Neurofibrillary tangles in senile dementia of the Alzheimer type share an antigenic determinant with intermediate filaments of the vimentin class.

A monoclonal antibody produced by a hybridoma between a plasmacytoma cell and a spleen cell from a mouse immunized with human brain microtubule fraction was demonstrated to stain neurofibrillary tangles of senile dementia of the Alzheimer type (SDAT). The antibody recognized at least 50% of the tangles in neuronal perikarya isolated from SDAT brains and stained a filamentous network in HeLa cells, fibroblasts, and astrocytes. It did not stain skin epithelial cells or neurons isolated from normal brains but reacted with Z bands in skeletal muscle. The monoclonal antibody stained coils in colchicine or colcemid-treated cultured cells in a pattern characteristic of 10-nm intermediate-sized filaments. Immunoblotting of Triton-insoluble cytoskeletal proteins of cultured cells electrophoresed in SDS polyacrylamide gels showed that the antigenic determinant is present in proteins of molecular weight 58,000 which comigrates with vimentin. Thus, it appears that the neurofibrillary tangles in SDAT share an antigenic determinant with vimentin.