Murine monoclonal antibodies cytotoxic to human glioma cells in vitro

Abstract

Six monoclonal antibodies (mABs) against human glioma cells (T2) were produced. T2 cells grown as solid tumors in nude mice, were dissociated and used to imrnunize Balblc rnice. After fusion of spleenocytes with myeloma cells, eight hybrids secreting mABs were selected according to their ability to react immunohistochernically with T2 cells, but not with normal adult human brain. Cytotoxicity of mABs was tested using (3~)-thymidinien corporation assays in vitro. Four mABs showed complement-mediated cytotoxicity for T2 cells, other human glioma cells (TI), and a human melanoma cell line. Incubation with one antibody, mAb2A1, lowered (3~)-thymidinein corporation in the T2 and T1 cells to ca. lo%, and in melanoma cells to ca. 35% of control levels. Another antibody, mAb3B2, displayed a similar cytotoxicity for T2 and T1 cells, but did not show measurable cytotoxicity for melanoma cells and rat primary astrocyte cultures. Moreover, this antibody did not crossreact with haematopoietic cells from patients bearing CNS tumors or normal subjects. MAb3B2, therefore, appears to recognize and epitope associated to human gliomas, will be a useful glioma tumor marker and may have some potential therapeutical value.