MONOCLONAL-ANTIBODIES TO GLIOMA-DERIVED GROWTH FACTOR(S)

Several monoclonal antibodies (mAb) reactive against a high-molecular- weight growth factor from human glioblastoma cell lines have been prod uced by immunizing mice with partially purified preparations from cond itioned media. Antibody-secreting colonies were selected by their capa city to bind S-35-labeled glioma cell protein and by reactivity in ind irect enzyme-linked immunoadsorbent assay (ELISA), using high-molecula r-weight gel filtration fractions and preparative isoelectric focusing fractions containing growth factor activities. Two of the select mAbs (20F3 and 12A12) depleted mitogenic activity (>50% inhibition, p < 0. 05) from gel filtration fractions by immunoprecipitation, but could no t neutralize mitogenic activity directly. Mitogenic activity recovered from affinity columns prepared with mAb 20F3 eluted at 48% and 52% ac etonitrile from HPLC C4 reversed-phase columns. Immunoprecipitation of S-35-labeled cell lysates with 20F3 followed by resolution with SDS-P AGE autoradiography revealed one unique protein of 170 kD. Established glioma cell line D-54 MG showed perinuclear and cytoplasmic staining with mAb 20F3. mAb 20F3 should prove useful in purification and charac terization of these glioma-derived growth factor(s).