Characterization of three restricted specificity monoclonal antibodies raised against the human glioma cell line D-54 MG

Abstract

Monoclonal antibodies (MCAs) have been derived from a fusion of P3-NS1/1-Ag 4-1 (NS1) myeloma cells and splenocytes immunized to human glioma cell line D-54 MG. MCAs 2F3, 4C7, and 5B7 were analyzed by cell surface radioimmunoassay (CS-RIA), quantitative absorption, indirect immunofluorescence, and peroxidase-anti-peroxidase (PAP) immunohistology of unfixed tissue samples. MCA 2F3 exhibits the most highly restricted pattern of reactivity we have observed, reacting only with 512 glioblastoma cell lines and 14 fetal skin lines by CS-RIA, and to 911 glioblastoma tissue samples by PAP and absorption analysis; this MCA is totally nonreactive with melanomas, neuroblastomas, meningiomas, and control non-central nervous system tumors, and to adult and fetal tissues including brain, thymus, spleen, liver, lung, heart, gut, skin, and muscle by PAP analysis. MCAs 4C7 and 5B7 demonstrate neuroectodermal tumor cross-reactivity profiles, reacting with either melanomas (5B7) or melanomas and neuroblastomas (4C7); both are reactive with fetal skin, brain, and thymus of ≤ 16 weeks of gestational age. Other than this latter fetal antigen reactivity, these MCAs share the same negative reactivity profile described above for MCA 2F3. Data from experiments using control or 0.02% EDTA-treated confluent cell monolayers of D-54 MG as antibody absorbents showed that the antigens detected are present in the extracellular matrix material remaining following cell removal. The data presented here establish that these highly restrictive anti-human glioma cell line MCAs are expressed in primary human gliomas; that the markers defined are developmental in nature, in that they are expressed by human fetal tissue, but not by adult tissue; and that in conjunction with previously characterized specificities, these markers of antigenic heterogeneity will be valuable in model system studies of therapeutic response heterogeneity.