Complement-mediated lysis of cultured osteosarcoma cell lines using chimeric mouse/human TP-1 IgG1 and IgG3 antibodies |
| |
Authors: | Tove Olafsen Charlotte K Munthe Lund Øyvind S Bruland Inger Sandlie Terje E Michaelsen |
| |
Institution: | (1) Division of Molecular Cell Biology, Department of Biology, University of Oslo, PO Box 1050 Blindern, N-0316 Oslo, Norway Tel.: +47 22854792, Fax: +47 22854605, NO;(2) Department of Medical Oncology and Radiotherapy, The Norwegian Radium Hospital, Oslo, Norway, NO;(3) Department of Vaccinology, National Institute of Public Health, Oslo, Norway, NO |
| |
Abstract: | Osteosarcoma is the commonest malignant tumour of the bones. The presence of micrometastases at the time of primary diagnosis
is associated with poor prognosis. Despite developments in surgery and aggressive chemotherapy, about 50% of the patients
still succumb to the disease. Thus, there is a need to develop alternative treatment modalities. One such strategy is to use
antibodies with improved effector functions. The two monoclonal antibodies, TP-1 and TP-3, recognize a tumour-associated antigen
on human osteosarcoma cells. In the present study, we describe the cloning of the TP-1 variable genes, and the production
of complete chimeric mouse/human monoclonal antibodies. Constructs containing the constant genes from human IgG1, IgG3 or
a mutant IgG3 with a shortened hinge region, called m15, were expressed in the mouse myeloma cell line, NS0. The m15 mutant
has been shown to be very potent in triggering complement-mediated lysis. Our goal was to investigate whether this mutant
could overcome the complement protection on human osteosarcoma cells, which is generally present on all human cells. We found
that the target cells expressed several membrane-bound complement inhibitors, and that masking of these inhibitors rendered
the cells sensitive to lysis. The m15 mutant exhibited greater lytic activity than both IgG3 and IgG1, although it could not
cause extensive killing of the target cells alone.
Received: 21 January 1999 / Accepted: 3 June 1999 |
| |
Keywords: | Cancer Chimeric Monoclonal antibodies Complement CD59 CD55 (DAF) CD46 (MCP) |
本文献已被 SpringerLink 等数据库收录! |
|