Expression of Human Fetal Brain Antigens by Human Tumors of Neuroectodermal Origin As Defined by Monoclonal Antibodies

The antigenic relationships between human tumors of neuroectodermal origin and fetal brain were investigated by the production of hybridoma antibodies derived from a fusion of P3-NS1/1-Ag 4-1 (NS1) myeloma cells with splenocytes from a mouse multiply immunized with an homogenate of second-trimester human fetal brain tissue. Two monoclonal antibodies (MAs), 4D2cl 6 and 7H10cl 4, were studied in detail by cell surface radioimmunoassay (CS-RIA), quantitative absorption, indirect immunofluorescence, and peroxidase-anti-peroxidase (PAP) immunohistology. MA 4D2cl 6 binds to 5 of 14 glioblastoma (GBM) cell lines, 1 of 2 melanoma cell lines, 1 of 3 neuroblastoma cell lines, and 1 of 5 fetal fibroblast lines by CS-RIA and to 13 of 13 GBM, 1 neuroblastoma, and fetal brain, liver, spleen, and adult spleen unfixed frozen tissue by PAP analysis. MA 7H10cl 4 binds to 13 of 14 GBM, 1 of 3 neuroblastoma, and 1 medulloblastoma cell line(s) by CS-RIA analysis and to 13 of 13 GBM, 1 neuroblastoma, fetal brain, liver, spleen, thymus, and adult spleen by PAP analysis. Control non-central nervous system tumors and normal adult tissue, including brain, were unreactive with both MAs by CS-RIA, PAP, and absorption analysis. Tissue distribution and localization analyses established that MAs 4D2cl 6 and 7H10cl 4 recognize specificities of shared fetal-neuroectodermal-lymphoid distribution which are operationally specific within the adult central nervous system and which are not related to previously described oncofetal or onconeural antigens.