Reactivity of human brain antiserum with neuroblastoma cells and nonreactivity with thymocytes and lymphoblasts

Brain-associated antigens have been detected on human and mouse thymocytes. Also, murine neuroblasts and brain cells have common antigens. In this study we compared the reactivity of rabbit anti-human brain (HB) serum with neoplastic neuroblasts and normal and neoplastic lymphoid cells. The binding of HB antiserum to viable cells was assessed by immunofluorescence and an indirect radiolabeled antibody assay. HB antiserum reacted with greater than 80% of neuroblasts derived from two human cell lines and five children with neuroblastoma, but with less than 1% of human thymocytes, bone marrow lymphoid cells, and lymphocytic leukemia cells. HB antiserum also reacted with 5 to 10% of peripheral blood lymphocytes. Absorption with neuroblasts did not alt-r this reactivity. Rabbit antisera raised against normal human thymocytes and leukemic T-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. We conclude that 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.