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).