PubMed Health⌕ Search

Biomedical subjects

M R Hirsch

Publications and source records attributed to M R Hirsch.

23 records · Page 2Linked to original sources

Monoclonal antibody to neural cell surface protein: identification of a glycoprotein family of restricted cellular localization.

A monoclonal antibody, designated anti-NSP-4 (anti-Neural cell Surface Protein-4), was obtained from a hybridoma generated by fusing rat myeloma cells with splenocytes of a rat immunized with membranes from the cerebella of weaver mutant mice. This antibody reacted with several high-molecular weight polypeptides in extracts prepared from the newborn and adult CNS of wild-type mice. The main NSP-4-reactive bands from neonatal cerebellum and spinal cord migrated with apparent molecular weights of 220,000 and 140,000. Major bands of 160,000 and of 175,000, 160,000 and 140,000 molecular weight were revealed in the adult cerebellum and spinal cord, respectively. Reaction of the antibodies with concanavalin A-binding proteins demonstrated the glycoprotein nature of the antigen. Cell types expressing NSP-4 antigen were determined using indirect immunofluorescence on monolayer cultures of early postnatal mouse cerebellar and dorsal root ganglion cells and on sections of developing and adult mouse cerebellum. In cerebellar cultures, the antibody reacted with the surface membrane of a subpopulation of astrocytes and of a small subset of neurones. In dorsal root ganglion cultures, anti-NSP-4 antibodies were highly specific for a subclass of small neurones. Staining for NSP-4 in sections of adult cerebellum was confined to the granular layer where the antibody seemed to label astroglia. In the developing cerebellum, NSP-4 staining outlined cell bodies of neuroblasts and migrating granule cells in the external granular layer. Post-migratory granule cells and Purkinje cells were negative. As in the adult, the labeled structures in the internal granular layer were probably astrocytes. Our results on the in vivo and in vitro localization of NSP-4 show its expression by subclasses of neurones and astrocytes in the cerebellum and by a subclass of neurones in cultures from the peripheral nervous system. The developmentally-regulated changes in the molecular weight forms of the NSP-4 antigen together with the shift in its cellular localization during cerebellar ontogeny suggest a functional significance for this antigen in developmental processes.

Animals↗

A new brain cell surface glycoprotein identified by monoclonal antibody.

Of 207 monoclonal antibodies produced against cultured mouse cerebellar cells, 16 reacted with cerebellar cell surfaces and 4 reacted with glycoproteins. One of them, called an anti-BSP-3 (Brain cell Surface Protein-3) defines a 48,000 molecular weight protein which can be iodinated at the surface of cultured cerebellar cells. Lectin-binding and sugar incorporation studies established the glycoprotein nature of the antigen. Astroglia (glial fibrillary acidic protein-positive cells) in primary cerebellar cultures were labelled intensely for this antigen by the indirect immunofluorescence method while neuronal cells and their processes were more weakly labelled. Fibronectin-positive cells were negative for BSP-3. In cerebellar sections using the immunoperoxidase method at both the optical and electron microscope levels, the difference in staining intensity between astrocytes and neuronal cells was not significant: in Purkinje cells and in the large neurones present in the deep cerebellar nuclei the immunoperoxidase percipitate was confined to the plasma, membrane while in both astrocytes and granule cells cytoplasmic labelling was also observed. Oligodendrocytes do not appear to react with the anti-BSP-3 monoclonal antibody; neither do endothelial or leptomeningeal cells. The availability of a monoclonal antibody produced by a stable hybridoma line will be a powerful tool in attempts to purify the BSP-3 antigen and to elucidate its function.

Animals↗

A surface marker for murine vascular endothelial cells defined by monoclonal antibody.

Spleen cells from a rat immunized with mouse cerebellar cells were fused with mouse myeloma cells. One of the hybridomas secreted a monoclonal antibody that reacts with a surface antigen on vascular endothelial cells. The antibody stained endothelial cells lining blood vessels in brain, heart, lung, kidney, and liver. It did not, however, stain endothelial cells lining hepatic sinusoids. Parenchymal cells were always negative. So far, an antigen of similar tissue distribution has not been described in the mouse and we have called it mouse endothelial surface antigen-1 (MESA-1). The antibody could be used as a highly specific usefulness for identifying endothelium-derived cells in culture has been demonstrated on cultures of dissociated mouse cerebellum, where it stained a subclass of fibronectin-expressing cells.

Animals↗

Identification and immunolocalization by monoclonal antibody of NSP-5, a surface polypeptide of neural cells.

A monoclonal antibody, termed anti-NSP-5 (anti-Neural cell Surface Protein-5) was obtained from an hybridoma generated by fusing rat myeloma cells with splenocytes of a rat immunized with membranes from the cerebella of weaver mutant mice. This antibody reacted with the surface membrane of a subset of neurones in cultures from cerebella and dorsal root ganglia. In both culture systems, only tetanus toxin-positive cells were stained by the antibody. In sections of adult cerebellum a punctate pattern of staining was seen in the molecular layer, the Purkinje cell layer and the upper part of the granule cell layer. The white matter was strongly positive whereas granule cell and Purkinje cell bodies were clearly negative. In sections from adult dorsal root ganglia anti-NSP-5 labeled most sensory neurones including their axones in the dorsal roots. The expression of the antigen was developmentally regulated. It could not be detected in cerebellar cultures prepared from animals younger than 7 days, in good agreement with the data obtained on tissue sections. Similarly, the antigen could not be detected by immunoblotting in neonatal spinal cord, but a NSP-5-reactive band was present at postnatal day 7. The antibody bound a polypeptide of around MW 180 000 in extracts prepared from adult mouse spinal cord or cerebellum. When purified by immunoaffinity chromatography the antigen co-eluted with numerous strongly associated polypeptides. Upon subcellular fractionation most of it remained associated with a Triton-X100 insoluble fraction thus co-distributing with the cytoskeleton.

Animals↗