REACTIVITY OF HUMAN-BRAIN ANTISERUM WITH NEUROBLASTOMA-CELLS AND NON-REACTIVITY WITH THYMOCYTES AND LYMPHOBLASTS

Abstract

Brain-associated antigens have been detected on human and mouse thymocytes. Murine neuroblasts and brain cells have common antigens. In this study reactivity of rabbit anti-human brain (HB) serum with neoplastic neuroblasts and normal and neoplastic lymphoid cells was compared. Binding of HB antiserum to viable cells was assessed by immunofluorescence and an indirect radiolabeled antibody assay. HB antiserum reacted with > 80% of neuroblasts derived from 2 human cell lines [neuroblastomas SK-N-SH and IMR-32] and 5 children with neuroblastoma, but with < 1% of human thymocytes, bone marrow lymphoid cells and lymphocytic leukemia cells. HB antiserum reacted with 5-10% of peripheral blood lymphocytes. Absorption with neuroblasts did not alter this reactivity. Rabbit antisera raised against normal human thymocytes and leukemic T[thymus derived]-cells specifically bound to thymocytes but did not bind to neuroblasts. The reactivity of anti-HB serum against SK-N-SH neuroblasts was removed by absorption with HB, but not with human kidney or liver, or mouse and guinea pig brain. Apparently, human neuroblastoma cells possess cell-surface antigens that are present on HB. These antigens appear to be species specific and are not present on normal or malignant thymic cells. Conversely, thymus-associated antigens are not expressed on neuroblasts.