Autoantigens in human neuroblastoma cells
Neuroblastoma cells are frequently used as targets in studies of autoimmune diseases of the nervous system. We examined the human neuroblastoma cell line, LAN-5, for the presence of autoantigens that react with naturally occurring autoantibodies in human sera. Antibodies to the HNK-1 and Gal(beta 1-3)GalNAc epitopes, which have been implicated in human autoimmune neuropathy and motor neuron disease, respectively, immunostained the surface of the neuroblastoma cells, and antibodies to the 200 kDa high molecular weight neurofilament protein (NFH) immunostained the cytoplasm and cell processes. The NHK-1 and Gal(beta 1-3)GalNAc epitopes were associated with several glycoprotein bands in Western blots of the neuroblastoma cells, and the HNK-1 epitope was also shared by a glycolipid which co-migrated with 3-sulfoglucuronyl paragloboside (SGPG) from peripheral nerve, indicating that SGPG is synthesized in neuronal cells. Northern blot analysis revealed a single RNA band of 4800 bp for NFH in normal brain but two RNA species of 4800 and 3800 bp in both neuroblastoma and adrenal cells, confirming their common origin. The neuroblastoma cells appear to contain antigens that bind to naturally occurring autoantibodies in human serum and might therefore be useful for detecting and investigating the effects of anti-neuronal antibodies. The antibody populations being investigated, however, should be distinguished from other autoantibodies which might be present in the patients' serum.