TY - JOUR A1 - Rasche, Leo A1 - Duell, Johannes A1 - Morgner, Charlotte A1 - Chatterjee, Manik A1 - Hensel, Frank A1 - Rosenwald, Andreas A1 - Einsele, Hermann A1 - Topp, Max S. A1 - Brändlein, Stephanie T1 - The Natural Human IgM Antibody PAT-SM6 Induces Apoptosis in Primary Human Multiple Myeloma Cells by Targeting Heat Shock Protein GRP78 JF - PLoS ONE N2 - In contrast to other haematological malignancies, targeted immunotherapy has not entered standard treatment regimens for de novo or relapsed multiple myeloma (MM) yet. While a number of IgG-formatted monoclonal antibodies are currently being evaluated in clinical trials in MM, our study aimed to investigate whether the fully human IgM monoclonal antibody PAT-SM6 that targets a tumour-specific variant of the heat shock protein GRP78 might be an attractive candidate for future immunotherapeutic approaches. We here show that GRP78 is stably and consistently expressed on the surface on tumour cells from patients with de novo, but also relapsed MM and that binding of PAT-SM6 to MM cells can specifically exert cytotoxic effects on malignant plasma cells, whereas non-malignant cells are not targeted. We demonstrate that the induction of apoptosis and, to a lesser extent, complement dependent cytotoxicity is the main mode of action of PAT-SM6, whereas antibody dependent cellular cytotoxicity does not appear to contribute to the cytotoxic properties of this antibody. Given the favourable safety profile of PAT-SM6 in monkeys, but also in a recent phase I trial in patients with malignant melanoma, our results form the basis for a planned phase I study in patients with relapsed MM. KW - cytotoxicity KW - apoptosis KW - immunohistochemistry techniques KW - enzyme-linked immunoassays KW - multiple myeloma KW - cell staining KW - cell binding KW - complement system Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130125 VL - 8 IS - 5 ER - TY - JOUR A1 - Beilhack, Andreas A1 - Chopra, Martin A1 - Kraus, Sabrina A1 - Schwinn, Stefanie A1 - Ritz, Miriam A1 - Mattenheimer, Katharina A1 - Mottok, Anja A1 - Rosenwald, Andreas A1 - Einsele, Hermann T1 - Non-Invasive Bioluminescence Imaging to Monitor the Immunological Control of a Plasmablastic Lymphoma-Like B Cell Neoplasia after Hematopoietic Cell Transplantation N2 - To promote cancer research and to develop innovative therapies, refined pre-clinical mouse tumor models that mimic the actual disease in humans are of dire need. A number of neoplasms along the B cell lineage are commonly initiated by a translocation recombining c-myc with the immunoglobulin heavy-chain gene locus. The translocation is modeled in the C.129S1-Ighatm1(Myc)Janz/J mouse which has been previously engineered to express c-myc under the control of the endogenous IgH promoter. This transgenic mouse exhibits B cell hyperplasia and develops diverse B cell tumors. We have isolated tumor cells from the spleen of a C.129S1-Ighatm1(Myc)Janz/J mouse that spontaneously developed a plasmablastic lymphoma-like disease. These cells were cultured, transduced to express eGFP and firefly luciferase, and gave rise to a highly aggressive, transplantable B cell lymphoma cell line, termed IM380. This model bears several advantages over other models as it is genetically induced and mimics the translocation that is detectable in a number of human B cell lymphomas. The growth of the tumor cells, their dissemination, and response to treatment within immunocompetent hosts can be imaged non-invasively in vivo due to their expression of firefly luciferase. IM380 cells are radioresistant in vivo and mice with established tumors can be allogeneically transplanted to analyze graft-versus-tumor effects of transplanted T cells. Allogeneic hematopoietic stem cell transplantation of tumor-bearing mice results in prolonged survival. These traits make the IM380 model very valuable for the study of B cell lymphoma pathophysiology and for the development of innovative cancer therapies. KW - B cells KW - T cells KW - Bioluminescence imaging KW - Bone marrow cells KW - Bone marrow transplantation KW - Cancer treatment KW - Spleen KW - Lymphomas Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111341 ER -