Expression of Melanoma-associated Antigens by Normal and Neurofibroma Schwann Cells1

The cell surface antigen distribution on traumatic neuroma Schwann cells and neurofibroma Schwann-like cells was characterized using mono clonal antibodies that define melanoma-associated antigens. Immunofluorescence staining of cultured cells, immunoprecipitation of radioiodinated antigens from cells placed in short-term cultures, and immunoperoxidase staining of frozen tissue sections revealed most of the melanomaassociated antigens tested on traumatic neuroma and neurofibroma Schwann cells and on fetal and adult femoral nerve. The cross-reactivity of the antibodies with neural cells may reflect the common neural crest embryological origin of Schwann cells and ntelanocytes. Cell sorter analysis of neurofibroma cells using a monoclonal antibody directed against the melanoma nerve growth factor receptor resulted in cell cultures highly enriched for Schwann-like cells which may bear the genetic defect responsible for neurofibromatosis. The antigen detected by this monoclonal antibody is the neurofibroma nerve growth factor recep tor and the antibody was a potent inhibitor of nerve growth factor binding to neurofibroma cells.