Vimentin-crossreactive antibodies induce cell death in primary cultures of embryonic spinal cord

Sera from guinea pigs inoculated with spinal cord gray matter were cytotoxic for embryonic day 14 (ED14) primary spinal cord cell cultures. All cell types including astroglia and neurons were affected. Immunoglobulin (IgG) from inoculated animals and biologically active complement proteins were both identified as necessary components for the observed cytotoxicity. Adsorption with cytoskeletal constituents removed the cytotoxic effect. Adsorption with purified vimentin substantially reduced cytotoxicity, while adsorption with glial fibrillary acid protein (GFAP) had no cytoprotective effects. Antiserum from vimentin-immunized guinea pigs was also toxic to spinal cord cell cultures. Antibody and complement-mediated toxicity appeared to result from interaction with vimentin bound to the surface of embryonic cultured glia and neurons, although interaction with a cross-reacting epitope could not be definitely excluded. Cytotoxic vimentin-directed antibody was not noted in control sera, and the presence of this antibody in guinea pig and human sera did not correlate with the clinicopathological state.