from healthy donors as effectors.These data establish SPM-1 as a useful tool for a kinetic analysis of the cytolytic reactions mediated by γδ T and NK cells and as an agent deserving further development towards clinical use for the treatment of B-lymphoid malignancies.
Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany.
Christian B
CB
Schiller
Division of Hematology and Oncology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
Todd A
TA
Braciak
Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany.
Nadja C
NC
Fenn
Department of General Paediatrics, Oncology/Haematology, University Children's Hospital Tübingen, Tübingen, Germany.
Ursula J E
UJ
Seidel
Division of Hematology and Oncology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
Claudia C
CC
Roskopf
Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany.
Sarah
S
Wildenhain
Annemarie
A
Honegger
Department of Biology, University of Erlangen-Nuremberg, Erlangen, Germany.
Ingo A
IA
Schubert
Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany.
Alexandra
A
Schele
Division of Hematology and Oncology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
Kerstin
K
Lämmermann
Westend-Innovation, Munich, Germany.
Georg H
GH
Fey
Westend-Innovation, Munich, Germany.
Uwe
U
Jacob
Department of General Paediatrics, Oncology/Haematology, University Children's Hospital Tübingen, Tübingen, Germany.
Peter
P
Lang
Department of Biochemistry and Gene Center, Ludwig-Maximilians-University, Munich, Germany.
Karl-Peter
KP
Hopfner
Division of Hematology and Oncology, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany.
Fuat S
FS
Oduncu
D018941:Antigens, CD19 / Q000276:immunology*; D000074322:Antineoplastic Agents, Immunological / Q000276:immunology / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D000075942:Intraepithelial Lymphocytes / Q000187:drug effects* / Q000276:immunology; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D007700:Kinetics; D008213:Lymphocyte Activation / Q000187:drug effects; D016246:Lymphocytes, Tumor-Infiltrating / Q000187:drug effects* / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D000069283:Rituximab / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D018941:Antigens, CD19; D000074322:Antineoplastic Agents, Immunological; C000604811:CD19 molecule, human; D000069283:Rituximab
antibody-dependent cellular cytotoxicity; gamma delta T cell; immunotherapy; leukemia; single chain triplebody