Surface antigenic characteristics of human glial brain tumor cells

The surface antigenic characteristics of human glial brain tumor (HGBT) cells were studied by complement-dependent cytotoxic antibody assays and indirect membrane immunofluorescence. Eight permanent, well-characterized cell lines derived from human gliomas were used for analysis with antisera raised by hyperimmunization of nonhuman primates (Macaca fascicularis) with glioblastoma multiforme tissue or established HGBT cells lines. Exhaustive absorption of these antisera to remove predominantly antispecies activity rendered HLA nonreactive "preabsorbed" antisera, which reacted with a large panel of gliomatous and nongliomatous human tumor cells; 1 carcinoma, 2 sarcomas, 2 melanomas, 1 neuroblastoma, and 8 HGBT cell lines. Four lymphoblastoid lines and 2 carcinomas were unreactive. After further absorption with a human osteogenic sarcoma cell line, the antisera demonstrated significant levels of reactivity for 8 tested HGBT cell lines and no longer reacted with the nongliomatous cultured tumor cells lines. Therefore, extensive absorption of nonhuman primate anti-human glioma sera removed all activity for the nongliomatous cell lines tested, but it left significant reactivity against a glial tumor cell line-associated antigen(s) present on all 8 human glioma cell lines tested.