Monoclonal antibodies as neural cell surface markers.

A comparison is made of the immunohistochemistry at the ultrastructural level of three monoclonal antibodies directed against surface components of DNS cells. Hybridomas secreting these antibodies were obtained from two cell fusions of a rat myeloma cell line and immune splenocytes derived from rats immunized either with primary mouse brain cultured cells or membrane components. In cultures one antibody, anti-BSP2 (Brain Surface Protein-2), was preferentially directed against neurons while another, anti-BSP-3 (Brain Surface Protein-3), preferentially labeled astrocytes. In mouse cerebellar sections, both labeled the surface of Purkinje cells, granule cells and astrocytes. In addition a cytoplasm localization was apparent in granule cells and astrocytes. Another antibody anti-MESA-1 (Mouse Endothelial Surface Antigen-1) reacted exclusively with the surface of endothelial cells lining blood vessels. These data are discussed with reference to the biochemical nature of the corresponding antigens and to known glycoproteins of neural cell membranes.